Neuro Exam Lecture Flashcards
what are the components of the neuro exam?
mental status, cranial n., motor system, sensory, reflexes
what neuro dz presents episodically?
MS
what are the components of a mental status exam?
level of alertness, appropriateness of response, orientation
what cranial n. exits at telencephalon?
CN I
what cranial n. exits at the diencephalon?
CN II
what cranial n. exits at the mesencephalon?
CN III and IV
what cranial n. exits at the metencphalon?
CN V
what cranial n. exits at the myelencephalon?
CN IX-XII
what part of the brain is the midbrain?
mesencephalon
what part of the brain is the pons?
metencephalon
what part of the brain is the medulla?
myelencephalon
what cranial nerves exit at the pontomedullary junction?
CN VI, VII, VIII
what kinds of things can cause loss of smell?
smoking, chronic sinus dz, head trauma, aging, PD, use of cocaine
CN I lesion is what side?
ipsilateral
lesions to the optic n. anterior to chasm cause what sided blindness?
ipsilateral
What are the nerves (afferent and efferent) involved in the pupillary light reflex?
CN II and (efferent) CN III
what nerve is responsible for the consensual light reflex?
CN III (efferent to opposite eye)
What is opticokinetic nystagmus?
normal physiologic response to fixating on a moving target
what can asymmetric loss of opticokinetic nystagmus be due to?
frontal or parietal lesion on side to which target is moving to
If there is a lesion of CN III what can present?
ptosis, pupillar dilation or asymmetry, position change of eye “down and out”
what is involved in a near reaction?
pupils constrict, eyes converge, and accommodation occur (thickens lens)
what kinds of things can lead to compressive brainstem lesions effecting CN III?
hematomas, large strokes, abscesses, tumors, space occupying or expanding masses, aneurysms
diabetes mellitus can present with in regards to eye?
extraocular m. weakness but often spares the pupilloconstrictor fibers
why is CN IV particularly susceptible to trauma?
long course around brainstem
what can lesions of CN IV result in?
extorsion (eye drifts laterally), weakness of downward gaze, VERTICAL diplopia (increases when looking down), ** Head tilting** to side opposite of lesion (can be misdiagnosed as idiopathic torticollis
what CN is the most common isolated CN palsy? due to?
CN VI, due to its long peripheral course
what pts often have a CN VI lesion?
subarachnoid hemorrhage, late syphilis and trauma
what do pts with CN VI lesion present with?
convergent (medial) strabismus (estropia)- inability to ABDUCT eye
HORIZONTAL diplopia
pts with CN V lesions present with?
decreased sensation of face and mucus membranes, loss of corneal reflex, weakness of m. of mastication, jaw deviation (toward weak side- due to unopposed action of the opposite lateral pterygoid m.)
What nerves are involved in corneal reflex?
afferent- CN V
efferent- CN VII
what is CN VII involved in?
motor- face expression
sensory- taste to anterior 2/3 of tongue
parasympathetic- secretion of saliva and tears
general sensation- external ear
what do lesions of CN VII result in?
paralysis of the m. of facial expression= Bell’s palsy
loss of corneal reflex
hyperacusis
crocodile tears syndrome- tears with chewing
What can cause bilateral facial palsies?
miller-fisher variant of Guillian-Barre Syndrome
how does supra nuclear (central) facial palsy? why important?
upper face spared and lower face palsy, associated with hemiplegia; important in determining weakness is central or peripheral
what are the 2 tests for the hearing division of CN VIII?
Weber and Rinne tests
what can lesions in the vestibular division of CN VIII result in?
dysequilibrium and -nystagmus
What can destructive lesions of the cochlear division of CNVIII lead to? example?
sensorineural hearing loss; acoustic neuroma
what can irritative lesions cause? example?
tinnitus; medications (aspirin, some antibiotics, etc.)
what does weber test for?
lateralization
(this is more for knowledge outside this lecture but it
how does Weber result if there is conductive hearing loss?
sound lateralizes to impaired ear; seen with occlusion of ear
how does Weber result if there is sensorineural hearing loss?
sound lateralizes to good ear
what is the Rinne test used to compare? what is normal?
air to bone conduction; AC>BC
how is the Rinne test done?
virbrating fork put on mastoid and then near ear canal (with U facing forward)
what is the result of the Rinne test in conductive hearing loss?
