[Neurophysiological evaluation of cognitive functions in patients with anorexia nervosa--preliminary report]

Anorexia nervosa (AN) is a disease with multi factorial etiology. Recent studies search the cause of its origin in impairments in neuroendocrinal transmission, genetics, psychological and socio-cultural factors. This disturbance affects the patient's attitude to eating. Many complex physical and psychiatric symptoms of AN require wide approach to the patient on the biological, psychiatric and psychological level.

The purpose of this studies was to determine implications in cognitive functioning in patients with AN.

10 patients with AN and 20 healthy as a control group were recruited. Cognitive functioning was evaluated using P300 wave component of event related potentials (ERP) and Wisconsin Card Sorting Test. International Federation of Clinical Neurophysiology (IFCN) recommendations for recording and analyzing of ERP were used. These studies were performed using Viking Quest (Nicolet ViaSys Healthcare, U.S.A.). They were recorded using the "oddball paradigm" procedure. The reception of potentials was completed by unipolar method with far-field recording (Fz, Cz, Pz and 10, EOG, 10-20 system). The latencies of the first negative wave N1, next positive P2, the following N2 negative and positive component P300 were evaluated. Moreover, the amplitude differences N1-P2, P2-N2, N2-P3 were analyzed.

It was found that both latencies of P300 potential components and WCST results were quite normal. However, reduction of P300 amplitude was observed in patients with AN compared to control group, what can be the result of diminished absorption of cognitive structures during analyzing the stimuli.

The results did not show significant differences in cognitive functioning in patients. Changes in the components of P300 wave indicate the need for further neurophysiological research on larger group to determine the degree of impairments in cognitive functioning in patients with AN.