Chapter 65 review of the neurologic function

Spinal nerve PNS

-31 pairs of spinal nerves -8 cervical -12 thoracic 5 lumbar 5 sacral 1 coccygeal -each spinal root has a ventral and dorsal root -the dorsal root transmits sensory impulses in specific areas of the body known as the dermatomes to the dorsal horn ganglia. the sensory fiber may be somatic, carrying information about pain, temperature, touch, and position sense from the tendons, joints and body surfaces or visceral carrying information to internal organs -the ventral roots are motor and transmit impulses from the spinal cord to the body they are somatic or visceral. they also control the cardiac muscles and glandular secretions

PNS; autonomic nervous system

-ANS regulates activities of internal organs like the heart, lungs, blood vessels, digestive organs, and glands. -ANS is responsible for homeostasis and restoration for internal organs -two major divisions the sympathetic nervous system; excitatory response (fight or flight) and the parasympathetic nervous system which controls mostly visceral functions -the ANS innervates most body tissues this system is considered apart of the PNS it also is regulated by centers in the spinal cord, brain cord brain stem, and hypothalamus. -the hypothalamus is a major subcortical center for the regulation of autonomic activities. serving as an inhibitory excitatory role. -the hypothalamus has connections that link the autonomic system with the thalamus, the cortex, the olfactory apparatus, and the pituitary gland -the hypothalamus has visceral and somatic reactions that are associated with emotional stress (fear, anger and anxiety); for the control of the metabolic processes including fat, carbohydrate and water metabolism for the regulation of body temperature arterial pressure and all muscular and glandular activities of the gastrointestinal tract; for control o genital functions and sleep cycle =the ANS is sympathetic and parasympathetic and most of the organs have both of these controls parasympathetic causes contraction or urinary bladder muscles and decreases heart rate. the sympathetic produces relaxation of the urinary bladder, and increases the heart rate and force of the heart beat.

Cerebrospinal fluid

-CSF has a clear and colorless fluid that is produced in the choroid plexus of the ventricles and circulates around the surface of the brain nd spinal cord. -there are four ventricles: the right and left lateral ventricle and the third and forth ventricle -the two later open open into the third ventricle at the intraventricular foramen -the third and forth ventricles connect via the aqueduct of Sylvius -the forth ventricle drains CSF into the subarachnoid space on the surface of the brain and spinal cord where it is absorbed by the arachnoid villi -blockage of the flow of CSF anywhere in the ventricular system produces obstructive hydrocephalus - the CSF has important immune and metabolic functions in the brain. it produces a rate of about 500mL/day the ventricles and subarachnoid space contain approximately 150mL of fluid. -the composition of the CSF is similar to the extracellular fluid ( blood plasma) but the concentrations differ. -labratory value of the CSF indicates color (clear), specific gravity (1.007) , protein count,, cell count, glucose count, and other electrolyte values. -normal CSF contains a minimal amount of WBC, and no RBC -the CSF may be tested for immunoglobulins or bacteria -CSF may be obtained from a lumbar puncture or intra ventricular catheter

Electroencephalography

-EEG electrical activity of the brain -obtain from electrodes applied to the scalp or through microelectronics placed on the brain tissue -it assess cerebral electrical activity -useful for diagnosing seizure disorders, coma, or organic brain syndrome -tumors, clots, brain abscesses and infection can cause abnormal patterns in electrical activity -EEG is used to determine amount of brain death -electrodes applied to the scalp record electrical activity in varies sections of the brain. -the amplified activity of the neurons between these two electrodes is recorded continuously through moving paper this record is called encephalogram -for baseline recording the patient lies quietly with both eyes closed -the patient may be asked to hyperventilate for 3-4 minutes, or look at bright flashing lights for photic stimulation these activations are to evoke abnormal electrical discharges such as seizure potentials -an EEG can be done during sleep because some abnormal waves occur only while the person is sleeping. if the epileptogenic are is inaccessible to conventional scalp electrodes then the nasopharyngeal electrodes may be used. -depth recording of EEG is performed by introducing electrodes stereotactically (radiologically placed using instrumentation) into a target area of the brain as indicated by the patients seizure pattern and scalp EEG. -it is used to identify who may benefit from surgical excision of epileptogenic foci -special transsphenoidal, mandibular, and nasopharyngeal electrodes can be used and video recording combined with EEG monitoring and telemetry is used in hospital settings to capture seizure abnormalities and their sequence Nursing interventions -to increase seizure activity readings it is sometimes advised that the patient be deprived of sleep the night before the EEG. -anticonvulsant agents, tranquilizers, stimulants, and depressants should be withheld 24-48 hours before the procedure because these medications alter the EEG wave patentor mask the abnormal wave patterns of seizure disorders. -coffee, tea, cola drinks are omitted from the meal before the test because they are stimulators -however the meal itself should not be omitted because the EEG can detect glucose changes in brain wave patterns -the patient is informed that the procedure takes 45-60 minutes; a sleep EEG requires 12 hours -the patient is assured that the procedure does not cause an electric shock and that the EEG is a diagnostic test, not a form of treatment -EEG requires the patient to lie quietly, sedation is not advisable because it will lower the seizure threshold and alter brain wave activity -the nurse needs to check the prescription of anticonvulsant medication prior to the procedure -Routine EEG are water soluble lubricant for electrode contact which can be wiped offend removed by shampooing -Sleep EEG involve the collodion glue for electrode contact which requires acetone for removal.

Electromyography

-EMG is obtained by inserting needle electrodes into the skeletal muscles to measure changes in the electrical potential of the muscles. -shown on an oscilloscope and amplified so that both the sound and appearance of the waves can be analyzed -useful in determining neuromuscular disorders and myopathies. -it distinguishes between weakness due to neuropathy (functional or pathologic changes in the peripheral nervous system) from weakness resulting form other causes. Nursing interventions -the procedure is explained -the patient is warned to expect a sensation similar to that of an intramuscular injection as the needle is inserted into the muscles. -the muscles examined may ache for a short amount of time.

