Clinical Neuroscience Exam 1
Deep tendon reflexes are graded on what scale?
0- absent reflex 1+- trace 2+- Normal 3+- Brisk 4+- Nonsustained clonus 5+- Sustained clonus
What are the 10 principles of neuroplasticity? (Kleim and Jones, 2008)
1. Use it or lose it- if you don't drive a brain function is will degragade 2. Use it and improve it- If you drive a brain function, it will improve 3. Specificity- nature of training will dictate type of training 4. Repetition matters 5. Intensity matters- pt. must be trained at a specific intensity for change to occur 6. Time matters- Different plasticity occurs at different times 7. Salience matters 8. Age matters- Occurs more readily in younger brain 9. Transference 10. Interference- plasticity can interfere with other behaviors
How many cranial nerve pairs and spinal nerve pairs are in the spinal cord?
12 CN pairs 31 SN pairs (peripheral nerves)
30-50% of the population has a SNP on the BDNF gene. This results in a what deficit?
25% reduction in activity dependent secretion of BDNF in CNS
Recent memory requires the patient to recall 3 items of a story, after how long?
3-5 minutes
According to evidence, how much time and intensity with exercise, would lead to increased BDNF levels in patients with chronic disorders?
30 at 60% max HR
What is the neocortex
6 cell layer structure, based on the gray matter of the cerebral cortex
What is collateral sprouting?
A neuron sprouts and can help out in a neighboring neuron or synapse
What is the corticospinal tract?
AKA "pyramidal tract* Involved with motor control.
Describe what Wernicke's area is
AKA "receptive aphasia" or fluent aphasia Deficits in language comprehension, and lacks auditory comprehension (speaks with tone or inflection and don't realize they are making up words)
What is a Scout images?
AKA localizer images, with exact angle and comparison of between scans
What is Broca's aphasia?
AKA, "expressive aphasia or motor aphasia" Patient can't articulate, and may get frustrated since they can't express what they want to say
Describe the name and function of CN VI
Abducens nerve: Functions: Lateral rectus muscle, causes abduction of eye
What is defined as, "Loss or impairment of the ability to make decisions or act independently"
Abulic
Describe the name and function of CN XI
Accessory nerve Functions: Innervation to SCOM and Upper trapezius
Acetylcholine is a neurotransmitter associated with which nervous system? Norepinephrine is associated with which nervous system?
Acetylcholine- PNS and ANS neurotransmitter Norepinephrine- ANS neurotransmitter
Define Neural plasticity
Adaptive capacities of the CNS. Ability to modify its organization and function. Involve neruochemical, receptor and neuronal structural change
Since neurons don't increase after stage 2 of development, what attributes for the increase in brain size
Addition of axons, dendrites, mylein and vasculature
According to the Mang article in the physical therapy journal. How does aerobic exercise lead to an increased ability for neural plasticity?
Aerobic exercise --> Increase neurotrophic growth factors --> Increase in neurogrowth factors --> synaptogenesis and neural protection
Place the following tissues in order from lowest hounsfield unit to highest HU, which expresses density for a CT: Air Water CSF Gray matter Fat Blood Bone White Matter
Air: -1000 to -600 Fat: -100 to -60 Water: 0 CSF: 8-18 White matter: 30-34 Gray matter: 37-41 Blood: 50-100 Bone: 600+
What is the dorsal portion of the neural tube called when the sulcus limitans divides the tube in half during cell proliferation?
Alar plate
Why do certain areas of a MRI appear brighter or darker than others?
Amount of water or fat content
______________ depolarizes tissue increasing activity; _____________ depolarizes tissue decreasing activity
Anodal; Cathodal
What 2 arteries give blood supply to the spinal cord?
Anterior spinal artery Posterior spinal arteries
What 4 superficial structures make up the limbic system?
Anterior/medial temporal lobe Anterior insula Inferior medial frontal lobes Cingulate gyri
What is mass effect in relation to a CT scan?
Anything that distorts the brain's usual anatomy by displacement Viewed as compression of ventricular space and effacement of sulci
What disorder if caused by lesions in many regions of language areas and adjacent structures of the dominant hemisphere?
Apraxia
What is a topographically oranized-adjacent areas?
Areas mapped to adjacent fibers in white matter pathways to adjacent regions of the cortex
What are the 4 structures in the brain that usually take up contrast dye?
Arteries Venous sinus Choroid pleuxus Dura
What are the 2 main arteries and 1 main vein that give blood supply to the brain
Arteries: Internal carotid artery Vertebral artery (basilar artery) Vein: Internal jugular vein
How are the densities of the X-ray beams displayed on an X-ray?
As a total image that looks like a cross section through the head
How would you test remote memory?
Ask the patient about historical or verifiable personal events
What is defined as a lesion of cerebellum-disorders associated with coordination and balance?
Ataxia
Describe in detail what BDNF actually does
BDNF facilitates long term potentiation, through activity-dependent secretion. Vital to neuroplasticity
What is the ventral portion of the neural tube called when the sulcus limitans divides the tube in half during cell proliferation?
Basilar plate (future site for efferent more portion)
Systemic levels of BDNF are increased 10-60 minutes following exercise, what does this benefit overall?
Better cognitive functions
What kind of neuron have a single dendrite and axon?
Bipolar neuron (vision and olfaction cells)
Air or less dense structures are hypodense, which appear how on a CT scan?
Black
Why does blood appear as hyper dense right after a hemorrhage?
Blood coagulates quickly
What are the 6 important external signs of cranial trauma?
