Exam #5 Flashcards
structures and fxns of nervous system
- central nervous system
- brain
- spinal cord
- crainal nerves I and II
- Peripheral Nervous system
- cranial nerves III and XII
- spinal nerves
- autonomic nervous system
Neurons
- neurons
- primary functional unit
- characterized by: excitability (start impulse), conductivity (transmit impulse), and influence (ability to influence other neurons, muscle cells or glandular cells by transmitting nerve impulses to them)
- consists of: cell body, dendrites, axon covered by myelin sheath
Glial cells
- provide support, nourishment and protection to neuron
- more numerous than neurons
- types:
1) microglia capable of phagocytosis
2) macroglia
A astrocytes: most abundant, phagocytosis of debris from injury, form the BBB
B oligodendrocytes: produce the myelin sheath
C ependymal: aid in secretion of CSF
Regeneration and Impulses
- nerve regeneration (repair)
- attempt to grow back
- PNS more successful than CNS in regeneration
- nerve impulses affected by neurotransmitters
- acetylcholine: activates muscles, decreased in alzheimers disease and mysethenia gravis
- dopamine: affects mood, decreased in parkinson’s disease
Cerebrum
- right and left hemispheres, 4 lobes
- frontal: high cognitive fxn, memory retention, voluntary eye movements, voluntary motor movement, speech in broca’s area
- temporal: integrates somatic, visual, and auditory data and contains wernicke’s speech area
- parietal: sensory and spacial
- occipital: sight
- gray matter on outer layers, white matter on inner layers
- basal ganglia: voluntary movements, learning
- thalamus: relays sensory and motor input to and from cerebrum
- hypothalamus: regulates endocrine and autonomic fxns
- limbic system: feeding and sexual behavior
brainstem
- autonomic nervous system
- midbrain
- pons
- medulla: respiratory, vasomotor, and cardiac fxn
- nuclei of cranial nerves III and XII are in the brainstem
cerebellum
- trunk stability and equilibrium
- coordinates voluntary movement
peripheral nervous system
- all neural structures that lie outside the CNS
- spinal and cranial nerves, gnglia, and portions of ANS
- spinal nerves: dorsal (afferent) ventral (efferent), motor, sensory
- spinal cord is grey matter inside and white outside
- dermatomes: skin
- myotomes: muscle group inervated by primary motor neurons of single ventral root
- cranial nerves
- ANS: involuntary, cardiac muscles
- sympathetic: fight of flight
- parasympathetic: rest and digest, conserves energy
cranial nerves
1 o s - olfactory: smell
2 o s - optic: vision
3 o m - oculomotor: eye movement
4 t m - trochlear: superior oblique muscle eye movement
5 t b - trigeminal: S = facial feeling, front of tongue; M = chewing
6 a m - abducens: lateral rectus of eye
7 f b - facial: M = muscles of expression and cheek; S = taste from anterior 2/3s of tongue
8 v s - Vestibulocochlear: hearing, balance
9 g b - glossopharyngeal: S = taste, posterior tongue; M = swallowing
10 v b - vagus: S = throat and abdoment; M = larynx and swallowing; heart, lungs, digestive system
11 a m - accessory: sternocleidomastoid and traps muscles, shoulder shurgs
12 h m - hypogloassal: muscles of tongue
brain protection
- blood brain barrier: protects from harmful agents, lipid soluable agents enter easily, water soluable agents enter slowly
- skull: 8 cranial bones and 14 facial bones, foramen magnum (hole that brainstem goes through)
vertebral column
- 33 vertebrae
- 7 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 4 coccyx
genontologic considerations of nervous system
- CNS: loss of neurons, enlargement of ventricles, decreased brain weight/ cerebral blood flow/ CSF production
- PNS: decreased nerve conduction, decreased coordinated neuromuscular activity (affects blood pressure changes)
- decreased memory
- decreased sensory/neuromuscular fxn (body temp maintenance)
- decreased reaction time, taste, smell, sit, hearing (high pitch lost first), nigh vision, peripheral vision
neuro assessment
- cerebral fxn: mental status, general appearance, cognition, mood/affect
- cranial nerves
- motor system: weakness, muscle tone, balance/coordination
- sensory system: touch, pain, position
- reflexes
neuro diagnostic studies
- CT
- MRI and MRA
- PET and SPECT: metabolic activity, need IV, looks for blood flow, can catch dimentia
- ultrasound: patency and stenosis of vessels
- cerebral angiography: look for lesions or tumors in vessels
