Name of the Procedure:

Sinusoidal Vertical Axis Rotational Testing (SVAR)

• Common name: Rotational Chair Testing
• Technical term: Sinusoidal Harmonic Acceleration (SHA)

Summary

Sinusoidal Vertical Axis Rotational Testing (SVAR) is a diagnostic procedure used to evaluate the function of the vestibular system, which is part of the inner ear involved in balance. During the test, the patient sits in a chair that rotates at varying speeds, allowing specialists to assess eye movements in response to the motion.

Purpose

SVAR is used to diagnose and assess balance disorders and dizziness. The primary goals are to identify abnormalities in the vestibular system and to determine the cause of vertigo or balance issues, aiding in effective treatment planning.

Indications

• Persistent dizziness or vertigo
• Unsteady gait or difficulty walking
• Suspected vestibular disorders
• Unexplained falls
• Vestibular neuritis or labyrinthitis

Preparation

• Patients may be advised to avoid caffeine, alcohol, and certain medications (like sedatives and antivertigo drugs) for 24 hours before the test.
• Fasting is typically not required.
• An initial hearing test or audiometry may be performed.

Procedure Description

1. The patient is seated in a motorized rotational chair within a darkened room.
2. Special goggles with infrared cameras are placed over the patient's eyes to record eye movements (nystagmus) during the rotations.
3. The chair rotates back and forth at varying speeds and sinusoidal frequencies.
4. Data on eye movements is collected and analyzed to assess vestibular function.

Duration

The procedure typically takes about 30-60 minutes.

Setting

SVAR is usually performed in a specialized outpatient clinic or an ENT (ear, nose, and throat) specialist's office equipped with the necessary technology.

Personnel

• An audiologist or vestibular specialist conducts the test.
• Support staff may assist with equipment setup and patient care.

Risks and Complications

• Common: Temporary dizziness, mild nausea
• Rare: Vomiting, headache
• Complications are generally mild and self-limiting, managed with rest and reassurance.

Benefits

• Accurate diagnosis of vestibular disorders
• Provides data for targeted treatment plans
• Helps determine the cause of dizziness and balance issues
• Immediate feedback on vestibular function

Recovery

• Patients can usually resume normal activities immediately after the test.
• It's advisable to arrange transportation home if dizziness persists.
• Follow-up appointments may be scheduled to discuss results and treatment options.

Alternatives

• ENG/VNG (Electronystagmography/Videonystagmography)
• MRI or CT scan of the brain
• Caloric testing
• Each alternative has its advantages and disadvantages, often used in conjunction with SVAR for comprehensive evaluation.

Patient Experience

• The patient may feel mild to moderate dizziness during the rotations.
• Efforts are made to ensure patient comfort, and breaks are provided if needed.
• No pain is involved, and any discomfort is generally short-lived.
• Patients are encouraged to communicate any distress to the examiner promptly.