Patient Information

Nerve Conduction Study and EMG Test

Why have you been referred for a nerve conduction study/ EMG test?

  • These tests can be used to diagnose a variety of nerve or muscle problems.

Before coming for the tests;

  • Avoid putting creams, lotions to arms or legs – these make electrode recordings difficult
  • If possible, try to wear loose clothing which can be rolled up above elbows and knees
  • If possible, remove bracelets and watches from arms. Rings are usually not a problem.

Continue to take prescribed medication unless instructed otherwise.

What do the tests involve?

  • You may have to change into a hospital gown.
  • Tests involve tiny electric pulses delivered to the nerves through the skin. The pulses can feel uncomfortable in the beginning but most people get used to the pulses quite quickly.
  • Sometimes fine needles are used to study muscles. However not everyone will need to have this done. If you are afraid of needles, then discuss with the doctor performing your tests as the test may not be needed or could be avoided.
  • Most people are able to tolerate the tests well. However, if the you find tests too uncomfortable the tests will not be continued.

Inform the neurophysiologist;

  • If you have a pacemaker or defibrillator or any electrical devices fitted in the body.
  • If you take blood-thinning medications such as warfarin or Apixaban. Aspirin and Clopidogrel are usually fine. If You suffer from excessive bleeding or any bleeding disorders

You are afraid of needles.

Electro-encephalography (EEG) Test

An EEG is a special test to examine brain wave activity. This test is carried out by an experienced healthcare technician or trained physiologist. The test involves recording electrical activity generated by brain cells from the surface of brain. No electric pulses are delivered and electrodes do not transmit any sensations. These just record your brain wave activity. The brain wave activity recorded shows up as wavy lines on an EEG recording. Results are analysed and a report is formulated by Consultant Clinical Neurophysiologist. The test provides useful information about the function of brain and also provides useful diagnostic and prognostic information in certain conditions including seizure disorders, epilepsy, brain injuries, states of brain dysfunction and coma and other brain disorders.

Before the test;

It is easier to carry out the test if the hair can be washed the night before the test. Ideally, patients should avoid using any hair products and preparations including any hair gels, hairs sprays, hair oils etc.; Please continue to take any tablets prescribed to you by your doctor and do not stop any medications you regularly take, for the sake of this test.

What is involved during the test?

The test usually takes about 45 to 60 minutes. Small metal disc electrodes with wires at the ends, are attached to the scalp using a special adhesive soluble glue or paste. Physiologist or technician measures the head and marks the points on scalp with a special pen where electrodes need to be attached. These areas on scalp are at times scrubbed with a gritty cream to improve the contact of the electrodes which improves quality of the recording. This can feel slightly uncomfortable. Sometimes a special elastic cap fitted with electrodes can be used instead. The electrodes are connected with wires to an amplifier which is again connected to a computer. Video is also recorded at times if the patient consents.

Once the electrodes and wires are attached, the patient is asked to sit back in recliner chair or lie on a bed and the recording is commenced which usually runs for 20 minutes but can take longer and up to 60 minutes. During the test patients are asked to open and close eyes a few times. Sometimes are patients are allowed to fall asleep for a short period. Some special techniques are used at times during the test which include taking deep breaths for about 2 to 3 minutes and looking into strobe lights / flashing light ate various flash frequencies.

After the test;

  • Once the recoding is complete, the disc electrodes are removed using a solvent if the glue has been used. You are allowed to go home. After the test Physician Neurophysiologist analyses the recording and formulates and issues a report which is sent to the referring doctor.
  • The test is generally safe and painless and well tolerated. However, at times certain stimulating exercises are used such as strobe lights and breathing exercises.
  • These are used to provoke epileptic changes and increase diagnostic yield of the test. Use of these techniques comes with a small risk of triggering a seizure during the test, especially in patients with epilepsy. However, the test is carried out in a hospital setting with appropriate medical care available if needed.