Bony step-off- Change in skull shape CSF rhinorrhea- Exaudation of CSF from nose CSF otorrhea- Exaudation of CSF from ear Hemotympanum- dark purple blood Battle's sign- dark purple ecchymoses over mastoid process Raccoon eyes- dark purple ecchymoses around eye
The cervical and lumbosacral enlargement are also known as what? Are they made up of more gray or white matter?
Brachial plexus Lumbosacral plexus (made up of more gray matter, more cell bodies)
What is a key mediator of motor learning and "priming the brain" for plasticity?
Brain Derived Neurotrophic factors (BDNF)
What makes up the central nervous system?
Brain and spinal cord
A functional assessment can depend on brain metabolic activity. What does this help us indirectly measure?
Brain electrical activity/neuronal firing
At the cellular level, they respond to injury and diaschisis occurs. What is this phenomenon?
Brain or neurons go into shock. They loose synaptic effectiveness and we need alternative mechanisms to substitute for the loss
All information from the cerebral hemispheres and SC must pass through what?
Brainstem
What structure has motor functions such as nausea/vomiting, neurotransmitter responses, and nuclei that controls heart rate, BP and respiration?
Brainstem
Bone shows up as what color on a CT scan without contrast?
Bright white color
What is a gyri?
Bump or ridge between sulci
Muscles of fascial expression, test which nerves?
CN 7
What CN, help with muscles of articulation?
CN V, VII, IX, X, XII
Hearing and vestibular sensation are tests for which CN?
CN VIII
What makes up the peripheral nervous system?
CN and ganglia Spinal nerves and ganglia Enteric nervous system Sympathetic and parasympathetic
What is the preferred imaging technique for patients with head trauma and suspected hemorrhage?
CT
What are the 3 most common neuroimaging modalities?
CT MRI Neuroangiography to include ultrasound, MRA and CT angiography
What 2 types of X-rays are mostly 2 dimensional slices?
CT and MRI
Describe what a CT measures and how long does it take to complete?
CT measures density of tissues 5-10 min to complete
What kind of imaging modality slices are obtained simultaneously?
CT scan
Describe the 4 characteristics of neural plasticity according to our unit 4 PP.
Can be "good" or bad Occurs throughout the CNS Occurs with motor learning Occurs with recovery of function
How does tDCS (transcranial detect current stimulation) help prime motor learning?
Can increase or decrease neuron activity
What is the one down-fall of T2 making the appearance of CSF very bright?
Can obscure pathology and (FLAIR) is used
The angle of CT is adjusted a few degrees for what purpose?
Capture best "picture" of brain and minimize radiation to eyes
A spiral CT angiogrpahy is a rapid injection of contrast used with helical CT scan to quickly obtain images of vessels and 3-D images. What pathologies can this help detect?
Carotid stenosis Aneurysms
tDCS enhances neuronal excitability or inhibits over excitability in the network of neurons. What kind inhibits neurons and what kind excites neurons?
Cathodal inhibits; Anodal excites
What are the 5 gray matter structures that make up the basal ganglia?
Caudate nucleus, Putamen, globus pallidus, subthalamic nucleus, substantia nigra
What is gray matter?
Cell bodies
What is the 2nd step of nervous system development?
Cell proliferation within the nerual tube
The MRI, sensitive technique, can help detect what?
Cellular changes associated with acute ischemic stroke within 30 minutes of onset
What separates the frontal and parietal lobe?
Central sulcus
What are the 2 primary flexures that help contain and align the neural tube within the closed skull
Cephalic flexure (1st to develop) Cervical flexure (2nd to develop)
What 2 structures are feedback systems designed to refine movement?
Cerebellum and Basal ganglia
List some examples of gray matter structures?
Cerebral cortex Nuclei Basal ganglia Thalamus Cranial nerve nuclei
Define functional plasticity
Changes in the efficiency or strength of synaptic connections
What is structural neural plasticity?
Changes in the organization and #'s of connections among neurons
What are 10 parts of the structure of History and Physcial exam?
Chief complaint History of present illness Past medical history Review of systems Family History Social and environmental history Medications and allergies Physical exam Laboratory Data Assessment and plan
What structure creates the cerebrospinal fluid?
Choroid plexus (vascular structure that sits within the ventricles)
The anterior and posterior blood supplies from the carotid and vertebrobasilar systems joint together and form a ring at the base of the brain called what?
Circle of Willis
What are some genetic variations that can effect the efficacy of your rehab techniques
Common single nucleotide polymorphic (SNP) on the BDNF gene. Valine replaced by MEthionine
What is the goal of a general history and physical exam?
Communication
What type of imaging, uses multiple X-ray beams that pass through patient so the same structures are calculated form a variety of angles?
Computerized Tomography (CT)
What is synatopgenesis?
Connections between nerve cell to nerve cells or muscle cells (final step of nervous system development)
Layer 1 of the neocortex is also called the molecular layer. What is the main connection or purpose of this layer?
Connections to dendrites and axons from other layers
What are the 2 mechanisms for secreting BDNF?
Constitutive and activity dependent pathways
Intravenous contrast dye is used to facilitate viewing possible neoplasms or brain abscess. Describe the proprieties of this process.
Contains iodines, which is denser than brain and appears as hyperdense (white) Arteries, venous sinus, choroid plexus and the dura, usually take up the contrast
A lesion in the corticospinal tract above the pyramidal decussation would lead to what deficits?