- lumbar puncture: r/o infection, look at CSF, look for menningitis, cancer cells
- myelogram
- EEG
- EMG
lumbar puncture
- sterile technique
- increased intracranial pressure = no LP
- may feel pain down leg
- needle between vertebral bodies
- post: best rest, band aid, headache, band aid
myelogram
- xray of spinal chors w contrast
- done on tilt table and moved during test
- post: bed rest, fluids, n/v
cerebral angiography
- looks for tumors/lesions
- time-sequenced radiographic images
- hematomas, arterial spasms
- post: observe for bleeding
electrographic studies
- EEG: brain elec activity
- Electromyography and nerve conduction studies: needles in muscles
- evoked potentials: nerve conduction
Stroke risk factors
- non-modifiable: age, gender, ethnicity, family history
- modifiable: HTN (#1 cause of stroke), heart disease, smoking, diabetes, alcohol, obesity, sleep apnea, lack of exercise, poor diet, drug abuse = atherosclerosis
Transient Ischemic Attacks (TIAs)
- transient neuro problems caused by ischemia without actual infarction
- a warning sign
- can have a variety of symptoms depending on where the blockage is
- symptoms usually last
types of strokes
- Ischemic: 80-90%
- thrombotic: most common cause, usually have had some TIAs prior, S/s no decrease in LOC, symptoms progress for 72 hours
- embolitic: usually have a cardiac history, less likely to have had any warning signs, recurrence is common, s/s sudden onset of severe symptoms, usually remain conscious, atherosclerosis
- hemorrhagic: 10%
- intracerebral: rupture of vessle, increased intracranial pressure, much worse is pt is on blood thinners, poor prognosis, usually caused by HTN, s/s sudden onset of severe symptoms with rapid progression, severe headache, n/v
- subarachnoid: rupture of anyerysm, could be from trauma or cocaine use, s/s silent killer, worst headache of your life, patients dont typically know they have an anyeurism
3 stroke assessment signs
- facial droop
- motor weakness
- language difficulties
Face: facial droop, uneven smile
Arms: numbness, weakness
Speech: slurred, difficulty speaking or understanding
Time: call 911 and get to hospital immediately
stroke symptoms
- left
- slow, cautious
- depressed
- anxious
- slow speech
- right paralysis
- right
- impulsive
- denies problems
- talks fast
- safety risks
- left paralysis
- left side neflect
symptoms of stroke
- motor: contralateral flaccidit then spasticity within 48 hours, hemiplegia, hemiparesis
- communication: aphasia (receptive or expressive), nonfluent speech requires lots of effort, fluent speech is meaningless, non sensical, dysarthria muscles for speech are weak, dysphasia receptive, expressive global
- affect: cant control emotions
- intellect: left: cautious, right impulsive
- spatial perceptual: more problems in right sided strokes, homonymous hemianopsia (only see 1/2 vision), agnosia (inability to recognize familiar objects)
- elimination: urinary problems are temporary, constipation is long term
stroke diagnostic studies
- CT is most important, distinguishes stroke and ischemic vs hemorrhage
- CT angiography
- MRI
- transcranial doppler, bleeds
- LICOX monitoring, can tell if stroke is progressing
stroke treatment
- prevention: control HTN, diabetes, heart problems, no smoking, limit alcohol intake, if having TIAs look for cause
- Antiplatelet drugs for TIAs: ASA, plavix, warfarin (prevent clots but don’t dissolve)
- surgery: carotid endarterectomy, transluminal angioplasty, stenting, EC-IC bypass
treatment by type of strokes
- ischemic: time of onset is most important, give tPA within 3-4.5 hours of onset (Gold standard), ABCs, no seizure prophylaxis, no heparin but may give ASA, keep BP slightly high, dont overhydrate, keep fever free
- hemorrhagic: no anticoagulants or platelet inhibitors, give seizure prophylaxis, prevent HTN keep BP
acute stroke interventions
- respiratory: high risk of atelectasis & pneumonia (esp aspiration pneumonia), may need an artificial airway, swallowing issues, loss of gag reflex
- Neuro: assess baseline, post 24 hours, 7-10 days and 3 months; use HTN stroke scale, mental status, pupil changes, extremity movement/strength, Vital signs
- cardiovascular: oftentimes have limited reserves, maintain F&E balance, prevent HTN, prevent DVTs
- musculoskeletal: prevent joint contractures and muscle atrophy, ROM (active or passive), positioning
- skin: prone to breakfown due to loss of sensation, decreased circulation, pressure relief, skin hygiene
