Cranial Nerves Flashcards
How do you tests the olfactory nerve?
-Sense of smell in each nostril (close one nostril at a time
-Pt is blindfolded or closes their eyes
-Utilize familiar scent
What are abnormal findings when olfactory nerve?
-Anosmia – inability to select smells
How do you test the optic nerve?
-Visual acuity test with Snellen eye chart
-Visual field testing: Test temporal and vertical peripheral vison
How do you test the oculomotor nerve?
Shine light into eye — pupil constriction
-Eye accommodates to light
-Pupils move medial when viewing object at close range
What are abnormal findings when testing oculomotor nerve?
-Absence of pupillary constriction
-Lateral strabismus (exotropia)
-Anisocoria (unequal pupils)
-Horner’s Syndrome, CN III paralysis (ptosis)
How do you test oculomotor, trochlear, and abducens nerve?
-Test saccadic movements: ask Pt to look up, down, medial, and lateral
-Test purist eye movements: ask Pt to follow moving finger
-Test one eye at a time: other eye occluded
What are the abnormal findings when testing the oculomotor, trochlear, and abducens nerve?
-Lateral strabismus: eyeball turns lateral; can cause diplopia or nystagmus
-Impaired eye movements
-Ptosis
-Medial strabismus: eyeball turns inward; can cause diplopia or nystagmus
How do you test the trigeminal nerve V1 the opthalmic division?
-Test pain
-Light touch sensation
-Forehead, cheeks, inner oral cavity (occlude vision)
What are the abnormal findings when testing the trigeminal nerve V1 the opthalmic division?
Loss of facial sensation —– numbness with CN V lesion
Trigger area with trigeminal nerve
How do you test the trigeminal nerve V2 the maxillary division?
Test cornea reflex — Touch lightly with the wisp of a cotton
What are the abnormal findings when testing the trigeminal nerve V2 the maxillary division?
Loss of corneal reflex ipsilaterally (blinking in response to corneal touch)
How do you test the trigeminal nerve V3 the mandibular division?
-Palpate temporal and masseter muscle
-Observe spontaneous movements
-Have Pt open mouth, move jaw side to side, bite down on tongue dispenser, hold against resistance
What are the abnormal findings when testing the trigeminal nerve V3 the mandibular division?
-Weakness, wasting or muscle
-When opened, deviation of jaw to ipsilateral side
-Asymmetry of jaw
-Asymmetry of jaw strength
How do you test the facial nerve motor devision?
Test strength and symmetry of facial muscles: have patient elevate eyebrows and forehead, smile, frown, and pucker lips, close eyes tightly, puff out both cheeks
What are abnormal finding when testing the facial nerve motor devision?
-Paralysis
-Inability to close eye drooping corner of moth, difficulty with speech articulation
-Unilateral LMN: Bell’s Palsy (PN)
-Bilateral LMN: Guillain – Barré
-Unilateral UMN: stroke
How do you test the facial nerve sensory devision?
Apply salty, sweet, and sour solution to outer and lateral portions of anterior tongue using a cotton swab (occlude vision)
What are abnormal finding when testing the facial nerve sensory devision?
Incorrectly identifies solution decreased taste
How do you test the vestibulochoclear nerve (vestibular function)?
Test balance and protective functions: vestibulospinal function (VSR)
Test eye-head coordination: vestibular ocular reflex (VOR)
What are abnormal findings when testing the vestibulochoclear nerve (vertibular function)?
-Vertigo, decreased balance, decreases protective responses (disequilibrium)
-Gaze instability with head rotation, nystagmus (constant, involuntary cyclical movement of the eyeball)
How do you test the vestibulochoclear nerve (cochlear function)?
-Test auditory acuity finger rub test
-Weber test for lateralization: place vibrating tuning fork on top of head, mid-position; check if sound heard in one ear or equally in both
-Rinne test: Compares air bone conduction, place vibrating tuning fork on mastoid bone, then close to ear canal; sound head longer through air than bone
What are abnormal findings when testing the vestibulochoclear nerve (cochlear function)?
-Deafness, impaired hearing, tinnitus
-Unilateral conductive loss: sound lateralized to impaired ear sensorineural loss: sound heard in good ear
-Conductive loss: sound heard through bone is equal to or longer than air
-Sensorineural loss: sound head longer than air
How do you test the function for the glossopharyngeal nerve (sensory funtion)?
Apply sweet, salty, and sour solutions to posterior tongue
What are the abnormal finding when testing the glospharyngeal nerve (sensory function)?
Incorrectly identifies solution — loss of taste on posterior tongue
How do you test the glosopharyngeal and vagus nerve (phonation)?
Listen to voice quality
What are the abnormal finding when testing glosopharyngeal and vagus nerve (phonation)?
Dysphonia: Hoarse voice; denotes vocal cord weakness, nasal quality denotes palatal weakness
How do you test the glosopharyngeal and vagus nerve (swallowing)?
Examine for difficulty in swallowing: glass of water, different consistence of food
What are the abnormal finding when testing glosopharyngeal and vagus nerve (swallowing)?
Dysphagia: Difficulty swallowing; loss of swallowing reflexes
How do you test the glosopharyngeal and vagus nerve (Palatal, pharynx control)?
Have patient day “ah”, observe motion of soft palate (elevates) and position of uvula (remains midline)
What are the abnormal finding when testing glosopharyngeal and vagus nerve (Palatal, pharynx control)?
-Dysarthria: difficulty articulating words clearly, slurs words
-Palate fails to elevate, (lesion of CN X); asymmetrical elevation with unilateral paralysis
How do you test the glosopharyngeal and vagus nerve (gag reflex)?
Stimulate back of throat lightly on each side
What are the abnormal finding when testing glosopharyngeal and vagus nerve (gag reflex)?
Loss of gag reflex lesion of CN IX; possibly CN
How do you test the spinal accessory nerve (motor function, spinal nerve, trap muscle)?
-Examine bulk strength
-In sitting, ask pt to elevate shoulders upward against resistance applied in direction of depression
What are the abnormal findings when testing the spinal accessory nerve (motor function, spinal nerve, trap muscle)?
LMN: atrophy, fasciculations, weakness
-Weakness, inability to approximate the acromion and the occiput
How do you test the spinal accessory nerve (SCM)?
In supine, ask patient to flex head anterolaterally and rotate head to opposite side; resistance is applied in an obliquely posterior direction
What are the abnormal findings when testing the spinal accessory nerve (SCM)?
Weakness, inability to flex head laterally and forward, rotate head contralateral side
How do you test the spinal accessory nerve (cranial nerve root)?
Examine laryngeal elevation by placing index and middle finger over Pt’s Adams apple (laryngeal muscles); ask pt to swallow
What are the abnormal findings when testing the spinal accessory nerve (cranial nerve root)?
Dysphagia due to decreased laryngeal elevation
How do you test the hypoglossal nerve?
-Listen to Pt articulation
-Examine resting position tongue
-Ask patient to protrude tongue, move tongue side to side
What are the abnormal findings when testing the hypoglossal nerve?
-Dysarthria (seen with lesion of CN X and CN XII, also V, VII)
-Atrophy or fasciculations of tongue (LMN, ALS)
-Impaired movements with deviation of tongue to weak side
-UMN lesion: tongue deviates away from weak side of cortical lesion
-Check for tongue movement tremors or involuntary tongue movements
