Again, it occurs more frequently in women than men in a ratio of three to two. The muscles of the face, throat, larynx and neck become weak, often resulting in difficulty in breathing, speaking, chewing and swallowing. Weakness of the muscles of the arms or legs makes simple tasks like combing the hair or going up stairs difficult. It has been found that abnormalities of the thymus gland are present in 75 per cent of myasthenia gravis sufferers, and in 10 per cent of these a form of tumour of the thymus gland develops. It is thought that the initial abnormal response in myasthenia gravis may be against acetylcholine receptors on epithelial cells in the thymus causing cross reactivity between the acetylcholine receptors in the thymus and muscles.
Drugs used include neostigmine, distigmine, and pyridostigmine.
Occasionally high doses of steroids or azathioprine may be used to block the immune process when treating myasthenia gravis. Myositis Myositis is a disorder occasionally found in people aged 40 and 60. It causes weakness of the muscles, particularly those involved in movement of the shoulders and hips and affects three times as many women as men. Inflammation and destruction of muscle occurs which may be treated with steroids or with drugs to suppress the immune system. Dermatomyositis Dermatomyositis is similar to myositis and is caused by inflammation of the muscles and skin.