What are Neurophysiological Tests?
These tests measure the electrical activity of nerves and muscles. Common tests include Nerve Conduction Studies (NCS), Electromyography (EMG), Evoked Potentials (EP), and Electroencephalogram (EEG).
Electroencephalogram (EEG)
An EEG is performed to diagnose, classify, and prognosticate cases of Epilepsy. It records the brain's electrical activity via electrodes placed on the scalp and can help identify abnormal patterns associated with seizures and other brain conditions.
Nerve Conduction Studies (NCS)
NCS measures how quickly electrical signals travel along your nerves. Small electrodes are placed on the skin over nerves. Mild electrical impulses are delivered to stimulate the nerve, and the response is recorded. It helps diagnose nerve damage or disease (neuropathy).
Electromyography (EMG)
EMG records and analyzes the electrical activity in your muscles. A fine needle electrode is inserted into a muscle to record its activity during rest and contraction. EMG helps diagnose muscle disorders (myopathy), nerve root compression (radiculopathy), and problems with nerve-to-muscle signal transmission (e.g., Myasthenia Gravis).
Evoked Potentials (EP)
EP studies measure the electrical activity in the brain in response to specific sensory stimulation (visual, auditory, or touch). Electrodes are placed on the scalp. This helps assess the integrity of sensory pathways and can be useful in diagnosing conditions like Multiple Sclerosis. Visual Evoked Potential (VEP) and Brain Stem Auditory Evoked Potential (BAER) are specific types of EP studies that are particularly helpful in diagnosing certain brain disorders affecting these pathways.
What to Expect During These Tests
NCS may cause a brief tingling sensation. EMG can cause minor discomfort when the needle is inserted. EEG involves electrodes being attached to your scalp, which is painless. The tests are generally safe. You will be given specific instructions on how to prepare if needed (e.g., avoid lotions on the skin, wash hair before EEG).
Why are these tests done?
These tests help your neurologist to pinpoint the location and extent of nerve or muscle injury, differentiate between various types of neurological disorders (like epilepsy, neuropathy, myopathy), monitor disease progression, and guide treatment decisions.
Disclaimer
The information provided on this page is for general educational purposes only and does not constitute medical advice. It is essential to consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment. Dr. Ritwiz Bihari and this website do not guarantee the accuracy, completeness, or timeliness of the information provided.