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Spinal and scalp recorded somatosensory evoked potentials in diabetics
S170
F288 SPINAL AND SCALP RECORDEDSOMATOSENSORYEVOKED POTENTIALS IN DIABETICS
SEKO K, YASUDA Y, MATSUOKAY, HIRABAYASHI J, AKIO I , AOJI O, FUJIWARA T*~ Kyoto City Hospital and *Central C l i n i c a l Laboratory, Kyoto U n i v e r s i t y Hospital, Kyoto, Japan Approximately 50% of diabetics are reported to have signs of peripheral neuropathy. On the other hand, central nervous system changes in diabetics have not been well documented e l e c t r o p h y s i o l o g i c a l l y , although there are many neuropathological reports. 21 diabetics were examined with SEPs (somatosensory evoked pot e n t i a l s ) and EESGs (evoked electrospinograms). Following stimulation of the posterior t i b i a l nerve at the ankle, the r e s u l t s showed: SEP: N48=51.8 + 6.6 ms (normal; 48.1 + 1.7 ms), conductive cervical EESG: N31=32.2 T 4.2 ms (normal; 31.3 ~ 1.8 ms), segmental T12 EESG: N22=24.8 T 3.3 ms (normal; 22.7 ~ 1.1 ms). Following stimulation of the median nerve aT the w r i s t , the results-showed: segmental cervical EESG: N14=14.8 + 1.4 ms (normal; 13.8 + 0.4 ms), SEP: N19=20.7 ¥ 0.7 ms (normal; 19.3 T 0.4 ms), 1.6 ms (normal; 5.4 T 0.4 ms). central conduction time = 6.1 Other parameters calculated were as followsT PNCV (peripheral nerve conduct i o n v e l o c i t y ) of upper extremity) =47.9 + 5.0 ms (normal; 53.4 + 1.6 ms), PNCV of lower extremity =40.7 T 5.1 ms (normal; 47.1 ~ 1.1 ms), spinal cord conduction v e l o c i t y =41.2 ~ 9.9 ms (normal; 52.9 ~ 5.4 ms). In some of the cases, morphological abnormaTities of SEP and/or EES~were also noted. These f i n d i n g s suggest that the diabetic process influences the patient's neurophysiological functions not only in the peripheral nerves but also in the central nervous system.
F289 CORTICAL EVOKED POTENTIALS FOLLOWING CUTANEOUSSTIMULATION OF THE L4, L5 AND $1 DERMATOMESIN NORMALADULTS SELMAR P., Department of C l i n i c a l Neurophysiology, Glostrup Hospital, DK-2600 Glostrup, Denmark SEP techniques stimulating peripheral mixed.or sensory nerves are not s u f f i c i e n t l y selective identifying a single spinal root affection of the lower extremities. The purpose of this study was to examine the cortical SEPs to electrical stimulation of small skin areas supplied by a single spinal root. The fourth lumbar dermatome was stimulated on the medial side of the ankle, just proximal to the internal malleolus. The f i f t h lumbar dermatome was stimulated on the middle of the dorsum of the foot, and the f i r s t sacral dermatome was stimulated on the lateral side of the foot. The dermatomal somatosensory evoked potentials (DSEP) were recorded from the mid-parietal scalp region. The values of DSEP latency and amplitude in a group of normal adult subjects are presented. The p~sterior t i b i a l nerve was stimulated at the ankle of the same normals. The mixed nerve potentials were recorded from the gluteal region, the lower thoracic spine and the parietal region. These results are reported for comparison.
F288 SPINAL AND SCALP RECORDEDSOMATOSENSORYEVOKED POTENTIALS IN DIABETICS
SEKO K, YASUDA Y, MATSUOKAY, HIRABAYASHI J, AKIO I , AOJI O, FUJIWARA T*~ Kyoto City Hospital and *Central C l i n i c a l Laboratory, Kyoto U n i v e r s i t y Hospital, Kyoto, Japan Approximately 50% of diabetics are reported to have signs of peripheral neuropathy. On the other hand, central nervous system changes in diabetics have not been well documented e l e c t r o p h y s i o l o g i c a l l y , although there are many neuropathological reports. 21 diabetics were examined with SEPs (somatosensory evoked pot e n t i a l s ) and EESGs (evoked electrospinograms). Following stimulation of the posterior t i b i a l nerve at the ankle, the r e s u l t s showed: SEP: N48=51.8 + 6.6 ms (normal; 48.1 + 1.7 ms), conductive cervical EESG: N31=32.2 T 4.2 ms (normal; 31.3 ~ 1.8 ms), segmental T12 EESG: N22=24.8 T 3.3 ms (normal; 22.7 ~ 1.1 ms). Following stimulation of the median nerve aT the w r i s t , the results-showed: segmental cervical EESG: N14=14.8 + 1.4 ms (normal; 13.8 + 0.4 ms), SEP: N19=20.7 ¥ 0.7 ms (normal; 19.3 T 0.4 ms), 1.6 ms (normal; 5.4 T 0.4 ms). central conduction time = 6.1 Other parameters calculated were as followsT PNCV (peripheral nerve conduct i o n v e l o c i t y ) of upper extremity) =47.9 + 5.0 ms (normal; 53.4 + 1.6 ms), PNCV of lower extremity =40.7 T 5.1 ms (normal; 47.1 ~ 1.1 ms), spinal cord conduction v e l o c i t y =41.2 ~ 9.9 ms (normal; 52.9 ~ 5.4 ms). In some of the cases, morphological abnormaTities of SEP and/or EES~were also noted. These f i n d i n g s suggest that the diabetic process influences the patient's neurophysiological functions not only in the peripheral nerves but also in the central nervous system.
F289 CORTICAL EVOKED POTENTIALS FOLLOWING CUTANEOUSSTIMULATION OF THE L4, L5 AND $1 DERMATOMESIN NORMALADULTS SELMAR P., Department of C l i n i c a l Neurophysiology, Glostrup Hospital, DK-2600 Glostrup, Denmark SEP techniques stimulating peripheral mixed.or sensory nerves are not s u f f i c i e n t l y selective identifying a single spinal root affection of the lower extremities. The purpose of this study was to examine the cortical SEPs to electrical stimulation of small skin areas supplied by a single spinal root. The fourth lumbar dermatome was stimulated on the medial side of the ankle, just proximal to the internal malleolus. The f i f t h lumbar dermatome was stimulated on the middle of the dorsum of the foot, and the f i r s t sacral dermatome was stimulated on the lateral side of the foot. The dermatomal somatosensory evoked potentials (DSEP) were recorded from the mid-parietal scalp region. The values of DSEP latency and amplitude in a group of normal adult subjects are presented. The p~sterior t i b i a l nerve was stimulated at the ankle of the same normals. The mixed nerve potentials were recorded from the gluteal region, the lower thoracic spine and the parietal region. These results are reported for comparison.