Evaluation of Vestibular System Flashcards
What are the structures for hearing and balance?
- Cochlea
- Semicircular Canals
- 8th Nerve
For vestibular dysfunction, what are the common concerns?
- Disequilibrium & Vertigo
- Can be acute/chronic
- Ranges from mild-severe
- Most recover spontaneously
For Vestibular Dysfunction, who’s at a greater risk?
Elders
What causes of Vestibular Dysfunction should an audiologist care about? and what of vestibular dysfunction are they?
- Meniere’s Disease
- Perilymph Fistula
- Vestibular Neuritis
- Benign Paroxysmal Positional Vertigo
They are Peripheral Vestibular Dysfunction
What are the symptoms for Meniere’s Disease?
- Fluctuating low frequency SNHL
- Typical unilateral
- Roaring (low frequency sound) tinnitus
What is the cause for Meniere’s disease?
An increase in endolymphatic fluid pressure
What are the symptoms for Vestibular Neuritis?
- Sudden onset of vertigo
- Nausea
- Vomiting
- Usually w/o auditory symptoms
What is the cause for Vestibular Neuritis?
Thought to be a viral infection of vestibular portion of VIIIth nerve
What are the symptoms for Perilymph Fistula?
- Fluctuating and typically unilateral but not limited to low frequencies
- Tinnitus
- Vertigo
What causes Perilymph Fistula and what is?
a. It’s caused by abnormal communication between ME and IE
b. It’s essentially an extra opening in the cochlea
Why can a Perilymph Fistula occur?
- Trauma
- Surgery
- Congenital Anomalies
What’s the main different between Perilymph Fistula & Meniere’s Disease?
Meniere’s Disease only pertains to low frequencies while Perilymph Fistula does not
For BPPV, what are most cases?
Idiopathic
What is the most frequent cause of vertigo?
BPPV
What test do we use to assess the Peripheral Vestibular Dysfunctions?
Nystagmus
What is Nystagmus?
It’s a rocking motion of the eyes
When does nystagmus occur?
Always with true vertigo
Can nystagmus occur spontaneously? What is it called?
Yes, Congenital Nystagmus
For the many tests used for vestibular function to look at nystagmus, what do we analyze?
- Presence
- Degree
- Type in comparison to norms
For Nystagmus, which assessment is commonly used?
Electronystagmography (ENG)
For Nystagmus, what is VNG or ENG?
It analyzes eye movement through an electrical response since our cornea has a positive charge and the retina has a negative charge
For VNG or ENG, what does the difference in the electrical potential tells us?
As our eyes moves the ENG will obtain an objective measurement of nystagmus to determine if the patient really have nystagmus
While we’re doing an ENG or VNG, what are we doing?
A caloric test
What is the purpose of a caloric test?
To get them dizzy and see if they truly have vertigo
For caloric testing, what do you do to make the patient have vertigo?
Irrigate the ear canal with warm or cold water or air to stimulate the vestibular system
For caloric testing, what does irrigate the EAC do?
Stimulate the vestibular system. The warm temperature would stimulate the vestibular system in one way while the cold temperature would stimulate the vestibular system in another way
For caloric testing, what’s the rule for direction of nystagmus?
COWS: Cold opposite, Warm Same
For caloric testing. how can the response be classified?
- Normal
- Absent
- Hyperactive
- Hypoactive
Define Rotary Chair
Mechanized chair that rotates at varying velocity in both clockwise and counterclockwise directions
The purpose of the Rotary Chair is to…?
View nystagmus during movement since we’re trying to make our client have a vertiginous reaction
What two tests does not use nystagmus?
- Computerized Dynamic Posturography
2. Vestibular-Evoked Myogenic Potential (VEMP)
What does the Computerized Dynamic Posturography assess?
- The ability to coordinate movement by measuring vestibulospinal reflexes
What does the Computerized Dynamic Posturography measure?
The patient’s ability to compensate for various disruptions in balance
What is VEMP?
A test that measures the sound-evoked muscular reflex of our sternocleidomastoid muscle by placing electrodes on the sternocleidomastoid muscle
What’s the purpose of the sternocleidomastoid muscle?
Purpose of reflex is thought to stabilize the head in response to unpredictable movements
What causes the sternocleidomastoid muscle to contract?
The saccule, which is responsible for linear acceleration sends a message to this muscle
When we identify that the patient has difficulty, what do we do about it?
- Balance Rehabilitation
- Medical
- Surgical
For medical treatment for Peripheral Vestibular Dysfunction, what are the factors and what do we treat?
- Depends on cause
- Typically provide symptomatic treatment
The medication would treat: Nausea and Vestibular Suppressant
For surgical treatment for Peripheral Vestibular Dysfunction, what are the factors and what do we treat?
- Depends on cause
- Most invasive treatment
- Two types of procedures: Preservation & Ablation