Magnetic resonance imaging

-MRI get powerful images of all the body -more clear than any other test -provides information on cell chemical changes, useful particularly for stroke, tumor, MS Nursing interventions -education and adequate history - history of working with metal fragments is assessed -the patient is questioned about implants of metal objects (aneurysm clips, orthopedic hardware, pacemakers, artificial heart valves) the object could malfunction, dislodge or heat up -cochlear implants may be inactivated -before patient enter the room all metal objects and credit cards need to be removed this includes medication patches that have metal backing, metallic lead wires -no metal objects can be brought into the room this includes oxygen tanks, IV poles, ventilators or stethoscopes -lie with heading a frame on a flat platform that is moved into a tube housing the magnet -the tubes narrow person with wide girth may not fit -this is painless patient may hear loud sounds -patient may experience claustrophobia they can be sedated under these circumstances -educate about relaxation techniques they need to be told they can talk to staff in microphone

The peripheral nervous system; cranial nerves

-PNS include cranial nerves, spinal nerves, and the autonomic nervous system twelve pairs of cranial nerves emerge from the lower surface of the brain and pass through the openings in the base of the skull -three cranial nerves are entirely sensory (I,II,VIII) -five are motor (III,IV,VI,XI, XII) -four are mixed sensory and motor (V,VII, IX, X)

Single photon Emission Computed tomography

-a perfusion study that captures a moment of cerebral blood flow at the time of injection -this approach allow overlying structures or background to be viewed greatly increasing the contrast between normal an abnormal tissue. -inexpensive and same amount of time as a CT. -useful in detecting the extent and location of abnormally perfused areas of the brain allowing, detection, localization and sizing of stroke (before it is visible by CT scan) Nursing interventions -patient preparation and patient monitoring -educating on what to expect before the test this can help with anxiety and help with cooperation. -pregnancy and breast feeding are contraindicated.the nurse may need to -the nurse may need to accompany the patient during transport to the test room -patients are monitored during and after the procedure.

Assessing intellectual functioning

-a person with an average intellectual quotient can repeat seven digits without faltering and can recite five digits backwards -the examiner may ask the patient to count backward from 100 or to subtract 7 from 100 and then 7 from that and so forth (Serial 7s) -the capacity to interpret well known proverbs test abstract reasoning, which is higher intellectual functioning for example does a patient understand " a stitch in time saves nine"? -the intellectual function of patients with damage to the frontal cortex appears intact until one or more test of intellectual capacity are performed -questions designed to assess this capacity might include the ability to recognize similarities like whats the similarity between a pen or pencil? -can the patient make judgements about a situation ex: if a patient arrive home without a house key what are the alternatives?

Myelography

-an X-ray of the spinal subarachnoid space taken after injected contrast agent into the spinal subarachnoid space through lumbar puncture -the water based contrast may disperse upward through the CSF to outline the subarachnoid spinal space and shows any distortion of the spinal cord or spinal dural sac caused by tumors, cysts, herniated vertebral discs, or other lesions -performed infrequently today because of sensitivity of CT and MRI Nursing interventions -the patient is educated about what to expect during the procedure and made aware that changes in position may be made during the procedure. -after the myelography the patient lies in bed with the head elevated to 30-45 degrees the patient is advised to lay in bed for 3 hours -drinking liberal amounts of fluid for rehydration and replacement of CSF may decrease the incidence of post lumbar puncture headache. -the blood pressure pulse, RR, and temperature are monitored as well as the patients ability to void -untoward signs include headache, fever, stiff neck, photophobia, seizures, and signs and symptoms of chemical or bacterial meningitis

Nerve conduction studies

-applying external stimulus to specific peripheral sensory receptors with measurements of electrical potential generated -changes are detected by computerized device and display it on the oscilloscope and store the data in a magnet tape -for neurologic diagnosis they reflect nerve conduction times in the PNS -in clinical practice the visual, sensory and somatosensory are most often tested -IN visual evoked responses the patient looks at visual stimulus (flashing lights, checkerboard pattern or screen) -the average stimuli is recorded by EEG leads placed over the occipital lobe the transit time from the occipital lobe to the retina is measured using a computer averaging method -brainstem auditory responses ar measured by applying a repetitive auditory stimulus an dmeasured using transiet time via brainstem to brain cortex specific lesions in the auditory pathway modify or delay the response. used to diagnose brain stem abnormalities in determining brain cells death. -in somatosensory evoked response the peripheral nerves are stimulated through skin electrodes and transit time along the spinal cord to the cortex is measured and recorded from scalp electrodes. used to detect spinal cord or peripheral nerve conduction and to monitor spinal cord function during surgical procedures nursing interventions -the nurse explains the procedure and reassures the patient and encourages him or her to relax -the patient is told remain still throughout the recording to artifacts (signals not generated by the brain) that interfere with the recording

Though content

-are the patients thoughts spontaneous, natural, clear, relevant, and coherent? -does the patient have fixed ideas, illusions, or preoccupations? -what are there insights on these thoughts? -preoccupation with death, hallucinations, and paranoid ideation are examples of unusual thoughts or perceptions

Gerontologic conditions

-as the brain ages the neurons are lost leading to decreased synapse and neurotransmitters -slowed nerve conduction and response time -ventricle size increases to maintain cranial volume -brain blood flow is decreased metabolism is reduced leading to slower mental function -temp regulation less effective -visual and auditory nerves degenerate -taste buds atrophy -offactory bulb degenerate -inner ear, cerebellum and pastoral areas in the brain degenerate -DTF decreased or absent -sleep is reduced -pupillary response is decreased

Older adult nursing interventions

-assess assistive devices, coping and ADLs -fall risk must be evaluated and prevention measures -visual and hearing deficits require adaptations in activities such as preoperative education, diet therapy, and education about new medications -visual materials for education or menu selection, adequate lighting without glare, large print, are used. -explain diagnostic test purpose -take into account slow response and impaired hearing -older adult hears adequately if you speak in a low pitched clear voice shouting only makes it harder for the patient to understand -provide auditory and visual cues if patient has sufficient visual and hearing loss assistive devices, a signer, an interpreter or translator may be needed -give instructions an uncrushed pace and use reinforcement to enhance learning and retention -vocab is matched to the patients ability and terms are clearly defined the older adults needs adequate time to receive and respond to stimuli, learn and react these measures allow comprehension, memory and formation of association and concepts

Emotional status

-assess consciousness, and cognition includes the patients emotional status -is the patients affect (external manifestation of mood) natural and even, or irritable and angry, anxious, apathetic or flat or euphoric? -does their mood fluctuate normally? or does the patient swing from joy to sadness in the interview -is affect appropriate to words and though content? -are verbal communications consistent with nonverbal cues

Pathologic reflexes

-babinski sign is the stroking of the foot the toes contract and draw together -if you have CNS disease of motor system then the toes fan out and draw back -abnormal reflexes pursing lips, sucking motion when lips are touched, palmar grasping when touched

Assessing mental status

-begins by observing the patients appearance, and behavior, noting dress, grooming, and personal hygiene -postures, gestures, movement and facial expression provide important information about the patient. does the patient seem to be aware of and interact with he surroundings? -assessing orientation to person, time, place -assessment of immediate and remote memory is the capacity of immediate memory intact?

