Encephalopathy associated with Hashimoto thyroiditis: diagnosis and treatment.

Six patients with Hashimoto thyroiditis (HT) and associated encephalopathy (HE) are described and compared with 14 well-documented cases retrieved from the literature. HE typically affects patients when they are euthyroid and, in an appropriate clinical situation, antithyroid autoantibodies are the main indicators of HE. Since clinical features of HE are unspecific, other aetiologies such as infectious, metabolic, toxic, vascular, neoplastic, and paraneoplastic causes have to be excluded. Our own six cases and those from the literature show that two types of initial clinical presentation can be differentiated: a vasculitic type with stroke-like episodes and mild cognitive impairment in nine patients, and a diffuse progressive type with dementia, seizures, psychotic episodes or altered consciousness in 11 patients. These types may overlap, particularly in the long-term course without treatment. Response to steroids was usually excellent with complete remission in 80%. Eighteen of the 20 patients were women. Characteristic, though unspecific, findings were abnormal EEG (90%) and CSF (80%). Together with quantitative neuropsychological testing, these proved sensitive for monitoring the efficacy of therapy. Conversely, antithyroid autoantibody titres did not correlate with the severity or type of clinical presentation. The link between HE and HT is not clear. A pathogenetic role for antithyroid autoantibodies in the central nervous system seems unlikely.

Effects of prolonged infusions of potassium chloride, adrenocorticotrophin or angiotensin II upon serum aldosterone concentration and the conversion of corticosterone to aldosterone in rats.

The temporal relation between alterations in serum aldosterone and in the conversion of labelled corticosterone to aldosterone by incubated adrenal tissue was studied in conscious rats receiving long-term infusions of KCl, ACTH or angiotensin II. When potassium-deficient rats were given KCl, a marked increase in serum aldosterone was observed only after 12 h, i.e. at a time when the conversion of corticosterone to aldosterone had become normal. After 24 h of ACTH infusion into sodium- and potassium-replete rats the serum aldosterone was markedly elevated, whereas the conversion of corticosterone to aldosterone was significantly decreased. After 48 h of continued ACTH infusion the serum aldosterone returned to normal and there was a further decrease in the conversion rate. A 24-h angiotensin II infusion into sodium- and potassium-replete rats induced significant increases in both the serum aldosterone and the conversion. After 48 h of continued angiotensin infusion the serum aldosterone returned to normal while the conversion and the blood pressure remained elevated. These results indicate that the activity of the enzymes involved in the final steps of aldosterone biosynthesis may become rate-limiting for the secretion of aldosterone during potassium deficiency and during prolonged ACTH treatment. On the other hand, the observed transiency of aldosterone stimulation by exogenous angiotensin II was not due to a suppression of the final steps of aldosterone biosynthesis and remains unexplained.

[Cushing's syndrome in bronchial carcinoid: suppressible ectopic ACTH selection]. / Cushing-Syndrom bei Bronchuskarzinoid: supprimierbare ektopische ACTH-Sekretion.

In a 60-year-old woman Cushing's syndrome was induced by an ACTH producing bronchial carcinoid. In spite of the presence of an ectopic ACTH syndrome, the clinical, radiological and biochemical findings and the positive dexamethasone suppression test were compatible with Cushing's disease. Selective enucleation of an adenoma or total hypophysectomy was therefore felt to be indicated. Following total hypophysectomy, however, the Cushing's syndrome persisted and this suggested the possibility of an ectopic ACTH syndrome. As tumor localization was impossible, bilateral adrenalectomy was planned, but before this could be done the patient had to be hospitalized for staphylococcal septicemia and died. Autopsy revealed a subpleurally located bronchial carcinoid as the source of ACTH.