Electromyography to Diagnose Neuromuscular Disorders
Electromyography to Diagnose Neuromuscular Disorders
This study will investigate problems with muscle weakness and control using
 electromyography-a test of nerve-muscle cell communication. Advanced techniques called single
 fiber electromyography and macro-electromyography, which evaluate individual muscle fibers,
 will be used. Besides aiding in diagnosis, these tests provide information about disease
 progression that may be useful in guiding therapy.

 Adult patients with suspected neurological disorders of muscle control and weakness may be
 eligible for this study. Normal volunteers may also participate. For the electromyography
 procedure, a special needle is inserted into a muscle. The patient will slightly tense the
 muscle and maintain the tension while electrical signals from the muscle fibers are being
 recorded. The electrical signals are played through a loudspeaker, providing feedback to help
 the patient tense the muscle the appropriate amount. The test, which is usually done for only
 one muscle, takes 1 to 2 hours. If needed, short breaks can be taken.

 If the patient cannot maintain tension in the muscle for the entire test period, a nerve will
 be stimulated to activate the muscle. A thin needle is inserted near the nerve, and a series
 of small electrical shocks are given to activate a nerve fiber. The electromyography needle
 is inserted into the muscle to measure the response, as described above.

 A neurologist receiving specialized training in clinical neurophysiology will do the
 electromyography procedure under the direct supervision of an experienced neurologist.
This is a training protocol to enable fellows in clinical neurophysiology to learn and
 perform technically advanced electrodiagnostic studies, such as single fiber EMG and macro
 EMG, on patients with neuromuscular diseases.
INCLUSION CRITERIA:

 Adult patients with weakness or motor dysfunction: 8/year.

 Normal volunteers, adults: 2/year.

 EXCLUSION CRITERIA:

 Anticoagulation or uncorrected bleeding disorder.

 Children are not optimal subjects for fellows undergoing training in these techniques and
 will be excluded.