PSYC 301 - Exam 1

The vertebrate nervous system is composed of 2 divisions

1. Central Nervous System (CNS) - inside the brain and spinal cord 2. Peripheral Nervous System (PNS) - outside brain and spinal cord

Glossopharyngeal and Vagus Examination Technique

1. Check palatial elevation by having the patient sustain an "ah". When observing palatal movement, look at the palate rather than the uvula 2. Assess the gag reflex by gently stroking the soft palate on each side 3. Swallowing can be assessed by giving the patient a sip of water and observing them swallow 4. Listen to the patient's speech. Is there a nasal quality? 5. Assess palatal articulation with a "KA" sound, guttural with a "GO" sound and labial with a "PA" sound Normal Response: - the palate should elevate symmetrically, both when sustaining an "AH" and in response to stimulation on either side. Some patients however do not have a gag response and this can be normal if it is absent bilaterally. Patients should also be asked if they can feel the stimulus Abnormal Response: - with unilateral palatal weakness, the palate fails to elevate on the weak side and the gag reflex will be absent on that side

Behavioural Neurology is Different From Clinical Neuropsychology in the Following Ways:

1. Clinical neuropsychology is inclined to follow the tradition of empirical psychology, while behavioural neurology is more inclined to emphasize the conceptual or notional dimensions of behaviour 2. Clinical neuropsychology emphasizes the measurement of continuously distributed variables within a psychometric tradition: behavioural neurology emphasizes, within the neurological tradition, dichotomous classification through the use of the pathological sign approach 3. Behavioural neurology emphasizes the individual case analysis and the elucidation of syndromes in terms of the presence or absence of the signs and symptoms thought to be associated with the syndrome in question; clinical neuropsychology strongly relies on psychometric measurement of behaviour

Are there rehabilitation approaches that improve cognitive performance after stroke?

1. Compensatory approaches - involve adapting the external environment to altered cognitive abilities - electric paging system - can also be internally generated 2. Restorative approaches - ex. the realization that neural plasticity is present throughout life and can be influenced by training has generated hope in this area

Structural Imaging Techniques

1. Computed tomography (CT) 2. Magnetic Resonance Imaging (MRI) 3. Diffusion Tensor Imaging (DTI)

Cuts in the Brain

1. Coronal (frontal) section - from ear to ear 2. Mid-sagittal section - right down the medial 3. Sagittal - front to back, but not medial 4. Horizontal section - like a birds eye view

Position Sense Examination Technique

1. Demonstrate to the patient with eyes open that you will be moving their digit up or down 2. Ask the patient to close their eyes 3. Stabilize the distal interphalangeal joint of the upper extremity and make minimal movement upwards or downwards and ask the patient to report after each movement the direction of movement 4. Similarly in the lower extremities, stabilize the interphalangeal joint and move the large toe up or down

Neurons

1. Dendrites (contacted by other neurons - receive info) 2. Cell body - nucleus (in the center) 3. Axon initial segment 4. Axon 5. Terminal bouton - vesicles inside where neurotransmitters are

When a neurotransmitter molecule binds to a postsynaptic receptor, it can have one of two localized effects:

1. Depolarize the membrane (e.g. decrease membrane potential from -70 to -67) = Excitatory postsynaptic potential (EPSP) - increase the likelihood that the postsynaptic neuron will fire an action potential (AP) 2. Hyperpolarize the membrane (e.g. increase the membrane potential from -70 to -72) = Inhibitory postsynaptic potential (IPSP) - decrease the likelihood that the postsynaptic neuron will fire an AP

Multiple Sclerosis

A disorder that progressively damages myelin Tends to be seen more in colder climates Common for these patients to have depression Starts with numbness and/or visual weakness - comes and goes Considered an autoimmune disease

Cerebral Ischemia

A disruption of the blood supply to some area of the brain Three main causes: 1. Thrombosis - a plug, could be a bubble, protein build up, blood clot 2. Embolism - thrombus on wheels, starts moving through body 3. Arteriosclerosis - narrowing of blood vessels - combination can occur

How does communication occur within a single neuron?

A healthy neuron has a resting membrane potential (or membrane voltage) of between -60 and -80 mV (the voltage inside the neuron is 60-80 mV less than outside the neuron) More negative charges inside the neuron than outside More K+ ions inside the cell than outside More sodium ions outside than inside

Why does the penumbra die off even if the stroke has stopped?

A lot of release of neurotransmitters Extra synaptic receptors, usually inhibitory - tell the whole system, you're overreacting Apoptosis - programmed cell death - target this to stop penumbra from dying Excytotoxicity - reason penumbra is dying because it targets apoptosis

Drug Effects on Receptors

Agonists Antagonists - competitive antagonists - noncompetitive antagonists Partial agonists Allosteric Regulators - positive or negative modulators

Are Stroke Characteristics Associated with the Profile of Cognitive Deficits?

Depends on location In the acute stage of stroke, cognitive impairments were detected in 74% of patients Stroke etiology also plays a part in cognitive outcome: cortical deficits such as aphasia and neglect were more common after cardioembolic stroke than either large-vessel or small-vessel disease stroke

If a cell is moving towards 0 it is...

Depolarized

MSE: Executive Function

Judgement - real life scenario (e.x envelope in front of mailbox, what do you do with it?) Verbal fluency - ex. how many words can you think of that start with F Luria 3 step Drawing loops, alternating patterns == tests of perservative behaviour Regions involved: - prefrontal cortex and/or associated projections

Potassium Channels

K+ can move freely via K+ channels that are always open Na+ cannot move freely across the membrane - it has channels, but they are usually closed

Motor Function

Key features to examine: - gross appearance of muscle - muscle tone, strength Upper vs. lower motor lesions - effect on reflexes

Structural Brain Imaging: Diffusion Tensor Imaging (DTI)

Looking only at white matter See which way do things appear to be moving - are there certain axons that move freely - we see just the axons that move along the planes Can see a tumor easily

Coma

Loss of consciousness is complete Cycles of waking and sleeping disappear, and the eyes remain closed Rarely lasts more than two to four weeks, is usually temporary Afterward, patients emerge into consciousness or vegetative state, minimally conscious state, or locked-in syndrome

Limitation of Studies That Have Combined Different Types of Neuroimaging Modalities

Most have been conducted with patients at the chronic stage of stroke recovery FOr imaging to play a role in rehabilitation, it needs to provide useful prognostic information at the acute an sub-acute stages, when therapy is being planned

XI Accessory

Motor Movement of muscles of head rotation and shoulder shrug Head resistance Ask patient to turn head to the left Then ask patient to turn right While you try to resist it Ask patient to shrug shoulders while you try to resist it Observing how much strength they have

Cranial Nerves III, IV, and VI

Motor Eye movement III - eye movement and eyelid movement - does most of it Can get lesions that could make movements strange But you also can get weakness Gaze palsy - problem with voluntary movements Nystagmus - "dancing eyes" - can look for this just with observation - involuntary rapid eye movements Follow an object/light without moving their head Gaze restrictions

XII Hypoglossal

Motor Movement of tongue muscles (speech, swallowing) Stick out the tongue, lateral movement Ask patient to push tongue against cheek - palpate and assess for the strength

VII Facial

Motor Taste from anterior tongue, a little facial sensation, all muscles of facial expression Ask patient to look up and wrinkle their forehead Ask patient to smile Observe patient's nasolabial fold Ask patient to close eyelids Facial asymmetries - ex. Bell's palsy - drooping of the face All facial expressions

The Amines

Not targeted, hitting many neurons Ex. dopamine, epinephrine (adrenaline), norepinephrine (noradrenaline), histamine, serotonin All metabotropic - play a modulatory role - changing, turning up or turning down the experience people are already having

Parasympathetic Nervous System

Parasympathetic nerves act to conserve energy "Rest and digest" Immune functioning Increases digestion

Somatic Nervous System (SNS)

Part of PNS The SNS interacts with the external environment Ex. muscles on your arms, what you can control It has afferent nerves that carry sensory signals in from the skin, skeletal muscles, joints, eyes, ears, etc., into the CNS It also has efferent nerves that carry motor signals from the CNS out to the skeletal muscles

Autonomic Nervous System

Participates in the regulation of the internal environment Has afferent nerves that carry sensory signals from internal organs to the CNS Has efferent nerves that carry motor signals from the CNS to internal organs

Vegetative State -Article

Patients are in an unresponsive state, but you want to know if they're conscious envision one type of activity - a certain area lights up - different activity - results in a different pattern of activity in the brain - can communicate with these barely conscious individuals 10-30% of these patients were able to communicate using this

Minimally Conscious State

Patients may seem vegetative but sometimes show signs of awareness, such as reaching for an object, following a command or responding to their environment

Functional Magnetic Resonance Imaging and Predictors of Recovery After Stroke

Pattern of cortical activity during voluntary movement of the paretic limb is related to impairment at the time of scanning , and may predict the reduction of impairment at later stages of recovery

Serotonin

Primarily from the raphe nuclei (brain stem) Precursor: trypotophan -ex. eat turkey dinner, get sleepy, tryptophan is in turkey Involved in mood, sleep, eating, sociability, Tryptophan can only cross blood-brain barrier when eating carbohydrates - ex. no carb diet = grumpy

