Visual Evoked Potential (VEP)--dependable marker for CNS affection in thyroid diseases.

The mean latency and amplitude of P100 component of VEP were studied in forty three controls and eighty nine cases of thyroid dysfunction [Hypothyroid-28; Hyperthyroid-32 and probable Thyroiditis-29 (inclusive of 21 cytology proved)]. The mean latency in hypothyroid, hyperthyroid and probable thyroiditis subjects were 110.69, 111.41 and 109 m.sec in comparison to 101.91, 102.0 and 101.08 m. sec. respectively in controls (p < 0.005). The mean amplitude being 1.34, 6.34 and 2.41 microvolts in hypothyroid, hyperthyroid and probable thyroiditis subjects in comparison to 4.79, 4.16 and 4.59 microvolts respectively in controls (p < 0.005).