The tests, Electroencephalograms (EEG) and electromyograms (EMG) help physicians understand the nervous system. The EEG is a simple, painless test, which takes approximately an hour. It records the electrical waves in the brain. While an EMG test evaluates nerve and muscle function in the arms and legs (indicating what may be happening in the brain, neck or back) and is typically done in conjunction with a Nerve Conduction Velocity (NCV). The length of the test varies based on the number of limbs tested, and it can be mildly uncomfortable for some patients.

Electroencephalogram (EEG)

Electroencephalography (EEG) is a method of tracking neural activity in the brain via placement of electrodes on the scalp. EEGs are typically used to identify seizures, but researchers can also use this same technology to investigate brain functions and how they relate to human cognition and behavior. Rather than delivering electrical energy to the brain via electrodes, scalp electrodes which are connected to EEG machines are used to only record the brain’s natural electrical activity. Therefore, there are no major risks associated with this entirely noninvasive brain monitoring technique. The technologist removes the electrodes at the end of the test and cleans any leftover paste. The results of an EEG are not limited. The test is interpreted by a neurologist who has special training in interpreting EEGs and sending the report to the referring physician.

Electromyography (EMG)

Electromyography (EMG) is a method of recording electrical impulses that originate from muscles. In neuromodulation research, electromyography is often used to measure motor effects that are caused by stimulations in the motor regions of the brain. EMG is often used in clinical settings to diagnose abnormalities of the muscles and nerves. In the clinic, electromyography may involve a tiny needle inserted into the muscle in order to record the electrical activity. However, most Center investigators record the electrical activity of the muscle of interest with surface electrodes that are placed on the skin. Therefore, the EMG machines employed by our researchers involve no invasive procedure and present no health hazards. The physician usually gives a brief explanation of the results after the test. EMG and NCV testing do not impose restrictions or limitations. Patients may experience mild discomfort in certain areas of their limbs, but this generally settles within 30 minutes.

While not routinely ordered, EEG and EMG are reliable and safe methods of evaluating a variety of neurological conditions. If you have questions regarding your test, you can discuss it with your physician, but you can also speak to the technologist who is performing the test at the neurodiagnostic laboratory. Additionally, most hospitals offer educational materials on their websites to answer any questions in advance.