Glutamate

Primary excitatory neurotransmitter - passing a signal, driven by this Used throughout the brain Ionotropic - AMPA - NMDA - Kainate Metabotropic - mGluR Not a great target for drugs, why? - involved in a lot of processes, so if you want to affect one thing, you're also going to hit a bunch of other processes

Ventricles

Provide nutrition Act as the equivalent of an airbag Buoyancy (ex. a little fish tank for your brain to float in) Inside ventricles is where the cerebrospinal fluid is created

Separating Pleasure from Motivation

Salamone (1990s) - low effort, low reward vs. high effort, high reward Rats can run to the open arm and het 2 sugar pills or they can run down a barrier (high effort) and get 4 sugar pills Can give them dopamine antagonist - find that rats all switch to low effort, low reward option 3rd condition, give option for 2 sugar pills and 4 sugar pills with no barrier - and they all choose 4 sugar pills - show that dopamine must play a role in motivation, but not pleasure

Drugs: Dopamine (Antagonists)

Schizophrenia medications Dopamine antagonists: - decrease motivation but not pleasure - can be systemic or directly injected into VTA

Reading on Junior Seau

Seau complained of headaches, episodes of dizziness, and insomnia since as early as the 1990s After his retirement, he drank heavily, made reckless business and financial decisions, became more aggressive and violent Had CTE NFL has now published a protocol dealing the protective measures a player must follow after a concussion

VIII Vestibulocochlear

Sensory Sound, sense of balance Auditory perception Close one ear, whisper to another ear, ask patient "can you tell me what you heard?" Left/right side of sound world, represented bilaterally across the brain Ex. if you lose hearing in one ear, it's a nerve not cortex Balance relies on visual, vestibular (labyrinth in each ear, filled with fluid) - when you move, fluid moves and let you know where you are in the world - combine with patient information, if they're alcoholic

I Olfactory

Sensory Smell Travel through cribiform plate/ethmoid ridge Getting a mild head injury can lead to a loss of smell

Locked-In Syndrome

Technically, this state is not a disorder of consciousness, because patients are fully conscious However, they cannot move and may be mistakenly deemed vegetative or minimally conscious Many patients do regain the ability to blink and move their eyes

Diffusion Tensor Imaging and Predictors of Recovery After Stroke

Useful for assessing structural integrity of white matter pathways Greater damage is related to greater impairment at the time of scanning and at later stages of recovery

Weighted Anatomical Image and Predictors of Recovery After Stroke

Useful for identifying lesion location Extent of lesion overlap with posterior limb of the internal capsule related to motor impairment at the time of scanning

Tau and Neurofibrillary Tangles

What we look for in CTE Clumps of protein aggregates = neurofibrillary tangles - made of Tau Tau is a protein Tau starts to aggregate in cases of CTE - clump together and get a loss of microtubules (structure of cell) Neurofibrillary tangles also show up in neurodegenerative disorders Alzheimer's and Parkinson's Disease Use a stain that is sensitive to tau - more tau = darker -affects certain areas more -starts in sulcus (starts in inward folds, rather than outside) - in cortex - as it gets more severe, becomes more widespread Spreads more to the prefrontal cortex first - in alzheimers it starts in memory areas, hippocampus, amygdala PET scan = where radioactive isotope binds to Tau - compared post-mordem slices to pet scan

Default Mode Networks (Networks of Activity)

What you see when you are daydreaming Do this in fMRI - measures of changes in blood Want to see areas of activity that correlate Not doing anything = lots of activity in the brain Medial prefrontal cortex and left and right inferior parietal cortex and posterior cignulate

Exocytosis

When neurotransmitters are released from the cell

Grey Matter

Where there are cells

The Sodium-Potassium Pump

Embedded in cell membrane Protein Extremely important - consumes 2/3rds of all neuronal energy Pushes 3 Na+ out and 2 K+ in - i.e. active process that requires energy Creates chemical gradient - sodium wants to get in Inside charge is negative (absence of positive = negative)

Selective Serotonin Reuptake Inhibitors (SSRI)

Ex. Prozac For depression Transporters - get rid of neurotransmitter and only have it in the synapse when it is supposed to SSRIs block transporter/more serotonin in synapse - don't allow serotonin to get back into presynaptic membrane - block serotonin from being removed from the synapse Effects of SSRIs quick, improvements slow - usually takes weeks before people notice benefits

Open-Head Injuries

Ex. gun shot wound, puncture Goes through skull Ex. Phineas Gage, iron rod went through his eye and brain (front of brain must not be all that important is what people thought because he still was conscious) - years later everyone said he was a different person - can be quite severe

Chronic Traumatic Encephalopathy

Get a lot of subconcussive hits to the head many times Can't accurately diagnosis until after death 71/73 in a study of NFL players showed signs of CTE Another study with all types of athletes, almost all showed early signs of CTE

PSPs vs. APs

Graded: -PSPs = Yes - APs = No (either happens or they don't) Decremental: - PSPs = Yes - APs = No (gets regenerated) Rapid: -PSPs = Yes - APs = Less so

Types of Synapses

1. Axosecretory - axon terminal secretes directly into bloodstream 2. Axoaxonic - axon terminal secretes into another axon 3. Axodendritic - axon terminal ends on a dendritic spine 4. Axoextracellular - axon with no connection secretes into extracellular fluid 5. Axosomatic - axon terminal ends on soma 6. Axosynaptic - axon terminal ends on another axon terminal

Drugs: Glutamate (all antagonists)

1. Barbiturates - sleeping 2. Nitrous Oxide - laughing gas 3. Ketamine - horse tranquilizers 4. Ethanol - alcohol All depressant, dampening whole system

Drugs: GABA (all agonists)

1. Benzodiazepines (calming, relaxing) 2. Ethanol - alcohol 3. Chloroform 4. Ether - drug that used to be used in surgery Glutamate antagonists and GABA agonists have similar effects

Treatment Options for Strokes

1. 'Clipping' - clip off a piece and keep it sealed - very invasive, complications: mild brain damage, infections 2. 'Coiling' - starts in artery in thigh - run a tube all the way up to the brain and a coil can seal it off - minimally invasive, less effective Base of brain very hard to get at Right away some of the cells are going to die - loss of penumbra is more dangerous (takes a few days to die) - really early intervention to stop penumbra from dying is great

Clusters and Bundles

1. A cluster of cell bodies is called a nucleus in the CNS 2. A cluster is called a ganglia in the PNS 3. A bundle of axons is called a tract in the CNS 4. A bundle of axons is called a nerve in the PNS - axons are also often commonly referred to as 'fibers'

Components of the Motor Exam

1. Abnormal involuntary movements 2. Posture 3. Muscle bulk 4. Tone 5. Power 6. Co-ordination 7. Deep Tendon Reflexes

Refractory Periods

1. Absolute Refractory Period - can't have another action potential while the protein is blocking the sodium channel - from the point where sodium channels (repolarization phase) become inactive until we reach resting membrane potential 2. Relative Refractory Period - you can still have an action potential, but it takes a little bit more to cause one - during the hyperpolarization phase

Two purposes have guided the development of neuropsychological test batteries

1. Accuracy in predicting organic disturbance 2. Understanding of the nature of organic dysfunctions

Drug Types

1. Agonist = increase neurotransmitter release 2. Antagonist = block neurotransmitter release (decrease) - by binding and blocking 3. Other - eg. transporter blocker, reuptake inhibitor, enzyme inhibitor = all have agonist like effects

Spinal Cord comprises 2 different areas

1. An inner H-shaped core of gray matter - composed largely of cell bodies and unmyelinated axons 2. A surrounding area of white matter - composed of myelinated axons

4 Types of Glia

1. Astroglia 2. Microglia 3. Oligodendrocyte

Mental Status Examination - Cognitive Component

1. Attention and orientation 2. Language 3. Memory 4. Visuospatial function 5. Executive functions

Trigeminal Nerve - Corneal Reflex Examination Technique

1. Avoid a visual threat response by asking the patient to look up and to the opposite side 2. Stimulate the cornea since the scleral conjunctiva is less sensitive 3. Touch the cornea lightly with a wisp of cotton, observe the direct (same) eye and consensual (opposite) eye blink in response to corneal stimulation 4. Repeat on opposite side

The CNS is composed of 2 divisions

1. Brain 2. Spinal cord - as you go up the spinal cord your adding more sensory neurons and losing motor neurons

Summary of Brain Structures

1. Diencephalon - thalamus - hypothalamus - optic chiasm - pituitary gland 2. Mesencephalon - tectum (superior colliculi and inferior colliculi) - tegmentum (reticular formation, cerebral aqueduct, periaqueductal gray, substantia nigra, red nucleus) 3. Metencephalon - reticular formation - pons - cerebellum 4. Myelencephalon of Medulla - reticular formation 5. Telencephalon - cerebral cortex (isocortex, hippocampus) - major fissures (central fissure, lateral fissure, longitudinal fissure) - major gyri (precentral gyrus, postcentral gyrus, superior temporal gyrus, cingulate gyrus) - four lobes (frontal lobe, temporal, parietal, occipital) - limbic system (amygdala, hippocampus, fornix, cingulate cortex, septum, mammillary bodies) - basal ganglia (amygdala, caudate, putamen, globus pallidus) - cerebral commissures (corpus callosum)

