Electroencephalography (encephalon = brain), or EEG, involves recording all the electrical activity generated by the brain from electrodes placed on the scalp surface. The test is used to detect problems related to electrical activity of the brain. An EEG tracks and records brain wave patterns. It is used to help diagnose the presence and type of seizure disorders, to look for causes of confusion, and to evaluate head injuries, tumors, infections, degenerative diseases, and metabolic disturbances that affect the brain. It is also used to evaluate sleep disorders.


Electromyography is used to assess the health of muscles and nerve cells (motor neurons) that control the muscles. There are two parts to an EMG test: the nerve conduction study and needle EMG. The nerve conduction involves placing small sensors on the skin to assess the ability of the motor neurons to send electrical signals. Needle EMG involves directly inserting sensors called needle electrodes, into muscle tissue to evaluate muscle activity when at rest and when contracted. EMG is recommended in cases when someone is showing symptoms of a muscle or nerve disorder. These symptoms may include tingling, numbness, or unexplained weakness in the limbs. EMG results can help the doctor diagnose muscle disorders, nerve disorders, and disorders affecting the connection between nerves and muscles.

Nerve Conduction Velocity

Nerve Conduction Velocity or NCV measures how quickly electrical signals move through your peripheral nerves, which are located outside of your brain and along your spinal cord. This test measures the extent of nerve injury. Healthy nerves send electrical signals more quickly and with greater strength than damaged nerves. An NCV test can be used to diagnose a number of muscular and neuromuscular disorders, including sciatic nerve problems. . In this test, the nerve is electrically stimulated, and the electrical impulse 'downstream' from the stimulus is measured. The nerve is stimulated by a mild and brief electrical shock from the stimulating electrode. An EMG is carried out in order to run NCV test.