Neuro16 Flashcards
Common Cranial Nerve Lesions Hearing loss Facial lesions Mastication muscles
Symptoms of CN V motor lesion.
Jaw deviates TOWARD side of lesion
*d/t unopposed force from the opposite pterygoid m.
Symptoms of CN X lesion.
Uvula deviates AWAY from side of lesion.
*weak side collapses and uvula points away
Symptoms of CN IX lesion.
- Weakness turning head to Contralateral side of lesion (SCM)
- Shoulder drrop on side of lesion (trapezius m.)
Which Sternocleidomastoid m. contracts to help head turn to the Right?
Left SCM
Symptoms of CN XII lesion (LMN).
Tongue deviates TOWARD side of lesion (“lick your wounds”)
*d/t weakened tongue muscles on affected side
Conductive hearing loss:
- Rinne Test
- Weber Test
Conductive hearing loss:
- Rinne Test: Abnormal (bone > air)
- Weber Test: Localizes to affected ear
Sensorineural hearing loss:
- Rinne Test
- Weber Test
Sensorineural hearing loss:
- Rinne Test: Normal (air > bone)
- Weber Test: Localizes to unaffected ear
What causes Noise-Induced hearing loss?
Damage to stereocilliated cells in organ of Corti
In Noise-Induced hearing loss, what loss is noticed first?
High-Frequency
Sudden extremely loud noises can produce hearing loss due to what?
Tympanic Membrane Rupture
A lesion of the motor cortex or connection between cortex and facial nucleus results in what?
Contralateral paralysis of Lower face
*Forehead spared d/t bilateral UMN innervation
A LMN facial lesion leads to what?
Ipsilateral paralysis of Upper & Lower face
What causes Facial nerve palsy (aka Bell’s Palsy)?
Complete destruction of facial nucleus itself or its banchial efferent fibers (facial n. proper)
What are the findings in facial nerve palsy?
Peripheral Ipsilateral facial paralysis with inability to close eye on involved side
*can occur idiopathically (Bell’s palsy); gradual recovery in most cases
What muscles are involved in Closing the jaw?
Masseter m.
teMporalis m.
Medial pterygoid m.
“M’s munch”