- GI: prevent constipation, stool softeners
- Urinary: may have some incontinence, usually does resolve, bladder training, watch for restlessness
- nutrition: ST to assess swallowing ability, keep upright, assess a gag reflex, pureed diet is too smooth or bland, use thick-it, chin tuck and double swallow, watch for pocketing
- communication: ask yes or no questions, may not be able to read words, give plenty of time to respond, picture boards
- sensory-perceptual: homonymous hemianopsia, eye patches for diplopia, neglect syndrome, high risk for injury
- coping: clearly communicate, repeat teaching often, help with arranging follow up care, depression can be common
- PT
- OT
- ST
Home interventions stroke
- musculoskeletal: if muscles are still flacid prognosis is poor, balance training, use of assistive devices
- nutrition: may need PEG, encourage self feeding
- bowels: prevent constipation, bowel retraining
- bladder: regular voiding schedule q 2 hours,
- sensory/perceptual: right - impulse, tend to deny problems, risk for injury, one sided neglect; left - slower to organize/perform tasks, fearful, anxious
- affect: left - mood swings; may be unable to conrol emotions, distraction may help, do not punish
- coping: many losses, often have depression,
olfactory nerve assessment (CN I)
- test both nostrils are patent then close one nostril and have them do a smell test
- disturbance of smell may be associated with tumor or skull fractures
optic nerve assessment (CN II)
- assess visual fields and acuity
- have pt look at their nose: visual field defect may mean lesions of optic nerve, optic chiasm or tract,
- test visual acuity by asking the pt to read a snellen chart
Ocluomotor, trochlear and abducens nerve assessment (CN III, IV, and VI)
- always tested together, help test eye movement
- test 6 carinal gaze test with pen light
- this test can find a disconjugate gaze (not moving together), nystagmus (rapid jurking movements)
- test pupilary restriction and accomodation
- PERRLA
- look for ptosis (drooping eyelid) and eye muscle weakness
Trigeminal nerve assessment (CN V)
- test light touch and pinprick on face with eyes closed
- clench teeth and palpate masseter muscles
Facila nerve assessment (CN VII)
- raise eyebrows, close eyes tightly, purse lips, smile, frown
- taste of salt and sugar on front 2/3 of tongue
vestibulocochlear (acoustic) nerve assessment (CN VII)
- close eyes and whisper very quiet in ear
glossopharyngeal and vagus nerve assessment (CN IX and X)
- test gag refex
- test swallowing
- say “ah”
- cough for vagus nerve assessment
accessory nerve assessment (CN XI)
- shrug shoulders and turn head with resistence
hypoglossal nerve assessment (CN XII)
- protrude tongue
- move tongue around and against resistence of a tongue blade
motor system neuro assessment
- ROM tests
- Strength tests
- hypotonia: flaccidity
- hypertonia: spacicity
- myoclonus: spasm of muscles
- athetosis: slow, writhing, involuntary movements of extremities
- chorea: involuntary, purposeless, rapid motions
- dystonia: impairment of muscle tone
- cerebellar function: balance and coordiation, observe pt stature and gait, finger to nose test
romberg test
- tests proprioception
- stand with feet together then close eyes
- if falls with closed eyes means vestibulocochlear dysfunction or diease in posterior columns of spinal cord
sensory tests
- two point discrimination test
- graphesthesia: ability to feel writing on skin
- stereognosis: ability to preceive the form and nature of objects
neuro assessment abnormalities
- speech: aphasia/dyspahsia (loss of or impaired language faculty, comprehension, expression or both); dysarthria (lack of coordination for speech)
- eyes: anisocoria (inequal pupil size), diplopia (double vision), homonymous hemianopsia (loss of vision in one side of visual field)
- cranial nerves: dysphagia (diff swallowing), ophthalmoplegia (paralysis of eye muscles), papilledema (swelling of optic nerve head)
- motor: apraxia (inability to perform learned movements despite having desire to do so), ataxia (lack of coord of movement), dyskinesia (impairment of voluntary movement), hemiplegia (paralysis of one side), nystagmus (jerking or bobbing of eyes as they track moving objects)
- sensory: analgesia (loss of pain), anesthesia (absence of sensation), paresthesia (alteration in sensation), astereognosis (inability to recognizze form of object by touch)