Optic Nerve - Visual Acuity Examination Technique

1. Each eye is tested separately 2. Test best corrected vision using eyeglasses 3. Any patient with uncorrected visual acuity of less than 20/20 should be examined with a pinhole. Improvement of vision through a pinhole indicates that the error is refractive 4. Test distant vision using a Snellen chart at 10 or 20 feet or test vision using a near vision card at 14 inches 5. The patient is instructed to read progressively smaller lines of letter until they can go no further Normal response: - most young healthy individuals have vision of 20/20, i.e. at 20 feet, the patient reads a line that a normal eye sees at 20 feet - record for each eye separately, right eye = OD, left eye = OS Abnormal Response (examples): - 20/30 - 2: the patient missed two letters of the 20/30 line - 20/200: legally blind. at 20 feet the patient reads a line that a normal eye could see at 20 feet - CF: if a patient is unable to read the top line, have him count fingers at maximal distance - HM: if a patient cannot count fingers, ask them to determine direction of hand motion - LP: if a patient cannot perceive hand motion, see if they can perceive a light - NLP: no light perception

Functional Imaging Techniques

1. Electroencephalography (EEG) 2. Positron emission tomography (PET) 3. Functional Magnetic Resonance Imaging (fMRI)

Limitations to the Soviet Approach

1. Emphasis on the individual case study rather than on group statistics as a source of generalizable data

2 Types of Brain Tumours

1. Encapsulated = self contained, meaning if you can get rid of it it is unlikely to come back 2. infiltrating - wiggle their way into a lot of areas where important cells are

Tone Examination Technique

1. Ensure the patient is relaxed 2. For assessment in the upper extremities, the patient may be lying or sitting. In the lower extremities, tone is best assessed with the patient lying down 3. Spasticity (clasp knife) is velocity dependent and should be assessed by a quick flexion/extension of the knee or the elbow or quick supination/pronation of the arm 4. Rigidity (lead pipe) is continuous and not velocity dependent and the movement should be performed slowly 5. "Activated" rigidity; minor degrees of rigidity may be enhanced by having the patient activate the opposite limb 6. Rigidity in the neck can be assessed by slow flexion, extension, and rotation movements Normal response: - normally minimal, if any resistance to passive movement is encountered Abnormal Response: - spasticity is a feature of an upper motor neuron lesion and maybe minor such as a spastic catch or a very stiff limb that cannot be moved passively. Accompanying features may include spasms, clonus, increased deep tendon reflexes and an extensor plantar response - rigidity is a continuous resistance to passive movement and is seen in extrapyramidal disorders such as Parkinson's

Graphesthesia Examination Technique

1. Explain to the patient that you will be drawing a number in the palm of their hand 2. Explain to the patient what is up and down, the distal side is usually up as this is a typical orientation of the palm 3. Demonstrate with eyes open 4. Ask the patient to close their eyes 5. With a blunt item such as your fingertip draw a number across the palm and ask the patient to identify it

Stereognosis Examination Technique

1. Explain to the patient that you will be placing an item in their hand which they should then manipulate and identify with the eyes closed 2. Stimuli include different coins, a key, a safety pin, a paper clip, a coin, etc.

Trigeminal Nerve - Pain and Temperature Examination Technique

1. Explain to the patient that you will be touching them with a sharp object. Reassure them that it is disposable and has not been used on anyone else 2. For pain, use either a pin or the sharp end of a broken tongue depressor 3. Use a cold tuning fork to assess temperature - if necessary, the tuning fork can be cooled by running it under cold water 4. Ask the patient to report whether they feel sharp or dull or cold 5. Ask the patient if the two sides feel the same

Stance Examination Technique

1. General - ask the patient to stand with feet together and once they feel comfortable, close their eyes - if they cannot balance well with eyes open, do not have them close their eyes - stand close to the patient and be ready to support them should they fall to either side 2. Postural Stability (retropulsive or forced pull back test) - with eyes open, ask the patient to stand with feet comfortably apart, stand behind close to the the patient and explain that you will deliver a quick pull back - ask the patient to maintain their stability and try not to move backwards - be prepared to catch the patient under the arms should they fall backwards Abnormal response: - patients with extrapyramidal disorders often show retropulsion and may take several steps backwards and be unable to maintain their stability

The neurological exam consists of the following components:

1. Higher cognitive function as assessed by the mental status examination 2. Cranial Nerves 3. Motor System 4. Sensory Systems 5. Stance and gait

Three Basic Points of Departure from Luria's approach to neuropsychological assessment

1. His interpretation of cognitive activity as functional systems - group of interconnected biological operations that produces a particular biological effect 2. His emphasis on the individualized approach 3. The importance of the analysis of errors

Meningiomas

Grow between the meninges Encapsulated Benign tumours

Receptor Types

1. Ionotropic (channels) - aka ligand-gated ion channels - excitatory (depolarize) - inhibitory (hyperpolarize) - fast, transient effect 2. Metabotropic (signalling proteins) Receptors determine signal, not mt - aka g-protein-coupled receptors - don't cause inhibition or excitatory - cause signal cascades - one breaks off, signals to 2, that break off, and so on - modulate cell - modulate signals - important for how the cell functions overall - slow, longer lasting effect - cause signal cascades

Neuronal Communication is also electrical

1. Ions are positively and negatively charged (sodium and potassium are both positive) 2. As they move into or out of the cell, they change the potential (voltage) at the membrane - absence of ion = negative

Limitations of the Halstead-Reitan Neuropsychological Test Battery

1. It takes a long time to administer (6-8 hours) 2. It has to be distributed over days 3. It is unsuitable to administer, temporarily, if the patient has had a pneumoencephalogram that is likely to affect the validity of the test results if examination has begun 4. It is not suitable for the thorough examination of patients with sensory or motor handicaps or for speech analysis

Ischemia-produced brain damage has 3 important properties

1. It takes a while to develop 2. Damage is more likely in some parts of the brain (e.g. neurons in some parts of the hippocampus) 3. The mechanisms of ischemia-induced damage vary between brain structures

The Halstead-Reitan Neuropsychological Test Battery - developed to reflect the following methods of inference

1. Level of performance 2. Specific deficits of pathognomonic signs 3. Differential scores or patterns of ability 4. Comparison of the functional efficacy

Components of the Sensory Examination

1. Light touch 2. Pain and temperature 3. Vibration sense 4. Position sense 5. 2 point discrimination 6. Graphesthesia 7. Stereognosis 8. Double simultaneous stimuli (extinction)

Two general types of cells within the nervous system

1. Neurons 2. Glia

Two Implications of Luria's view that every patient should be considered as an individual case

1. Neuropsychological assessment is flexible and should be adapted to each patient 2. The examiner has to possess a vast amount of knowledge about the brain organization of cognitive activity in order to be able to reorient the evaluation permanently

Hypoglossal Nerve Examination Technique

1. Observe for any tongue atrophy or enlargement 2. Do not overcall tongue fasciculations. It is very difficult to relax the tongue 3. Ask the patient to protrude the tongue 4. Ask the patient to push the tongue into each cheek or alternatively to protrude the tongue and push it laterally against a tongue depressor 5. Ask the patient to move the tongue quickly from side to side 6. If there is facial weakness, correct this by supporting the upper lip on the side of the weakness, otherwise there may appear to be deviation of the tongue but once the facial weakness is corrected for, the tongue will no longer appear to deviate Normal response: - the tongue should be able to protrude relatively straight. Minimal degrees of deviation (only millimeters) affecting only the tip are insignificant Abnormal Response: - with tongue weakness, the tongue deviates towards the weak side

Facial Nerve - Motor Examination Technique

1. Observe for asymmetry - widening of the palpebral fissure or flattening of the nasolabial fold 2. Observe for involuntary facial movements 3. Ask the patient to wrinkle their forehead by raising their eyebrows and close their eyes tightly. Observe for asymmetry of ability to burry the eyelashes and palpate for differences of ability to resist eye opening. Ask the patient to show their teeth, puff out their cheeks and appose their lips 4. Recall that the efferent limb of the corneal reflex is through the 7th cranial nerve Normal response: - although patients may have an asymmetric face, there should be no facial weakness Abnormal Response: - lower motor neuron weakness causes weakness of the entire side of the face with equal involvement of the upper and lower facial muscles - an upper motor neuron lesion of the contralateral supranuclear pathway results in weakness primarily of lower muscles of facial expression. the upper muscles of facial expression are much less affected because the facial nucleus that innervates them receives partial input from the ipsilateral hemisphere

Spinal Accessory Nerve Examination Technique

1. Observe for atrophy or asymmetry of the muscles 2. Observe for quickness of shoulder shrug and ask the patient to shrug their shoulders against resistance 3. Ask the patient to turn their head to the opposite side against resistance, both watch and palpate the sternocleidomastoid muscle 4. Ask the patient to flex their head forward against resistance, placing your opposite hand against the back of the head gently to support the patient's neck should there be any weakness

Gait Examination Technique

1. Observe the patient walk 2. If there is a subtle abnormality this may be made more obvious by asking the patient to run 3. Ask the patient to perform tandem gait by walking heel to toe (eyes open)