Contralateral motor control impairments
Describe what 2 processes occur during stage 5 synaptogenesis during nervous system development?
Correlated with known types of permanent learning Basis for neural plasticity
Layer 2 and 3 of the neocortex is also called the small and medium pyramidal layer, respectively. What is the main connection or purpose of these layers?
Cortical-cortical connections
How do you test for the monosynaptic stretch reflex?
DTR: determines hyperactive or hypoactive pathways
Some people with the presence of the MET allele result in a 25% reduction in activity dependent secretion of BDNF. What pathologies is this associated with?
Decreased hippocampal activation Decreased motor system activation Increased gray matter atrophy Poorer memory function Poorer outcome after stroke Poorer learning and memory
What is a fissure?
Deep sulci or infoldings
What is included in the history of present illness
Detailed chronological list of all symptoms and help for the previous problem
Define synaptogenesis
Development of new synapses
What are the 3 deficits that could occur in conjunction with a limbic system lesion?
Difficulty forming new memories Behavioral changes Epileptic seizures
What are the indirect and direct effects of aerobic exercise on the brain?
Direct: Increase neurotrophic factors for brain priming Increases in neurotransmitters like dopamine and serotonin Indirect: Improves general health and fitness
What is defined as, "impaired judgment, a cheerful lack of concern about one's illness, inappropriate joking."
Disinhibited behaviors
Language dysfunctions is testing what part of the brain?
Dominant (usually left) hemispheric areas
What is used to detect carotid stenosis, and also used to measure flow in large vessels of the head and neck?
Doppler ultrasound
What pathway discriminates vibration and joint position?
Dorsal column sensory pathway
Describe the pathway of the posterior column sensory pathway
Dorsal root --> Ipsilateral white matter dorsal columns --> ascend to the dorsal column nuclei in medulla --> contralateral side in thalamus --> primary somatosensory cortex in post central gyrus
Describe the pathway of sensory information for the spinothalamic pathway
Dorsal root --> synapse in gray matter of SC --> 2nd neurons corss over to side of SC and ascend in anterolateral white matter to form spinothalamic tract --> thalamus --> primary somatosensory cortex
What is the falx cerebri?
Dura mater structure that dips between cerebral hemispheres, between longitudinal fissures
What dfects may occur due to problems with migration of nervous system development?
Dyslexia Lissencephaly- lesser intelligence, due to lack of infolding
Due to poor sensitivity and spatial resolution, this imaging modality has trouble detecting focal lesions. What imaging modality is this?
EEG
What imaging modality is useful for evaluating epileptic brain activity?
EEG
On day 14, the embryo undergoes gasturlation and forms the building blocks of our nervous system. What are the 3 parts to this ?
Ectoderm Mesoderm Endoderm
What are some examples of a mass effect seen via a CT scan?
Edema, neoplasm, hemorrhage
The entire nervous system is derived from what structure?
Embryonic ectoderm
What are the 6 main roles of the limbic system?
Emotion Memory Appetite Autonomic functions Neuroendocrine function Olfaction
Describe how you can "prime the system" with aerobic exercise
Engage in aerobic exercise close in time to your behavioral training and pair exercise with motor practice that can be done before or after exercise
How does aerobic exercise effect brain function?
Enhances BNDF levels and leads to increased BNDF gene expression
Week after a cerebral infarction, what would you expect to see happen within the ventricles?
Enlarged ventricles, persistent areas of hypodensity
What are the 3 layers the neural tube divides into during cell proliferation?
Ependymal or germinal layer (lining of central canal and ventricles) Intermediate or mantle layer (gray matter of spinal cord) Marginal layer (white matter)
CNS neurotransmitters include glutamate and GABA? Which one is an excitatory neruotrasmitter and which one is an inhibitory?
Excitatory- Glutamate Inhibitory- GABA
What can help us overcome the deficits that the MET allele leads too?
Extensive motor training
What is defined as a stimulus, is percieved normall when it is presented on one side, but when presented to opposite side, the lesion, the patient neglects the stimulus on the side opposite the lesion in the brain?
Extinction (due to R side parietal lobe damage)
What is anencephaly?
Failure of anterior neruopore to close during embryological development
What are some deficits or concerns of embryological development of the nervous system?
Failure of posterior neruopore to close- spina bifida Failure of anterior neruopore to close- anencephaly
True or False: Acute cerebral infarction cannot be seen on a CT within the first 4-6 hours?
False, Can't be seen within first 6-12 hours
Describe the name and function of CN VII
Fascial nerve: Muscles of fascial expression, stapedius muscle and taste to anterior 2/3 of tongue. Parasympathetic for lacrimation and supplying submandibular/lingual salivary glands
Which of the following is not an advantage of MRI over CT? Faster Examination Images can be acquired in any plane Images can be obtained in 2D or 3D Higher soft tissue contrast No ionizing radiation required
Faster examination
Epileptic seizures are a common effect of a lesion to the limbic system. What 3 things usually cause the seizures?
Fear Memory distortions Olfactory hallucinations
Unlike CT and MRI, Neuroangiography is invasive as a catheter is inserted where?
Femoral artery
What 5 structures make up the majority of the cerebellum?
Folia, vermis, arbor vitae, tonsils, peduncles (Anterior and posterior lobes)
What is the 4th step of nervous system development?
Formation and axonal and dendritic processes
What happens during stage 4, cell differentiation of nervous system development?
Formation of axonal and dendritic processes Development of cranial nerves
What is neurulation?
