Autonomic Imbalance and Borderline States of Thyrotoxicosis: (Section of Medicine).

Primary thyrotoxicosis may be regarded as having two main components-thyroid overactivity or dysfunction, and instability of the autonomic nervous system. Clinical observation suggests that the proportion of each component varies in individual cases. Results of treatment show that the larger the thyroid element the greater is the benefit of thyroidectomy or X-ray therapy, and the fewer the subsequent residual signs. When nervous instability predominates less relief is obtained by surgery or X-rays, and symptoms may be little changed or even made worse by the addition of hypothyroidism.Cases in which nervous instability predominates, with minimal thyroid dysfunction, have been termed "autonomic imbalance", "neurocirculatory asthenia", or "Basedow's disease with no thyrotoxicosis".Thirteen such cases are described, all of which were females, with average age of 32 years. 9 had enlarged thyroids, 11 complained of palpitations, and 8 of excessive sweating.The basal metabolic rate, estimated in 8 cases, did not exceed +10%. There was some loss of weight in 6 cases, but in none was the appetite increased. The average diurnal pulse-rate did not exceed 95 and sleeping pulse was significantly lower. X-rays of heart, taken in 6 cases, were normal. Psychological troubles in 6 cases. Three cases treated by X-ray therapy and I surgically with no benefit. Remaining 10 cases treated medically with improvement. The group is ill-defined and requires further investigation of cause and treatment.The recognition of autonomic imbalance is important in order to avoid useless thyroidectomy or X-ray therapy, and encourage more extended use of psychotherapy. Investigation of its cause may yield information of value in the aetiological problem of thyrotoxicosis.