Exploration of Patients with Ictal Supplementary Moter Area Symptomatology with Intracranial Recordings
Abstract number :
2.098
Submission category :
Year :
2001
Submission ID :
908
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
Y. Agha Khani, MD, Neurology, Golestan Hospital, Ahwaz University, Ahwaz, Khozestan, Islamic Republic of Iran; F. Dubeau, MD, Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, Montreal, QC, Canada; A. Olivier, MD, PhD, Neurology an
RATIONALE: Seizures associated with tonic posturing of the upper limbs (with or without head deviation) are typically presumed to result from ictal discharge in the supplementary motor area (SMA). A retrospective analysis of patients presumed to have SMA seizures who were investigated with intracranial electrodes was undertaken in order to determine how useful the clinical seizure pattern was in localizing the patients epileptic generator.
METHODS: All patients implanted with intracranial electrodes who had seizures associated with tonic upper limb posturing evaluated between January 1, 1994 and March 31, 2001 were included in the study. Patient charts, imaging, scalp and invasive EEG records were reviewed in order to determine the location of the patient[ssquote]s epileptic generators. For this study, the definition of the epileptic generator was based on the results of the intracranial ictal recordings.
RESULTS: Ten patients with a SMA seizure pattern were studied. Of the ten patients: three were found to have focal seizure onset in the SMA, one had onset in a focal region of cortical dysplasia located in the dorsolateral frontal convexity with late spread to the SMA, one had focal onset in the temporal neocortex without any ictal SMA activity and for the five remaining patients, seizure onset could not be determined. For the five patients where a clear ictal EEG onset was not found, the initial EEG changes were either observed after the first ictal clinical manifestations or occurred diffusely from onset.
CONCLUSIONS: Ictal supplementary motor area symptomatology can be associated with focal seizure onset in the SMA, however, our results demonstrate that this clinical pattern can also be seen with generators outside the SMA (with or without subsequent SMA involvement). As well, in five patients the epileptic generator was not determined despite intracranial investigation including electrodes in the SMA. Our results demonstrate that although this clinical seizure pattern is often associated with ictal SMA activity, it is not unique to the SMA. Therefore, it is essential to consider the possibility of epileptic generators outside the SMA when investigating these complicated patients.