Causes of Brain Dysfunction

1. Open head injuries - something that goes through your head - ex. gunshot 2. Closed head injuries

Trigeminal Nerve - Motor Examination Technique

1. Palpate the temporalis and masseter muscles on either side when the patient clenches their teeth 2. Ask the patient to open their mouth and repeat this against resistance. Observe for any deviation of the jaw to one side 3. With their mouth open, ask the patient to protrude their jaw to either side against resistance 4. The jaw-jerk reflex is elicited by the examiner placing their index finger over the middle of the patient's chin with the mouth slightly open and the jaw relaxed. The index finger is then tapped with a reflex hammer, delivering a downward stroke. The afferent impulse for this reflex is the sensory portion of the trigeminal nerve Normal response: - the jaw should not deviate to either side - the jaw-jerk is usually absent or weakly present Abnormal Response: - the jaw deviates towards the side of weakness - the jaw-jerk is exaggerated and pathologically brisk with lesions affecting the pyramidal pathways above the 5th nerve motor nucleus, especially if the lesions are bilateral

Infiltrating Tumours

Grow diffusely through surrounding brain tissue Malignant tumours Real issue Very pervasive Keep growing

Overview of Common Components of Neurological Exam

1. Patient History - past surgeries, medical history, medication, smoker, left vs. right handed (important for language) - could be caused by accidentally consuming something - dementia - age, education, job - family medical hisotry - use of medication - disease process: - temporal profile: sudden vs. gradual; acute vs. chronic - change over time: static, improvement, worsening - identify triggers/relievers of symptoms - gauge severity of symptoms 2. Cranial nerve function - peripheral damage: damage to cranial nerves - central damage: brain stem - innervating face, neck, head - most of the sensory and motor stuff at these parts 3. Motor function (e.g. reflexes) 4. Somatosensory function 5. Coordination 6. Mental status

Abnormal Involuntary Movements, Posture and Bulk Examination Technique

1. Patient should be sufficiently undressed but draped to preserve modesty 2. Compare left to right and proximal to distal 3. Observe for asymmetry, atrophy, or hypertrophy 4. Observe for abnormal involuntary movements

Power Examination Technique

1. Power or strength is tested by comparing the patient's strength against your own 2. Start proximally and move distally 3. Compare one side to the other 4. Grade strength using the MRC scale - 0 = no contraction - 1 = flicker or trace of contraction - 2 = active movement with gravity eliminated - 3 = active movement against gravity - 4 = active movement against gravity and resistance - 5 = normal power

Neuronal communication is chemical

1. Primarily the result of two ions, sodium and potassium 2. Ions move into or out of the cell, but not freely

Deep Tendon Reflexes Examination Technique

1. Queen Square hammer preferred 2. The patient should be relaxed 3. Before concluding that reflexes are absent, have the patient re-enforce by performing an isometric contraction of other muscles (e.g. clench teeth) 4. Before concluding that ankle reflexes are absent, position the patient in a chair by having them kneel where one would normally sit, squeeze the back of the chair for reinforcement, deliver the strike to the Achilles' tendon Babinski Response: 1. Stroke the lateral aspect of the sole of each foot and then come across the ball of the foot medially with a sharp object Clonus: 1. Ask the patient to relax 2. Support the knee in a partly flexed position 3. Quickly dorsiflex the foot and observe for rhythmic clonic movements Abdominal Reflexes: 1. The patient should be lying down and relaxed with their arms by their side 2. A blunt object such as a key or tongue blade may be used 3. Stroke the abdomen lightly on each side in an inward direction above and below the umbilicus 4. Note the contraction of the abdominal muscles and and deviation of the umbilicus towards the stimulus

How does one neuron transmit its message to another?

1. Signal travels to the terminal bouton - calcium channels open - intense cellular signal - signals vesicles to fuse to the membrane - neurotransmitters get released - muscle fibres receive neurotransmitters

Types of Neurotransmitters

1. Small-Molecule Neurotransmitters: 1. Amino acids - glutamate - GABA 2. Monoamines - catecholamines (dopamine, epinephrine, norepinephrine) - indolamines (serotonin 3. Acetylcholamine 4. Unconventional neurotransmitters 2. Large-Molecule Neurotransmitters 1. Neuropeptides

the PNS is composed of 2 divisions

1. Somatic Nervous System (SNS) 2. Autonomic Nervous System (ANS)

Problems with Interpreting fMRI studies?

1. Spatial Averaging - some people might have activity on different sides, when you average this, you get an average that doesn't represent the true location of either 2. Spatial Resolution - said to be mm^3 (1x1x1) but there are thousands of neurons - but you could have a lot of cells in one area, so you really aren't that narrowed in 3. Temporal Resolution - we aren't seeing the true speed of things 4. Not necessarily necessity - seeing a brain region everytime they do a task, but might not need that region to do the task - ex. when you do language tasks you see a lot of activity in right hemisphere, but lesions to this hemisphere doesn't have a lot of implications in language 5. Focus on increases in activity - sometimes inhibition of activity can be just as important as an increase in activity - default mode networks 6. Regional Hemodynamics - not consistent across the brain, 6 second activity delay might be different in different areas 7. Confound: Anxiety - baseline level of anxiety/arousal goes up when you go in the machine 8. Drugs - ex. drinking coffee will make your brain activity look different 9. Anticipatory Hemodynamics - if an area is active over and over, the hemodynamics response predicts that they will do that activity - activity occurs before task - brain learns that a certain part of the brain will need to be active 10. Reliability - recent meta-analysis, test-retest was only about 30% 11. Statistics - ex. dead salmon study - showed there was brain activity when the dead salmon was looking at emotionally intense pictures - the point: the problem with false positives - when you have 1 million voxels, you have 5% chance of false positives - some people don't correct for this false positive - but you can alter your statistics to the amount of tests you are doing

Olfactory Nerve Examination Technique

1. Stimulant should be non-irritating 2. Test one nostril at a time with the opposite side occluded 3. Patient should not be able to see the stimulus 4. Cloves ideal stimulant since it preserves it's scent 5. Improvise at bedside with soap, toothpaste, or perfume Normal response: - to perceive the scent with either nostril Abnormal response: - a unilateral loss is more likely to be significant and may imply a structural brain lesion affecting the olfactory bulb or tract but could also be due to local causes such as a deviated septum or blocked nasal passage - bilateral loss can occur rhinitis or damage to the cribriform plate

The efferent nerves of the autonomic nervous system are of two types

1. Sympathetic Nerves - comprise the sympathetic nervous system 2. Parasympathetic Nerves - comprise the parasympathetic nervous system

Extinction (Double Simultaneous Stimuli) Examination Technique

1. Tactile (sensory) - with eyes open demonstrate to the patient that you will touch them on the left side, right side, or both - this should only be done if the patient can perceive a unilateral stimulus (i.e. if there is loss of pain and temperature, or light touch on one side, there would be no point assessing extinction) - have the patient close their eyes and as you deliver a gentle touch, report whether they feel it on the left side, right side, or both sides 2. Visual Extinction - wiggle a finger in the left, right, or both visual fields and ask the patient to report where they see it 3. Auditory Extinction - snap your fingers on the left, right, or both sides and have the patient report where they hear the stimulus - when testing for extinction, it is important to deliver bilateral stimuli simultaneously with no time lag in between

Halstead-Reitan Battery Consists of the Following Tests

1. The Category Test - a test of abstracting ability in which the subject's task is to figure out the principle relating stimulus subtests and signal his answer by pressing the appropriate keys on a keyboard 2. The Tactual Performance Test - measures the total time required for the blindfolded subject to complete a memory task with right hand, the left hand, and both hands, the number of correct figures localized from memory, and the number of figures recalled 3. The Seashore Rhythm Test - the patient is asked to discriminate between like and unlike pairs of musical beats 4. The Speech-Sounds Perception Test, which is an auditory test that assesses the subject's ability to discriminate between similar-sounding consonants 5. The Finger Tapping Test

Oculomotor, IV Trochlear, VI Abducens Extraocular Movements Examination Technique:

1. The examiner places themself approximately 1 meter in front of the patient 2. Ask the patient to look to each side, up and down following an "H" pattern 3. Pursuit: ask the patient to follow a target such as your finger or a pen with their eyes without moving their head 4. Pause at the ends of each direction of gaze to observe for nystagmus 5. Assess saccadic eye movements by having the patient make quick horizontal and vertical eye movements 6. Optokinetic nystagmus is performed by having the patient follow a series of moving horizontal or vertical stripes and oberving for nystagmus

Two different aspects in Luria's neuropsychological assessment

1. The specific tests he used for pinpointing the cognitive deficits 2. His particular clinical approach

Facial Nerve - Taste Examination Technique

1. The tongue is protruded and held gently by the examiner 2. A small sample of solution is appleid to one side of the anterior two-thirds of the tongue using a cotton tipped applicator saturated with the solution 3. With the tongue still protruded, the patient should be asked to point to a sign displaying one of four possible tastes 4. The patient is then given a small sip of water and the test is repeated using an alternate stimulus 5. The reason the tongue is maintained protruded is because if the patient were allowed to put their tongue back in their mouth in order to verbalize their response they could masticate and transfer the stimulus to the opposite side which could be affected if there was a lesion of the 7th nerve