Balanced and coordination

-cerebellar and basil ganglia influence the motor neuron system is reflected in balance and control and coordination -coordination in the hands and upper extremities is tested by having the patient perform rapid, alternating movements and point-to-point testing -first the patient should pat the thigh as fast as possible with each hand separately -the patient should pronate and supinate the hand as rapidly as possible -last the patient is asked to touch each of the fingers with the thumb in consecutive motion -speed, symmetry, and degree of difficulty is noted -point-to-point is done by having the patient touch the examiners fingers and then their own nose. this is repeated several times -coordination of the lower extremity is tested by having the patient run the heel down the anterior surface of the other leg each leg is tested intern -Ataxia is incoordination of voluntary muscle action particularly in the muscle groups used for walking or reaching objects -tremors are noted at rest or with movement -Romberg test is screening test for balance that can be done with the patient seated or standing. the patient can be seated with feet together and arms at the side first with eyes open and with both eyes closed for 20 seconds. the examiner stands close to support the standing patient incase they fall slight swaying is normal, but loss of balance is abnormal and is considered a positive romberg sign -hoping in place -alternating knee bends -and heel to toe walking both forward and backward

Physical assessment assessing consciousness and cognition

-cerebral abnormalities can cause disturbances in mental status, intellectual functioning, thought content, and emotional status there may be alterations in lifestyle and language abilities

Level of consciousness

-consciousness is the patients wakefulness and ability to respond to the environment -LOC is a sensitive indicator of neurologic function -observe for alertness and ability to follow commands -if the patient is alert and able to follow commands the examiner observes for eye opening, verbal response, motor response to stimuli and the type of stimuli needed to obtain response -noxious stimuli should be used first than painful stimuli if no response is observed - in a patient with decreased LOC, motor and cranial nerve function become primary assessments

Central nervous system; brain stem

-consists of midbrain. pons and medulla. -the midbrain connects the pons and the cerebellum with the cerebral hemispheres it contains sensory and motor pathways and serves as the center for auditory and visual reflexes -cranial nerves III and IV originate in the midbrain. -the pons is situated in front of the cerebellum between the midbrain and the medulla and is the bridge between the two halves of the cerebellum and between the midbrain and the medulla. cranial nerves V and VIII originate in the pons. -the pons contains motor and sensory pathways. portions of the pons help regulate respirations. -motor fibers from the spinal cord to the brain and sensory fibers from the spinal cord to the brain are located in the medulla. cranial nerves IX and XII originate in the medulla. -located in the medulla are reflexes for coughing, vomiting, respiration, blood pressure, heart rate, swallowing and snezing -the reticular formation responsible for arousal and the sleep wake cycle begins in the medulla and connects with numerous higher structors

Structures protecting the brain

-contained in the rigid skull which protects from injury -the major bones in the skull are the frontal, parietal, occipital, temporal and sphenoid bones. these bones join the suture line and form for the base of the skull. -indentations of the skull are known as fossae -the anterior fossa contain the frontal lobe -the middle fossa contains the temporal lobe, and the posterior fossa contains the cerebellum and the brain stem. -the meninges (fibrous connective tissue that cover the brain and spinal cord) provide protection, support and nourishment. -the layers of the maninges are the dura mater, arachnoid and pia mater 1)Dura matter: the outermost layer, covers the brain and the spinal cord. it is tough, thick, inelastic, fibrous, and gray. the three major extensions of the dura: falx cerebri, which folds between which falls between the two hemispheres the tenitorium, which folds between the two occipital lobes and cerebellum to form a tough membraneous shelf and the falx cerebelli which is located between the right and left side of the cerebellum. when excess pressure occurs in the cranial cavity, brain tissue may be compressed against the dural folds and displaced around them this is called herniation. a potential space exists between the dura and the skull and between the periosteum and the dura in the vertebral column. known as the epidural space. another potential space, the subdural space, also exists below the dura. blood or abscess can accumulate in these spaces. 2) arachnoid: the middle membrane, an extremely thin, delicate membrane that closely resembles a spider web. the arachnoid membrane has CSF in the space below it known as the subarachnoid space. the membrane has arachnoid villi which is unique finger like projections that absorb CSF into the venous system. when blood or bacteria enter the subarachnoid space the villi become obstructed and communicating hydrocephalus ( increased size of ventricles) 3) pia mater: the innermost, thin, transparent layer that hugs the brain closely and extends into every fold of the brains surface

Examining cranial nerves

-cranial nerves are assessed with LOC is decreased, with brains stem pathophysiology, and the presence f peripheral nervous system disease Motor ability: -assess muscle sized tone, strength, coordination, balance -ask patient to walk across the room to observe gait and posture -muscles are palpated and inspected for size and symmetry -any evidence of atrophy or tremors or tics -muscle tone to see if theres tension by palpating muscle groups at rest and during passive movement resistance is assessed and documented -abnormalities in tone include spasticity increased muscle tone, rigidity (resistance to passive stretch, and flaccidity Muscle strength -assess the patients ability to flex and extend the extremities against resistance -flex the patients leg and ask them to push against force is they can't they'll be weak -you compare both extremities to see if they're even in strength -clinicians use a 5 point scale for muscle strength -5 is full power of contraction against gravity and resistance or normal muscle strength -4 indicted fair but not full strength against gravity and moderate amount of resistance or slight weakness -3 indicates just significant strength to overcome the force of gravity or moderate weakness -2 the ability to moo but not overcome the force of gravity or severe weakness -1 indicates minimal contractile power (weak muscle contraction can be palpated but no movement is noted) or very severe weakness -0 indicates no movement -assess the strength of proximal muscles on both extremities -the strength of the finer muscle control is the hand grasps and the foot (dorsiflexion and plantar flexion)

