Neurological muscle testing can help your doctor determine if your nerves and muscles are working correctly. Doctor use an electromyogram test to look for muscle abnormalities and to evaluate the way your muscles receive signals from your nerves. Results of the test allow your doctor to determine the cause numbness, pain, tingling or weakness in your muscles.
Muscle Testing
Before the test begins, a doctor or technician inserts an electrode into your muscle with a needle. The electrodes measure electrical activity in your nerves when your muscles are at rest and when you voluntarily move your muscles and transmit a record of the activity to a computer. Viewing electrical activity at these times helps your doctor determine if your muscles are moving normally. Under normal conditions, electrical activity will increase when you move your muscles. An EMG can help doctors differentiate between muscle weakness caused by injury of a nerve attached to a muscle and weakness due to neurologic disorders.
Nerve Conduction Testing
Your doctor may recommend that you have a nerve conduction test as part of the EMG test. Electrodes on the surface of your skin measure the response of your nerves when a minor electrical current is released. You may feel mild pain or spasms during this part of the test. Doctors use the nerve conduction test to evaluate the strength of nervous system signals and measure how long it takes the signals to reach your muscles.
Disorders
EMG and nerve conduction tests help doctors diagnose disorders that cause muscle weakness and other symptoms. Your results will allow your doctor to determine if the problem occurs in your muscles, happens as a result of a problem in the nerve that serves a muscle or occurs as a result of a problem originating in the brain, spinal cord or peripheral nerves. Doctors use the EMG test to diagnose such conditions as carpal tunnel syndrome, herniated spinal disks, sciatica, Guillain-Barre syndrome, muscular dystrophy and multiple sclerosis.
Considerations
Before undergoing an EMG test, you must bathe to remove oils from your skin that can interfere with placement of the electrodes. Tell the neurologists and technicians if you have a pacemaker, have hemophilia or are taking blood-thinning medications. While there are usually no complications after an EMG test, the area tested may be sore or bruised for several days after the test. Some bleeding may occur at the site of needle electrode insertions, particularly if you have a bleeding disorder condition or take blood thinners.
