methimazole and Hyperthyroxinemia

A 15-year-old girl presented with chorea as a first sign of Graves' hyperthyroidism. Chorea abated with antithyroid drug treatment and reappeared when hyperthyroidism recurred but not when thyrotropin receptor antibodies increased after administration of (131)I. Therefore, chorea in this patient is associated with hyperthyroxinemia and not with autoantibodies.

Topics: Adolescent; Anemia, Sickle Cell; Antithyroid Agents; Bone Marrow Transplantation; Chorea; Comorbidity; Diagnosis, Differential; Drug Therapy, Combination; Female; Follow-Up Studies; Graves Disease; Humans; Hyperthyroxinemia; Methimazole; Neurologic Examination; Thyroid Function Tests; Thyroxine; Transplantation Conditioning

Numerous clinical observations have provided evidence for a tight connection between impairments in the functions of the hypothalamo-hypophyseal-thyroid system and nervous and mental disorders. The aim of the present work was to compare the effects of experimental decreases and increases in blood thyroxine levels on the extents of two types of pathological freezing reaction in male Wistar rats--spontaneous catalepsy and catalepsy evoked by pinches at the nape of the neck (pinch-induced catalepsy). Chronic administration of the thyroxine synthesis inhibitor propylthiouracil (5 mg/kg/day for 28 days) significantly decreased the blood hormone level and sharply increased the proportion of animals showing spontaneous catalepsy and the immobility time, but had no effect on the extent of pinch-induced catalepsy. At the same time, chronic administration of thyroxine (0.1 mg/kg/day for 28 days), which produced significant increases in blood hormone levels, had no effect on the extent of spontaneous catalepsy but significantly increased the proportion of animals showing pinch-induced catalepsy and the duration of this type of catalepsy. It is concluded that both insufficiency and excess of thyroid hormones have cataleptogenic actions, but enhance different types of catalepsy.

Topics: Animals; Antithyroid Agents; Behavior, Animal; Drug Administration Schedule; Freezing Reaction, Cataleptic; Hyperthyroxinemia; Male; Methimazole; Propylthiouracil; Rats; Rats, Wistar; Thyroid Hormones; Thyroxine; Time Factors