BC>AC, negative test
what is the result of the Rinne test in sensorineural hearing loss?
AC>BC; positive test
– because both AC and BC are diminished keeping ratios the same
What does CN IX do?
motor- stylopharyngeus m.
sensory- taste to posterior 1/3 of tongue, sensation to palate and pharynx, skin of ext. ear & afferent of gag reflex
what does the gag reflex?
CN IX and X
lesions of CN IX present as?
loss of gag reflex, sensation in pharynx and posterior 1/3 of tongue, slight dysphagia
what does the lesions of CN X present as?
dysphonia, dysphagia, dyspnea, loss of gag or cough reflex
what does the cranial division of CN XI innervate?
innervation of the m. of larynx except the Cricothyroid m.
what does the spinal division of CN XI innervate?
innervates trapezius (with contributions from C2) and sternocleidomastoid (with contribution from C3 and C4)
what direction does the left SCM turn the head?
right
what does a CN XI lesion result in?
ipsilateral shoulder droop
what does hypoglossal n innervate?
all intrinsic and extrinsic tongue muscles except palatoglossus (CN X)
how do you test the hypoglossal n?
have pt protrude tongue into opposite cheek.
what does a CN XII lesion result in?
deviation to the weak side “lick your wounds”
what is dysarthria?
slurred speech
what is dysphagia?
partial or complete impairment of ability to communicate
what is aphasia?
inability to get words out or understand what is being said
what do you do to assess the motor system?
inspetion, m. tone, involuntary movement, m. power, body position
what does a m. strength grade of 0/5 mean?
no m. contraction detected
what does a m. strength grade of 1/5 mean?
evidence of contraction, no joint movement
what does a m. strength grade of 2/5 mean?
active movement with gravity eliminated
what does a m. strength grade of 3/5 mean?
complete ROM against gravity
what does a m. strength grade of 4/5 mean?
complete ROM against gravity with some resistance
what does a m. strength grade of 5/5 mean?
complete ROM against gravity with full resistance
what m. and n. control shoulder abduction, flexion, and extension?
deltoid-C5
what nerves control elbow flexion? and extension?
flex- C5, C6
extension-C6, C7, C8
what nerves control wrist flexion and extension?
C6 and C7
what n. do hand grip?
C7, C8, T1
what n. are involved in finger abduction?
C8, T1
what n. are involved in opposition of the thumb?
C8, T1
what m. and n control hip flexion?
psoas and iliacus- L2, 3, 4
what m. and n. control hip extension?
gluteus maximus- S1
what n. control hip adduction?
L2, 3, 4
what n. control hip abduction
L4, 5, S1
what m. and n. control knee flexion?
hamstrings- L4, L5, S1, S2
what m. and n. control knee extension?
quadriceps- L2, L3, L4
what m. and n. control plantar flexion of the ankle?
gastrocnemius- S1
what m. and n. control dorsiflexion of the ankle?
primarily tibialis anterior- L4, L5
sensory dermatome for the shoulder?
C4
sensory dermatome for the radial aspect forearm and thumb?
C6
sensory dermatome for the little finger?
C8
sensory dermatome for the little toe?
S1
sensory dermatome for the hallucis?
L5
sensory dermatome for the nipple?
T4
sensory dermatome for the umbilicus?