Formation of the neural crest and neural tube (1st step of nervous system development)
What are the recommendations for aerobic exercise according to the FITT principles?
Frequency: 4x/week Intensity: 70% max HR Time: more than 30 min Type: combine aerobic exercise with resistance training
What are the 4 major lobes of the cerebral hemispheres?
Frontal Temporal Parietal Occipital
Sequencing tasks and frontal release signs dysfunctions, is a test for problems in what part of the brain?
Frontal lobe
What is the largest area of the association cortex?
Frontal lobe
What is defined as, "primitive reflexes that are normal in infants, such as grasp, root, suck and snout reflexes, but can also be seen in adults with frontal lobe lesions"
Frontal release signs
A lesion to the frontal lobe association cortex, would lead to personality and cognitive functioning impairments, what are some examples of these impairments?
Frontal release, signs, grasp, root, suck and snout reflexes Perservation Disinhibited behaviors Abulic Magnetic gait Urinary incontinence
Describe the functional area, location and function of Brodmann's area 44
Functional area: Broca's area Location: Inferior frontal gyrus Function: Speech, movement planning
Describe the functional area, location and function of Brodmann's area 8
Functional area: Frontal eye fields Location: Superior middle frontal gyri Function: Saccadiac eye movement
Describe the functional area, location and function of Brodmann's area 43
Functional area: Gustatory cortex Location: Insular cortex, frontoparietal operculum Function: Taste
Describe the functional area, location and function of Brodmann's area 22
Functional area: Higher-order auditory cortex Location: Superior temporal gyrus Function: Hearing, speech
Describe the functional area, location and function of Brodmann's area 29,30,31,32,33
Functional area: Limbic association cortex Location: Cingulate gyrus and retrosplenial area Function: Smell and emotions
Describe the functional area, location and function of Brodmann's area 23,24,25,26.,27
Functional area: Limbic association cortex Location: Cingulate gyrus, subcallosal area and parahippocampal gyrus Function: Emotions
Describe the functional area, location and function of Brodmann's area 37
Functional area: Parietal-temporal-occipital association cortex Location: Middle/inferior temporal gyri at junction Function: Perception, vision, reading, speech
Describe the functional area, location and function of Brodmann's area 40
Functional area: Parietal-temporal-occipital cortex Location: Inferior parietal lobule Function: Perception, vision, reading, speech
Describe the functional area, location and function of Brodmann's area 39
Functional area: Parietal-temporal-occiptal association cortex Location: Inferior parietal lobule Function: Perception, vision, reading, speech
Describe the functional area, location and function of Brodmann's area 7
Functional area: Posterior parietal association area Location: Superior parietal lobule Function: Visuomotor;perception
Describe the functional area, location and function of Brodmann's area 47
Functional area: Prefrontal association cortex Location: Inferior frontal gyrus Function: Thought, cognition, planning behavior
Describe the functional area, location and function of Brodmann's area 46
Functional area: Prefrontal association cortex Location: Middle frontal gyrus Function: Thought, cognition, planning behavior, aspects of eye movement
Describe the functional area, location and function of Brodmann's area 9,10,11,12
Functional area: Prefrontal association cortex Location: Superior, middle frontal gyri Function: Thought, cognition, movement planning
Describe the functional area, location and function of Brodmann's area 45
Functional area: Prefrontal association cortex Location:Inferior frontal gyrus Function: Thought, cognition, planning behavior
Describe the functional area, location and function of Brodmann's area 41
Functional area: Primary auditory cortex Location: Heschl's gyri and superior temporal gyrus Function: Hearing
Describe the functional area, location and function of Brodmann's area 4
Functional area: Primary motor cortex Location: Precentral gyrus Function: Voluntary movement control
Describe the functional area, location and function of Brodmann's area 28
Functional area: Primary olfactory cortex Location: Parahippocampal gyrus Function: Smell, emotions
Describe the functional area, location and function of Brodmann's area 34,35,36
Functional area: Primary olfactory cortex Location: Parahippocampal gyrus Function: Smell, emotions
Describe the functional area, location and function of Brodmann's area 38
Functional area: Primary olfactory cortex Location: Temporal pole Function: Smell/emotions
Describe the functional area, location and function of Brodmann's area 1,2,3
Functional area: Primary somatosensory cortex Location: Postcentral gyrus Function: Touch
Describe the functional area, location and function of Brodmann's area 17
Functional area: Primary visual cortex Location: Banks of calcarine fissure Function: Vision
Describe the functional area, location and function of Brodmann's area 42
Functional area: Secondary auditory cortex Location: Heschl's gyri and superior temporal gyrus Function: Hearing
Describe the functional area, location and function of Brodmann's area 18
Functional area: Secondary visual cortex Location: Medial and lateral occipital gyri Function: Vision/Depth
Describe the functional area, location and function of Brodmann's area 6
Functional area: Supplementary motor cortex Location: Precentral gyrus and rostral ajacent cortex Function: Limb and eye movement planning
Describe the functional area, location and function of Brodmann's area 5
Functional area: Tertiary somatosensory cortex Location: superior parietal lobule Function: Stereognosis
Describe the functional area, location and function of Brodmann's area 19
Functional area: Tertiary visual cortex Location: Medial and lateral occipital gyri Function: Vision, color, motion, depth
Describe the functional area, location and function of Brodmann's area 20
Functional area: Visual inferotemporal area Location: Inferior temporal gyrus Function: Form vision
Describe the functional area, location and function of Brodmann's area 21
Functional area: Visual inferotemporal area Location: Middle temporal gyrus Function: Form vision
What is used as a contrast medium to display a bright signal in areas of increased vascularity or breakdown of blood-brain barrier?