Two 2 Major Types of Strokse

1. Those resulting from cerebral hemorrhage - blood is spilling out of a vessel, seeping into the brain - more severe 2. Those resulting from cerebral ischemia - blockages, bloods not getting where it needs to go

Order of Neuropsychological Assessment

1. To describe the general pattern of changes taking place in cognitive ability of a patient 2. To identify the fundamental defect(s); that is, to find the factor(s) underlying their signs and symptoms 3. To propose therapeutic procedures

Trigeminal Nerve - Light Touch Examination Technique

1. Touch a cotton wisp to the forehead, cheek and chin (avoid the angle of the jaw which is innervated by the upper cervical roots

Temporal Summation

1. Two EPSPs in rapid succession synergize to produce a larger EPSP 2. Two IPSPs in rapid succession synergize to produce a larger IPSP If they aren't close in time, there won't be a temporal summation

Spatial Summation

1. Two simultaneous EPSPs sum to produce a greater EPSP 2. Two simultaneous IPSPs sum to produce a greater IPSP 3. A simultaneous EPSP and IPSP cancel each other out

Vibration Sense Examination Technique

1. Use a 128 hertz vibration fork 2. Apply the stimulus over the distal phalanx of the index finger or large toe 3. Ask the patient to report whether they feel vibration sense and then to report when it stops in order to assess the minimal threshold to perceive the stimulus 4. Compare to own extremities

Temperature Examination Technique

1. Use a cold vibration fork 2. If necessary, the fork can be cooled by running it under cold water 3. Ask the patient if they perceive the vibration fork as cold

Light Touch Examination Technique

1. Use a cotton whisp 2. Apply a gentle touch (do not drag the stimulus) 3. Ask the patient to close their eyes and report "yes" every time they perceive the stimulus

Pain Examination Technique

1. Use a disposable pin 2. Ask the patient to close their eyes and report whether they feel sharp or dull 3. Be sure to apply the sharp stimulus to all sites since if only the dull stimulus is applied, pains sensation has not been assessed

Two Point Discrimination Examination Technique

1. Use either calipers or a opened paper clip with 2 parallel ends 2. Demonstrate to the patient with eyes open by applying either one or two points of the stimulus to the fingerpad 3. Ask the patient to close their eyes 4. Deliver the stimulus and ask the patient to report whether they feel one or two points Normal Response: - normal values over the fingerpads are 2-4 mm

Acetylcholine

The neuromuscular junction Also basal forebrain - wakefulness, attention, etc. - overall levels of arousal Nicotine = acetylcholine agonist - makes you feel jittery, a little more alert

Voxel

3 Dimensional tile 3D equivalent of a pixel

Skull and MeningesSkull and Meninges

3 Layers of Meninges: 1. Dura mater 2. Arachnoid mater 3. Pia mater

Spinal Cord

32 sections Ones at the top = cervical nerves (~8) Next 12 = thoracic Mid-lower back = lumbar Underneath (really lower back) = sacral Butt = coccygeal Same general shape Dorsal part is mainly sensory information (afferent) Ventral side is where motor information is exiting (efferent)

Strokes

3rd leading cause of death, leading cause for why an adult might have a disability Sudden onset cerbrovascular disorders that cause brain damage Infarct = area of dead or dying tissue - directly damaged - by the time doctors find it it is usually dead (only takes 4 minutes with no blood flow) - not trying to treat this Penumbra = dysfunctional area surrounding the infarct; tissue in that area may either recover or die - treatments aimed at this - diminished blood flow - surrounds infarct

Neoplasm

=Tumor All these newly generated cells (cell growth where you shouldn't have cell growth)

What is a Neurological Exam?

A series of tests conducted by a neurologist to evaluate the integrity of the nervous system for many reasons, including (but not limited to): - following trauma or stroke - when there are suspected neurodegenerative changes - following exposure to a neurotoxic agent

Concussion

A subset of mild traumatic brain injuries, although mild TBI can include subconcussive impacts as well

Adenosine

ATP is a cellular energy - when things are bonded, when the bond is broken, energy is released - break phosphate off Adenosine is ATP byproduct Adenosine receptors When there is a high amount of adenosine, you feel sleepy Coffee, energy drinks = adenosine antagonist

Major Divisions of the Brain: Myelencephalon

Aka medulla Composed largely of tracts carrying signals between the rest of the brain and the body One part of your hind brain Where a lot of what starts to make a living thing is Further back in the brain is where you breath from, what makes you live, not cognitive abilities Reticular formation: ~100 nuclei involved in myriad functions - their axons spread across entire brain - don't have directed synapses, just fire into space

Drugs: Dopamine

All addictive drugs directly or indirectly increase dopamine transmission

Brain Death

All functions of the brain and brain stem have permanently ceased

MSE: Language Problems

Aphasia = problems with language production and/or comprehension Alexia = problems with reading Agraphia = problems with writing Regions involved: - focal or diffuse damage to the left hemisphere language network Problems with prosidy or emotional content in language = right hemisphere

Basal Ganglia

Around thalamus Memory, motivated behaviour (addiction, reward) Ventral striatum Nucleus accumbens

To Test Covert Consciousness

Asked patient to imagine playing tennis if they could hear the researcher Significant brain activity showed up in the premotor cortex When asked to walk through their home - significant brain activity in the parietal lobe and parahippocampal gyrus Indicated consciousness By assigning "yes" to tennis and "no" to walking through their house - able to communicate

Tripartite Synapse

Astroglia surrounds the axon and dendrite

Is there a distinct profile of cognitive impairment arising from stroke?

Attention, memory, language, and orientation were most affected by stroke, yet patients also had marked deficits in visuospatial skills and abstract reasoning Tasks of attention, visuospatial ability, and verbal fluency were the most affected, but language and memory performance was also down It is now thought that stroke tends to have greater deleterious impact on attention and executive function than on memory Cognitive slowing is a common complaint after stroke, and a majority of patients exhibit marked slowness of information processing

Babinski Reflex

Baby will fan out toes if you tap bottom of foot As you get older you curl toes in, but if theres peripheral nerve damage, you fan toes out

Cerebral Hemorrhage: Aneursym

Basically like a water balloon; bubble of blood - if it gets too big or too high of pressure, it will burst Really common along base of brain; near where cranial nerves come out - circle of Willis - flow, connecting everything, different directions = prone to getting aneursyms A lot of people may have them, they don't all burst though - only found in adults Often not symptomatic, unless it is pressing on something - like a fire hose

Why does the signal of an action potential only travel in one direction?

Because of the absolute refractory period Once it moves down the ion channels behind it will be inactive

V Trigeminal

Both Facial sensation, movement of biting/chewing/swallowing jaw muscles Motor function 3 roots, forehead, cheek, chin - test for feeling in these spots Sensory parts of your face also chewing, swallowing Motor- get people to bite down hard Sensory - use cotton and touch these areas: forehead, cheek, jaw - ask if they can feel Reflex - place cotton on cornea, see if patient blinks and use tendon hammer to demonstrate jaw jerk Motor - place your finger on: massester muscle and temporalis muscle - then, ask patient to clinch their teeth, feel the muscle contracting

Hemorrhaging

Can't clear away the problem of toxic blood everywhere

MSE: Attentional Problems

Caused from stroke 1. Contralateral Neglect - failure to attend to the left side of world - damage in right parietal lobe - visual information is coming in, bot a problem with perception - they are just unable to pay attention to that side - when these individuals are told to pay attention, they can - but if you just told them to draw the cat, they couldn't - damage to left parietal lobe, you don't see 2. Anosognosia - failure of individual to self-reflect that they have a disorder - ex. people say they didn't have a stroke - come up with confabulations - ex. my arm is just hanging because im too tired to hold it up - ex. dont identify with a leg being theirs - common in schizophrenia - medications can help

Localization

Cerebral Hemisphere (Telencephalon) Internal Capsule Brainstem (where? Diencephalon, Mesencephalon, Metencephalon, or Myelencephalon?) Spinal cord Cranial nerves Neuromuscular junction Muscle Sometimes white matter bundles may be damaged (ex. internal capsule) - information may be sent but it may not be received Sensory side = dorsal side - spinal cord

Electrical Gradients

Charge/potential wants to flow from high concentration to low concentration, too Sometimes electrical and chemical gradients are at odds, causing an equilibrium that =/= 0mV - force pushing in two directions

The Limbic System

Cingulate cortex - involved in assessing cost-benefit - cognitive and emotional Hippocampus - spatial navigation, emotion regulation Amygdala - link emotional qualities and values to cues

Adjustments to the Classic View

Claim 1: Each cell has a single input - true at the neuromuscular junction: each muscle fiber receives input from only one motor neuron - but the neuromuscular junction is an exception. Most cells in the nervous system receive input from many cells Claim 2: Neurotransmitters are deactivated by enzymes - true at the neuromuscular junction, where an enzyme deactivates acetylcholine - but rare at non-cholinergic synapses, where reuptake is the major mechanism for deactivation of neurotransmitters Claim 3: Neurotransmitters produce one of either EPSPs or IPSPs - true at the neuromuscular junction for skeletal muscles, where ACh produces EPSPs - whether or not a neurotransmitter produces an EPSP or IPSP was later shown to be a function of the receptor type/subtype Claim 4: Each neurotransmitter has a single receptor - it was discovered that some ACh receptors bind nicotine better than muscarine, whereas for others the reverse is true - nicotinic and muscarinic receptors are ionotropic and metabotropic receptors, respectively Claim 5: Each cell releases a single neurotransmitter - 'coexistence' of different transmitters has been found in many cells in the nervous system In general: Neurotransmission is a complicated and heterogeneous activity

