A Stereoelectroencephalographic (SEEG) Study of Light-Induced Mesiotemporal Epileptic Seizures
Article first published online: 3 AUG 2005
Volume 39, Issue 10, pages 1098–1103, October 1998
How to Cite
Isnard, J., Guénot, M., Fischer, C., Mertens, P., Sindou, M. and Mauguière, F. (1998), A Stereoelectroencephalographic (SEEG) Study of Light-Induced Mesiotemporal Epileptic Seizures. Epilepsia, 39: 1098–1103. doi: 10.1111/j.1528-1157.1998.tb01296.x
- Issue published online: 3 AUG 2005
- Article first published online: 3 AUG 2005
- Accepted March 18, 1998.
- Light-induced seizures;
- Temporal lobe epilepsy;
- Epilepsy surgery
Summary: Purpose: This study explored the mechanism of light-induced complex partial seizures by using ictal intracerebral recordings in a patient with refractory epilepsy of the right temporal lobe.
Methods: Presurgical evaluation of this patient was realized by means of video-EEG recordings, WADA test, magnetic resonance imaging (MRI), F18-deoxyglucose and C11-flumazenil positron emission tomography (PET) interictal neuroimaging data, and stereoelectroencephalographic (SEEG) ictal recordings.
Results: SEEG investigations demonstrated the right mesiotemporal origin of all the patient's seizures. This result was confirmed by a successful right temporal lobectomy. Moreover, SEEG recordings revealed a frequent interictal spiking activity in the right occipital visual cortex that was undetectable on scalp recordings. However, the occipital cortex was not involved at the onset of mesiotemporal ictal discharges and was not hyperresponsive to focal electrical stimulation.
Conclusions: This study shows that, in spite of interictal occipital spiking, the photosensitivity of mesiotemporal seizures can be observed in both the absence of occipital cortex involvement during ictal discharges and demonstrable hyper-excitability of the occipital cortex to light or direct electrical stimulation.