MYXEDEMA, a peculiar state of the nerve tissues of the body causing many nutri tive changes in the body. Its cause is a loss of function of the thyroid gland (q.v.) and a resulting diminution in the supply of its secre tion to the blood. It is strictly a fibrosis of the thyroid. The disease was first described by Sir William Gull of London in 1873. A similar condition results from removal of the gland by operation. Women are the principal sufferers, furnishing 80 per cent of the cases. Myxedema is found in cold climates, and prob ably most frequently in Europe; in certain dis tricts for instance in Switzerland, France and Italy, it appears to be endemic. It is believed that certain mineral constituents in the water in these regions is the cause of the endemic cretinoid degeneration, as the water was brought from a distance to a certain goitrous region in Rupperwill and the disease disap peared. The onset of the disease is gradual, and the symptoms are loss of activity, sensi tiveness to cold, falling of the hair, decay of teeth and nails, rough, dry skin, spongy gums, diminution of perspiration, yellow tint and swelling of the face, paleness of the mucous membrane, subnormal temperature, constipation, albuminuria, impairment of sight and hearing, headache, slow intellection, hallucinations and, in some cases, a hypothyroid psychosis. A most striking symptom is the oedema, which de velops principally in the loose subcutaneous tissues, appearing like a considerable swelling. The face, the back of the hands and the upper limbs first present enlargement; but in time it involves the whole body. The thickening and
enlargement of the face renders the patient un recognizable.
What has been called infantile myxedema by some writers is characterized by a failure of the child to develop bone in the normal man ner, the result being a fat dwarfish individual. The dentition is imperfect and the anterior fontanelle does not close for many years.
Treatment consists in the administration of thyroid gland and of tonics. Grafting of a partial or entire thyroid gland taken from an animal into the subcutaneous tissue has not been very successful. Internally a glycerine ex tract of sheep's thyroid is given, or a dry ex tract, or an emulsion may be made and used hypodermically. This treatment was first suF gested by Murray, of Newcastle-upon-Tyne, in 1891. The remedy must be used cautiously, especially if cardiac or vascular disease exists. Thyroid may cause vomiting, diarrhoea, fever, profuse perspiration, headache, glandular swell ings and prostration. The dose should be graduated so as to avoid these symptoms of poisoning. After many months of treatment the disease disappears. The dose should then be diminished, but the patient must continue to take thyroid all her life, lest the myxedema re turn. (See CRETINISM; THYROID GLAND). Con sult Gull, 'On a Cretinoid State Supervening in Adult Life in Women' (in Clinical Society's (Transactions,' London 1874) ; Gimlette, 'Myxcedema and the Thyroid Glands' (London 1895); Jelliffe and White, 'Diseases of the Nervous System' (3d ed., 1919, (Endocimo