Lec 14

Question 1

What is a VEMP

what two pathways does it influence

what part of vest syst does it affect

why it affect some parts and not others

Answer 1

vestibular evoked myogenic potential

vestibulo-occular reflex
vestibulocohclear reflex

short bursts of sound affect via headphones create muscular reflex (e.g. eyes and soleus) contralateral eye reflex (from ear that heard it) and ipsilateral lower body reflex.

affect otolith organs (ut and sacc)

because ut and sacc are closer to cochlea that senses sound

Question 2

diff between periph and central vest lesions

Answer 2

per - dmg to labyrynths or vestibulo-occular nerve (VIII)

central - dmg to vestibular nuclei or cerebellum

Question 3

symptoms of unilateral vestibular lesions

Answer 3

• vertigo (not just being dizzy, earth has to actually be spinning)
• nausea
• postural instability

Question 4

what causes nausea regarding vestibular syst

Answer 4

mismatch between what you see and what vest syst senses (e..g car sickness)

vestibular autonomic connections ????

Question 5

what are some tests for postural instability

Answer 5

Rhomberg test - stand eyes closed, observe swaying - suggests sensory ataxia (not getting reliable proprio info

Fukuda test - stand feet together, eyes closed, march on spot. Patient start to turn/rotate = lesion to the side they turn towards

dynamic posturography - test reflexes on moving platform

Question 6

what VOR

Answer 6

vestibulo ocular reflex helps you look at moving targ.

eyes stay fixed on point while head moves actively or passively.e

Question 7

causes of unilateral ves lesions

Answer 7

• Tumours pressing against (CN VIII) Vestibulo-cochlear nerve.
• vestibular neuritis inflamation or infection of vest coch nerve
• surgery (intentional or not)