Gadolinium
What is the embryo called at day 14 of development? day 21? and day 28?
Gastrula Notochord Neural tube
What 7 factors affect your recovery after a brain injury?
Genes Age Size/type of lesion Onset time Experience and environment Pharmacology Use/training
A lesion to the inferior left parietal lobe may lead to what impariments?
Gerstmann's syndrome: Difficulty with calculations, R/L confusion, finger agnosia and written language or APRAXIA
Describe the name and function of CN IX
Glossopharangeal nerve Functions: Stylopharyngeus muscle, taste of posterior 1/3 of tongue, sensation from pharynx and innervation of baroreceptors of carotid body and parotid gland
Most local synaptic communication in the CNS occur in what type of matter?
Gray matter (white matter transmits longer communication over greater distances)
The midbrain, pons, and medulla all make up the brainstem. What important functions do these structures have?
HR, Blood pressure and respiration
What are the 3rd cranial nerves to develop during cellular proliferation?
Hearing: CN 8
What is the function of the association cortex?
Higher-order information processing
What functions take place in the unimodal association cortex?
Higher-order processing for a single sensory or motor modality
What are the 4 deep structures of the limbic system?
Hippocampal formation Amygdala Nuclei in thalmus, hypothalamus, BG, spetal area and BS Fornix
Aerobic exercise increases BDNF gene expression in what 4 structures?
Hippocampus Cerebellum Cerebral cortex Spinal cord
What are the different types of slices for a CT or MRI?
Horizontal Coronal Sagittal
How will an acute hemorrhage appear on a CT scan? 1 week post hemorrhage? 3 week post hemorrhage?
Hyperdense because blood coagulates quickly Isodense after 1 week Hypodense after 2-3 weeks Becomes less dense over time
MRI relates to brightness of the signal. Would a hyperintense or hypo intense area be brighter?
Hyperintense- brighter areas
How would blood present on a CT scan after cell death occurs?
Hypodense
Describe the name and function of CN XII
Hypoglossus nerve Functions: Innervation to intrinsic muscles of tongue
A pupillary response would test which CN?
II and III
Extrocular movements are used to test which CN?
III, IV, and VI
The palate eleveation and gag reflex test which CN?
IX and X
What kind of apraxia is occurring if the patient can only perform awkward movements that only minimally resemble those requrested?
Ideomotor apraxia
What is retrograde amnesia?
Impaired memory of events for a period of time immediately before lesion with sparing early memories
According to animal studies, describe what learning impairments occur when BDNF is disrupted?
Impaired skilled motor performance and decreased cortical map plasticity
What is apraxia?
Inability to execute a motor plan, generally upon command
What is finger agnosia?
Inability to identify fingers by name
What is achromatopsia?
Inability to recognize colors
What is prosopagnosia?
Inability to recognize faces
What is anterograde amnesia?
Inability to remember new facts and events occurring after lesion onset
What are paraphasic errors?
Inappropriately substituted words or syllables
How does TMS (transcranial magnetic stimulation) help with motor learning?
Increases or decreases corticomotor excitiability
What is a sulci?
Infoldings of the cerebral hemisphere
What is the function of the heteromodal association cortex?
Integrates functions from multiple sensory or motor modalities
What arteries make up the Circle of Willis?
Internal carotid ---> ACA and MCA Vertebrobasilar system --> PCA
What 3 things happen to neuronal functioning if you have an injury to the CNS?
Interrupting axonal projections from injured area Denervation of population of neurons innervated by injured neurons Some neurons are removed entirely
What is the parietal lobe divided by, which divides into superior and inferior parietal lobe?
Intraparietal sulcus
Since neoplasms appear as hypodense, hyperdense or isodense, what is helpful in imaging these disorders?
Intravenous contrast dye
What are neologisms?
Invented words
Describe the characteristics of a brain derived neurotrophic factor
Involved in neuroprotection, neurogenesis and neuroplasticity. Neurotrophin family Key mediatory of motor learning and "priming the brain" for plasticity Secreted by constitutive and activity dependent pathways
A lesion in the corticospinal tract below the pyramidal decussation would lead to what deficits?
Ipsilateral motor control impairments
What kind of structures will appear as gray on a CT scan?
Isodense structures
Why is CT a better imaging modality for patients with emergent pathologies?
It is faster and can diagnosis faster.
About 85% of fibers in the cortico-spinal tract cross to control movement in opposite sides of body-hence pyramidal decussation. Where does this occur?
Junction of medulla and spinal cord
What is the purpose of the meninges?
Keep brain from moving around in the skull
If your patient presents with weakness, atrophy, fasciculations, decreased reflexes and decreases tone, would you assume an upper or lower motor neuron lesion?
LMN lesion
Since vision is more about receiving sensory information, what is the major layer of the neocortex in this part of the brain?
Layer 4 of neocortex, since it recieves input from the thalmus
Gesrstmann's syndrome, tests what part of the brain?
Left parietal dysfunctinos
What are the 4 main parts of the mental status part of the neurological exam?
Level of alertness Orientation Memory Language
An EEG is an array of electrodes applied to the scalp and detect weak electrical signals transmitted through the brain. What is this commonly used for?
Levels of alertness
Memory dysfunctions will be due to problems in what part of the brain?
Limbic and global functions
What is the 2 important things to use, when reaching a correct diagnosis?
