ElectroMyoGram - EMG
- Is an important test used in Neurology, it is used to diagnose diseases of the nerves and muscles.
- It is performed by a neurologist.
- The neurologist will know the patient’s symptoms and exactly what they are hoping to find out.This is important because EMG is not a standardised test, but a technique which looks for changes in nerve and muscle function. The doctor needs to know more or less what they are looking for and where.
- Throughout the test the doctor interprets the results and will examine other areas and expand the test parameters if necessary.
A normal EMG exam has three parts:
- the neurological examination,
- During the neurological examination the doctor tests the patient’s movement, strength and reflexes in order to identify any deficiencies and to decide which questions need answering during the test. This is very important as most errors that occur during EMG testing happen when the doctor doesn’t know precisely what they are looking for and where.
- During electroneurography the doctor tests the capacity of the nerves to respond to and conduct signals. Electrical stimulation is applied to the nerves (generally in the arms and legs) and the way in which the impulse is conducted to the muscles is recorded via small electrodes taped to the skin which record the muscle’s response.
- During electromyography the doctor inserts a fine needle into particular muscles as muscle function is altered when there are changes to nerve function. According to the type of alterations recorded certain diseases can be identified.
- The test can be a little painful, but most patients do not find it a problem. The needles used are very fine (like acupuncture needles) and no electrical stimulation is applied. The electrical activity of the muscles is recorded, it is as if a microphone has been placed over the muscle to hear what it is saying.