Major Divisions of the Brain: Mesencephalon

Composed of the tectum and the tegmentum Tectum: in mammals, is composed of 2 pairs of bumps: the inferior colliculi and the superior colliculi Superior colliculi - integrate visual info and linking it to an action of orienting your eyes Inferior colliculi - integrate auditory info and directs your attention Tegmentum: contains the top of the reticular formation, fibers of passage, the periaqueductal grey, the substantia nigra, and the red nucleus Red nucleus - specific behaviour (ex. dog barking, rat squealing) Substantia nigra - produce dopamine and spit it to different areas Mid brain Tectum - roof (dorsal) Tegmentum - floor (ventral)

Acute Stroke Diagnosis

Computed tomography (CT) and magnetic resonance imaging (MRI) techniques are used

Functional Brain Imaging: Positron-Emission Tomography (PET)

Create something that is radioactive and you have to do it right before you use it Only use it for unique cases when nothing else will work FDG - radioactive glucose - measure activity in the brain by measuring this Not looking at action potentials Scanner picks up the radiation Takes a long time to run

MSE: Visuospatial Problems

Different type of agnosias - inability to perceive a type of object 1. Prosopagnosia - can't recognize faces - can look at individual nose, eye, but can't put it all together - part of the brain that is sensitive to faces: fusiform face area (in temporal lobe ) - area that's damaged with prosopagnosia - not just for faces, it's useful for becoming an expert in a certain area of things -ex. cant tell apart bird species, or types of vehicles 2 Constructional Apraxia = difficulty putting pieces of an object together 3. Dressing apraxia = difficulty getting dressed

MSE: Memory

Digit span - remembering growing number of digits (~7 average) - specific to working memory Pointing span - variant of digit span - point out corners of the room and do the same order as doctor Verbal, visual object learning - issue to retain beyond a few seconds Regions involved: - medial temporal structures (eg. hippocampus), thalamus, basal forebrain, prefrontal cortex

Closed-Head Injuries

Don't see outward signs, blood isn't coming out of head 1. Contusion - closed-head injuries that involve damage to the cerebral circulatory system - producing internal hemorrhaging and a resultant hematoma - occur when the brain slams against the skull - skull doesn't have to be damaged - tissue is damaged - person will be unconscious for a while, positively correlated with the extent of the brain damage - frequent contrecoup injuries: the blow causes the brain to strike the inside of the skull on the other side of the head - get damage on both sides - brain is bouncing against the skull 2. Concussion (or mild traumatic brain injury) - when there is a blow to the head but no evidence of a contusion or other structural damage - problems with focusing, impulsivity, irritability (common symptoms) - can have something less than a concussion (don't lose consciousness) but still considered a mild TBI - can often hit your head many times without a lot of noticeable signs, but if you get a 2nd concussion after the first one has healed can get really bad issues - a twisting movement is worse than just a slam on head

Dopamine and Parkinson's Disease

Dopamine is in substantia nigra and Ventral Tegmental Area When symptoms show, 90% of damage has already occurred Inability to initiate or stop movement L-Dopa

Functional Brain Imaging

Easiest way is to just drop a needle into a brain, but we can't do that Can do it with epilepsy patients, to detect activity Non-invasive non-direct measures - correlate with activity (measuring things related to brain activity) Other than electrical - can measure blood flow (more blood flow = more activity) - can measure glucose (can infer that more glucose consumption is more active) - measure oxygen

Conduction of Action Potentials

Effect of subthreshold stimulation of an axon: - an excitatory potential is produced, but it is not sufficient to elicit an AP Effect of suprathreshold stimulation of an axon: - an excitatory potential is produced that exceeds the threshold of excitation and produces an AP

How do you measure the resting membrane potential?

Extracellular electrode measures outside membrane's voltage in extracellular fluid Intracellular electrode (very fine tip) = measures membrane's voltage

Axon Myelination

Fatty sheaths that are wrapped around axon Jump between nodes of Ranvier = Saltatory Conduction

Sympathetic Nervous System

Fight or flight Being ready to take action Mobilize energy resources in threatening situations (e.g., via adrenal glands) Stops your digestion Heart rate faster, pumping more oxygen to brain High state of arousal

MSE: Language

Fluency, naming, repetition, prosody, comprehension, reading, writing, praxis Measuring ability to speak fluently Repetition - ex. telling a story every 10 minutes Prosody - what words you stress and don't - problems with this can be an issue, problems with temporal lobe Praxis - carrying out directions when instructed - ability to say and also do - ex. apraxia = inability to move in a meaningful way (wouldn't be able to mimic the action of cutting bread)

uMajor Divisions of the Brain: Diencephalon

Forebrain Composed of 2 structures: 1. Thalamus - comprises many different types of nuclei - some are sensory relay nuclei - relaying information from spinal cord to brain stem to rest of brain - cortico-thalamic loops: feedback activity between cortex and thalamus - represent neural basis of consciousness/awareness 2. Hypothalamus - plays a role in eating, memory - in part via its effects on the pituitary gland

Structural Brain Imaging: Computed Tomography (CT)

Form of x-ray Getting a rotation around the patient - get a 3D image Many x-rays, then do a reconstruction - stacking - (gives you a 3D image) Improvements: - 1977: could see if there was a lot of fluid, but wouldn't be able to differentiate white matter and grey matter - now: done digitally Problems: radiation; can't keep using it on a person

Optic Nerve - Fundoscopy Examination Technique

Fundoscopy = the assessment of the fundus using an opthalmoscope 1. Dim the lights 2. Ask the patient to fixate on a distant target 3. Approach the patient from the side 4. Examine the optic nerve and surrounding retina

GABA

Gamma-Aminobutyric acid Primary inhibitory neurotransmitter Used throughout brain Ionotropic and metabotropic Again, not a great target for drugs

Functional Brain Imaging: Electroencephalogy (EEG)

Gel allows for better contact, better signal Voltage changes have to cross through the brain through the meninges, the skull, to electrodes Recording from hundreds of thousands of neurons Getting constant waves Waves have 2 qualities about them: 1. Amplitude (height of waves) 2. Frequency (how many times per second -width) Cycles per second = Hertz Slow waves/Big = means they fire at same time and slow at same time Fast/small waves = lots of activity, but not synchronized very well Delta waves - really slow and tall, seen during sleep More awake you are, the faster and smaller the waves Gamma waves - recorded in monks - high activity even when meditating

Vestibulocochlear (Acoustic) Nerve Examination Technique

Hearing: 1. Mask the opposite ear and whisper numbers. The patient should not be able to read your lips. Ask the patient to repeat the numbers. If they cannot do so, increase the volume of your voice and repeat as needed. Note any asymmetry 2. Compare the air versus bone conduction using the Rinne test. Apply the vibrating fork against the mastoid process. Ultilize the 512 Hertz tuning fork. Ask the patient when they can no longer hear it, then place it in front of the ear 3. Test for lateralization using the Weber test. Apply the vibrating tuning fork to the center of the forehead and ask the patient where they hear it Vestibular Function: 1. Observe for nystagmus when extraocular movements are assessed Normal response: - rinne - air conduction (perceiving the sound of the tuning fork in front of the ear) is greater than bone conduction (with the tuning fork held against the mastoid process) - Weber - normally, patients will either hear it equally from both ears or respond that they are not sure Abnormal Response: - Rinne - in conductive hearing loss, bone conduction is greater than air conduction. In sensorineural deafness, air conduction is greater than bone conduction - The weber is abnormal if the patient clearly lateralizes it to one ear. With a conductive hearing loss, the patient lateralizes the sound to the affected ear. With sensorineural deafness the sound is best heard by the non-involved ear

Covert Consciousness

Hidden awareness in patients who had been declared vegetative

Structural Imaging

High resolution images produced by MRI allow stroke lesions to be identified with relative ease

Structural Brain Imaging: Magnetic Resonance Imaging (MRI)

Hydrogen atoms have a pull in different directions (magnetic) - use this to influence how you see them - when hydrogen atoms are near a magnet, they will align 3 Tesla is about 60x stronger than the magnetic field of earth - mri can be 3T, 5T, 7T Don't want to bring metal around the magnetic field Results with slices of pictures of the brain - see white matter and grey matter Don't want to put kids in it, it's loud, claustrophobic, can't use if you have metal in you We are made of a lot of water, do we have a lot of hydrogen atoms, once you go in MRI, all the atoms they all line up the same way Step 1: Align all the protons with the large magnetic field - magnet is always on Step 2: Momentarily perturb that alignment with a second varying magnetic field - send a pulse through - knocks all atoms out of alignment, sensors pick this up - rays fly off all over the places energy is released Step 3: Measure radiofrequency (RF) signal produced during realignment with the large magnetic field ('relaxation') - 3T-5T have some drawbacks - 11T is the strongest MRI

If a cell is moving away from 0 it is...