Educating patients

-family and patient need education on precautions and care after the procedure -what to watch for, steps to take, -make sure transportation, post procedure care and monitoring occur -contact the patient and the family after the procedure. -education is reinforced and the patient is reminded to make a follow up appointment -patients, health care workers, families are focused on the immediate needs, issues, or deficits that necessitated the diagnostic procedure

Sympathetic nervous system

-fight or flight response -under stress of either physical or emotional causes, sympathetic impulses increase greatly -the bronchioles dilate for easier gas exchange, the pulse rate increases, the hearts contractions are stronger and faster; the arteries to the heart and voluntary muscle dilate carrying more blood to the organs; the pupils dilate, peripheral blood vessels constrict, making the skin feel cool but shunting the blood to central organs, the liver releases glucose for quick energy; peristalsis slows; hair stand son end and perspiration increases the sympathetic NS releases primarily norepinephrine which releases epinephrine -sympathetic neurons are located in the thoracic and lumbar segments of the spinal cord, and their axons

Lower motor neuron lesions

-it is a low motor neuron lesion if the damage is located between the spinal cord and the muscle. -the result of lower motor neuron damage is muscle paralysis -reflexes are lost and the muscle become flaccid and atrophied from disuse. -if the patient has injured spinal trunk the use of muscle connected to that section of spinal cord may be regained. but if the anterior motor horn is damaged the cells can not regenerate -flacid paralysis and muscle atrophy of the affected muscle are signs of lower motor neuron disease -can result from trauma, infection (poliomyelitis), toxins, vascular disorders,congenital malformations, degenerative processes, and neoplasms. -compression of nerve roots from herniated discs are a common cause of lower motor neuron dysfunction

Mental status older adults

-mental process decreases with age -memory, judgement, language, remain intact -change in mental status is not a normal part of aging -Delirium: confused state begins with disorientation and if not treated can lead to decreased LOC, irreversible brain damage. and death -older adults at risk for delirium along with those who have CNS damage or acute condition of infection, medication, dehydration, depression impair memory and attention -the Confusion Assessment Method (CAM) is commonly used -deliruim needs to differentiated from dementia

Computed tomography scanning

-narrow x-ray beam to scan body parts produce cross sectional views of the brain distinguishing different tissue densities of the skull, cortex, subcortical structures and ventricles -IV contracts helps highlight differences better -CT is performed first without contrast -patient lies on table with head in headrest while scanning system rotates -the patient must lie with the head held perfectly still without talking or moving the face -CT is quick and painless -brain tissue have different tissue density the surroundings brian tissue -CT can detect tumors or masses, infarction, hemorrhage, displacement of the ventricles, cortisol atrophy -CT angiography; allows visualization of blood vessels Nursing management -preparation for the procedure and patient monitoring -preparation includes educating patient on the procedure, and telling them they need to lie quietly reviewing relaxation techniques are helpful if the patient has claustrophobia -sedation is agitated, restless, confused, interferes with study -if contrast assess for iodine, shellfish allergy and kidney function period of fasting 4 hours usually they are monitored during and after the procedure for changes in kidney function fluid intake is encouraged to get contrast out

Neurotransmitters

-neurotransmitters communicate messages from one neuron to another or from neuron to a target cell such as muscle cell or endocrine cells -as an electrical action potential moves along the axon and reaches the nerve terminal neurotransmitters are released into the synapse. the neurotransmitter is transported into the synapse binding to the receptors on the postsynaptic cell membrane. -a neurotransmitter can either excite or inhibit activity of the target cell. -usually multiple neurotransmitters are t work in the neural synapse. -one released, the neurotransmitters either destroy the neurotransmitter or reabsorb ir into the neuron for future use. -many neurologic disorders are due to an imbalance in neurotransmitters like parkisons disease develops develops from decreased availability of dopamine. whereas myasthenia gravis is the acetylcholine binding to the muscle cells is impaired. -all brain functions are modulated through neurotransmitters. -positron emission tomography (PET) can identify serotonin, dopamine, and acetylcholine -single-photon emission computed tomography (SPECT) can detect some changes in neurotransmitters like dopamine in Parkinson

Language ability

-normal can understand, communicate in spoken and written language -does the patient answer the question appropriately? -can he or she read a sentence for a newspaper and explain it -can the patient write their name or copy a figure -a deficiency in language function is called aphasia

Impact on lifestyle

-nurse assesses the impact of any impairment on the patients lifestyle -consider cognitive deficit and the patients role in society including family and community role -the nurse needs to make a plan to support adaptation and continued function to the extent possible within the patients support system

The central nervous system; cerebellum

-posterior to the midbrain and pons, and below the occipital lobe -cerebellum integrates sensory information and provides smooth coordinated movement -it controls fine movement, balance, and position sense or proprioception (awareness of position of extremities without looking at them)

PET scan

-produces images of actual organs functioning -the patient either inhales radioactive gas or injected with a radioactive substance that emits positively charged ions -gamma rays can be detected because the device produces two dimensional views at various levels of the brain. -PET permits measurement of blood flow, tissue composition, and brain metabolism, and thus indirectly evaluates brain function. -the brain is one of the most metabolically active organs PET measures this activity and can also detect glucose changes in the body. -PET is useful for metabolic changes (alzheimer's), locating lesions (brain tumor, and epileptic lesions), identifying blood flow and oxygen metabolism in patients with stroke NURSING INTERVENTIONS -key nursing intervention includes patient preparation and explaining the test and educating patients about inhalation techniques and the sensations (dizziness, lightheadedness, and headache) that may occur -relaxation exercises may reduce anxiety before the test.