Localization, based on neruoanatomical clues from the H&P Neruologic differential diagnosis
What kind of neuron is located in the anterior horn of gray matter of psinal cord or in brainstem motor nuclei?
Lower motor neruon
Since neuroangiography is an envasive procedure, what are 3 other ways to visualize blood vessels in less invasive ways?
MRA Doppler ultrasound Spiral CT angiogrpahy
MRI or CT: Provides high contrast imaging and preferred imaging technique for detecting low-contrast/small lesions
MRI
What imaging modality is based on resonance of protons, which can be modified using "pulse sequences" and modified using galdlinium contrast?
MRI
What imaging modality is completed by placing a person in a static magnetic field and then probed with a pulse of magnetic energy?
MRI
What is the preferred imaging technique used for low-contrast lesions or brainstem/base of skul lesions?
MRI
What kind of imaging uses "true horizontal slices"?
MRI
Pair MRI and CT with their definitions, which one goes with which? Faster and Less expensive, but requires ionizing radiation Slower but reveals images with much higher contrast
MRI: Slower but reveals images with much higher contrast CT: Faster and Less expensive, but requires ionizing radiation
What is defined as, "Feet in close contact with floor"
Magnetic gait
One can affect neural plasticity through neuromodulation. What 3 ways can we incorporate neuromodulation?
Medications Rehabilitation techniques Neuromodulation tools, TMS, DBS
Lesions to the medial temporal lobes and medial diencephalon are associated with what impairment?
Memory impairment
What are the 6 subdivisions of a neurological exam?
Mental status Cranial nerves Motor exams Reflexes coordination and Gait Sensory exam
What are the main components of our brainstem?
Midbrain Pons Medulla
What is the 3rd step of nervous system development?
Migration and aggregation of cells within definitive locations
What is the most well studies reflex arc that provides rapid local feedback for motor control?
Monosynaptic stretch reflex
The cerebellum and basal ganglia recieve major inputs from what?
Motor cortex, brainstem and sc
The cerebellum and basal ganglia are vital components to what system?
Motor system
What kind of neuron has several dendrites and axons?
Multipolar
Describe the monosynaptic stretch reflex
Muscle spindle detects rate of muscle stretch --> sensory neruons convey info to dorsal roots into spinal cord gray matter --> multiple synapses with sensory neurons to include some direct synapse on LMN's in anterior horn --> LMS's project to ventral roots, back to muscles, causing it to contract.
What is white matter?
Myelinated axons
What type of imaging modality is used for patients that cannot recieve MRI, but need enhanced visualization of nerve roots and impingement of the CSF space?
Myelography-CT scan
How is a myelography-CT scan performed?
Needle is introduced in CSF by lumbar puncture and iodinated dye is introduced into CSF
Describe the mnemonic arrowhead of neurologic differential diagnosis?
Neruological Disorders that are more acute and require immediate attention are on top of arrowhead. Trauma --> Vascular --> Epileptic --> CSF ciruclation --> Toxic --> Infectious disease --> Degenerative disorders --> Referred pain --> Psychological --> non neuro
Describe the following terms- Neurons Cell body Dendrites Axons Glia
Neruons- nerve cells cell body- Nucleus Dendrities- Short process receives inputs to cells Axon- Carries outputs Glia- Support cells
What are the 5 steps of embryological development of the nervous system?
Neurulation Cell proliferation Migration and aggregation Formation of axonal and dendritic processes Synatopgenesis
Does the cerebellum and basal ganglia directly project to LMN's?
No
What is transcranial magnetic stimulation?
Non invasive brain stimulation that measures excitability of motor cortex maps
Describe the name and function of CN III
Oculomotor nerve: Extraocular muscles. Parasympathetics to pupil constrictors and to ciliary muscles of lens
What is the only sensation that does not synapse in the thalamus?
Olfaction
What are the 4th cranial nerves to develop during cellular proliferation?
Olfaction: CN 1
Describe the name and function of CN I
Olfactory nerve Function: Olfaction
The mylein sheath, has 2 parts that cover the axons. Mylein forming glia cells in the CNS are termed what? PNS?
Oligodendrocytes in CNS Schwann cells in PNS
Where is the choroid plexus located?
On floor of lateral ventricles or the roof of the 3rd ventricle
Where does the UMN synapse?
Onto the LMN
Describe the name and function of CN II
Optic nerve Function: Vision
Describe the distribution of gray and white matter in the cortex
Outter surface is gray matter and inner surface is white matter
What does the anterolateral pathway indicate in relation to sensory information?
Pain, temperature, sense and crude touch
What is the rest or digest part of the ANS?
Parasympathetic nervous system (acetylcholine)
What structures make up the visual association cortex?
Parietal-occipital lobe Inferior temporal lobe
What is defined as a hypokinetic movement disorder , that is characterized by infrequent, slow and rigid movements?
Parkinson's disease
What is anosognosia? (due to non-dominant parietal lobe damage)
Patient is unaware of their body parts on the left side thinking, there arm doesn't belong to them
What is hemineglect?
Patient may have distortions of the perception on the contralateral side. If drawn a clock, the numbers would be filled all on one side
The nerual crest cells form most of what nervous system?
Peripheral nervous system
What is defined as, "particular difficulty when asked to perform a sequence of actions or to change from 1 activity to another. They repeat a single actions over and over without moving on to the next one."
Perseverate
What is Palinopsia?
Persistence or reappearance of an objected viewed earlier
What is the first for the of history and physical exam, where we actually put our hands on the patient?
