Nerve and Muscle Disorders

Nerve and Muscle Disorders (Neuromuscular Disorders) affect the nerves that control your voluntary muscles. Voluntary muscles are the ones you can control, like in your arms and legs. Your nerve cells, also called neurons, send the messages that control these muscles. When the neurons become unhealthy or die, communication between your nervous system and muscles breaks down. As a result, your muscles weaken and waste away. The weakness can lead to twitching, cramps, aches and pains, and joint and movement problems. Sometimes it also affects heart function and your ability to breathe.

Examples of neuromuscular disorders include:

  • Amyotrophic lateral sclerosis

  • Multiple sclerosis

  • Myasthenia gravis

  • Spinal muscular atrophy

Many neuromuscular diseases are genetic, which means they run in families or there is a mutation in your genes. Sometimes, an immune system disorder can cause them. Most of them have no cure. The goal of treatment is to improve symptoms, increase mobility and lengthen life.


In many cases testing of nerve and muscle function requires tests:

  • Nerve conduction studies

  • EMG (Electromyography)


Electromyography (EMG) is a diagnostic procedure that measures muscle response or electrical activity in response to a nerve’s stimulation of the muscle. The test is done to find problems that damage muscle tissue, nerves, or the spots where nerves and muscles join and is used to help detect neuromuscular abnormalities.

A related procedure that may be performed is Nerve Conduction Study (NCS). NCS is a measurement of the amount and speed of conduction of an electrical impulse through a nerve. NCS can determine nerve damage and destruction, and is often performed at the same time as EMG. Both procedures help to detect the presence, location, and extent of diseases that damage the nerves and muscles.

Nerve conduction studies are used mainly for evaluation of paraesthesia’s (numbness, tingling, burning) and/or weakness of the arms and legs. A physical exam and thorough history also help to direct the investigation.

EMG results are often necessary to help diagnose or rule out a number of conditions.



If you or someone you know has been diagnosed with or suspects nerve and/or muscle disorders and are looking for a specialist neurologist, please feel free to contact Synapse Neurology for a consultation on 03) 8582 6945.