The Medical Treatment of Simple and Exophthalmic Goitre.

NZMJ, 1926

A paper read before the Annual Conference by

F. V. Bevan-Brown, M.D., M.R.C.P.

I propose in this paper to take exophthalmic goitre first, and to discuss some points in its pathogenesis before passing on to its treatment. The latter can hardly be dealt with in a rational manner unless the essential features of the underlying causes of the disease, as far as they are known, are at the same time borne in mind. Grave’s disease is not primarily a disease of the thyroid gland, but a condition in which there is present a persistent stimulation, varying in intensity, of the sympathetic nervous system, including the suprarenals. A secondary effect of the resultant activity is stimulation of certain other glands of the body, including the thyroid gland. Hypertrophy and hyperplasia of the latter occurs, its vesicles actively secrete and eventually become exhausted and emptied of their colloid, and the iodine content of the gland, as shown by Marine and Lanhart, falls very low. Direct and indirect evidence is plentiful to show that the essential feature of Grave’s disease is a hyperactivity of the sympathetic system. Cannon showed, by uniting the proximal end of one phrenic nerve to the sympathetic trunk of that side that certain of the cardinal symptoms, including exophthalmos, could be reproduced. Marine found damage to the suprarenal cortex of rabbits, produced experimentally, caused a rise in the basal metabolic rate (increased heat production), loss of iodine content of the thyroid gland, and general symptoms of loss of weight, exhaustion and myocardial changes.

The primary cause of Grave’s disease is the stimulus that over-activates the sympathetic nervous system. One recognised form of stimulus is a psychic one—sudden fright or shock, prolonged anxiety, prolonged fatigue. Crile’s work in this connection will be recalled. A second form of stimulus that is not generally accepted is the toxic. This is so threadbare and unsatisfactory an explanation of many obscure diseases that one instinctively feels sceptical about it when it is brought forward. There is, however, in Grave’s disease an outstanding indication of the presence in the organism of a persistent and abnormal chemical stimulus, and in practical support of this idea one has the definite fact that cases do get well that receive no other treatment beyond the elimination of a toxic focus. It is my personal belief that in the great majority of cases this toxic focus is the alimentary tract. Failure to recognise this fact and the difficulty one has of correcting the condition are two reasons why the view of toxic absorption from the bowel as one of the underlying causes of Grave’s disease is not more generally accepted. These two sources of stimuli, the psychic and the toxic, occur so commonly that one would expect Grave’s disease to have a much higher incidence than it does, and it is clear that other and unknown factors are present in its development.