T10
what kinds of changes in m. tone and reflexes occurs when there is UMN injury? what is the pattern of weakness?
hypertonia, hyperreflexia;
pyramidal pattern of weakness-weak extensors in arms and weak flexors in legs
how do you test for an UMN injury?
pronator drift- arms held extended for up to 2 mins, arms drift down and supinate
what kinds of changes in m. tone and reflexes occurs when there is LMN injury? what is the pattern of weakness?
hypotonia, hyporeflexia;
peripheral pattern of weakness- weak flexors in arms, weak extensors in legs
what happens at NMJ in LMN injury?
fatigable weakness
what 4 things can be tested for the sensory system?
pinprick and temp
proprioception, 2pt tactile discrimination and vibratory
light touch
discriminative sensations
what tract does pain and temp travel in?
spinothalamic tract
what tract does proprioception, 2 pt tactile discrimination and vibratory travel in?
posterior columns
what are the 4 discriminative (cortical) sensations?
sterognosis, graphesthesia, 2 pt discrimination, double simultaneous stimulation (extension)
what is sterognosis?
ability to ID objects or recognize objects placed in the hand
what is graphesthesia?
ability to ID numbers written on the palm
what is the scale that DTRs are rated on?
0-4
what is a normal DTR?
2/4
what does a DTR of 4/4 mean?
hyperactive with clonus
what does a hyperactive reflex indicate?
lesion of CNS
what does a hypoactive reflexes indicate?
lesion of PNS
what does a DTR of 3/4 mean?
brisk, spread to involve movement across more than one joint
what n. is tested with DTR of biceps?
C5*, (6)
what n. is tested with DTR of triceps?
(C6,) 7*
what n. is tested with DTR of brachioradialis?
(C5,) C6*
what n. is tested with DTR of patella?
(L2, 3) L4*
what n. is tested with DTR of achilles?
S1*
what does a Babinski’s sign indicate?
critical sign of UMN dysfxn
how do you test for a Babinski’s sign?
scratch foot from heel to toe and across transverse arch
what is a positive Babinski’s?
great toe extends and remainder spread
what does clonus indicate? what is it?
UMN sign, abnormal pattern of NM activity characterized by rapidly alternating involuntary contraction and relaxation of skeletal m.
what kind of reflexes are frontal lobe release reflexes?
rooting, grasping, glabellar, and palmo-mental
what 3 reflexes are superficial tendon reflexes? describe?
abdominal reflex- test for all 4 quadrants, stroking abdomen, umbilicus moves toward area of stimulation
cremasteric reflex- afferent L1, efferent L2, scrotum rises on side of stroking
anal wink reflex- cauda equina or sacral lesions
what 4 systems are involved in coordination?
motor, vestibular, sensory, and cerebellar***
what kinds of tests can be done for cerebellar testing?
finger to nose, heel to shin, rapid alternating movement, saccades
what is heel walking sensitive for testing?
corticospinal tract lesions or distal m. weakness
romberg test tests for what?
proprioception (sensory test)
how is the romberg test performed?
pt stands in front of examiner with back, pt feet together and arms outstretched, pt closes eyes, pt should maintain balance
what part of walking is pathognomic for parkinson’s dz?
en bloc turns: taking 5-6+ steps to turn around
what kind of gait is scissoring? often seen with?
not Liz or Kenna’s, but with feet crossing and toes dragged over; CP or MS
sensory ataxia can indicate what? what does it look like?
posterior column damage and peripheral neuropathy; high stoppage, broad based gait
magnetic gait looks like? indicative of?
small steps, feet on ground; frontal lobe processes and hydrocephalus
Astasia-abasia gait is what?
psychogenic
what kinds of abnormal gaits are asymmetrical?
hemiplegic, waddling pelvis, foot drop
what does does a resting (pill rolling) tremor indicate?
basal ganglia disease (parkinson’s)
what are the 2 meningitic signs and how do you do them?
Kernig’s- flex thigh then straighten leg, pt will experience pain in neck
Brudzinski’s- doc lifts pt head, pt lifts knees in response
what are the 2 coma postures and what do they look like?
Decorticate- arms flexed and legs extended
Decerebrate- arms and legs extended
