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Clinical applications of the central somatosensory conduction time (CCT)
$91 of acute stroke. This means that the absence of later clinical improvement of acute stroke, at least to the level of independence in ADL, can be predicted as early as the first day after admission to hospital.
opposite with respect to normal changes. The difference between these two subgroups seems to be related to the degree of the diabetic control measured by the HbA1C fraction of the glycosylated haemoglobin; the patients who showed an abnormal resistance to ischemia had also the higher HbA1C levels.
P 4.06 CLINICAL APPLICATIONS OF THE CENTRAL S O M A T O S E N S O R Y C O N D U C T I O N TIME (CCT).
M. Ueda, O. Sato, H. Murase, M. Yamamoto and Y. Suzuki
P 4.08 PARIETAL AND PRE-ROLANDIC SEP C O M P O NENTS IN PATIENTS WITH ACUTE CEREBRAL FOCAL ISCHEMIA.
(Kanagawa-Ken, Japan) Measurement of the central conduction time (CCT) has proved to be useful for measuring brain function in a number of neurological disorders. We have recorded CCT in a large series of neurological diseases and tried to prove the usefulness of CCT for providing prognostic information of the brain. Somato sensory evoked potentials were recorded simultaneously from the neck and the scalp following stimulation of the median nerve at the wrist in 360 subjects aged 16-80 years using the CADWELL 5200 instrument. The CCT was calculated as the difference in peak latency between N13 and N20. The patients of brain tumours or cerebral haemorrhage following head injury had asymmetrical CCT. In comatose patients, CCT correlated with the level of consciousness during recovery. The hemiplegic patients following CVD had persistent asymmetry of the CCT for a long time. It is concluded that the CCT is a good parameter for detecting the intracranial lesion or predicting brain function following cerebral attacks:
P 4.07 RRG, VEP AND SEP M O D I F I C A T I O N S DURING ISCHEMIA IN DIABETIC SUBJECTS.
O. Scarpino, A.M. Mauro, M. Guidi, G. Pelliccioni, O. Mercante and C. Valazzi (Torrelte Ancona, Italy) Two groups of subjects are considered in this study, one consisting of diabetic patients, none having proliferative retinopathy or severe peripheral neuropathy and the other of normal subjects. ERG and VEPs to flash stimulation were monitored before and during the retinal ischemia obtained for a l'20"-period by an ophthalmic dynamometer applied to the eye. SEPs to median nerve stimulation at the wrist were recorded every 3' before and during a 30'-period of ischemia obtained in the arm by the inflation of a pneumatic cuff. lschemic changes of evoked responses in normal subjects differed according to the sensory modality investigated and to the level explored in the sensory pathway, but were homogeneous in the whole group. In diabetic patients two subgroups can be identified, the former in whom ischemic changes approximated that of normal subjects, and the latter in whom modifications were severely delayed in time and of a minor degree or even
G. Abbruzzese, D. Dall'Agata, L. Spadaveccia. G. Bino and E. Favale (Genoa, Italy) The recording of somatosensory evoked potentials (SEPs) has so far proved of uncertain value in the localization of cerebral hemisphere lesions. However, it has been shown recently that the parietal (N20, P27, P45) and pre-Rolandic (P22, N30) SEP components, involving separate neural generators, can be affected selectively by circumscribed cerebral lesions (Mauguiere et al., Brain, 1983, 106; 271). We evaluated the clinical relevance of SEPs by recording parietal and pre-Rolandic components (with both midfrontal and earlobe references) in patients with acute cerebral focal ischemia presenting with either small unilateral cerebral lesions, as shown by the CT scan, or reversible ischemic attacks without CT abnormalities. Even minimal lesions (less than 1 cm 3) in the Rolandic region could usually be detected by selective abnormalities of either parietal or pre-Rolandic SEP components. On the contrary, pre-frontal or temporo-occipital lesions proved not to be relevant to the occurrence of SEP changes, irrespective of their size. Abnormal SEPs were also recorded in some patients without CT scan evidence of focal brain lesions. Selective abnormalities of parietal and pre-Rolandic components could be observed in some patients with a midfrontal reference, but the use of an earlobe reference made the recording more sensitive to minimal changes, particularly in subjects with pre-Rolandic involvement. Correlations of SEP changes and evolution of clinical and CT scan findings are discussed.
P 4.09 EVOKED POTENTIALS TO VERBAL STIMULI AND THEIR P O S S I B L E CLINICAL APPLICATION.
