Home » What is Myasthenia?

What is Myasthenia?

Myasthenia Gravis (MG)

Myasthenia gravis is an autoimmune disease which is characterized by fluctuating muscle weakness, which in rare cases may be fatal, particularly if left untreated. The body’s immune system, in the form of antibodies, attacks and damages the nerve signal reception areas on the muscles – causing a breakdown in communication between nerve and muscle; this results in a loss of effectiveness of the muscle. The weakness commonly affects the muscles of speech, swallowing, eyes or breathing, as well as the legs and arms.

It is rare – one in 10,000 – but even rarer in children. The cause of this auto-immune reaction is not yet known.

An MGA booklet providing further information is available here. A short video is also available on the MGA site here.

Lambert-Eaton Myasthenic Syndrome (LEMS)

LEMS is at least ten times less common than MG. Although muscle weakness is the main problem, this fluctuates less than in MG. It is also a ‘bottom up’ pattern of weakness, affecting the legs and arms but less commonly the muscles of speech, swallowing, eyes or breathing. LEMS comes in two forms: about half of patients have a ‘small cell’ lung cancer and usually starts after the age of 40. In the other half of patients there is no tumour, and children as young as nine years old can be affected. Like MG, LEMS is caused by auto-antibodies.

An MGA booklet providing further information is available here.

Congenital Myasthenic Syndrome (CMS)

Congenital myasthenic syndromes (CMS) represent a group of currently uncurable genetic conditions due to a number of defects in different faulty genes affecting various parts of the neuromuscular junction.

The syndrome has an occurrence of just one or two in a million. A faulty gene affects the structure of the neuromuscular junction and thus the transmission of messages from nerve to muscle – the muscles fatigue and weaken rapidly making repetitive movements, like walking, difficult or impossible.

Many children have problems with movement, breathing, eating and drinking, and keeping their eyes open and in focus as the fault affects all skeletal muscles. Some are more mildly affected, others more seriously – severity can vary even within families carrying the same gene fault. A few of the children are wheelchair-dependent, most however are mobile for short distances but need chairs for anything further.

The children are on frequent medication (for example, every three hours) relevant to their specific gene fault to help boost the nerve signal and prevent a myasthenic crisis – where the muscle weakness can affect breathing, with life threatening consequences.

More information on this condition can be found here.

A new MGA booklet providing further information is available here. A short video on the MGA site is available here.