Physical exam, includes neurological exam
Describe the 3 layers of the meninges
Pia mater- most inner layer Archanoid matter Dura mater- superficial layer
What is the main somatosensory pathways?
Posterior column pathways Anterolateral pathways
Describe what function cortex occurs in the following areas: Precentral gyrus Postcentral gyrus Occipital lobes Transverse gyri of Heschl
Precentral gyrus- Primary motor cortex Postcentral gyrus- Primary sensory cortex Occipital lobes- Primary visual cortex Transvers gyri of Heschl- Primary auditory cortex
A chemical synapse has a presynaptic terminal and postsynaptic neuron. What occurs at the presynaptic terminal and postsynaptic neuron?
Presynaptic terminal- synaptic vesicles release a neurotransmitter Postsynpatic neuron- neurotransmitter receptor binds at this site
Where is language usually perceived first by the brain?
Primary auditory cortex in superior temporal lobe
What does the posterior column pathway indicate with sensory information?
Proprioception, vibration, sense, and fine discriminative, touch
A lesion to the visual association cortex can lead to what 3 complications?
Prosopagnosia Achromatopsia Palinopsia
During stage 3 of nervous system development, cells begin to migrate. What are the 2 types of migration?
Radial migration Tangenital migration
Describe the difference between radial and tangential migration
Radial migration- Occurs from spinal cord through telencephalon. Uses radial glial cells Tangential migration- Occurs within structures of brainstem. Shorter distances of neurons are moved later in development
During a neuroangiography, a catheter is threaded up the aorta and what is injected into the carotid and vertebral arteries?
Radio-opaque iodinated contrast material, that helps obtain images
Layer 4 of the neocortex is also called the granular layer. What is the main connection or purpose of this layer?
Recieves input from thalamus
A spiral (helical) CT- acquires data continuously as a patient moves through a scanner. What is the purpose of this type of CT?
Reduces patient radiation exposure
What is a clonus?
Repetitive vibratory contraction of the muscles
CSF will display a dark or light color on a CT scan without contrast?
Represented by black in the brain.
What plays an important role in regulating levels of consciousness and thalamic and cortical activity?
Reticular nuclei
Hemineglect is most common in lesions on what side of the brain?
Right (nondominant) parietal lobe
Neglect and contsructions dysfunctions is a test for what part of the brain?
Right parietal dysfunctions
What connects the brainstem, rostrally, dorsally and caudally?
Rostrally- diencephalon Dorsally-cerebellum caudally-spinal cord
What are the 4 parts of the corpus collosum (white matter structure)?
Rostrum (beak) Genu (bend) Body Splenium (tail)
According to animal studies, describe what learning improvements occur when BDNF is injected?
See increase in plasticity in the primary motor cortex
Layer 5 of the neocortex is also called the large pyramidal layer. What is the main connection or purpose of this layer?
Sends outputs to subcortical structures
Layer 6 of the neocortex is also called the polymorphic layer. What is the main connection or purpose of this layer?
Sends outputs to thalamus
The alar plate is the future site for what tracts?
Sensory neurons and tracts
What is the fluid attenuation inversion recovery (FLAIR) used on a T2 MRI?
Similar to T2 but CSF is dark and subtle abnormalities can be visualized
Parietal lobe damage in the non-dominant hemisphere may lead to what impairments?
Spatial awareness impairment to contralateral side
What sensory pathway senses pain and temperature?
Spinothalamic pathway
What are the 6 characteristics to test language in an exam?
Spontaneous speech Comprehension Naming Repetition Reading Writing
Describe the pathway of the corticospinal tract
Starts in primary motor cortex (4) precentral gyrus, through cerebral white matter, to brainstem, then spinal cord
When together, what do we call the caudate nucleus and putamen together?
Striatum
Describe the subdivisions, derivates and cavities of the mesencephalon, that develops during stage 1; neurulation
Subdivisions: Mesencephalon Derivates: Midbrain Cavities: Cerebral aquaduct
Describe the subdivisions, derivates and cavities of the rhombencephalon, that develops during stage 1; neurulation
Subdivisions: Metencephalon and Myelencephalon Derivates: Cerebellum, pons and medula Cavities: Fourth ventricle
Describe the subdivisions, derivates and cavities of the primitve nerual tube, that develops during stage 1; neurulation
Subdivisions: Neural crest and tube Derivates --> Cavities: Nerual tube --> spinal cord --> central canal Nerual crest --> Peripheral nerve ganglia
Describe the subdivisions, derivates and cavities of the prosencephalon, that develops during stage 1; neurulation
Subdivisions: Telencephalon and Diencephalon Derivates --> Cavities: Rhinoencephalon --> Lateral ventrical Thalmus, hypothalmus, optic nerves, neruophyophysis, pineal gland --> third ventricle
What divides the neural tube into a ventral and dorsal half?
Sulcus limitans
What are the 3 main arteries that arise from the vertebral and basilar arteries and supply blood to the brainstem and cerebellum?
Superior cerebrallar artery Anterior inferior cerebellar artery Posterior inferior cerebellar artery
What is the main function of the superior cerebellum? Middle and inferior cerebellum?
Superior: mainly carriers outputs from cerebellum Middle/Inferior: carrys inputs to cerebellum
What is deep brain stimulation?
Surgically implanted electrodes to provide electrical impulses, help with tremor, rigidity and slowness of movement and balance
What are the 1st cranial nerves to develop during cellular proliferation?
