Definition,- Tetany is a condition which has been considered by a large number of writers, and various ideas have been propounded as to its nature, and even regarding the essential features of the affect- ion. Osler's definition is characteristically brief and inclusive; he defines tetany as " an affection characterised by peculiar bilateral tonic spasms, either paroxysmal or continued, of the extremities1(1) Risien Russell states the same thing rather more fully and adds "in severe cases the muscles of the trunk, neck, face, eyes and larynx may become involy - ed in the spasm." (2). Dr Russell considers that "there are different gradations - -- from mild carpo- pedal contractions associated with rickets to sever: general spasms, which may even simulate tetanus ". Carpo- pedal spasm in children is not rare, and Pro - fessor Osler thinks it a mistake to call these cases true tetany.(3). Henoch (4) writing on tetany in children stated:- " This affection is classed with tkiany by many, but, in my opinion, it is well to separate the two diseases entirely. I have never been able to detect the symptoms regarded by Trousseau as distinctive -- in idiopathic contractures of children" But in this relation it must be noted that Trousseau'. symptom is sometimes not obtained in undoubted cases of tetany. (5). Probably the affection occurs under various circumstances, and the spasm can be produc- ed by more than one cause.
Tetany occurs in adults mainly in thre. ?conditions, First, in pregancy, lactation, menstrual disorders and the like.
Secondly, from deprivation of the thyroid gland (or.r para- thyroid.)
Thirdly, in association with gastro -intestinal dis- turbances, usually dilatation of the stomach or in- testines.
It occurs very rarely in oh L4 other conditions and in epidemics, and in children is usually assoc -, fated with rickets.(1).
This thesis deals 'specially with the third adult variety, but in the attempt to elucidate the fundamental etiology and pathology it will be necessary t to refer to other varities.