Somatosensory Evoked Potential (SEP) and EEG of patients undergoing hemodialysis
Egawa, Shouko The University of Tokushima
Nagamine, Isao The University of Tokushima
Ogawa, Yuuji The University of Tokushima
Furuta, Noriko The University of Tokushima
Ikuta, Takumi The University of Tokushima
The SEP (Somatosensory Evoked Potential) and EEG were studied with 19 patients undergoing hemodialysis (dialyzed group, 41~65 y. o.), consisted of non-diabetic group (13 patients with chronic gromerulonephritis) and diabetic group (6 patients with diabetic nephropathy), comparing with those of 20 healthy subjects (normal group, 38~66 y. o.). EEGs containing SEPs evoked by median nerve stimulation were recorded with 1024 msec of analysis time through the two derivations (1CH : C3'→F3' and 4CH : C3'→A1+2). The group-mean SEPs were obtained with each group, and compared with each other, and then the differences of latencies and peak-to-peak amplitudes of the components were tested statistically between the groups.
The EEGs were subjected to the quantitative frequency analysis. Correlation coefficients were tested between the latencies, peak-to-peak amplitudes and EEG power %, and between the latencies, peak-to-peak amplitudes and blood data. The following results were obtained.
1. The waveforms of group-mean SEP of normal group and non-diabetic group had hexaphasic contour, consisted of the components Pl~8, N1~8. But, in that of diabetic group the contour deteriorated at around the long latency components.
2. The latencies were longer in the ascending order normal group, non-diabetic group and diabetic group, and peak-to-peak amplitudes were larger in the ascending order diabetic group, normal group and non-diabetic group.
3. In the SEP of non-diabetic group, latencies were increased and amplitudes were decreased.
4. In the SEP of diabetic group, latencies were increased more than those of non-diabetic group, and amplitudes were decreased.
5. Quantitative frequency analysis of EEG, indicated decreased peak frequency of α waves in non-diabetic group, and decreased peak frequency of α waves and increased δ, θ waves in diabetic group, more than those in normal group.
6. The correlation coefficients of EEG power % between SEP-latencies indicated increased latencies due to decreased fast waves and increased slow waves, and those between SEP peak-to-peak amplitudes indicated increased amplitudes due to increased fast waves and decreased slow waves.
7. Between SEP-latencies, negative correlation was found with blood K, Ca, BUN, and positive correlation with dialyzed period (years), and between SEP-amplitudes, negative correlation with creatinin, Ca, hemogrobin, and positive correlation with BUN.
These results were attributed to more marked disturbances of GABA-inhibitory system in gray matter together with white matter in non-diabetics, and to severe disturbances of the central nervous system in both of gray and white matter in diabetics.
Shikoku Acta Medica
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