Vestibular testing consists of a series of tests.
These tests may be recommended if the patient is experiencing balance problems. The goal is to determine whether the symptoms are caused by issues with the vestibular organs within the inner ear, or if the issue is neurological.
Each of the tests will vary in length and the clinician will determine which exact tests are needed for the case.
What Is The Vestibular System?
The vestibular system is made up of two chambers within the inner ear. These chambers are the membranous labyrinth and the bony labyrinth. Each of these structures has a corresponding nerve system. These nerves are involved in balance and detect changes in acceleration. This is why, if a patient is experiencing balance problems, their practitioner may want to investigate their vestibular health.
The tests may rule out vestibular issues, in which case the physician would look into neurological explanations for the symptoms. The tests may also determine if there is a vestibular problem, such as benign paroxysmal positional vertigo, perilymph fistula, or vestibular neuritis.
Electronystagmography is currently the most commonly utilized form of vestibular testing. It is composed of four sub-tests, which are the tracking test, the calibration test, the caloric test, and the positional test. Each of the four sub-tests stimulate the vestibular system in a different way while the patient’s involuntary eye movement, or nystagmus, is tracked.
- During the caloric test, warm and cold water will be pushed into the ear canal and the response will be measured.
- The positional test will measure the patient’s level of dizziness when their head is in various positions.
- The calibration test measures the patient’s rapid eye movements.
- The tracking test further evaluates movement as the eyes track a moving object.
It is important to note that there are a few different ways that eye tracking can be achieved. When administered together, these tests have proven useful in diagnosing acoustic neuroma, vestibular neuritis, and benign paroxysmal positional vertigo.
Vestibular Evoked Myogenic Potential (VEMP)
Vestibular evoked myogenic potential is used to verify that each of the vestibular system’s parts and their associated organs are in working order. This is achieved by playing music through earphones and stimulating the vestibular system. If the system and nerves are as they should be, the nerves will cause a specific muscular reaction. This reaction will be measured using electrodes that are placed on the patient’s neck and under their eyes. This is non-invasive as the electrodes are stickers with sensors that attach to the surface of the skin, similar to those used in EKGs.
There are many other tests that may be performed in order to ensure an accurate diagnosis, including posturography and electrocochleography. Ultimately, the specialist will determine which tests are appropriate based on the symptoms.