Good surgical outcome in discordant ictal EEG‐MRI unilateral mesial temporal sclerosis patients

• Published in: Epilepsia (Copenhagen) 2008-08, Vol.49 (8), p.1324-1332
• Main Authors: Castro, Luiz H., Serpa, Mauricio H., Valério, Rosa M., Jorge, Carmen L., Ono, Carla R., Arantes, Paula R., Rosemberg, Sergio, Wen, Hung Tzu
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Anterior Temporal Lobectomy - methods; Biological and medical sciences; Child; Electrodiagnosis. Electric activity recording; Electroencephalography; Epilepsy surgery; Epilepsy, Temporal Lobe - diagnosis; Epilepsy, Temporal Lobe - etiology; Epilepsy, Temporal Lobe - surgery; Female; Follow-Up Studies; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Humans; Investigative techniques, diagnostic techniques (general aspects); Magnetic Resonance Imaging; Male; Medical sciences; Mesial temporal sclerosis; Middle Aged; Nervous system; Nervous system (semeiology, syndromes); Neurology; Sclerosis - complications; Sclerosis - diagnosis; Sclerosis - surgery; SPECT; Surgical outcome; Temporal Lobe - diagnostic imaging; Temporal Lobe - pathology; Temporal Lobe - surgery; Temporal lobe epilepsy; Tomography, Emission-Computed, Single-Photon; Treatment Outcome; Video EEG; Video-Assisted Surgery - methods
• ISSN: 0013-9580; 1528-1167
• DOI: 10.1111/j.1528-1167.2008.01714.x

Summary Purpose: Video electroencephalography (vEEG) monitoring of patients with unilateral mesial temporal sclerosis (uMTS) may show concordant or discordant seizure onset in relation to magnetic resonance imaging (MRI) evidence of MTS. Contralateral seizure usually leads to an indication of invasive monitoring. Contralateral seizure onset on invasive monitoring may contraindicate surgery. We evaluated long‐term outcome after anteromesial temporal lobectomy (AMTL) in a consecutive series of uMTS patients with concordant and discordant vEEG findings, uniformly submitted to AMTL on the MRI evidence of MTS side without invasive monitoring. Methods: We compared surgical outcome of all uMTS patients undergoing vEEG monitoring between January 1999 and April 2005 in our service. Discordant cases were defined by at least one seizure onset contralateral to the MRI evidence of MTS. Good surgical outcome was considered as Engel's class I. We also evaluated ictal SPECT concordance to ictal EEG and surgical outcome. Results: Fifty‐four patients had concordant (C) and 22 had discordant (D) scalp EEG and MRI. Surgical outcome was similar in both groups (C = 74% versus D = 86%). Duration of follow‐up was comparable in both groups: C = 56.1 ± 20.7 months versus D = 59.8 ± 21.2 months (p = 0.83, nonsignificant). Discordant single‐photon emission computed tomography (SPECT) results did not influence surgical outcome. Discussion: Surgical outcome was not influenced by contralateral vEEG seizure onset or contralateral increased flow on ictal SPECT. Although vEEG monitoring should still be performed in these patients, to rule out psychogenic seizures and extratemporal seizure onset, a potentially risky procedure such as invasive monitoring may not only not be indicated in this patient population, but may also lead to patients erroneously being denied surgery.