CITTO IULIAN TAISESCU, VIOREL BICIUSCA, LORENA SAS, GEORGIANA CAMEN, TEODOR SAS, CARMEN ALBU, OANA TAISESCU CHANGES OF VISUAL EVOKED POTENTIALS IN PATIENTS WITH THYROID DYSFUNCTION The visual evoked potentials technique records the cerebral bioelectric activity generated by light stimulation. Evoked potentials is a good method of assessing the electrical response of the brain to different stimuli and has been used extensively in the study of brain disturbances. We registered VEP on 18 hyperthyroid and 18 hypothyroid patients, without other endocrine, metabolic, ophthalmologic or neurological illnesses, the 2 groups having practically identical ages, but sex repartition, illness age and treatment duration being statistically different (p<0.001). Hormonal, radiological, biochemical dosages and physiological paraclinic determinations were performed on all 36 subjects, through classical methods, and VEP recordings, with a 4 channel polygraph through pattern reversal stimulation (1 Hz), measuring all parameters (latency, amplitude, duration, surface, steepness etc.) of N75 and P100 waves. Between groups, the recorded hormone levels and other recordings showed great differences, very highly statistically significant (p<0.001), only arterial pressures being just statistically significant (p<0.05). The Pearson’s r correlation coefficients indicated extremely high correlations (r=0.90-0.98) between all parameters. Between the 2 groups, hypothyroid patients had latencies of P100 wave higher with 17.88% (p=0.0028) and of the N75 wave with 9.98% (p=0.016), and the duration of the N75 wave lower with 26.37% (p=0.026), the other parameters of VEP waves modifying up to 52.35%, not statistically sgnificant due to high standard deviations. The duration of N75 correlates with the majority of humoral-paraclinical parameters, indicating a functional interdependency between them and the function of the cortex. The ratio of the amplitudes and of the areas of P100/N75 indicate a severe inhibition to hypothyroid patients, a precisely quantified reduction of the cerebral activity.