Examining the reflexes

-relfexes are involuntary contractions of muscles or muscle groups in response to stimulus -classified as deep tendon, superficial, or pathologic -testing reflex allows to determine the presence of afferent stretch receptors, spinal or brains stem synapses, efferent motor fibers Deep tendon reflexes -reflex hammer; hold the hammer loosely between the thumb and the index finger allowing a full swinging motion the wrist motion is similar to that used when percussing -the extremity is positioned so that the tendon is slightly stretched the tendon is then struck briskly and response is compared to the opposite side -its important that the reflexes are symmetrical both should relaxed and each tendon should be struck with equal force -if the reflex is absent the examiner may use isometric contraction of other muscle groups to increase reflex -if the lower extremity reflex is absent the patient is instructed to lock fingers together and pull in the opposite direction -having the patient clench the jaw or press the heels to the floor or table may elicit a bicep, tricep and bracheoradialis reflex -the absence of reflexes is important although the achillies reflex is absent in older adults -deep tendon reflexes are often graded on a response scale 0-4 and 2 is considered normal you can also say present, absent diminished Bicept reflex -stricking the bicep tendon over the slightly flexed elbow -the examiner supports the forearm at the elbow with one arm while placing the thumb against the tendon and striking the thumb with the reflex hammer -the normal response is flexion at the elbow and contraction of the bicep Tricep -arm is flexed at elbow and hanging freely at the side -examiner supports the patients arm palpates 5cm above the elbow a direct blow to the tendon produces contraction the tricep and extension of the elbow Brachioradialis reflex -forarm resting at lap or across the abdomen -gentle strike 5 cm above the wrist results in flexion and supination of forearm Patellar -strike below the patellar -patient in sitting or lying position -is supine the examiner supports the legs -contraction of quids and knee extension are normal responses Achilles -foot is dorsiflexed at the ankle the hammer strikes the tendon and normally produces plantar flexion -if can't get reflex instruct patient to kneel on a chair or similar elevated flat surface this position places muscles in dorsiflexion CLonus -is reflexes are hyperactive they are called clonus -the foot is abrutly dorsiflexed it may beat two or three times before it settles Superficial reflex -corneal reflex take swap and carefully touch the outer portion of the corner of the eye reflex is present if the person blinks -stroke or brain injury may result in loss of this reflex either unilaterally or bilaterally you need eye protection and lubrication if absent reflex to prevent corneal damage -gag reflex: gently touching the back of the pharynx with cotton tipped applicator -positive is equal elevation of vulva -absent on both sides is seen in stroke patients evaluate swallowing abilities to prevent aspiration

Sensory system function losses

-sensory impulses convey sensations of heat, cold, and pain; position and vibration -destruction of sensory nerves result in total loss of sensation in its area of distrubution -lesions affecting the posterior spinal nerve roots may impair tactile sensation, causing intermittent pain that is referred to the area of destruction -destruction of the spinal cord yields complete anesthesia below the level of injury -selective destruction or degeneration of the posterior columns of the spinal cord is responsible for loss of position, and vibratory sense in segments distal to the lesion, without loss of touch, pain or temperature perception -lesions in the thalamus, parietal lobe result in impaired touch, pain, temperature and proprioceptive sensations

assessment of the nervous system common symptoms

-symptoms can be subtle or intense, fluctuating or permanent, inconvenient or devastating Pain: -is an unpleasant sensory perception and emotional experience with actual or potential tissue damage -pain is subjective and multidimensional -can be acute or chronic -acute last for a relatively short period of time and remits as the pathophysiology resolves. -in neurologic disease, acute pain may be associated with brain hemorrhage, spinal disc disease, or trigeminal neuralgia -chronic pain in persistent and may represent a broader pathophysiology Seizures -reult of abnormal electrical discharges in the cerebral cortex that manifest as an alteration in sensation, behavior, movement, perception, or consciousness. -the alteration may be short such as blank stare that last only seconds or longer duration like a tonic-clonic grandma seizure that can last several minutes. -seizure activity reflects the area of the brain affected -seizures can occur as isolated events like alcohol, high fever, or drug withdrawal, or hypoglycemia or it can be an obvious sign of a brain lesion Dizziness and vertigo -dizziness is an abnormal sensation of imbalance or movement -common in older adults -common in viral syndromes, hot weather, roller coaster rides, and middle ear infections -its difficult to assess dizziness because it varies -about 50% of patients with dizziness have vertigo or illusion of movement in which the individual or surroundings are moving usually as rotation -vertigo is manifested as vestibular dysfunction it can be so severe as to result in spatial disorientation, lightheadedness, loss of equilibrium and nausea and vomiting Visual disturbance -normal vision relays on the retina and optic chasma and the radiations into the visual cortex -lesions in the visual cortex (stroke) interfere with visual acuity - Muscle weakness -weakness can be sudden or permanent in stroke

Geriatric motor alterations / temperature regulations

-tactile sensation is dulled -hard time identifying objects by touch -may be confused about body position because fewer tactile cues from bottom of feet -sensitivity to glare from decreased peripheral vision, constricted visual field = disorientation especially at night -takes longer to recover visual sensitivity when moving from light to dark areas use nightlight -loss of hearing can contribute to confusion, anxiety, disorientation, misinterpretation of environment, feeling inadequate and social isolation -decreased taste and smell= weight loss and disinterest in food -decreased smell= safety hazard unable to detect gas leaks smoke and carbon monoxide detectors are important Temperature regulations -may feel cold more than heat -need more blankets -high room temperature -reaction to painful stimuli is decrease d -use caution when using hot or cold packs -older patient may be burned or have frostbite and not be aware of it -abdominal discomfit and chest pain needs to be taken seriously -two common disease affect the older adult neuropathy system diabetes and neuropathies

Blood brain barrier

-the CNS is inaccessible to many substances that circulate in the blood plasma (dyes, medications, and antibiotic agents) -this barrier is formed by the endothelial cells of the brains capillaries which form continuous tight junctions creating a barrier to macromolecules -all substances entering the CSF must filter through the capillary endothelium cells and astrocytes. the blood brain barrier has a protective function but is altered by trauma, cerebral edema, and cerebral hypoxemia this means you need treatment

Cells of the nervous system

-the basic functional unit of the brain is the neuron, it is composed of dendrites, a cell body, and an axon -the dendrites are branch type structures for receiving electrochemical impulses - axons: long projection that carries electrical impulses away from the cell body. some axon have myelinated sheath that increases speed of conduction. -nerve cell bodies occurring in clusters are called ganglia -a cluster of nerve cell bodies with the same function is called a center (the respiratory center) -neurons are supported, protected and nurished by glial cells which are 50 times greater in number than neurons

Vertebral column

-the bone surround and protect the spinal cord and normally consist of 7 cervical, 12 thoracic, 5 lumbar, 5 sacrum -the vertebrae are separated by discs except for the first and second cervical and the sacral and coccygeal vertebrae. -each vertebra have a solid body, and a dorsal segment or arch which is posterior to the body.

