What is neuromuscular disease?
The term “neuromuscular disease” refers to a group of conditions affecting the nerves that control muscle function in the voluntary muscles (the muscles we can control, such as those in the arms and legs). They may also impair the transmission of sensory information to the brain.
While the various different types of neuromuscular disease work in different ways, all of them can be debilitating, as they damage or kill these neurones (nerve cells), causing a breakdown of communication between the brain and the muscles. The end result is often muscle atrophy – the muscles waste away, leading to a number of highly unpleasant physical symptoms that seriously affect quality of life.
Neuromuscular diseases can be sub-divided into:
- Myopathies, e.g. congenital myopathy, distal myopathy, metabolic myopathies, etc.
- Motor neurone diseases, e.g. Amyotrophic lateral sclerosis (ALS/Lou Gehrig’s disease), spinal muscular atrophy, etc.
- Muscular dystrophy (MD)
- Ion channel diseases, e.g. Anderson-Tawil syndrome
- Mitochondrial diseases, e.g. Friedrich’s ataxia (FA)
- Neuromuscular joint diseases, e.g. myasthenia gravis
- Peripheral nerve diseases, e.g. Guillain–Barré syndrome
- Demyelinating diseases, e.g. multiple sclerosis (MS)
What are the symptoms of neuromuscular disease?
Typically, all neuromuscular diseases will cause fatigue and muscle weakness, which becomes more pronounced as the conditions progress. Other symptoms will depend on the type of neuromuscular disorder, and the part (or parts) of the body affected. Some common symptoms to most of these conditions include:
- Loss of muscle mass
- Cramps, aches and pains
- Numbness or tingling
- Loss of balance
- Trouble controlling movement
- Drooping eyelids
- Difficulty swallowing
- Difficulty breathing/diaphragm weakness
- Double vision
The end point of most neuromuscular diseases is weakness of the respiratory muscles, and the subsequent respiratory failure. For this reason, respiratory physicians are usually involved in treatment.
Symptoms can begin at any stage of life, depending on the type of disease.
As there are many types of neuromuscular disease, it is essential to receive a proper diagnosis from a doctor.
Causes of neuromuscular disease
Different neuromuscular disease have different causes, but most are thought to either be genetic (either passed down through families or caused by spontaneous gene mutation) or autoimmune (in which the body’s own immune system malfunctions and attacks the nerves or muscles). In some cases, other factors may be involved, such as exposure to chemicals or poisoning, inflammatory muscle disorders, such as polymyalgia rheumatic, or even certain bacterial infections.
What is the treatment for neuromuscular disease?
At the current time, there is no known cure for any neuromuscular disease, nor any way to prevent it from happening. There are treatments for some specific types of neuromuscular disorder, such as pyridostigmine for myasthenia gravis, or replacement therapy for Pompe disease; however, for most neuromuscular diseases, treatment is focussed on managing the conditions, and making the patient’s quality of life as good as possible. This may be done via medication, physical therapy, and, in certain cases, surgery. Non-invasive ventilation is often required in the later stages, as the muscles that control breathing deteriorate.
Researchers continue to look for a solution, with a lot of work going into researching genetic therapies and new medications in the hope that one day we will be able to cure neuromuscular disorders.