Hyperpolarized

Contralateral Neglect

Inability to pay attention to the left side of space Damage to right parietal lobe - don't have a backup on the left side Symptoms: - dress oneside of body - draw on right side Nothing to do with eyes, involves brain processes associated with attention - attentional system is damaged Can distinguish between half a cat and whole cat - in her mind, her drawing is complete - imagination Common problem following ischemic stroke

Cranial Nerves

I Olfactory - sensory - smell II Optic - sensory - vision III Oculomotor - motor - most eye movement, eyelid movement IV Trochlear - motor - eye movement V Trigeminal - both - facial sensation, movement of biting/chewing/swallowing jaw muscles VI Abducens - motor - eye movement VII Facial - both - taste from anterior tongue, a little facial sensation, all muscles of facial expression VIII Vestibulocochlear - sensory - sound, sense of balance IX Glossopharyngeal - both - taste and sensation from posterior tongue, muscles of pharynx (speech, swallowing) X Vagus - both - outer ear canal sensation, motor control of heart, lungs, viscera, larynx (speech), more XI Accessory - motor - movement of muscles of head rotation and shoulder shrug XII Hypoglossal - motor - movement of tongue muscles (speech, swallowing) Trochlear is the smallest Trigeminal is the largest - most of your facial sensation Vagus is the longest

IX Glossopharyngeal and X Vagus

IX: Both Taste and sensation from posterior tongue, muscles of pharynx (speech, swallowing) X: Both Outer ear canal sensation, motor control of heart, lungs, viscera, larynx (speech), more Swallowing and voice Gag Reflex Ask patient to cough Ask patient to open mouth and say "AAA", palate should move upwards Observe uvula position - should be centrally located

Action Potential

If it happens, it always looks the same (all-or-none) - ex. like a gun firing, can't make it smaller or bigger Occurs

Action Potential Generation and Conduction

If the sum of the EPSPs and IPSPs that reaches the axon initial segment is sufficient to depolarize the membrane there above its threshold of excitation (e.g., -65 mV) then an action potential (AP) is generated - threshold potential is usually 5 mV higher than the resting membrane potential The AP is a massive momentary reversal of the membrane potential (e.g. from -70 to +55 mV) AP generation and conduction are both the result of voltage-activated ion channels Travels passively to the next channel, where it can be regenerated - constantly renewed by voltage-gated channels

Oligodendrocyte

In CNS Wrap myelin around many neurons

Directions in the Nervous System

In rats: - back: posterior/caudal (toward the tail) - front: anterior/rostral (toward the nose) - midline in the front: medial - going left and right from the midline = lateral = ex. ears are lateral to nose - top: superior/dorsal - bottom: inferior/ventral In humans: - top of head: dorsal - bottom of head: ventral - back: dorsal - stomach: ventral - face: anterior - back of head: posterior

Efferent Nerves

In the somatic nervous system - Carries motor signals from the CNS out to the skeletal muscles In the autonomic nervous system - Carries motor signals from the CNS to internal organs

Afferent Nerves

In the somatic nervous system - Carries sensory signals in from the skin, skeletal muscles, joints, eyes, ears, etc., into the CNS In the autonomic nervous system - carries sensory signals from internal organs to the CNS

Prosopagnosia

Inability to perceive faces or species Eyes are intact, due to head injury Can see people, but can't tell who they are Just sees "a face", can't tell its his face - incompleteness Can identify an eye or outh, but can't see the full picture - the Gestalt - we are more than just an eye or nose He sees a face, not just a blur Does he have a visual memory of what he looks like? - varies from person to person - in general, if an area is involved in a complicated conceptual process, if damaged it should effect memory as well

Cognition

Incorporates multiple domains including attention (focusing, shifting, dividing, or sustaining attention on a particular stimulus or task), executive function (planning, organizing thoughts, inhibition, control), visuospatial ability (visual search, drawing, construction), memory (recall and recognition of visual and verbal information), and language (expressive and receptive)

What would a glutamate agonist do?

Increase activity in the brain Panic, anxiety, mania, seizures = overactive brain

What would a GABA antagonist look like?

Increase spontaneous activity across the brain Anxious, manic

Microglia

Injury and immune response cells Start small Get large in a primed state (when there is an injury)

Glial Networks

Not an Action Potential Have a direct pore that moves

A. R. Luria

Introduced as the most typical figure of behavioural neurology and clinical neuropsychology

Chemical Gradients

Ions want to flow from high concentration to low concentration - ex. swimming pool, dye analogy

Limitation of Structural Neuroimaging

It provides no information about whether or how surviving tissues are working

Astroglia

Largest Maintain ionic balance Repair and scarring brain Connect to endophilia cells Influence over how neurons communicate

Optic Nerve - Pupillary Light Reflex/Eyelid Elevation Examination Technique

Light entering the eye travels along the optic nerve to the pretectal region of the mid brain to cause pupillary construction through the visceral motor and short ciliary nerve components of the ocular motor nerve 1. Observe the ptosis 2. Observe the pupils for size (measure the diameter of each pupil in mm) 3. Observe for any irregularities or asymmetry 4. Dim the lights, ask the patient to look into the distance, shine a bright light obliquely (approaching laterally) into the pupil - observe for the direct response (same eye) and consensual response (opposite eye) 5. Assess for an afferent pupillary defect (the swinging flashlight test) by moving the light from one pupil to the other, back, and forth 6. To assess the accommodation reflex, ask the patient to look in the distance and then at the tip of their nose (if the patient finds this manoeuvre difficult, have them follow their extended thumb as it is brought in towards the tip of their nose) Abnormal Response: - ptosis is present, if the eyelid covers part or all of the pupil when looking directly ahead

Major Divisions of the Brain: Metencephalon

Like the myelencephalon, houses many fiber tracts All those fibers, and the pontine nuclei, create a large bulge - called the pons Pons - fiber tracts, full of myelinated axons Has reticular formation too Cerebellum - despite taking up only 10% of the brain's volume, the cerebellum contains ~50% of all of its neurons - super important for emotion, cognitive aspects, coordination - people that don't have one have to correct their movement, have a resting tremor

MSE: Visuospatial Function

Line cancellation Copy of geometric designs Judgement of line orientation Object/face/colour recognition Regions involved: - right hemisphere's attention network

The Cell Membrane - Guardian

Lipid bilayer is tightly packed, both hydrophobic and hydrophilic, keeping out all dangerous entities

Functional MRI

Measures the blood oxygen level dependent (BOLD) signal from the brain during task performance and at rest - this signal is thought to reflect neural activity BOLD activation patterns after stroke are closely correlated with aspects of impairment, in both the motor and language domains

SSRI Efficacy

Meta-analyses: SSRIs no better than placebo for mild to moderate depression May help with major depression, but might just be regression to the mean - patients might just be returning to baseline

Glioblastoma

Most common type of malignant brain tumour in adults 12-15 months expectancy after diagnosis

Problems with conduction in an unmyelinated axon

Much slower Solution: - make neuron (or axon) bigger - less resistant, degrading at a slower speed - or insulate the wire (wrap something around it to decrease the loss of potential)

Cells are polarized

Na+/K+ pump pushing more Na+ out of cell than K+ into cell - Result: inside of cell more negative than outside ButK+ can move freely through its channels - Result: K+ wants to move with chemical gradient, out of the cell But this moving K+ is making the cell even more negative - Result: flow of K+ stops when force of electrical gradient equals force of chemical gradient End result: cell has resting membrane potential of ~-70mV Force of K+ wanting to move out = force of electricity wanting to move in Chemical driving force = electrical driving force = no movement

MSE: Attention and Orientation

Observe the patient's alertness Spelling a word backwards Counting backwards from 20 Auditory vigilance Current whereabouts, time Regions involved: - focal cortical or subcortical regions - origins may be diffuse (e.g. toxin) - could be as simple as acetylcholine death

Mean Difference Image

Obtained from Paired-Image Subtraction

Motivation for Brain Stimulation

Olds and Milner - wanted to stimulate rats brains, but they missed - rats would press lever at exclusion of anything else, so they would get food Dopamine projects from Ventral Tegmental Area to Nucleus Accumbens (NAcc) - involved in reward Dopamine isn't pleasure

Channels and Pumps

Only certain molecules and ions are permitted via channels and pumps Channels: allow passive diffusion (i.e. along chemical gradient) - ex. potassium can only flow through potassium channel Pumps: actively push ions against their chemical gradient - requires energy (ATP)

Norepinephrine

Originates in brain stem region called the locus coeruleus Enhancement of memory by stress/emotion - when there is a stressful event, this is released; increases our ability to attend to things, to remember Reconsolidation, potential PTSD treatment? - when things enter our memory, they are entered eventually into our long term memory by consolidation - every time you bring that memory back - it is in a labile state (fragile - can be manipulated and changed) - intense norepinephrine and memory link in PTSD = if we block the effects of norepinephrine in the labile state, overall experience of fear is diminished - still able to remember content of memory, but emotional response associated with memory is diminished

Overlau Plot

Overlay a bunch of different images of different brains to identify where problems may be that result in certain behaviour

Somatosensory Function

Pain Light touch and proprioception Testing for astereognosis Testing for agraphesthesia