Cerebral circulation

-the brain does not store nutrients and requires a constant supply of oxygen -the needs are met through cerebral circulation and 15% is from cardiac output approximately 750mL per minute of blood flow. -brain circulation is because venous and arterial vessels are not parallel as in other organs of the body this is related to the role the venous system plays in the absorption of CSF. the brain also has collateral circulation that allows the blood flow to be redirected on demand and third blood vessels in the brain have two rather than three layers which may make them more prone to rupture when weakened or under pressure. Arteries: -arterial blood supply to the anterior brain is from the carotid arteries which is the first bifurcation off the aorta. -the internal carotid arteries arise from the bifurcation of the common carotid. branches of the internal carotid arteries (the anterior and middle cerebral arteries) and their connections (anterior and posterior communicating arteries) form the circle of willis -the vertebral arteries branch from the subclavian arteries to supply most of the posterior circulation of the brain -at the level of the brains stem the vertebral arteries join the basilar arteries the basilar arteries divide into two to form the posterior cerebral arteries functionally the posterior and anterior portions of the circulation usually remain separate. -the circle of willis can provide collateral circulation through communicating arteries if the one of the vessels become occluded or is ligated -the bifurcation along the circle of willis are frequent sites of aneurysm formation. aneurysm are outpourings of the blood vessel due to vessel wall weakness. they can rupture and cause a hemorrhagic stroke. Veins: -venous drainage is different than any other part of the body. -the veins reach the brains surface, join larger veins, and then cross the subarachnoid space and empty into the dural sinuses which are the vascular channels embedded in the dura the network of the sinuses carries venous outflow from the vein and empties into the internal jugular veins, returning the blood to the heart -cerebral veins are unique because unlike other veins in the body they do not have valves to prevent blood flow from flowing backwards and depends on both gravity and blood pressure for flow.

Central nervous system; the brain

-the brain is divided into three major areas; the cerebrum, the brain stem and the cerebellum. -the cerebrum has two hemispheres the thalamus and the hypothalamus and the basal ganglia. -the brain stem include the midbrain, pons, and medulla. -the cerebellum is located behind the brainstem and underneath the cerebrum.

anatomic and physiologic overview

-the central nervous system including the brain and the spinal cord and peripheral nervous system which includes the cranial nerves, spinal nerves, and autonomic nervous system. -the function of the nervous system is to control sensory, control motor, autonomic, cognitive and behavioral activity.

Coordination of movement

-the motor system depends on the corticospinal tracts, basil ganglia and cerebellum that control and coordinate voluntary motor function -the smoothness, accuracy, and strength is from the cerebellum and the basil ganglia -the cerebellum the contraction of opposing muscles groups are adjusted in relation to each other to maximal mechanical advantages; muscle contraction can be sustained evenly at the desired tension and without fignificatn fluctuations, and reciprocal movements can be reproduced at high and consistent speeds -the basil ganglia plays an important role in coordinating motor movements and posture. it inhibits unwanted muscular movement (with the cerebellum and basil ganglia) -impaired cerebellar function may occur as a result of intracranial injury or an expanding mass like a hemorrhage or tumor. results in loss of muscle tone, weakness, and fatigue. - (think stroke) impaired cerebellar function; depending on the area of the brain you can have different moron impairments. the patient may demonstrate abnormal flexion, abnormal extension, or flaccid posturing -flaccidity: lack of muscle tone preceded by abnormal posturing in a patient with cerebral injury indicates severe neurologic impairment which may cause brain death - (think parkinson's disease) destruction or dysfunction of the basil ganglia leads NOT to paralysis but to muscle rigidity, disturbances in posture, and difficulty initiating and changing positions. the patient tends to have involuntary movement. this may appear as coarse tremors in the upper extremities, particularly the distal portions; athetosis (movement of slow, squirming, writhing, twisting type: or chorea marked by spasmodic, purposeless, irregular, uncoordinated motions of the trunk and extremities, and facial grimacing

Diagnostic evaluation

-the nurse should educate the patient about the purpose, what to expect and ant possible side effects related to testing -women who are premenopausal are advised to use contraception before and for several days after diagnostic testing using contrast

Central nervous system; cerebrum

-the outside surface of the hemispheres have a wrinkled appearance that result in many folded layers and or convolutions called gyri. which increase the surface area of the brain. -between each gyri is a sulcus or fissure that serves as an anatomic division -in between the cerebral hemispheres is the great longitudinal fissure that separates the cerebrum into the right and left hemisphere. -the two hemisphere are joined at the lower portion of the fissure by the corpus callosum. -the external or outer portion of the cerebral hemispheres is made up of gray matter it contains billions of neurons giving it a gray appearance -white matter makes up the innermost layer and is composed of myelinated never fibers and neuroglia that form tracts or pathways connecting connecting various parts of the brain to one another the pathways also connect to lower portions of the brain and spinal cord. -the cerebral hemispheres are divided into pairs of lobes 1) Frontal: largest lobe located in the front of the brain the functions of this lobe is concentration, abstract thought, information storage or memory, and motor function. it contains broca area which is located in the left hemisphere which is critical for motor control of speech. also responsible for the persons affect, judgment, personality and inhibitions. 2) Parietal: sensory lobe posterior to the frontal lobe. the lobe analyses sensory information and relays this other information to the cortical areas and is essential to a persons awareness to of position in space, size and shape discrimination, and right left orientation. 3)temporal: located inferior to the parietal and frontal lobes contains an auditory receptive area and plays a role in memory of sound and understanding of language and music 4) occipital: located posterior to the to the parietal lobes this lobe is responsible for visual interpretation and memory. -the corpus collosum a thick collection o nerve fibers that connect the two hemispheres is responsible for transmission of information from one side of the brain to the other. information transfers includes sensation, memory, and learned discrimination. - right handed people and some left handed people have cerebral dominance on the left side of the brain for verbal, linguistic, arithmetic, calculation and analytic functions. -the non dominant hemisphere is responsible for geometric, spatial, visual, pattern and musical function. -neucli for cranial nerves 1 and 2 are located in the cerebrum -the thalami lie on either side of the third ventricle and act primarily as a relay station for all sensation except smell. all memory, pain, and sensation impulses go through this section of the brain. -the hypothalamus is located anterior and inferior to the thalamus (in front of and below) -the infundibulum of the hypothalamus connects to the posterior pituitary gland -the hypothalamus plays an important role in regulating the endocrine system because it regulates the pituitary secretion of hormones that regulate metabolism, stress, reproduction, and urine production. it works with the pituitary gland to maintain fluid balance through hormonal release and maintains temperature regulation by promoting vasoconstriction and vasodilation. it is also the site of hunger and involved in appetite control. regulates sleep and wake cycle, blood pressure, aggressive and sexual behavior and emotional responses (blushing, rage, depression, panic, and fear) also controls and regulates ANS the optic chiasm (the point at which two optic tracts cross) and the mammillary bodies (involved in olfactory reflexes and emotional response to odors) are also located in this area. -the basal ganglia are masses of nuclei located deep in the cerebral hemispheres that are responsible for control of fine motor movements, including those of hands and the lower extremities.

