The outcome of interventional therapy in the field of neuromuscular disease has to be set against the natural history of the underlying condition.

For many, if not most, of neuromuscular disorders, such information is either scanty or just beginning to emerge. The majority of neuromuscular disorders have in the past been considered untreatable and attention has been paid more to management than to interventional therapy. Such therapies have applied mainly to the areas of inflammatory myopathy and myasthenia gravis. However, in these disorders, where treatment has been available for a very considerable time, there is no consensus as to which treatment modality is most appropriate.

The neuromuscular disorders considered in this chapter are those which are encountered frequently, i.e. anterior horn cell disease, diseases of the myoneural junction, inflammatory myopathy, Xp21 deletional myopathies, myotonic dystrophy, congenital myopathies and the metabolic myopathies (Table 17.1). Within the latter only those in which therapeutic intervention has been shown to be of benefit will be considered since in many of them, particularly the mitochondrial disorders, the natural history is as yet poorly understood.

Motor neurone disease (amyotrophic lateral sclerosis)

The term motor neurone disease (MND) is often used interchangeably with amyotrophic lateral sclerosis (ALS). However, ALS is one subdivision of MND, which also encompasses progressive bulbar palsy (PBP), progressive muscular atrophy (PMA) and primary lateral sclerosis (PLS).

ALS, the combination of upper and lower motor neurone signs and symptoms with the development of bulbar symptomatology, is the most common of these conditions.