What is an evoked potentials study?

一项诱发电位研究测量了大脑对视觉刺激的反应, sound, or touch. 当大脑受到视觉、声音或触觉的刺激时，信号就会沿着神经传递到大脑. 在那里，电极检测信号并显示给你的医疗保健提供者来解释. 诱发电位研究包括测量视觉反应的三个测试, auditory, and electrical stimuli.

• Visual evoked response (VER) test. 这个测试可以诊断出视觉神经和大脑中影响视力的其他视觉通路的问题. A healthcare provider places electrodes along your scalp. 当你观看屏幕上的棋盘图案闪烁几分钟时，他们会记录下电子信号.

• Brainstem auditory evoked response (BAER) test. 这项测试可以诊断听力，并指出可能的脑干肿瘤或多发性硬化症. 医疗保健提供者将电极放在你的头皮和耳垂上，并提供听觉刺激, such as clicking noises and tones, to each ear.

• Somatosensory evoked response (SSER) test. 这个测试可以检测出导致手臂和腿部麻木的脊髓问题. For this test, a healthcare provider attaches electrodes to your wrist, ankles, the back of your knee, neck, or other locations. They will apply a mild electrical stimulus through the electrodes. 然后，你头皮上的电极会决定电流沿着神经到达大脑所需的时间.

Why might I need an evoked potentials study?

您的医疗保健提供者可能会要求这些测试来评估听力或视力, especially in infants and children. They are also done to diagnose disorders of the optic nerve, 以及检测影响大脑和脊髓的肿瘤或其他问题. 它们也被用来评估昏迷期间的大脑功能，并帮助预测恢复的机会. They may also be used to monitor nerve function during some surgeries.

这些检查通常不能得出导致异常的具体诊断. 但诱发电位测试有时可以支持多发性硬化症的诊断.

您的医疗保健提供者推荐诱发电位测试可能还有其他原因.

What are the risks of an evoked potentials study?

Evoked potentials studies are considered safe procedures. The tests can cause a little discomfort. There may be risks depending on your specific medical condition. 在手术前与你的医疗保健提供者讨论任何问题.

某些因素或条件可能会干扰测试结果. These include:

• Severe nearsightedness

• Presence of earwax or inflammation of the middle ear

• Severe hearing impairment

• Muscle spasms in the head or neck

• 任何植入式装置，如脊髓刺激器、起搏器或心脏除颤器. 如果您有这些设备，请告诉技术人员，因为测试可能需要更改.

How do I get ready for an evoked potentials study?

询问你的医疗保健提供者，告诉你在测试前应该做些什么. Below is a list of common steps that you may be asked to do, if you are getting the test done as an outpatient procedure:

• You will sign a consent form that gives your permission to do the test. Read the form carefully and ask questions if something is unclear.

• 在大多数情况下，不需要镇静，你也不需要在这个测试中禁食. But children may need sedation to get accurate results. 如果需要镇静，请咨询您的医疗保健提供者有关任何具体指示.

• 告诉你的医疗保健提供者所有的药物(处方药和非处方药), vitamins, and herbal supplements that you're taking.

• Wash your hair the night before the test, 但不要使用护发素或使用任何发胶或其他护发产品.

• 根据您的医疗状况，您的医疗保健提供者可能会要求您使用其他特定的制剂.

• Don't put lotions or cream on your skin if you are getting SSER done.

What happens during an evoked potentials study?

诱发电位测试可以在门诊进行，这意味着你当天就可以回家了. Or it may be done as part of a hospital stay. 程序可能会根据您的情况和您的医疗保健提供者的做法而有所不同. 和你的医疗保健提供者谈谈在你的测试中会发生什么. 在某些手术过程中，诱发电位也可以在手术室中进行. 如果是在手术期间进行的，您可能不会意识到正在进行的测试.

Generally, the test follows this process:

• You will be asked to remove any clothing, jewelry, hairpins, eyeglasses, hearing aids, or other metal objects that may interfere with the procedure.

• If you are asked to remove clothing, you will be given a gown to wear.

• You will be asked to relax in a reclining chair or lie on a bed.

• A healthcare provider will attach the electrodes with a paste. 电极的位置将取决于所做的诱发电位测试的类型.

The test will generally proceed as follows.