The spinal cord

-the spinal cord is continuous with the medulla, extending from the cerebral hemispheres and serving as a connection between the brain and the periphery. -it extends from the foramen magnum at the base of the skull to the lower border of the first lumbar vertebra where it tapers into fibrous band called the conus medullaris continuing below the lumbar space are the nerve roots that extend beyond the conus -meninges surround the spinal cord -in a cross sectional view the spinal cord has a H shaped central core of nerve cell bodies (gray matter) surrounded by ascending and descending tracts (white matter) -the lower portion of the H is broader and corresponds to the anterior horns -the anterior horns contains cells with fibers that form the anterior (motor) root and are essential for voluntary and reflex activity of the muscles they intervene -the upper thinner posterior (upper horns) portion is for sensory and serve as a relay for the sensory reflex path -the thoracic region of the spinal cord has a projection at each side of the crossbar of the H shaped structure of gray matter called lateral horn.

the spinal tract

-the white matter of the spinal cord is composed of myelinated and unmyelinated nerve fibers -the fast conducting mylenated fibers form bundles; fiber bundles with a common function are called tracts -there are six ascending tracts -two tracts known as fasciculus cuneatus and gracilis or the posterior columns conduct sensation of deep touch, pressure, vibration, position, and passive motion from the same side of the body. before reaching the cerebral cortex they cross to the opposite side in the medulla -spinocerebellar tracts conduct sensory impulses from muscle spindles providing input for muscle contraction -the anterior and lateral spinothalamic tracts are responsible for conduction of pain, temperature, proprioception,, fine touch, and vibratory sense from the upper body to the brain. they cross the opposite side of the cord than ascend to the brain terminating in the thalamus -descending tracts; anterior and lateral corticospinal conduct motor impulses from the anterior horn from the opposite side of the brain. the three vestibulospinal tract descend uncrossed and are involved in autonomic functions like sweating, pupil dilation, and circulation. the corticobulbar is for voluntary head and face muscle movement. the rubrospinal and recticulospinal tracts are responsible for involuntary movement

Upper motor neuron lesions

-upper motor neuron lesions involve the motor cortex, the internal capsule, and the spinal cord gray matter -if the upper motor neurons are damaged or destroyed, as frequently occur with stroke and or spinal cord injury, paralysis results. however because of the inhibitory influences of intact upper motor neurons are impaired, reflex (involuntary movements) are uninhibited and hence hyperactive deep tendon reflexes, and pathologic reflexes such as bobinski response occurs (abnormal dorsiflexion) -severe leg spasms can occur as the result of upper motor neuron lesion; the spasm result from the preserved reflex arc, which lacks inhibition below the level of injury -there is little or no muscle paralysis and the muscle remains tense and does not atrophy exhibiting spastic paralysis -paralysis affecting the upper motor neurons lesions can affect whole extremity, both extremities, or an entire half of the body. -Hemiplegia ( paralysis of an arm and leg on the same side of the body) can be a result of an upper motor neuron lesion -if hemorrhage, an embolus, or thrombus destroys the fibers in the motor area in the internal capsule, the arm and leg of the opposite side become stiff, weak, or paralyzed, and the reflexes are hyperactive -if both legs are paralyzed this is called paraplegia -if all four extremities are paralyzed this is called tetraplegia or quadriplegia

Transcranial doppler

-use the same noninvasive techniques as carotid flow studies but records blood flow velocities of intracranial vessels -arterial flow velocities can be measured through thin areas of the temporal and occipital bones of the skull. -a handheld doppler permits a pulsed beam the signal reflected by the moving red blood cells within the blood vessels -transcranial doppler is a noninvasive technique that is helpful is assessing vasospasm (a complication following a subarachnoid hemorrhage), altered cerebral blood flow found in occlusive vascular disease, other cerebral pathology and brain death Nursing interventions: -describe the procedure to the patient -inform the patient that this is a noninvasive test, that a handheld transducer will be placed over the neck and the orbits of the eyes -tell the patient that a water soluble gel or lubricant is used on the transducer -it can be performed at the patients bedside

Noninvasive carotid flow studies

-uses ultrasound and Doppler measurements of arterial blood flow to evaluate carotid and deep orbital circulation. -the graph produced indicates blood velocity -increased blood velocity can indicate stenosis or partial obstruction -

Cerebral angiography

-x-ray study for the cerebral circulation with a contrast agent injected into a selected artery. - this is a valuable tool used to determine vessel patency, identify presence of collateral circulation, and provide vascular detail on vascular disease -Cerebral angiography is performed by catheter through the femoral artery through the groin and to the desired vessel -alternatively a direct punter through the carotid may be performed. -X-ray images are obtained as the contrast agent flows through the vessels; the carotid and vertebral arterial systems are visualized, as well as venous drainage arterial access may be used for placing coils in an aneurysm Nursing interventions -prio to angiography the patients blood urea nitrogen and creatine should be checked to ensure that the kidneys will be able to excrete the contrast agent. -the patient should be well hydrated and placed on clears permitted up to the procedure. -void immediately before the test -locations of the appropriate peripheral pulses should be marked with a felt tip pen -the patient is instructed to remain immobile during the angiography and is told to expect to feel warmth in the face behind the eye, or the jaw, teeth, tongue, and lips, and a metallic taste when the contrast agent is injected. -after the hair in the groin is clipped and prepared a local anesthetic agent is given to minimize the pain at insertion site and reduce the arterial spasm. -a catheter is introduced into the federal artery and flushed with saline and filled with contrast agent. -fluoroscopy is used to guide the catheter to the appropriate vessels. -neurologic assessment is done before and immediately after angiography to observe for embolism or arterial dissection that may occur during the test. signs and complications include alterations in LOC, weakness on one side of the body, motor or sensory deficits, and speech disturbances. -nursign care after includes observation of injection site for bleeding or hematoma because a hematoma at puncture site or embolization to a distal artery effects the peripheral pulses that were marked prior to the procedure. -the color and temperature of the extremity are assessed to detect possible embolism. -fluids are encouraged to facilitate clearance of the contrast through the kidneys -monitors for allergic reaction of the contrast agent

