Brainstem auditory evoked potential

Brainstem auditory evoked potential (BAEP), also known as auditory brainstem response (ABR), is a type of electroencephalogram that measures the electrical activity of the brainstem in response to auditory stimuli. This test is used to evaluate the function of the auditory nerve and the auditory pathways in the brainstem.

Overview

The BAEP test involves placing electrodes on the scalp and earlobes, and then playing clicks or tones through headphones. The electrodes pick up the electrical activity generated by the brainstem in response to the sounds. This activity is then recorded and analyzed.

The BAEP test is used to diagnose a variety of conditions, including hearing loss, tinnitus, acoustic neuromas, and multiple sclerosis. It can also be used to monitor brain function during brain surgery.

Procedure

The BAEP test is a non-invasive procedure that takes about an hour to complete. The patient is asked to lie down and relax, and electrodes are placed on the scalp and earlobes. Sounds are then played through headphones, and the electrical activity generated by the brainstem in response to the sounds is recorded.

The recorded data is then analyzed to determine the latency (time it takes for the sound to travel from the ear to the brain) and amplitude (strength of the response) of the brainstem's response to the sounds. These measurements can help diagnose various conditions and assess the function of the auditory nerve and brainstem.

Interpretation

The results of the BAEP test are interpreted by a neurologist or audiologist. The latency and amplitude of the brainstem's response to the sounds are compared to normal values. If the latency is longer than normal, it may indicate a problem with the speed of sound transmission through the auditory nerve or brainstem. If the amplitude is smaller than normal, it may indicate a problem with the strength of the response.

Risks and Complications

The BAEP test is generally safe and well-tolerated. However, as with any medical procedure, there are potential risks and complications. These may include discomfort or skin irritation from the electrodes, and anxiety or discomfort from the sounds played during the test.

See Also

• Electroencephalography
• Hearing loss
• Tinnitus
• Acoustic neuroma
• Multiple sclerosis