EXOPHTHALMIC GOITRE.—Exoph thalmos: Gr., &eprp0a2.11o;, prominent eyes.
Definition.—Exophthalmic goitre, or Graves's disease (called by the Germans Basedow's disease) is a chronic, not self limited affection, characterized by a great variety of signs and symptoms, the most familiar of which are enlargement of the thyroid gland, prominence of the eyeballs, nervous irritability, muscular tremor, and vasomotor affections of strik ing character.
Disorders of metabolism and of local nutrition also occur,, and many other manifestations, mainly due to disturb ances of the nervous functions, although associated with them are certain signs suggesting morphological disorders of growth, and others of myxcedematous like character.
These signs and symptoms are prob ably due, for the most part, to a vitiation of the blood by altered and excessive secretion from the thyroid gland, but it is still uncertain whether or not there exist, behind or in conjunction with this disease of the thyroid, some special sus ceptibility on the part of the nervous system. It is in favor of the latter view that a portion of the manifestations of the disease seem to reproduce, in morbid caricature, an assemblage of quasiphysi ological and related functions ("fright complex," as suggested by Mackenzie and others).
Varieties. — The attempt has been made by various writers to divide the cases of Graves's disease into a "pri mary," or pure, form, and a "secondary," or symptomatic, form. The symptoms of the latter variety are supposed to be excited—sometimes singly or in small number—by some special source of pe ripheral irritation, such as disease of the nose or of the genital or intestinal tract, or—and that pre-emiently—by pre existing goitre of one or another form acting as a mechanical irritant. This view is untenable except in a very limited sense, and introduces a needless confu sion into our conception of the nature and symptomatology of Graves's dis ease.
I.t is true that cases are now and then met with where the removal of one or another of these special sources of irri tation leads to rapid improvement, just as the relief of errors of refraction occa sionally leads to rapid improvement in cases of epilepsy or migraine, but to con clude in either case that the true cause of the disease has been found is to follow a misleading method of reasoning. When
the nervous system has been under the tax of bearing several loads at once the removal of any one of them may suffice to communicate a new "set" to the nerve functions or to provide the amount of relief needed to make recovery possible. It is not even safe to conclude, in such a case, that the special irritation in ques tion was originally the sole or principal exciting cause of the disease. The most that can be inferred is that it was acting, at the moment of its removal, as a con siderable cause of nervous instability, either general or local.
"Secondary" cases of Graves's disease are liable to become as severe and as com plex as "primary" cases, and when both are fully developed there is no criterion by which we can distinguish between them. Neither is such a criterion fur nished by differences in their modes of onset, since in some of the cases which would be designated as "primary" the symptoms come on very slowly, while, on the other hand, in any class of cases a slow progression or incomplete symptom complex is liable to give place suddenly to a rapid development.
The differences based on mildness or severity, completeness or incompleteness of the clinical picture, etc., although not of radical importance, and not suited to form a basis for classification, are, never theless, of great interest. In some cases the symptoms reach in a few days, or even hours, a degree of development for which, in other cases, years had been required. Even a fatal ending may occur in the course of days or weeks.
Some of the characteristics especially calling for study are the following: Those indicating an admixture of a true myxw dematous tendency, such as dry skin, non-pitting oedema, possibly falling of the hair, etc.; those indicating formative, morphological modifications of growths, as slenderness of the fingers and supple ness of the joints.