﻿ Diagnostic tests EMG, NCS, NCV for nerve, muscles pain and EEG

Diagnostic Testing

These diagnostic procedures will be done in office by our neurologists.

Electromyogram (EMG)

Nerve Conduction Study(NCS)

Electroencephalogram (EEG)

Spinal Tap/ Lumbar Puncture


Electromyogram (EMG) (NCS)

An EMG, used in conjunction with a neurological examination, helps establish a diagnosis and the extent of a problem by measuring the electrical activity of a muscle in response to stimulation.
An EMG is done by inserting electrodes in fine needles into the muscles being tested, and by placing electrodes on the skin over peripheral nerves.

  • The presence, size, and shape of the wave form produced on the oscilloscope (the action potential) provide information about the ability of the muscle to respond to nervous stimulation.
  • Each muscle fiber that contracts will produce an action potential and the size of the muscle fiber affects the rate (how frequently an action potential occurs) and size (amplitude) of the action potential(s).

An EMG may be used to evaluate a variety of problems, including the following:

  • Nerve damage from compression by a disk in the neck or the back
  • Nerve compression from carpal tunnel syndrome
  • Neuromuscular diseases such as amyotrophic lateral sclerosis (ALS), poliomyelitis, myasthenia gravis and muscular dystrophy
  • Peripheral neuropathy caused by such conditions as diabetes, pernicious anemia and heavy metal toxicity

In many instances, an EMG can provide critical diagnostic information that can not be obtained in any other way.
Although there is some discomfort associated with the procedure, an EMG is usually done on an outpatient basis.


No special preparation is usually necessary.


  1. The electrical activity detected by this electrode is displayed on an oscilloscope.
  2. You may be asked to contract the muscle.
  3. To perform intramuscular EMG, a needle electrode is inserted through the skin into the muscle tissue. A trained medical professional observes the electrical activity while inserting the electrode.


Nerve Conduction Study (NCS)

Nerve conduction studies are mainly used for the evaluation of paresthesias (numbness, tingling, burning) and/or weakness of the arms and legs. It can be used to diagnose disorders of the peripheral nerves and muscles.




The nerve is stimulated, usually with surface electrodes, which are patch-like electrodes (similar to those used for ECG) placed on the skin over the nerve at various locations.One electrode stimulates the nerve with a very mild electrical impulse. The resulting electrical activity is recorded by the other electrodes. The distance between electrodes and the time it takes for electrical impulses to travel between electrodes are used to calculate the nerve conduction velocity. Electromyography is the second part of this test and is often done within one week of the NCS.

How It Feels:

There should be no residual pain once the test is finished.


Electroencephalogram (EEG)

An EEG is used to help diagnose the presence and type of seizure disorders, confusion, head injuries, brain tumors, infections, degenerative diseases, and metabolic disturbances that affect the brain. It is also used to evaluate sleep disorders and to investigate periods of unconsciousness.


  1. Please wash your hair the night before the test. No oils, sprays, or lotion should be used on your hair.
  2. Please avoid all foods/drinks containing caffeine for 8 hours before the test.
  3. It may be necessary to sleep during the test, so you may be asked to reduce your sleep time the night before.


  • This procedure is performed by an EEG technician and typically lasts 20-40 minutes.
  • You may be positioned on your back, on a table, or in a reclining chair.
  • The technician will apply between 16 and 25 flat metal discs (electrodes) in different positions on your scalp.
  • The discs are held in place with a sticky paste. The electrodes are connected by wires to an amplifier and the recording machine which converts the electrical signals into a series of wavy lines which are drawn onto a moving piece of graph paper.

How It Feels:

This procedure is painless


Cerebral spinal fluid (CSF) collection
(Spinal Tap/ Lumbar Puncture)



How the Test is Performed




How to Prepare for the Test


How the Test Will Feel


Why the Test is Performed



We believe the key to quality patient care is the development of a strong doctor-patient relationship, providing special attention to patients and addressing their family concerns and needs.