Exam 2: Vestibular Examination Flashcards
What are the four main vestibular diagnoses?
- BPPV
- Unilateral hypofunction
- Bilateral hypofunction
- Central
What is the definition of VOR?
Maintains stability of an image on the fovea of the retina during rapid head movements
What direction do the eyes and head move during VOR?
Eyes will more the opposite of the head
What is the definition of VOR Gain?
Relationship of eye velocity to head velocity – head and eyes move in opposite directions are equal speeds
What is the definition of VOR Phase?
Relationship of amplitude between the eyes and head – equal
What value is considered a healthy VOR Phase?
0 Phase Shift
What is the Inhibitory Cut-Off?
Inhibition can only be recorded to a firing rate of 0
Describe an intact inhibitory cut-off
When you turn your head quickly to the right, the right vestibular system is responsible for detecting the change
Describe an impaired inhibitory cut-off
When you turn your head quickly to the right, the right side vestibular system is not able to excite to the capacity it needs to
The opposite side cannot help because it is inhibited at 0 spikes/second
What is the definition of UVH?
One vestibular apparatus is hypofunctioning with a low tonic firing rate
What are common diagnoses that can lead to UVH?
Vestibular neuritis, labyrinthitis, Meniere’s, Perilymph Fistula, Vestibular Schwannoma/Acoustic Neuroma, chronic BPPV
What percentage of people will experience a fall since the onset of UVH?
30%
What are the two possible vestibular dysfunction that can result from an infection?
Vestibular neuritis or labyrinthitis
What is vestibular neuritis?
Inflammation of the vestibular part of the nerve that results in vertigo only
What is vestibular labyrinthitis?
Inflammation of both branches of CN VIII that results in vertigo and hearing loss
Differentiate between the symptoms of vestibular neuritis and labyrinthitis
Neuritis only results in vertigo while labyrinthitis results in vertigo and hearing loss
What is Meniere’s Disease?
Abnormal fluctuations in endolymphatic fluid
What population is more likely to develop Meniere’s?
Females between 40-60
How long does a Meniere’s flare up last?
2-4 hours
What are symptoms of Meniere’s?
Low frequency hearing loss, episodic vertigo, sense of fullness in ears, tinnitus, nausea and vomitting
Is is recommended to perform vestibular rehab during a Meniere’s flare up?
No – it is contraindicated
What can result from chronic Meniere’s Disease?
UVH, will require rehab
What is the treatment for Meniere’s Disease?
Balance fluids by reducing fluid buildup, reduced sodium diet, avoid caffeine, alcohol, and smoking, surgical intervention
What is a Perilymph Fistula?
Rupture of the oval or round window that separates the middle from the inner ear
What can cause a Perilymph Fistula?
Excessive pressure changes, blunt head trauma, extremely loud noises
What is the pathophysiology associated with a Perilymph Fistula?
Perilymph fluid leaks into the middle ear
What are symptoms associated with a Perilymph Fistula?
Vertigo and hearing loss
What is the treatment for a Perilymph Fistula?
Rest, surgical repair, followed by vestibular rehab
Should you perform vestibular rehab for a Perilymph Fistula prior to surgical repair?
No
What is a Vestibular Schwannoma
Benign tumor of the Schwann cells that compresses CN VIII
What other nerve can be implicated with a Vestibular Schwannoma?
CN VII
What symptoms are associated with a Vestibular Schwannoma?
Unilateral hearing loss, tinnitus, vertigo
What is the treatment for a Vestibular Schwannoma?
Surgical excision followed by vestibular rehab
What are the acute symptoms associated with UVH?
Vertigo, nausea, spontaneous nystagmus, oscillopsia, disequilibrium, gait, posture
What timeframe is considered acute in relation to UVH symptoms?
Two weeks
What are sub-acute and chronic symptoms of UVH?
Gait instability, oscillopsia, head movement induced symptoms
What symptoms should have resolved as UVH progresses to a more chronic presentation?
Reduction of nystagmus and nausea due to the spontaneous rebalancing of the resting tonic firing rate
What direction is oscillopsia in?
Vertical
What is the cause of spontaneous nystagmus?
Brain stem is receiving greater afferent input from the intact labyrinth so it responds by generating nystagmus that the patient then interprets as vertigo
How is nystagmus named?
By the fast phase
If the fast phase of spontaneous nystagmus is directed left, which is the “good” and “bad” side?
Good side = left
Bad side = right
What is BVH?
Reduced of absent function of both peripheral vestibular sensory organs and/or nerves
What are common diagnoses that can lead to BVH?
Idiopathic, ototoxicity, meningitis, autoimmune disorders, bilateral Meniere’s, vestibular neuritis, neurotoxicity from cancer treatment, TIA of blood vessels, bilateral Schwannoma
How can ototoxicity lead to BHV?
Certain classes of antibiotics are gradually taken up by the hair cells and continue to build in the system rendering the cells unable to respond accurately to head movement
What are the two main types of drugs that can lead to ototoxicity?
Aminoglycosides, chemotherapy
What symptoms are associated with BVH?
Imbalance, gait ataxia, oscillopsia that causes decreased visual acuity with head movement, difficulty walking in the dark and on uneven surfaces
What percentage of people will fall since their onset of BVH?
50%
Are people more likely to fall with UVH or BVH?
BVH (50%) > UVH (30%)
Will patients have vertigo or nystagmus with a diagnosis of BVH?
No because both sides are affected, so there is no imbalance to cause the symptoms
What is Central Vestibular Dysfunction?
Pathology of the vestibular system proximal to the vestibular nuclei that begins in the brainstem and connects to the reticular formation, thalamaus, cerebellum, and cortex
What are common diagnoses associated with Central Vestibular Dysfunction?
AICA and PICA stroke, TBI or concussion, MS, Multiple System Atrophy, cerebellar pathology, migraine related dizziness, brain tumor