Mentally, the patient is retarded and slow, there is lack of interest, a disinclination to work, sleepiness and a slow monotonous type of speech and there is usually a gain in weight. The hair is dry, coarse and brittle. However, these patients, if they are aware of these deficiencies in their psyche, may then develop nervousness, fretfulness or peevishness. We find in these cases that there is a decreased muscle tone in the heart, with feebleness of cardiac action. There will be a low pulse pressure, with increased capillary permeability.
Pathologically, the changes which occur in the thyroid gland are pressure, destruction of the cellular elements which the gland depends upon for the production of this hormone and eventually the small thyroid gland which is left, represents no more than is left in a totally thyroidectomized patient, so far as its functional ability; goes.
(5) Non – toxic Nodular Goiter – Colloid changes with nodule formation and degeneration are common in apparently normal people over 45 years of age. Their presence indicates a gradually diminishing activity of the thyroid gland.
Nodular goiters arise from simple or subiodic goiters, from chronic Thyroiditis, and in congenitally aberrant thyroid tissue. They may appear as a result of diffuse hyperplastic goiter with hyper – thyroidism. There is a tendency for the follicular cells to pile up on one another to form metaplastic masses which later, through growth and coalescence, give rise to readily palpable masses.
The overgrowth of these cells is thought to be due to an increased stimulation by the thyrotropic hormone of the pituitary. These nodular goiters are commonest in the endemic areas of the world. Adenomas arising in such cases are functionally less active than the surrounding normal tissue. They take up less radio active iodine and produce encapsulated lesions, or diffuse, multiple enlargements merging almost imperceptibly into the normal elements of the gland. They are rarely neoplastic, but rather a metaplasia of the normal glandular elements.
The importance of these, aside from their unsightliness, must be stressed because of the complications which may arise, namely, malignancy, pressure syndromes and thyrotoxicosis. Cases which have this criteria must be operated upon. There is a school of thought which believes that all nodular goiters should be operated upon due to the possibility of some nodules being malignant. It is my belief that these nodules should be removed. Due to the tendency for recurrence in cases where nodules have been removed, it is good surgical practice to perform subtotal thyroidectomies in such cases.
(6) Hyperthyroidism or Toxic Goiter – These cases comprise Graves Disease (exophthalmic goiter) or Parrys Disease (primary hyperplastic goiter) with or without ophthalmos; Plummers Disease (toxic anenoma or toxic nodular goiter).
It may be noted here that the onset to toxic symptoms in Plummers syndrome usually occurs a number of years after the nodular goiter has been noticed. On the other is more acute in Graves Disease the thyrotoxic symptoms precede any noticeable enlargement of the gland. The onset is more acute in Gravers Disease. The goiter in toxic adenoma is nodular, usually asymmetrical and larger than we see in Graves Disease. GRavers Disease is seen in younger people, while Plummers Disease in those who are over 40.
It is believed that a neurohormonal mechanism is involved in the pathogenesis of toxic goiter. Nervous impulses stimulate the anterior pituitary to produce an increased output of thyrotropic or thyroid – stimulating hormone, followed in turn by increased activity of the thyroid cells, with over – production and release of thyroid hormone. There is a tendency for spontaneous remission and intermission, each of which will leave in its wake residual pathology. It is these cases which produce our mixed types of thyrotoxicosis in which hyperplastic and adenomatous changes may co – exist.
In a later stage, if hypertrophy and hyperplasia continue for a sufficient time, a stage of exhaustion from over – work will occur. The acini of the cells become smaller and atrophic. Aside from this, there is fibrous tissue replacement of the parenchyma of the gland. These are the cases which give rise to the so called “burnt out” type of goiter.
In a thyrotoxicosis most frequently there has been psychic trauma. This is noted in 90 percent of the cases of Gravers Disease and 40 percent Plummers Disease. However, there previously must have been a susceptible constitution.
In the symptoms, initially, we find fatigue and weakness and palpitation eventually running into fibrillation; and, if not treated, irritability and intolerance of heat, prominence of the eyeballs and increased sweating. In the female, there may be disturbances of the menstrual function, usually amenorrhoea; diarrhoea may be a frequent symptom in these cases.
In the fulminant cases of Graves Disease you will find that it is the vital organs such as the heart and liver which break down, rather than the thyroid itself. The thyroid crises which were common after thyroid surgery were due most often to disturbance in liver metabolism. The thought that cases of Graves Disease must have poor nutrition is not actually true. In fact, 4 percent of the cases are overweight. However, as time goes on, the patient will lose appetite and then there is ensuing rapid loss of weight. In a number of cases, there is marked irritability, the patient is restless and ill at ease. There is body hyper – activity and emotional instability. The mental picture may go on to a stage of manic – depressive disturbances and it is difficult at times to distinguish these cases from true psychoses.
Tremor may be so fine that it may only be detected by placing the tips of your fingers upon the outstretched hand of the subject. Your thyroid patient has a scared look with an anxious expression. There may be marked flushing of the face. The ocular changes, classically Stellwags sign, von Grafes sign and Moebius sign are well known to all of us. Commonly these signs are bilateral, but they are often more striking in one eye than in the other or occasionally confined to one side.
The goiter, on palpation, is usually smooth, uniformly enlarged and presents a thrill on palpation and a bruit during auscultation. In the laboratory tests for diagnosis, the basal metabolic rate is much more important than all the other laboratory methods. Evaluation of the basal metabolic rate must be made. There are cases in which a basal rate of plus 15 may be very significant, if it is known that previously this patient had a lower rate, for instance from minus 10 to a minus 20. It is found that the serum cholesterol is lowered in the thyrotoxic patient. Under treatment it is found that with reduction of the basal metabolic rate, there is an increase in the serum cholesterol value.
The blood iodine determination is a valuable test in determining the border line case. The protein – bound fractions in hyperthyroidism will vary from 8 to 22 gammas per 100 cc.; in hypothyroidism, the range will be from .0 to 4.0.
