Endocrine Abstracts

Cognitive dysfunctions, observed in the course of thyroid diseases (hyper- and hypothyroidism), have – in the recent years – been the subject of interest for many research teams. Even mild disorders of thyroid functionality are associated with hormone concentration changes which affect the general mood and cognitive functions. The efficiency of cognitive functions, which allow the man’s adaptation to environment al conditions, is determined by the activities of particular brain areas, while normal concentration of thyroid hormones is important to maintain proper brain functionality.

The goal of the reported study was an evaluation of the relationship between the efficiency of cognitive functions and concentrations of thyroid hormones (fT₃ and fT₄) and thyrotropin (TSH).

Fifty (50) patients with Graves’ disease (39 female and 11 male) were qualified into the study, the mean age: 41.1±10.7 years. Graves’ disease was confirmed in laboratory tests by increased concentrations of anti-TSH-R antibodies. The control group comprised 31 healthy volunteers (23 female and 8 male), the mean age: 40±10.3 years. The study group and the control group were matched with regards to their sex and age. Serum concentrations of TSH, fT₃ and fT₄ were measured in both groups.

The following neuropsychological tests were applied for assessment of cognitive functions: the Trail Making Test A&B (TMT A&B), Stroop Colour-Word Interference Test, the Verbal Fluency Test (FAS), the N-back Test and the Wisconsin Card Sorting Test (WCST).

The results, obtained in the group of patients with Graves’ disease, do not indicate any significant relationships between the concentrations of thyroid hormones and TSH and the efficiency of studied cognitive functions. Only in case of the WCST test, were significant correlations noted with the concentrations of the evaluated hormones, what provides some evidence for the higher sensitivity of working memory and executive functions to disorders resulting from hormonal variations.