Visual evoked potentials in two groups of prisoners of war after release from Serbian detention camps.

Visual evoked potentials (VEP) were determined in two groups of released prisoners of war (POWs) from Serbian detention camps during the war in Croatia 1991/92. The first group comprised 22 POWs (group I), examined 10 to 60 days after release, and the second group comprised 24 POWs (group II), examined 6 to 9 months after release. The third group comprised 36 control subjects. Statistically significant increases in the amplitude of waves P50, N75, P100, N145, and significant prolongation of the latencies of wave N145 were found in group I. In group II, significant increases were found in the latencies of waves P50, N75, P100 and N145, and increased amplitude of wave P50. The greater significance of wave latencies compared to amplitudes, and greater significance of changes in early VEP waves than later VEP waves, can be considered evidence of future progression of these changes in the released POWs. This was confirmed by the significant increases in VEP parameters in groups I and II, which exceed +/- 2SD of the relevant control group, and significantly greater number of the same parameters in group II in relation to group I. There was no significance (i.e. asymmetry) among the three groups when the parameters of the determined visual evoked potentials were compared for the left and right eye.