Neuromuscular diseases affect muscle function because of something wrong in the pathway from the spinal cord to the muscle fibres, which is the final stage for messages from the brain to the muscles. Messages from the brain cells are transferred to cells in the spinal cord called anterior horn cells. Neuromuscular diseases can arise at the anterior horn cells, in the peripheral nerves, at the myoneural junctions or in the muscle fibres. In peripheral neuropathies, the trouble is in the peripheral nerves. The list of causes is enormous.
Many peripheral neuropathies are hereditary, that is genetically determined.
The hereditary peripheral neuropathies are the only ones to be dealt with in detail in this Fact Sheet. There are dozens of non-hereditary causes, including poisons such as alcohol, some drugs which are used in treatment, diabetes mellitus and other diseases. When first used it was thought to refer to one disease. Since then it has become evident it is not just one disease. The process of distinguishing these diseases from one another is still incomplete and, as knowledge continues to be gained, there will be additional categories of peripheral neuropathy which can not yet be distinguished from one another.