Our body possess a huge ability to generate electricity and it is through this ability that allows us to achieve good health. The electricity that is generated will send important signals from all parts of the body to the brain and provides a source of instantaneous communication. These electrical signals are created by the nerves and instructions are sent to the muscles to carry them out. However, signals can easily be affected due to diseases or injuries. The presence of pain and numbness in different parts of the body can help doctors to diagnose the exact cause of injury and this is what electrodiagnostic testing is all about.
Electrodiagnosis employs the science of electrophysiology, using electrical pulses to study neurophysiology. There are two separate parts in this test: testing the nerves and testing the muscles. Both tests will evaluate the ability of both nerves and muscles to function as a single entity unit. This test will allow narrow down the list of possible causes of pain and weakness.
Nerve conduction studies (NCS)
NCS is done in conjunction with its muscle counterpart. The main purpose is to determine if a particular nerve is functioning properly. It is done by placing sensors over nerves in both the hands and legs and stimulating it with electrical pulses. Patients will experience a warm and itchy sensation similar to suffering from an ant’s bite. Through this test, doctors will be able to evaluate the performance of the nerves and to identify which nerves are not performing well. A healthy nerve will conduct electricity at an extremely fast rate up to 200km/h whereas a damaged nerve will have a much lower conduction rate.
EMG on the other hand analyses the electrical activity in muscles. When a muscle is in use, it will be buzzing with electrical signals as the muscle attempts to communicate with different parts of the body. Likewise when it is not in use, it will be electrically quiet. Unlike NCS, EMG will cause slight discomfort to patients as small needles are inserted to monitor and record electrical activities. The wires will be connected to a small TV that will broadcast these electrical signals. After the test, the needles will be removed and this will cause further trauma to the area, resulting in bruises in the following days.
Electrodiagnostic tests are pretty accurate due to the advancement of medical technology and devices. However, it is only able to identify whether the nerves are functioning properly and it is unable to identify the cause of pain.