Magnetoencephalographic localization of peritumoral temporal epileptic focus previous surgical resection

• Published in: Seizure (London, England) Vol. 12; no. 1; pp. 19 - 22
• Main Authors: AMO, CARLOS, SALDAÑA, CRISTÓBAL, HIDALGO, MERCEDES GONZÁLEZ, MAESTÚ, FERNANDO, FERNÁNDEZ, ALBERTO, ARRAZOLA, JUAN, ORTIZ, TOMÁS
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 2003
• Subjects: Adult; Anticonvulsants - therapeutic use; cavernoma; Central Nervous System Neoplasms - complications; Central Nervous System Neoplasms - pathology; Central Nervous System Neoplasms - surgery; Craniotomy; Drug Resistance; Electric Stimulation; Electroencephalography; Epilepsy, Temporal Lobe - etiology; Epilepsy, Temporal Lobe - physiopathology; Epilepsy, Temporal Lobe - surgery; Hemangioma, Cavernous, Central Nervous System - complications; Hemangioma, Cavernous, Central Nervous System - pathology; Hemangioma, Cavernous, Central Nervous System - surgery; Humans; Magnetic Resonance Imaging; Magnetoencephalography; Male; Monitoring, Intraoperative; neurosurgery; refractory epilepsy; Temporal Lobe - pathology; Temporal Lobe - physiopathology; Treatment Outcome; cavernoma; neurosurgery; refractory epilepsy; magnetoencephalography
• ISSN: 1059-1311; 1532-2688
• DOI: 10.1016/S1059131102001486

Magnetoencephalography (MEG) is suggested as a localizing technique of epileptogenic areas in drug-resistant seizure patients due to intracraneal lesions. A male 42-year-old patient who begins at 26 with partial complex drug-resistant seizures is put forward. MRI shows a 9
mm diameter lesion located in left superior temporal gyrus which seems compatible with cavernoma. Both conventional and sleep deprivation EEGs have proved normal. Sleep EEG shows sharp waves in left temporal region. MEG helps to localize interictal spike and spike-wave activity, as well as wide slow wave (2–7
Hz) activity areas. Craniotomy under analgesia and aware sedation conditions is carried out. Intrasurgery cortical electric stimulation assisted by neuronavigator causes a limited partial complex seizure which the patient recognizes to be exactly like his. Thus, MEG localization of the epileptogenic area is confirmed. Surgical resection of both the lesion and the epileptogenic area is carried out. The patient remains free from seizures 9 months after surgery. A control MEG study reveals no epileptogenic nor slow wave activity. Conclusion: in this particular case, MEG has proven to be a useful presurgical evaluation technique to localize epileptogenic activity, validated by intrasurgical cortical stimulation.