Electrodiagnostics

Electrodiagnostic examinations measure electrical activity generated by muscles and nerves. The results help physicians diagnose the cause of various symptoms, including numbness, pain, or weakness.

Patients having an electromyographic (EMG) test may feel only brief and mild discomfort as the physician inserts a tiny needle into various muscles. The needles are used only to record electrical activity in the muscles and not to deliver any treatment. Using a video monitor and auditory signals, the EMG specialist can evaluate how your muscles are functioning.

Electrodiagnostic testing can help diagnose the following conditions:

• Amyotrophic lateral sclerosis (Lou Gehrig’s disease)
• Epilepsy
• Movement disorders
• Multiple sclerosis
• Nerve conduction

• Neurophysiology
• Parkinson’s disease
• Sleep disorders
• Spinal cord injury
• Stroke

Depending on your condition, a UT Southwestern Medical Center physician may prescribe one or more electrodiagnostic examinations to determine how muscle or nerve damage may be contributing to your symptoms. Some of the most commonly prescribed electrodiagnostic tests include an EMG exam, a nerve conduction study, and an evoked potential study. 

The electrodiagnostic tests offered at UT Southwestern include:

Auditory evoked potential (AEP)

Auditory signals are presented to the ears to detect hearing problems

Brainstem auditory evoked response (BAER)

Auditory signals are transmitted to the ears to detect brain stem problems

Electroencephalography (EEG)

Electrodes (electrical measuring devices) are attached to the scalp to measure brain functions

Electromyography (EMG)

Electrodes are placed on the skin’s surface or in the form of tiny needles to measure activity in the muscle

Electroretinogram (ERG)

Anesthetic drops are placed in the eyes and electrodes are used to detect a loss of cells in the retina

Nerve conduction studies (NCS)

Electrodes are used to measure activity in the nerves

Somatosensory-evoked potential (SEP)

EEG electrodes measure the brain’s response to a stimulus applied to the skin

Visual-evoked potential (VEP)

EEG electrodes measure the brain’s response to a flash of light or a visual pattern

Our team approach to evaluate patients’ conditions and prescribe the most effective therapies available makes a valuable difference in each patient’s rehabilitation.