Following are the laboratory tests for the diagnosis of vestibular dysfunction except –
**Core Concept**
Vestibular dysfunction refers to a range of symptoms and signs resulting from disorders of the vestibular system, including balance and spatial orientation. Laboratory tests are used to diagnose and differentiate between various vestibular disorders, which can be caused by peripheral or central nervous system lesions.
**Why the Correct Answer is Right**
Vestibular function tests assess the function of the vestibular apparatus in the inner ear and the vestibular pathways in the brain. Caloric testing, electronystagmography (ENG), and rotary chair testing are commonly used to evaluate vestibular function. These tests can help diagnose conditions such as benign paroxysmal positional vertigo (BPPV), vestibular neuritis, or labyrinthitis.
**Why Each Wrong Option is Incorrect**
**Option A:** Electrocochleography (ECog) is a test used to evaluate the function of the cochlear portion of the inner ear, specifically the hair cells and the stria vascularis. It is not a test for vestibular dysfunction.
**Option B:** Auditory brainstem response (ABR) testing assesses the function of the auditory nerve and the brainstem, and is not a test for vestibular function.
**Option C:** Otoacoustic emissions (OAEs) testing evaluates the function of the cochlea and the auditory nerve, and is not a test for vestibular function.
**Clinical Pearl / High-Yield Fact**
When evaluating patients with vestibular dysfunction, it's essential to consider the patient's history, physical examination, and laboratory test results together to arrive at a diagnosis.
**Correct Answer: A. Electrocochleography (ECog) is a test used to evaluate the function of the cochlear portion of the inner ear, specifically the hair cells and the stria vascularis. It is not a test for vestibular dysfunction.**