At what angle is hallpike thermal caloric test done –
**Core Concept**
The Hallpike thermal caloric test is a diagnostic maneuver used to assess the vestibular function of the inner ear. It involves irrigating the ear canal with warm or cool water to stimulate the vestibular apparatus and observe the resulting nystagmus and other responses.
**Why the Correct Answer is Right**
The Hallpike test is performed with the patient's head in the supine position and the affected ear upwards. This position is crucial to ensure that the irrigant flows into the ear canal and stimulates the lateral semicircular canal, which is responsible for the vestibular response. The correct angle allows for optimal stimulation of the vestibular apparatus and accurate assessment of vestibular function.
**Why Each Wrong Option is Incorrect**
**Option A:** 45 degrees - This angle is not typically used for the Hallpike test, as it may not provide adequate stimulation of the lateral semicircular canal.
**Option B:** 90 degrees - This angle is not suitable for the Hallpike test, as it may cause the irrigant to flow out of the ear canal or stimulate other parts of the ear.
**Clinical Pearl / High-Yield Fact**
The Hallpike test is an essential tool for diagnosing vestibular disorders, such as benign paroxysmal positional vertigo (BPPV). It is crucial to perform the test correctly to ensure accurate results and avoid misdiagnosis.
**Correct Answer: C. 30 degrees**