Optic Nerve - Visual Fields Examination Technique

Peripheral visual field - wiggling fingers - counting fingers - white pin Central visual field - red pin 1. Visual fields are assessed by confrontation, i.e. the examiner compares the patient's visual field to their own and assumes that theirs is normal 2. First test each eye separately 3. Test both eyes together with wiggling fingers 4. The examiners places themselves approx. 1 meter away from the patient and advises the patient to look directly at the examiner's eye for monocular testing or nose for binocular testing 5. Test object is presented equidistant from the patient's and examiner's eye and the patient is asked either to state the number of fingers or say "yes" when they first see a moving target 6. For central vision a red pin is used - patient is instructed to state when they see the pin as red Normal response: - the normal monocular visual field extends approx. 100 degrees laterally, 60 degrees medially, 60 degrees superiorly and 75 degrees inferiorly

Receptor Locations

Postsynaptic Presynaptic - autoreceptors - there to say "hey, we've already sent out a lot of neurotransmitter" - heteroceptors - like a volume knob, regulates how much is released - binds to another presynaptic

The Case of Kate

Put Kate who was in a "vegetative" state - although she had sleep-wake cycles, lacked consciousness Put her in a PET scanner and showed her pictures of her friends and family by flashing them on a computer screen Her pattern of brain activity was similar to brain activity of healthy aware individuals seeing their loved ones Began to recover several months after her scan - uses a wheelchair, speaks with difficulty, but her cognitive faculties have returned, including her sense of humor and ability to appreciate the profound role that she and her brain played in the process of scientific discovery

Coordination

Quick, alternating movements Point-to-point movement Heel-to-shin test Standing/sitting Gait Romberg test

Ischemia

Recovery : ex. stem cell to prevent apoptosis from occurring - good evidence of recovery of function - time sensitive period: shortly after stroke where recovery will be more effective if treatments are done early Therapies: - brain is a use it or lose it system - ex. if movement in arm is lacking, they will use that arm even more - constraint-induced movement therapy: restrain the good arm and use only the "bad" arm - pretty effective, good recovery

Chronic Traumatic Encephalopathy

Repetitive mild TBI is thought to contribute to the development of chronic traumatic encephalopathy (CTE), a neurodegenerative disease pathologically confirmed by the presence of a unique pattern of hyperphosphorylated tau neurofibrillary and astrocytic tangles in the brain Can only be diagnosed in autopsy

PET: Diaschisis

Reveals how much energy is used after a stroke Can see changes in blood flow/glucose Can see hidden problems

II Optic

Sensory Vision If you have a problem in both eyes, it's damage to the brain If you have a problem in only one eye, it could be located to the eye or optic nerve damage Information from one eye is represented in both hemispheres - left visual field goes to right hemisphere Scnellan - standard visual acuity tests for each eye - get 6/9 rows Macula - darker spot in eye - fovea is in the middle Pupillary light reflex - make sure there's no issues with how the pupils open Look for ptosis - when one of the eyelids covers some of the pupil Visual Field confrontation Papilledema and intracranial pressure

Symptoms of CTE

Similar symptoms to concussions: irritability, impulsivity Substance abuse Paranoia, jealousy, delusions, lose touch with reality Depression, suicidality

Vegetative State

Sleep-wake cycles occur The eyes may open spontaneously or in response to stimulation, but the only behaviours displayed tend to be reflexive

Ionic Basis of Action Potentials

Slight change in shape, pore opens Opens up and ions can move through it 1. Once cell is depolarized enough, reach the threshold 2. Rising phase - starts with the sodium channels open (sodium moves in) - potassium channels open (extra ones slowly open) - force of sodium is so strong - ends with sodium channels inactive (ball and chain - protein - blocks the channel) - sodium channels are still open but nothing can flow through 3. Repolarization - potassium flows out - ends with potassium channels starting to close 4. Hyperpolarization - as the potassium channels are slowly closing, they overshoot the resting membrane potential - leads to refractory periods

Metastatic Tumours

Some infiltrating brain tumours grow from tumour fragments carried to the brain from another body part via the bloodstream Commonly originate from a breast cancer or a lung cancer Have a tumour somewhere else and then it moves up to your brain

An Ionotropic Receptor

Some neurotransmitter molecules bind to receptors on ion channels When a neurotransmitter molecule binds to an ionotropic receptor, the channel opens (as in this case) or closes, thereby altering the flow of ions into or out of the neuron

A Metabotropic Receptor

Some neurotransmitter molecules bind to receptors on membrane signal proteins, which are linked to G proteins When a neurotransmitter molecule binds to a metabotropic receptor, a subunit of the G protein breaks off into the neuron and either binds to an ion channel or stimulates the synthesis of a second messenger

Structural vs. Functional Brain Imaging

Structural = anatomy Functional = activity

Paired Image Subtraction

Take one picture subtract another picture = area that you want to know Ex. 1. Spatial working memory (visual + motor) Minus 2. Visuo-motor control = Working memory One condition where you measure what you want to see Comes with assumptions: - have basic processes that all come together - constituent cognitive processes - results depend on control condition - constituent cognitive processes: More complex form of cognition is made up of smaller forms of cognition

PLORAS (Predicting Language Outcome and Recovery After Stroke) System is Based on This System

That the ability to comprehend and produce speech after stroke depends on whether the areas of the brain that support language have been damaged This system requires a large number of patients with the following: 1. A detailed assessment of various language capabilities 2. Brain scans which are converted into 3D descriptions of the lesion 3. TIme since stroke A new subject's lesion image is compared with those from all the other patients already in the database to find one with a similar lesion

Assessment in Clinical Neuropsychology

The application of standardized psychometric procedures composed of items that are well studied and are of known acceptable reliability and validity

Major Divisions of the Brain: Telencephalon

The largest division of the brain The most prominent constituent of the telencephalon is the cerebral cortex The cortex is highly convoluted - convolutions increase the surface area while maintaining a small volume - the brains of humans are highly convoluted; many mammals are lissencephalic (smooth-brained) - the large furrows in the cortex are called fissures or sulci - the ridges between the fissures are called gyri - the largest of all the fissures is the longitudinal fissure The cerebral hemispheres are connected by only a few tracts called the cerebral commissures - the largest is the corpus callosum Corpus callosum - if cut, left and right hemispheres can't communicate

Assessment in Behavioural Neurology

The search for pathological signs and symptoms indicating brain dysfunction

Postsynaptic Potential

The transmission is graded, rapid, and decremental Travel like an electrical signal along an uninsulated wire Can be small or big but they become smaller and smaller

White Matter

Tracts of the axon with myelin

Endocannabinoids

Travel from dendrite to axon, i.e. backwards Marijuana mimics this system On post-synaptic side and sends to the presynaptic side Weakens connection between 2 cells at a synapse - forgetting can be a valuable thing

Lobes of the Cortex

Two major landmarks: Central fissure and lateral fissure 1. Central fissure - separates frontal and parietal 2. Lateral fissure - separates frontal and temporal Four Lobes: 1. Frontal 2. Parietal 3. Occipital 4. Temporal

Co-ordination Examination Technique

Upper Extremities: 1. Finger to nose 2. Rapid index to thumb movements or individual digits to thumb, rapid small index finger circles over the opposite dorsal webspace, rapidly alternate each hand palmar then dorsal aspect down over thigh or opposite hand Lower Extremities: 1. Ask the patient to place their heel on their opposite knee and slide their heel down their shin to the ankle 2. Ask to the patient to tap their opposite knee with their heel 3. Have the patient reach for your finger with their large toe 4. Ask the patient to perform rapid foot taps

Major Divisions of the Brain During Development

Very early in development, 3 swellings appear; These are termed forebrain, midbrain, and hindbrain

Classic View of Neurotransmission

Was based on work done at one synapse: the neuromuscular junction - releases one neurotransmitter: acetylcholine What was true for that synapse was once (incorrectly) generalized to all nervous system synapses: 1. Each cell has a single input 2. Neurotransmitters are deactivated by enzymes (e.g., acetylcholinesterase) 3. Neurotransmitters produce EPSPs or IPSPs 4. Each neurotransmitter has a single receptor 5. Each cell releases a single neurotransmitter

Functional Brain Imaging: Functional Magnetic Resonance Imaging (fMRI)

We have ratio of deoxygenated to oxygenated blood Hemodynamic repsonse - when an activity happens, 6 seconds later see a heightened amount of blood BOLD Signal - blood-oxygen-level-dependant signal - what we're talking about when the brain "lights up" - very active when you see this - increased blood flow to a specific area - functional hyperaemia (strongly driven by glutamate) - astrocytes during functional hyperaemia

Brain Imaging: History

X-Ray: X-rays absorbed - not useful for seeing a lot - x-ray emitter goes through brain and lands on other side (captures the waves) - 2D image, just like taking a picture Cerebral Angiography: - Lobotomy - based on one case of a chimp - did this to prisoners, kids, women who were "difficult" - supposed to make you less frustrated - same guy came up with the cerebral angiography - another form of x-ray - used iodine in the blood - absorb x-rays even more - iodine is a contrast agent -> increases the contrast between vascular and other tissue - still used in MRI - could see a hemorrhage or stroke