Auditory Evoked Potentials
A sense of balance is required for many everyday actions such as walking and running. If something is throwing this sense of balance out of whack, it can affect coordination and impact mobility and personal safety.
It’s the vestibular system in the inner ear that largely affects balance. This system also helps people detect position and motion of the head. If you are having sudden or worsening difficulties with balance, an audiologist may test auditory evoked potentials (AEPs) to determine if the vestibular system is working properly.
What Are Auditory Evoked Potentials?
Auditory evoked potentials (AEPs), also referred to as evoked responses, are a record of the time it takes nerves in the auditory system to respond to sound and electrical stimulation. Nerve signals are rapidly sent from parts of the ear to the brain and vice-versa. Testing that involves auditory evoked potentials allows an audiologist to determine if there is a block along neural pathways leading to the brain. Results from AEP tests can be useful in ruling out or confirming hearing-related problems related to nerves.
How Is Auditory Evoked Potential Testing Done?
Auditory evoked potential testing involves the placement of electrodes on the head. These electrodes are connected to a computer that records the nerve responses to stimulation. The sounds that stimulate nerves are delivered through earphones that the patient has on while resting quietly or sleeping, as is often the case when younger children or newborns are tested. When babies are tested, only one loudness level is checked. If there is a detectable nerve response, they’ll pass the test.
Who May Be AEP Tested?
In some instances, AEP testing may be done as part of the process of diagnosing patients who may have multiple sclerosis or other neurological disorders. This type of testing may also be recommended for patients with suspected auditory disorders that may be affecting hearing capabilities or causing issues with balance. Both children and adults may be tested.
Possible Benefits for Patients
Other types of hearing tests require patients to acknowledge certain tones or repeat words or phrases being said. The advantage of AEP testing is that it does not require any responses from adults or children being tested. Testing that’s done this way is considered highly accurate since all results will be clearly recorded and documented. Because of the way the evaluation is done, there are also fewer issues with misunderstanding instructions. AEPs from patients with some type of neurological impairment may also provide information that helps detect related abnormalities affecting nerves that wouldn’t otherwise be detected from behavioral-based audiological techniques.
If testing of auditory evoked potentials does not produce conclusive results or if an inner ear problem that could be affecting balance is suspected, an audiologist may perform other hearing tests to make an accurate diagnosis. These additional evaluations may involve checking for vertebrobasilar circulatory disorders affecting blood supply to the back of the brain, middle ear infections, or Meniere’s disease, a condition that can change fluid volume in ears enough to cause balance problems.