As the name suggests evoked potentials studies are diagnostic tests which are used to evoke or initiate an electrical activity in the brain and then record it. If the test results record any change in the speed of electrical conduction of the signals, it might serve as an indicator of a disease affecting the brain and the nervous system. The test is performed by a neurologist or a neurosurgeon in a hospital setup or a laboratory.
What is the principle of evoked potentials studies ?
The principle cause why evoked potentials studies are conducted are to check the speed at which the electrical activity functions in the brain and the nervous system. This tests uses electrodes which detect the signals when the nervous system and the brain is stimulated which in turn are displayed on a monitor for the doctors to interpret.
What are the uses of evoked potentials studies ?
Evoked potentials are used to diagnose the disorders of the nervous system and brain, like the demyelination of the nerve fibers and multiple sclerosis lesions.
How do you prepare for an evoked potentials studies ?
Evoked potentials studies are advised by your neurologist after a detailed examination and evaluation of your symptoms. You will be asked to report to the laboratory or the setup where the test is to be conducted and change into a hospital gown. Before you are posted for the evoked potentials study you will thoroughly examined for any past medical history, associated with diseases, family history of diseases associated and your detailed medication history.
What are the types of evoked potentials studies and how are they performed ?
Evoked potential studies, test the activity of the brain and the nervous system for responses generated for vision, sound, and touch sensations. The tests are mentioned below.
- Visual evoked response : To the problems associated with sight. Some electrodes are placed in your scalp area, and you are asked to watch a checkerboard pattern on a screen for a defined period. The test readings are recorded and evaluated by your neurologist.
- Brainstem auditory evoked response: This test is used to check your response against sound stimulation. The electrodes are placed on your scalp and near your ears and sound stimulation is performed i.e. various sounds are generated to assess your brains activity against them and your results are recorded.
- Somatosensory evoked response : This is test which is used to record any abnormality in the spinal cord which in turn is affecting your legs and hands to perform functions. In this test the electrodes are placed on the scalp, back of your knees, and your wrist. Then a mild electrical current is used to stimulate the brain and the spinal cord and the response is recorded.
These tests usually take about an hour or more and the test results are generated and discussed either on the same day or as per the hospitals policy.
How are the evoked potentials studies interpreted ?
After the tests are complete, a neurologist categorizes the results as abnormal and normal. If the test results are normal, it implies the nerve conduction is occurring at a normal rate and if the test results are abnormal, either too slow or fast conduction of signals they signal towards some abnormality like an optic nerve damage, demyelinating disease, or other neurological abnormalities.
Are there any risks associated with evoked potentials studies ?
The evoked potential studies utilize electric stimuli to assess the response of brain and the nervous system. Hence there are slight chances that a damage to the sight, hearing capability and spasms in the head and neck muscles might occur. It is important that you discuss the details of test and its side effects before aggreging for an evoked potentials study.
Disclaimer: The content provided here is meant for general informational purposes only and hence SHOULD NOT be relied upon as a substitute for sound professional medical advice, care or evaluation by a qualified doctor/physician or other relevantly qualified healthcare provider.
