血液透析患者の視覚性誘発電位(VEP)および脳波

The CNS (Central Nervous System) of 20 patients undergoing hemodialysis (dialyzed group, 38~65 y. o.) were studied by VEP (Visual Evoked Potential) comparing with 20 healthy subjects (normal group, 38~66 y. o.). The 20 patients were divided into non-diabetic group of 14 with chronic gromerulonephritis and diabetic group of 6 with diabetic nephropathy. EEGs containing VEPs evoked by flash stimuli once every 5 second were recorded by 100 sweeps with 1024 msec of analysis time, simultaneously through the two derivations (2CH : O1→A1+2 and 5CH : O1→Cz). The EEGs were subjected to the quantitative frequency analysis. These data of VEP were examined between these subject groups, with reference to the EEG and the blood data. The following results were obtained.
1 The waveforms of group mean VEP of normal group, dialyzed group and non-diabetic group had triphasic contour containing dominant components of N3, P6, N8 (2CH) or N3, P5, N8 (5CH), but that of diabetic group severely deteriorated and lost the contour.
2 In dialyzed group and non-diabetic group, latencies of early components (P1-P3) were longer and peak-to-peak amplitudes of late components were larger than those of normal group significantly.
3 Latencies of early components were longer in the ascending order normal group, non-diabetic group and diabetic group, and peak-to-peak amplitudes were smaller in the ascending order non-diabetic group, normal group and diabetic group.
4 Quantitative frequency analysis of EEG indicated that the peak frequency of α waves of dialyzed group and non-diabetic group were smaller, and θ power % of diabetic group were smaller than that of normal group.
5 From the correlation coefficients between the EEG power% and the latencies or the amplitudes of each compenent of VEP, δ power % correlated significantly with the latencies of middle and long latency components in 2CH and those of long latency in 5CH positively. β1 power % correlated significantly with peak-to-peak amplitude of long latency components in 5CH positively.
6 BUN and potassium correlated positively with latencies of early components. BUN correlated positively with peak-to-peak amplitudes. Hemoglobin correlated negatively with latencies.
7 These results indicte that the CNS of diabetic group was disturbed more severely than dialyzed group and non-diabetic group in VEP and EEG, and the inhibitory system (GABA) of optic center cortex related to late components was disturbed first.