Neuromuscular disease is a very broad term that encompasses many diseases and ailments that impair the functioning of the muscles, either directly, being pathologies of the voluntary muscle, or indirectly, being pathologies of nerves or neuromuscular junctions.
Neuromuscular diseases are those that affect the muscles and/or their direct nervous system control, problems with central nervous control can cause either spasticity or some degree of paralysis (from both lower and upper motor neuron disorders), depending on the location and the nature of the problem. Some examples of central disorders include cerebrovascular accident, Parkinson’s disease, multiple sclerosis, Huntington’s disease and Creutzfeldt–Jakob disease. Spinal muscular atrophies are disorders of lower motor neuron while amyotrophic lateral sclerosis is a mixed upper and lower motor neuron condition.[medical citation needed]
Neuromuscular disease can be caused by autoimmune disorders, genetic/hereditary disorders  and some forms of the collagen disorder Ehlers–Danlos Syndrome, exposure to environmental chemicals and poisoning which includes heavy metal poisoning. The failure of the electrical insulation surrounding nerves, the myelin, is seen in certain deficiency diseases, such as the failure of the body’s system for absorbing vitamin B-12
Diseases of the motor end plate include myasthenia gravis, a form of muscle weakness due to antibodies against acetylcholine receptor, and its related condition Lambert-Eaton myasthenic syndrome (LEMS). Tetanus and botulism are bacterial infections in which bacterial toxins cause increased or decreased muscle tone, respectively.Muscular dystrophies, including Duchenne’s and Becker’s, are a large group of diseases, many of them hereditary or resulting from genetic mutations, where the muscle integrity is disrupted, they lead to progressive loss of strength and decreased life span.
Further causes of neuromuscular diseases are :
Inflammatory muscle disorders
- Polymyalgia rheumatica (or “muscle rheumatism”) is an inflammatory condition that mainly occurs in the elderly; it is associated with giant-cell arteritis(It often responds to prednisolone).
- Polymyositis is an autoimmune condition in which the muscle is affected.
- Rhabdomyolysis is the breakdown of muscular tissue due to any cause.
In terms of the mechanism of neurological diseases, it depends on which one—whether it is amyotrophic lateral sclerosis, myasthenia gravis or some other NMD.One finds that in muscular dystrophy (Duchenne), gene therapy might have promise as a treatment, since the mutation in a nonessential exon, can be improved via exon-skipping.
Diagnostic procedures that may reveal muscular disorders include direct clinical observations. This usually starts with the observation of bulk, possible atrophy or loss of muscle tone. Neuromuscular disease can also be diagnosed by testing the levels of various chemicals and antigens in the blood, and using electrodiagnostic medicine tests including electromyography (measuring electrical activity in muscles) and nerve conduction studies.
In neuromuscular disease evaluation, it is important to perform musculoskeletal and neurologic examinations. Genetic testing is an important part of diagnosing inherited neuromuscular conditions.