S. Popov and D. Chavdarov (Sofia, Bulgaria) Visual and auditory evoked potentials (VEP and AEP) elicited by verbal stimuli were investigated in healthy subjects and in post stroke patients. For the purpose of AEP two sets of 16 sense and 16 nonsense verbal stimuli with similar acoustic parameters were used. Similarly, 10 sense and 10 nonsense
opposite with respect to normal changes. The difference between these two subgroups seems to be related to the degree of the diabetic control measured by the HbA1C fraction of the glycosylated haemoglobin; the patients who showed an abnormal resistance to ischemia had also the higher HbA1C levels.
P 4.06 CLINICAL APPLICATIONS OF THE CENTRAL S O M A T O S E N S O R Y C O N D U C T I O N TIME (CCT).
M. Ueda, O. Sato, H. Murase, M. Yamamoto and Y. Suzuki
P 4.08 PARIETAL AND PRE-ROLANDIC SEP C O M P O NENTS IN PATIENTS WITH ACUTE CEREBRAL FOCAL ISCHEMIA.
(Kanagawa-Ken, Japan) Measurement of the central conduction time (CCT) has proved to be useful for measuring brain function in a number of neurological disorders. We have recorded CCT in a large series of neurological diseases and tried to prove the usefulness of CCT for providing prognostic information of the brain. Somato sensory evoked potentials were recorded simultaneously from the neck and the scalp following stimulation of the median nerve at the wrist in 360 subjects aged 16-80 years using the CADWELL 5200 instrument. The CCT was calculated as the difference in peak latency between N13 and N20. The patients of brain tumours or cerebral haemorrhage following head injury had asymmetrical CCT. In comatose patients, CCT correlated with the level of consciousness during recovery. The hemiplegic patients following CVD had persistent asymmetry of the CCT for a long time. It is concluded that the CCT is a good parameter for detecting the intracranial lesion or predicting brain function following cerebral attacks:
P 4.07 RRG, VEP AND SEP M O D I F I C A T I O N S DURING ISCHEMIA IN DIABETIC SUBJECTS.
O. Scarpino, A.M. Mauro, M. Guidi, G. Pelliccioni, O. Mercante and C. Valazzi (Torrelte Ancona, Italy) Two groups of subjects are considered in this study, one consisting of diabetic patients, none having proliferative retinopathy or severe peripheral neuropathy and the other of normal subjects. ERG and VEPs to flash stimulation were monitored before and during the retinal ischemia obtained for a l'20"-period by an ophthalmic dynamometer applied to the eye. SEPs to median nerve stimulation at the wrist were recorded every 3' before and during a 30'-period of ischemia obtained in the arm by the inflation of a pneumatic cuff. lschemic changes of evoked responses in normal subjects differed according to the sensory modality investigated and to the level explored in the sensory pathway, but were homogeneous in the whole group. In diabetic patients two subgroups can be identified, the former in whom ischemic changes approximated that of normal subjects, and the latter in whom modifications were severely delayed in time and of a minor degree or even
G. Abbruzzese, D. Dall'Agata, L. Spadaveccia. G. Bino and E. Favale (Genoa, Italy) The recording of somatosensory evoked potentials (SEPs) has so far proved of uncertain value in the localization of cerebral hemisphere lesions. However, it has been shown recently that the parietal (N20, P27, P45) and pre-Rolandic (P22, N30) SEP components, involving separate neural generators, can be affected selectively by circumscribed cerebral lesions (Mauguiere et al., Brain, 1983, 106; 271). We evaluated the clinical relevance of SEPs by recording parietal and pre-Rolandic components (with both midfrontal and earlobe references) in patients with acute cerebral focal ischemia presenting with either small unilateral cerebral lesions, as shown by the CT scan, or reversible ischemic attacks without CT abnormalities. Even minimal lesions (less than 1 cm 3) in the Rolandic region could usually be detected by selective abnormalities of either parietal or pre-Rolandic SEP components. On the contrary, pre-frontal or temporo-occipital lesions proved not to be relevant to the occurrence of SEP changes, irrespective of their size. Abnormal SEPs were also recorded in some patients without CT scan evidence of focal brain lesions. Selective abnormalities of parietal and pre-Rolandic components could be observed in some patients with a midfrontal reference, but the use of an earlobe reference made the recording more sensitive to minimal changes, particularly in subjects with pre-Rolandic involvement. Correlations of SEP changes and evolution of clinical and CT scan findings are discussed.
P 4.09 EVOKED POTENTIALS TO VERBAL STIMULI AND THEIR P O S S I B L E CLINICAL APPLICATION.
S. Popov and D. Chavdarov (Sofia, Bulgaria) Visual and auditory evoked potentials (VEP and AEP) elicited by verbal stimuli were investigated in healthy subjects and in post stroke patients. For the purpose of AEP two sets of 16 sense and 16 nonsense verbal stimuli with similar acoustic parameters were used. Similarly, 10 sense and 10 nonsense