Swallow and gag nerves: CN 5, 7, 9, 10 and 12
What fissure seperates the frontal lobe and temporal lobe?
Sylvian fissure
What are the 2 divisions of the ANS?
Sympathetic (thoracolumbar) Parasympathetic (craniosacral)
What is the fight or flight part of the ANS?
Sympathetic nervous system (epinephrine/norepinephrine)
Where does the communication occur between neurons?
Synapses
What kind of MRI is better for identifying anatomy structures?
T1
What are the 2 different types of MRI's?
T1 and T2
Describe how a T1 MRI differs from a T2 MRI
T1 looks like an anatomical brain section. Gray matter is gray and white matter is white T2 looks like the film negative Gray matter is white and white matter is gray
An intracranial hemorrhage shows a characteristic series of changes on an MRI. Describe what happens on a T1 and T2 MRI
T1: First hours and 5 days: Gray 5 days-1 month: White Chronic: Dark gray T2: First 24 hours: Light gray 1-7 days: Dark gray 5-30 days: white Chronic: Black
What kind of MRI is better for detecting pathology?
T2
What are the 5 techniques that can prime motor learning?
TMS tDCS DBS Aeorbic exercise Neuropharmacology
What is the unique feature of a neurological exam?
Tests function
What is the gray matter structure deep within cerebral white matter? Egg shaped
Thalamus
What is the major relay station to the sensory and motor cortex?
Thalamus
What forms the diencephalon?
Thalamus, hypothalamus and epithalamus
What is the insular cortex?
The convergence between the frontal, parietal, occipital and temporal cortex
What are some disadvantages of an MRI?
Time: 20-54 minutes to complete Cost is higher than CT Inability to image acute hemorrhage Contraindication to those with pacemakers and metal implants
Imaging intensity in CT depends upon what property?
Tissue density
After going through the primary auditory cortex, where does the brain convey the information?
To Wernicke's area in left hemisphere --> broca's area in the frontal lobe
Why are MRI images reformatted into 3-D surface representations?
To detect subtle abnormalities not seen in 2D image
What are some examples of white matter in the CNS?
Tracts Fascicles Lemniscus Bundles Commissures
Within the spinal cord, in which matter are the ascending and descending tracts traveling?
Travel through white matter
Deep brain stimulation can help with what pathologies?
Tremors Rigidity Slowness of movement Balance
Describe the name and function of CN V
Trigeminal nerve Functions: Sensation of touch, pain, temperature and position for the face, mouth, nasal, and meninges. Also muscles of mastication and tensor tympani
Describe the name and function of CN IV
Trochlear nerve Superior oblique muscle innervation, causes eye to move downward and to rotate inward
The outer surface of our brain is gray matter where cortical-to-cortical communication occurs? True or false
True
True or false: Each part of the neruologic exam should be used to titrate the patinet's level of function?
True
True or false: The neurologic exam is part of the general exam, and both are parts are done together, treating the patient as a whole.
True
If your patient has weakness, increased reflexes and increased tone, would you assume an upper or lower motor neuron lesion?
UMN lesion
What are the 2 types of the association cortex?
Unimodal Heteromodal
What kind of neuron has both axon and dendrite from a single process coming off cell bodies?
Unipolar neuron
What kind of neuron projects from the cortex down to spinal cord and brainstem?
Upper motor neuron
Describe the name and function of CN X
Vagus nerve Functions: Swallowing, vocal cords, parasympathetics to heart, lungs and GI tract, taste from glottis. sensation from posterior meningies, regions near ear, aortic arch chemo and baro recpetors
Describe the name and function of CN VIII
Vestibulocochlear nerve Hearing and vestibular sensation
Neuroangiography is one of the oldest neuroradiological technqiues, that is used for what purpose?
View integrity of blood vessels and lesions
How would you test for CNII?
Visual acuity Color vision Visual fields Visual extinction
What are the 2nd cranial nerves to develop during cellular proliferation?
Visual motor system: CN 2, 3, 4 and 6
Describe the appearance of water, CSF, fatty tissue and gray matter on a T1 MRI
Water and fat: appears dark and fatty tissue appears bright CSF: appears dark Gray matter: due to water concentration it appears gray
Describe the appearance of water, fats and CSF on a T2 MRI
Water: appears bright Fat: dark CSF: Appears very bright
What are some characteristics to look for in a lower motor neuron lesion?
Weakness Atrophy Fasciculations Reflexes Tone
What are some characteristics to look for in an upper motor neuron lesion?
Weakness No atrophy No fasciculations Increased reflexes Increased tone
Bone/dense structures are hyper dense structures. How would they appear on a CT scan?
White
What are the main gray and white matter structures in the PNS?
White matter- peripheral nerves Gray matter- ganglia (cluter of cell bodies)
What is used to determine conversion between calculated density values and gray scale used for display?
Window and level adjustments
Computerized tomography is from what other imaging modality?
X-ray
When together, what do we call the putamen and globus pallidus together?
lenticular nucleus
What should be included in the past medical history?
list prior medical and surgical problems that don't relate to the HPI
Describe the relation between the 2: The anterior commissure is ___________________ compared to the posterior commissure Thalamus is ______________ frontal lobe Cerebellum is _____________ to pons Anterior horn of SC is ________________ to posterior horn of SC
rostral; caudal; dorsal; ventral
What delivers low-intensity direct electrical current to the brain?
tDCS
tDCS vs. TMS: Which one is safer, more confortable, easier to do and more affordable, while producing better response?
tDCS