Pattern reversal and flash visual evoked potentials in essential tremor

Abstract

BACKGROUND: There is evidence that nonmotor clinical findings may occur in essential tremor (ET). The aim of the study was to determine whether there is a subclinical impairment of visual pathways in ET by conducting visual evoked potential (VEP) studies on patients with ET. METHODS: Healthy individuals and patients with ET were included in the study. Individuals with visual impairment, eye disease, neurodegenerative diseases, or migraine were not included in the study. Pattern reversal VEP (PrVEP) and flash VEP (FVEP) were applied to all individuals. N75, P100, and N135 waves were obtained by PrVEP, whereas N1, P2, N2, P2, N3, and P3 waves were obtained by FVEP. The latencies and amplitudes of these waves were analyzed. RESULTS: Thirty-five healthy individuals (12 male, 23 female) and 29 patients with ET (16 male, 13 female) were included in the study. The mean age of the patients in the control group and the patients with ET was 33.9 ± 8.5 and 35.9 ± 16.8 years, respectively. Age and gender were not statistically significantly different between the two groups. The mean right/left P100 wave latencies of the control group and ET group were 90.3 ± 7.3/91.5 ± 6.1 ms and 99.4 ± 9.1/101.1 ± 7.8 ms, respectively (P = 0.009/P < 0.001). The mean right/left P2 wave latencies of the control group and ET group were 104.9 ± 15.1/104.8 ± 13.8 ms and 117.6 ± 15.4/118.3 ± 15.6 ms, respectively (P = 0.001/P = 0.001). CONCLUSION: This study showed that subclinical involvement of visual pathways may occur in ET.