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Multimodality evoked potentials in severe head injury: A neurophysiological scale for early prognosis
S42 unknown (1). Electrophysiologically, all showed regular continuous motor unit potential activity of variable intensity (mean 2.51-0.9 on an arbitrary scale from 0 to 4) distributed over all levels of the affected hemiface. This was predominant at orbicularis oris and was asynchronous and uninfluenced by voluntary contraction (apart from 1 case). In 7 cases there were intermingled grouped discharges characteristic of myokymia (bilateral distribution in 5). Maximal voluntary activity was deficient in 5 cases and reciprocal innervation was preserved in all but 1 case. The blink reflex (BR) was impaired on the hemispasm side with significantly prolonged latencies of Rl and R2. In one case, BR was normal and in another, it showed a greater alteration on the asymptomatic side. R2 diffused to the frontalis muscle in 1 patient. These well-defined electrophysiological findings are sufficient to permit differential diagnosis of tonic facial hemispasm from other facial dyskinesias. The site of the lesion must be at pontine level and the physiopathological mechanism is probably hyperexcitability of the facial pathway by damage to the nucleus facialis or its axonal intra-axial prolongations.
somatosensory evoked potentials from median nerve (SEPs): (b) the relationship between sensory and m:,tor dysfunction in comatose patients. MEPs (following magnetic stimularion) and SEPs (using a non-cephalic reference) were recorded $11the same session in 13 patients comatose as a result of head injui l (4), stroke (7) or anoxia (2). Five patients died, 3 remained vegetative, 2 were severely disabled and 3 showed a good recovery. SEPs were significantly related to outcome (P = 0.043). MEPs were significantly related to the Glasgow Coma Scale (P = 0.01) but did not show a significant correlation with outcome. Only 1 of 7 patients with abnormal MEP showed a good recovery. Comparing SEPs with ipsilateral MEPs showed: 9 of 26 traces suggesting a combined sensorymotor dysfunction: 2 only sensory dysfunction; 4 a normal picture. Our results suggest that SEPs and MEPs may improve the assessment of sensory-motor dysfunction in comatose patients. A significant relationship between MEPs and clinical data appears to exist but the assessment of MEP reliability in coma states requires further study.
SEVEN-CHANNEL MAGNETOENCEPHALOGRAPHY (MEG) IN PATIENTS WITH GENERALIZED CHANGES WITHOUT EPILEPTIC SEIZURES.
MIJLTIMODALITY EVOKED POTENTIALS HEAD INJURY: A NEUROPHYSIOLOGICAL EARLY PROGNOSIS.
IN SEVERE SCALE FOR
E. Fucco, M. Munari, F. Toffoletto, Meroni. L. Pasini and G.P. Giron
B. Dona,
EEG
A. Fabian and Ch. Lefebre (Free University,
Berlin, F.R.G.)
For several years, magnetoencephalography (MEG) has proved its usefulness in basic neurophysiological sciences, e.g., in researching the functional topography of the auditory cortex or event-related potentials. The possibilities improved when multichannel MEG and shielded rooms were constructed. First experiences of using the new method and its possible three-dimensional function imaging in terms of localization of epileptogenic foci in patients suffering from focal epilepsies as part of ‘clinical routine’ seem to be promising. Using the new method, it may also be possible to localize the origin of the generalized sharp-slow-wave changes in the EEG in patients without evidence of epileptic seizures. Using the Berlin shielded room and a ‘I-channel gradiometer, our first MEG findings, in a patient with generalized EEG changes, without evidence of epileptic seizures, will be demonstrated. The complexity of the problem and the promising results will be shown.
SENSORY-MOTOR TOSE PATIENTS:
CONDUCTION A PRELIMINARY
E. Facto, M. Munari, F. Baratto, Liviero and G.P. Giron (University
of Padua,
Padua,
TIME IN REPORT.
R. Bnmo,
COMA-
E.M. Cavartelli
Italy)
The aim of this study was to evaluate: (a) the prognostic power of motor evoked potentials from thenar muscles (MEPs) and
(University
of Padua,
Padua,
A. Behr,
M.
Italy)
The aims of this study were: (a) to verify the prognostic power of both ABRs and SEPs; (b) to evaluate whether SEPs from median nerve, recorded using a non-cephalic reference, may provide information on brain-stem function, likewise the ABR: (c) to work out a neurophysiological scale for early outcome prediction. 53 patients (age range 14-65 years) were subjected to ABR and SEP in the same session, during the acute phase of post-traumatic coma. ABRs were classified as follows: (1) normal picture; (2) interpeak latency V-l (IPL V-l) > 4.50 msec; (3) amplitude ratio V/l (AR V/l) < 0.5; (4) absent wave V. The SEPs were graded as follows: (1) normal picture; (2) N13-N20 > 8.08 msec: (3) P14-N18 > 4.80 msec; (4) absent N20, with present N18; (5) absent N18. 29 patients died (54.6%), 6 remained vegetative (11.4%), 3 severely disabled (5.7%) and 15 (28.3%) recovered. The ABR was significantly related to outcome, according to our previous report (Facto et al., Electroencephalogr. Clin. Neurophysiol.. 1985, 62; 332) (P < 0.001); both the IPL V-l and the AR V/l appeared to be reliable parameters. In SEP recordings, the N13-N20 and the absence of N20 showed a high prognostic power, while the P14-N18 was not related to the outcome. Neither SEPs nor ABRs were able to exclude false negatives, but the combined use of both modalities was able to improve the outcome prediction in comparison to the use of only one modality.
