neuro exam II Flashcards
How do you do the corneal reflex test? What does it test?
touch cornea w a wisp of cotton and look for direct and consensual eye blink. tests CNV and CNVII. Afferent (sense) from CNV (opthalmic division), and efferent info from CNVII
What division of CNV innervates the muscles of mastication?
V3: mandeibular division
What is seen in a LMN lesion of the facial nerve? Example?
LMN lesion: ipsilateral weakness to the entire half of the face
aka Bell’s Palsy
What is seen in an UMN lesion of the facial nerve?
contralateral weakness that involves only the lower half of the face. may be due to lesions to motor cortex or to the corticobulbar tract.This is because upper faces gets bilateral coritcal innervation.
What nerve branch provides taste to anterior 2/3 of tongue?
chorda tympani of CNVII
What are the two forms of hearing loss and how do you differentiate between them?
conductive hearing loss: lesion to outer or middle ear; can’t voncert air conduction into bone conduction.
Sensorineural hering: lesion involving the inner ear or CNVIII.
differentiate with Rinne test and Weber test
Rinne test: how do you perform? How do you interpret results?
place 512 vibrating fork on mastoid process until sound isn’t heard anymore. then, move to the external ear- pt should be able to hear because air conduction normall better than bone conduction. if the sound is not longer heard, suspect conductive hearing loss
Weber test: how do you perform? How do you interpret results?
512 tuning fork placed at the vertex of the skull. ask pt to localize the sound. should be heard equally in both ears. sound localized to the “bad ear” in conductive hearing loss; goes to the “good ear in sensori-neural hearing loss
What is the Nylen-Barany maneuver?
test for labyrinthine stimulation . quickly move from sitting to supine position w head positioned 45 degrees below the plane of the table and turned to one side. maintain for 1 minute and observe for nystagmus. repeat test w/ head turned to the other side. vestibular function may be present if pt reports vertigo or nystagmus develops
What is caloric testing?
method for stimulating the labryinth. hot or cold water put in the external auditory meatus. Watch pt for devo of nystagmus. irrigate both ears sequentially. degree of nystagmus following irrigation is compared
What are some key differences btw the nystagmus and vertigo that result from a central lesion vs. a lesion of the vestibular apparatus with the Nylen-Barany test? What about with the caloric test?
Cenral lesions cause faster development of nystagmus, it lasts longer, and it isn’t fatiguable. Vertigo intesity is only slight (vs. intense for peripheral lesions), and both head positions elicit vertigo. You see hyperactive (vs. no) responses to the caloric test in cases of central lesions.
Gag reflex: which nerve carries afferents, and which efferents?
afferents: IX (glossopharyngeal)
efferents (X: vagus)
What muscles are innervated by CNXI? relevant facts for testing CNXI?
sternocleidomastoid and upper third of trapezius
contraction of left SCM allows for turning the head to the right
Interpretation of CNXII exam?
Lesion of the hypoclossal nerve will cause atrophy to the IPSILATERAL side. tongue will deviate TOWARD the side of the lesion.
What nerves are tested with the jaw jerk reflex?
V is both afferent and efferent. this is basically a stretch reflex of the masseter muscle