Types of aphasia

Auditory receptive: temporal lobe Visual receptive: parietal and occipital areas expressive speaking: inferior posterior frontal areas Expressive writing: posterior frontal area

Lumbar puncture and examination of CSF

Lumbar puncture or spinal tap is carried out by inserting needle into the subarachnoid space to withdraw CSF. -test is performed to obtain CSF to measure and reduce CSF pressur, determine presence or absence of blood in the CSF and to administer medication -needle is inserted into eh subarachnoid space between third and forth or firth lumbar vertebrae because the spinal cord ends at the first lumbar insertion of the needle below the level of the third lumbar prevents puncture of the spinal cord. -successful puncture requires the patient to be relaxed if you're anxious this may increase the pressure reading. -CSF pressure with the patient in a lateral recumbent position is normally 80-110 mmH2O or 8-14 Hg -a lumbar puncture is risky with intracranial mass lesions because intraspinal pressure is decreased by removal of CSF and the brain may herniate downward through the foramen magnum Cerebral spinal fluid analysis -CSF should be clear and colorless -pink blood tinged or bloody CSF may indicate a subarachnoid hemorrhage -CSF may be bloody initially because of trauma and becomes clearer as more fluid is drained -specimens are obtained for cell count, culture, glucose, protein, and other tests -specimens sent to lab immediately because changes take place if the specimens just stand Post lumbar puncture: -headache ranging from mild to severe for a few hours to several days -severe when sitting or standing but less severe when the patient lies down. -HA is caused by CSF leakage at the puncture site that continues to leak into the tissues by way of needle track. as a result leak supply in the cranium is depleted to a point which it is insufficient to maintain proper mechanical stabilization of the brain. when patient is upright position, tension and stretching of the venous sinuses and pain sensitive structures occur. -PLP HA may be avoided is small needle is used and is the patient remains prone after procedure. patient is placed supine for 4-8 hours -postpuncture headache is managed by rest, analgesic agents. and hydration other complications -herniation of intracranial content, spinal epidural abscess, spinal epidural hematoma, and meningitis are rare but serious -other complications are troubles voiding, slight elevation of temperature, backache or spasm, and stiffness of neck

Assisting with lumbar puncture

PREprocedure - explain the procedure -explain they may feel cold as the site is cleaned, a needle prick when anesthetic is used -tell patient to void before hand Procedure -positioned on one side at the edge of the bed with back toward the physician the thighs an legs ae flexed to help increase space between the spine with entry of the subarachnoid space. -small pillow for head and for legs to maintain the spine in horizontal position and prevent the leg from rolling forward -nurse helps the patient maintain the position to avoid movement -encourage patient to relax -describe procedure step by step -the physician cleanses the site and drapes the site -the physician injects anesthetic and then inserts the needle into the 3rd, 4th, or 5th lumbar interspace, pressure reading is obtained. -CSF specimen is removed and collected in three test tubes labeled in order of collection the needle is then withdrawn -physician applies small dressing to site -tubes are sent to lab asap postprocedure -instruct the patient to lie prone to separate alignment of dural and arachnoid needle punctures in the meninges to reduce leakage - monitor for complications of puncture notify HCP is something occurs -encourage increased fluids to reduce risk of headache

Examining sensory system

sensory is largely subjective -assessment involves tests for tactile sensation, superficial pain, temperature, vibration, and proprioception -during the sensory assessment the patient eyes are closed simple directions and reassurance that the examiner will not hurt or startle the patient encourage cooperation -tactile sensation is assessed by lightly touching a cotton wisp or finger swab to corresponding areas of each side of the body proximal parts are compared with distal parts and right and left sides are compared -Pain and temperature sensation are transmitted together in the lateral part of the spinal cord so it is unessecary to test for temperature sense in most circumstances. determining patients sensitivity to sharp objects assess superficial pain -pain sensation is usually reserved for patients who do not respond to or cannot discriminate touch sensation -the patient is asked to differentiate between sharp and dull objects like dull ends of broken wooden cotton swab or tongue blade don't use a safety pin. both sharp and dull objects are applied with equal intensity and the two sides are compared -patient with altered LOC you use different alternative testing methods -virbration and proprioception are transmitted together in the posterior part of the cord -vibration may be evaluated from a low frequency tuning fork. the handle of the vibrating fork is placed against the bony prominence and the patient is asked if he or she feels a sensation and is instructed to signal the examiner when the sensation stops -vibratory test locations are the distal toe, proximal thumb joint. if the vibrations not felt at the distal joint of the toe the examiner proceeds upward until the vibration if felt -position sense is determined by asking the patient to close both eyes and indicated as the great toe or index finger is moved up and down in which direction movement has taken place -integration in the brain is evaluated by two point discrimination. patient is touched with two sharp objects simultaneously on the opposite sides did the patient feel two or was it perceived as one? if only one is identified it is termed extinction -tactile identification the patient is asked to close both eyes and identify an object like a coin or key that is placed in the hands of the examiner inability to identify the object is known as tactile agnosia or astereognosis -agnosia is the inability to recognize similar objects through a particular sensory system. -the patient can be shown similar objects and asked to identify the name if they can't this is called visual agnosia -sensory deficits result from peripheral neuropathy, or spinal cord injuries -destructive lesions can affect one side of the body. stroke affecting a portion of the sensory cortex Agnosia -Visual: occipital lobe auditory: temporal lover tactile: parietal lobe body parts and relationships: parietal lobe