somatosensory evoked potentials from median nerve (SEPs): (b) the relationship between sensory and m:,tor dysfunction in comatose patients. MEPs (following magnetic stimularion) and SEPs (using a non-cephalic reference) were recorded $11the same session in 13 patients comatose as a result of head injui l (4), stroke (7) or anoxia (2). Five patients died, 3 remained vegetative, 2 were severely disabled and 3 showed a good recovery. SEPs were significantly related to outcome (P = 0.043). MEPs were significantly related to the Glasgow Coma Scale (P = 0.01) but did not show a significant correlation with outcome. Only 1 of 7 patients with abnormal MEP showed a good recovery. Comparing SEPs with ipsilateral MEPs showed: 9 of 26 traces suggesting a combined sensorymotor dysfunction: 2 only sensory dysfunction; 4 a normal picture. Our results suggest that SEPs and MEPs may improve the assessment of sensory-motor dysfunction in comatose patients. A significant relationship between MEPs and clinical data appears to exist but the assessment of MEP reliability in coma states requires further study.
SEVEN-CHANNEL MAGNETOENCEPHALOGRAPHY (MEG) IN PATIENTS WITH GENERALIZED CHANGES WITHOUT EPILEPTIC SEIZURES.
MIJLTIMODALITY EVOKED POTENTIALS HEAD INJURY: A NEUROPHYSIOLOGICAL EARLY PROGNOSIS.
IN SEVERE SCALE FOR
E. Fucco, M. Munari, F. Toffoletto, Meroni. L. Pasini and G.P. Giron
B. Dona,
EEG
A. Fabian and Ch. Lefebre (Free University,
Berlin, F.R.G.)
For several years, magnetoencephalography (MEG) has proved its usefulness in basic neurophysiological sciences, e.g., in researching the functional topography of the auditory cortex or event-related potentials. The possibilities improved when multichannel MEG and shielded rooms were constructed. First experiences of using the new method and its possible three-dimensional function imaging in terms of localization of epileptogenic foci in patients suffering from focal epilepsies as part of ‘clinical routine’ seem to be promising. Using the new method, it may also be possible to localize the origin of the generalized sharp-slow-wave changes in the EEG in patients without evidence of epileptic seizures. Using the Berlin shielded room and a ‘I-channel gradiometer, our first MEG findings, in a patient with generalized EEG changes, without evidence of epileptic seizures, will be demonstrated. The complexity of the problem and the promising results will be shown.
SENSORY-MOTOR TOSE PATIENTS:
CONDUCTION A PRELIMINARY
E. Facto, M. Munari, F. Baratto, Liviero and G.P. Giron (University
of Padua,
Padua,
TIME IN REPORT.
R. Bnmo,
COMA-
E.M. Cavartelli
Italy)
The aim of this study was to evaluate: (a) the prognostic power of motor evoked potentials from thenar muscles (MEPs) and
(University
of Padua,
Padua,
A. Behr,
M.
Italy)
The aims of this study were: (a) to verify the prognostic power of both ABRs and SEPs; (b) to evaluate whether SEPs from median nerve, recorded using a non-cephalic reference, may provide information on brain-stem function, likewise the ABR: (c) to work out a neurophysiological scale for early outcome prediction. 53 patients (age range 14-65 years) were subjected to ABR and SEP in the same session, during the acute phase of post-traumatic coma. ABRs were classified as follows: (1) normal picture; (2) interpeak latency V-l (IPL V-l) > 4.50 msec; (3) amplitude ratio V/l (AR V/l) < 0.5; (4) absent wave V. The SEPs were graded as follows: (1) normal picture; (2) N13-N20 > 8.08 msec: (3) P14-N18 > 4.80 msec; (4) absent N20, with present N18; (5) absent N18. 29 patients died (54.6%), 6 remained vegetative (11.4%), 3 severely disabled (5.7%) and 15 (28.3%) recovered. The ABR was significantly related to outcome, according to our previous report (Facto et al., Electroencephalogr. Clin. Neurophysiol.. 1985, 62; 332) (P < 0.001); both the IPL V-l and the AR V/l appeared to be reliable parameters. In SEP recordings, the N13-N20 and the absence of N20 showed a high prognostic power, while the P14-N18 was not related to the outcome. Neither SEPs nor ABRs were able to exclude false negatives, but the combined use of both modalities was able to improve the outcome prediction in comparison to the use of only one modality.