Peripheral Vestibular Disorders Pt.2

Question 1

what is an acoustic neuroma?

Answer 1

slow-growing tumor derived from Schwann cells of the vestibulocochlear nerve or internal auditory canal

Question 2

describe the clinical presentation of an acoustic neuroma

Answer 2

1. Gradual or sudden onset of tinnitus, hearing loss, vertigo or disequilibrium
   
   • hearing loss, tinnitus most common 1st symptom
   • balance, vertigo, disequilbirum (~50%)
2. Symptoms tend to depend on location of tumor
   
   • small tumor → hearing may be preserved, pt may be asymptomatic
   • as it grow, it can compress CN V or VII
   • can cause pressure on brainstem or cerebellum if large enough

Question 3

how is an acoustic neuroma diagnosed?

Answer 3

1. MRI w/contrast - gold standard
2. Audiogram

Question 4

What are some interventions for acoustic neuroma?

Answer 4

1. Surgical removal
2. Radiation
3. Monitoring (depening on size/location)
4. Vestibular rehab only once tumor has been fully resected

Question 5

what is a perilymph fistula?

Answer 5

an opening in between middle and inner ear that is caused by rupture of the oval window resulting in perilymph leaking into middle ear

Question 6

what are typical causes of perilymph fistula?

Answer 6

most commonly associated with head trauma

• usually trauma involves direct blow to the ear
• other causes:
  
  • ear trauma
  • objects perforating ear drum
  • rapid increases in ICP (weighlifting, childbirth)

Question 7

describe the clinical presentation of perilymph fistula

Answer 7

1. sudden onset of:
   
   • vertigo
   • motion intolerance
   • ear fullness
   • fluctuating hearing
   • severe HA, N/V can also occur
2. Symptoms worsen w/activity but improve w/rest
3. Tulio’s phenomenon

Question 8

what types of things worsen symptoms of perilymph fisutla?

Answer 8

changes in altitude

valsalva-eliciting activities

Question 9

what is Tulio’s phenomenon?

Answer 9

use of one’s own voice or musical instrument will cause dizziness

Question 10

how is perilymph fistula diagnosed?

Answer 10

A confident dx is difficult

1. Fistula test
   
   • pressurizing test while recording eye movements
2. Valsalva test
   
   1. pt holds breath while recording eyes
3. Audiogram → helps determine involved side
4. ENG/VNG
5. MRI (rule out CNS)

Question 11

List some intervention strategies for perilymph fistulas

Answer 11

1. Smaller fistulas → conservative management
   
   • rest
   • avoid lifting or any activity that would increase ICP
   • if pt can take it easy, most cases resolve on their own
2. Surgical repair
   
   • exploratory tympanotomy
   • vestibular nerve section
3. Vestibular Rehab post-surgical repair often warranted

Question 12

what is SCC Dehiscence?

Answer 12

the bony labyrinth that surrounds the membranous labyrinth of our canals degrades over time

fistual due to lack of temporal bone covering of superior SCC

Question 13

which canal is most common affected by SCC dehiscence?

Answer 13

superior/anterior canal

(aka SCDS)

Question 14

what is the incidence of SCC dehiscence?

Answer 14

1. middle age disorder
2. up to 60% can report premorbid trauma that shifted symptoms
3. 25% bilateral

Question 15

describe the clinical presentation of SCC dehiscence

Answer 15

1. Transient vertigo precipitated by coughing, loud noises and pressure changes in ear
2. Pressure sensitivity
   
   • sneezing, coughing, Valsalva, lifting, bowel movement
3. Sound sensitivity
   
   • Internal → heel strike w/gait, eye movement, hear beat, own voice
   • External
4. Imbalance
   
   • may be constant
   • accentuated w/head movement, dark environment
5. Hearing loss, tinnitus, aural fullness

Question 16

how is SCC dehiscence diagnosed?

Answer 16

1. Bedside eval
   
   • Test for Tulio’s phenomena
   • Valsalva test
   • Bone conduction sensitivity test
     
     • tuning fork on lateral malleoli (+test = pt hears sound in inner ear)
2. Radiographic imagining (CT scan)
3. Audiogram

Question 17

What are some intervention options for SCC Dehiscence?

Answer 17

Will not benefit from rehab

1. Conservative
   
   • avoid offending stimuli
     
     • noise (earplug)
     • exertion
2. Surgery
   
   • canal “plugging”
   • resurfacing surgery
3. Rehab possibly after surgery

Question 18

what causes bilateral vestibular hypofunction?

Answer 18

1. Idiopathic in 50% of cases
2. Typically caused by otoxic agents
3. Other etiologies include:
   
   • autoimmune inner ear disease
   • chemo agent → Cisplatin
   • sequential vestibular neuritis
   • meniere’s disease
   • meningitis
   • neurodegenerative conditions

Question 19

describe the clincial presentation for bilateral vestibular hypofunction

Answer 19

1. primary complian → severe oscilopsia
   
   • particulary during walking (imbalance, possibly due to hearing loss)
2. Vertigo only if loss is sequential in nature
3. functional tasks become inefficient and exhausting

Question 20

how is bilateral vestibular hypofunction diagnosed?

Answer 20

1. Clinical exam
   
   • +HIT (bilaterally)
   • +Dynamic Visual Acuity
   • +Caloric testing
2. Rotary chair test - gold standard

Question 21

List some interventions for bilateral vestibular hypofunction

Answer 21

1. Medical management
   
   • meds typically not helpful
   • vestibular suppressant meds typically worsen symptoms
2. no surgical intervention available to restore vestibular function
3. Vestibular rehab

Question 22

what is the impact of vestibular rehab on bilateral vestibular hypofunction?

Answer 22

1. improvement in postural control and gaze stability w/predictable > unpredictable head movements noted
2. sig functional improvements noted by pts
   
   • however, typically w/residual impairment
     
     • difficulty driving due to oscillopsia, especially at night
     • imbalance w/moving about in dark environment