Nerve damage causes a variety of troublesome symptoms, but it can be difficult to accurately diagnose. If nerve damage is suspected, your doctor may decide to conduct nerve studies to properly diagnose and treat your condition.
The Initial Appointment
If you're experiencing unexplained tingling, numbness, muscle weakness, pain, or other symptoms involving the peripheral nervous system, your doctor will need to gather information. First, the doctor will ask you about the frequency, severity, and duration of the symptoms, as well as anything else of relevance to get the overall picture of how this is affecting you. Depending on your answers, the doctor may decide the next step is to test for nerve damage.
Testing for Nerve Damage
A nerve conduction study assesses how healthy your nerves are. When a nerve is damaged, it is less effective in sending and receiving electrical signals. A nerve conduction study tests the speed and strength of signals produced in the peripheral nervous system, the more than 100 billion nerve cells that enable your brain and spinal column to communicate with the rest of your body. There are two types of nerve signals: (a) motor signals, which coordinate muscle movements, and (b) sensory signals, which send information to the brain about the state of the body. The effectiveness of these signals is critical for a healthy body. For instance, if you touch something sharp, the affected sensory nerves send signals to the brain, which interprets these signals--“pain, possible damage, avoid”--and then sends a message back to the appropriate motor neurons to signal the muscles to move. All this happens lightning fast, of course, and a failure anywhere in the process can cause problems. By measuring the signals, a nerve conduction study can isolate where the signaling process breaks down.
How Does a Nerve Conduction Study Work?
The nerve conduction study, sometimes also referred to as a nerve conduction velocity test, measures how fast a nerve signal gets from point A to point B, usually using electrodes attached to the skin. A nerve is stimulated with a very low dose of electricity, and the speed with which the signal travels between electrodes is measured. The strength of the signal is measured as well. Each nerve is tested in this manner to isolate areas of weakness. An electromyography (EMG) is often done at the same time. An EMG assesses how well the muscles respond to to the nerve signals. This helps isolate whether the problem is in the nerves or the muscles.
What Do the Results Mean?
When the testing is complete, your doctor will study all the information that has been gathered to determine whether or not there is nerve damage and, if there is, the location and extent of the damage. Variations in the test results can point to a traumatic nerve injury, for instance, or a trapped nerve, or perhaps a chronic condition such as Guillain-Barré syndrome. Once there is enough data to confirm a diagnosis, the doctor will prescribe a treatment plan, or course of action, to help eliminate or ease your symptoms. As you follow the treatment, your doctor will monitor how well your nerves are responding and adjust the treatment as needed.
In summary, a nerve conduction study provides the detailed information your doctor needs to help you get better.