QUEST Volume 8, Number 4, August 2001
Simply Stated . . .Neuromuscular Terminology
Medical terminology can be a confusing morass of words that
sound similar but have different meanings — or words that sound
different but mean the same thing.
One way to simplify "Medspeak" is to break it into its basic
components. In neuromuscular diseases, those components are often
Greek root words.
Here is a quick glossary to help you understand how the names of
various neuromuscular diseases arose, and the differences among
From the Greek words myo, meaning muscle, and
pathos, disease or suffering
any disease or abnormal condition of voluntary muscle
From the Greek words neuron, meaning nerve or
sinew, and pathos, disease or
Definition: any disease of the
nervous system. Amyotrophic lateral sclerosis and spinal muscular
atrophy, in which loss of nerve cells prevents muscles from working,
are neuropathies, as are diseases in which nerve fibers malfunction,
such as Charcot-Marie-Tooth and Dejerine-Sottas disease.
From the Greek words dys, meaning abnormal or
faulty, and trophe,
Definition: a disorder caused by
defective "nutrition" or metabolism
This term is actually a misnomer based on the wrong
assumption made many years ago that muscle was being damaged by a
lack of nutrients. In modern usage, it refers to a group of genetic
myopathies in which a muscle protein is absent, deficient or
The disorders classified as "muscular dystrophies"
are myopathies in which a genetic defect results in structural
damage to the muscle. Other myopathies involve damage to the
muscle's contraction apparatus or energy production system.
From the Greek words a, meaning not, and
decrease in the size of an organ or tissue (wasting). Common causes
of diseases involving muscle atrophy are a lack of nutrients or
blood supply or loss of signals from nerve cells.
The muscle wasting or atrophy in this genetic disorder
results from loss of signals from nerve cells in the spinal
From myo, meaning muscle; a, without;
and sthenos, strength
weakness or lack of strength. Today, "myasthenia" refers
specifically to muscle weakness resulting from faulty communication
between nerve and muscle at the place where nerve and muscle meet
(the neuromuscular junction).
From myo, meaning muscle, and tonos,
Definition: inability to relax muscles
This genetic disorder involves (but isn't limited to)
both myotonia and structural damage to muscles (dystrophy).
From the Greek word myo, meaning muscle, and
the Greek suffix itis, meaning inflammation
Definition: an inflammation of the muscle,
which can result from infection, injury, or attack by the immune
system on muscle tissue