Localization of the Electrical Generator of Continuous Cortical Myoclonus by Dipolar Source Analysis.
Abstract number :
1.104
Submission category :
Year :
2001
Submission ID :
2707
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
W. Szurhaj, MD, Clinical Neurophysiology, CHRU, Lille, France; P. Derambure, MD, Neurophysiology, CHRU, Lille, France; J-L. Bourriez, PhD, Neurophysiology, CHRU, Lille, France; F. Cassim, MD, Neurophysiology, CHRU, Lille, France; E. Laureau, MD, Neurophys
RATIONALE: To study the pathophysiology of the continuous cortical myoclonus in epileptic patients and the links between cortical myoclonus and the epileptogenic focus.
METHODS: We have studied epileptic patients presenting with an epilepsy of varied etiologies and with continuous myoclonus. Before the study, the epileptogenic focus has been well defined by a video EEG exploration. The patients were explored by EMG-EEG polygraphy with back-averaging, study of somesthesic evoked potentials. Then a dipolar source analysis was performed in order localize the electrical generator of the pre-myoclonus potential, the N20, and of the epileptic spikes.
RESULTS: The EEG with back-averaging revealed pre-myoclonus spikes in more diffused regions than epileptic spikes. The localization of dipolar sources of pre-myoclonus spikes and of epileptic spikes were different. The sources of pre-myoclonus was located in sensorimotor areas, although the sources of epileptic spikes did not concern the sensorimotor areas. Moreover, the localization of the sources of premyoclonus spikes were different between the patients.
CONCLUSIONS: The sources of cortical myoclonus are different from the epileptic focus. These results are in favour of different pathophysiology for continuous myoclonus and critical epileptic discharges. The cortical hyperexcitability responsible for cortical myoclony seems to be more diffused than the epileptogenic focus.