Vestibular Disorders

Question 1

Vertigo

Answer 1

Illusion of mvmt

Question 2

Questions to ask a pt who p/w vertigo

Answer 2

Duration?
Periodicity?
Circumstance?
Other neuro S/Sx?
Hearing loss?

Question 3

Central compensation for vestibular injury

Answer 3

Occurs via CBL
A “clamping” response to the injured vestibular system to reduce the effects of the abnl vestib signal
Enhanced by vestibular activity
Delayed by prolonged use of medical vestibular suppression

Question 4

3 strategies of vestibular rehab programs

Answer 4

1. Habituation exercises (facilitate central compensation by extinguishing pathologic responses to head motion)
2. Postural control exercises
3. General conditioning exercises

Question 5

Steps in a Vestibular Evaluation

Answer 5

1. H&N exam incl CN
2. Spontaneous and gaze-evoked nystagmus w/ Frenzel glasses
3. Smooth pursuit (“follow my finger”)
4. Saccades (“look to R and L”)
5. Head thrust
6. Headshake (“10 deg, 2 cycles/sec, 20 sec”)
7. Dynamic visual acuity (“Look at Schnell chart with head shake”)
8. Fixation suppression (“Look at your thumb during rotation”)
9. Positional testing - Dix-Hallpike
10. CBL (F-to-N, RAM, H-to-S)
11. Posture (Romberg)

Question 6

Spontaneous and gaze-evoked nystagmus with Frenzel glasses

Answer 6

Direction: fixed-periph, changing-central
Form: jerk-periph, pendular-central
Fixation: suppresion-periph, enhanced-central

Question 7

Saccades

Answer 7

Dysmetric: CBL
Slow: Brainstem
Late: Frontal lobe
Disconjugate: MS

Question 8

Head thrust

Answer 8

Nl: no refixation saccade
Abnl: refixation saccade (peripheral)

Question 9

Head shake (10 deg, 2 cycles/sec, 20 sec)

Answer 9

Nl: no nystagmus
Abnl: horizontal nystag - periph; vertical-central

Question 10

Dynamic visual activity (look at schnell chart and head shake)

Answer 10

Nl: < 3 line drop
Abnl: 3 or more line drop- b/l vestib loss

Question 11

Fixation suppression (look at thumb during rotation)

Answer 11

Nl: no nystagmus
Abnl: nystagmus-central (flocculus)

Question 12

Positional testing - Dix Hallpike

Answer 12

Nl: no nystagmus
Abnl: downbeating, fatigable, rotatory nystagmus

Question 13

BPPV (Benign Paroxysmal Positional Vertigo)

Answer 13

Canal has debris either attached to cupula or free floating
M/C in PSCC
Sudden, short (10-20 sec), positional
Dx: Dix-hallpike (latent nystagmus, mixed w/ a torsional and vertical component; is geotropic - down-beating & rotatory; fatigable)
Tx: Epley maneuver (reposition debris into utricle)

Question 14

What if a BPPV pt does not respond to Tx

Answer 14

1. Get an MRI w/ gad to r/o brainstem, CPA, IAC lesions

2. Consider PSCC occlusion (with muscle, fascia, or bone pate or collapse w/ laser) or ablating the nerve to the PSCC