Role of Electrocorticography at Surgery for Lesion-related Frontal Lobe Epilepsy

• Published in: Canadian journal of neurological sciences 1999-02, Vol.26 (1), p.33-39
• Main Authors: Wennberg, Richard, Quesney, Luis Felipe, Lozano, Andres, Olivier, André, Rasmussen, Theodore
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Biological and medical sciences; Brain Diseases - complications; Brain Diseases - surgery; Brain Neoplasms - complications; Brain Neoplasms - surgery; Child; Electroencephalography; Epilepsy, Frontal Lobe - etiology; Epilepsy, Frontal Lobe - physiopathology; Epilepsy, Frontal Lobe - surgery; Female; Hamartoma - complications; Hamartoma - surgery; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Humans; Intracranial Arteriovenous Malformations - complications; Intracranial Arteriovenous Malformations - surgery; Male; Medical sciences; Middle Aged; Nervous system (semeiology, syndromes); Neuroleptanalgesia; Neurology; Original Articles; Treatment Outcome; Tuberous Sclerosis - complications; Tuberous Sclerosis - surgery
• ISSN: 0317-1671; 2057-0155
• DOI: 10.1017/S0317167100054202

The prognostic significance of epileptiform activity (EA) recorded intraoperatively at electrocorticography (ECOG) in patients with lesion-related frontal lobe epilepsy (FLE) is unknown. The results of ECOG performed in 22 patients with intractable FLE and a circumscribed frontal lobe structural lesion were compared with postoperative seizure control. Three patients underwent re-operation for a total of 25 cases, 23/25 with post-resection ECOG. Lesions were neoplasms (12), hamartomas (6) and arteriovenous malformations (4). Outcomes were 15/25 Class I, 5/25 Class III and 5/25 Class IV (Engel classification). Class I outcome was associated with pre-excision EA recorded from < or = 2 gyri (p < 0.05) and absence of EA, or EA limited to the resection border, at post-excision ECOG (p < 0.01). Complete lesion excision was highly correlated with Class I outcome (p < 0.001). The most significant correlations were seen when ECOG and lesionectomy variables were considered together: all 12 cases with complete lesionectomy and absent post-excision EA distant to the resection border had Class I outcome (p < 0.00015) and all 13 cases with complete lesionectomy and pre-excision EA recorded from < or = 2 gyri had Class I outcome (p < 0.00005). Postoperative seizure control in lesion-related FLE is assured in the setting of complete lesion resection with pre-excision EA recorded from < or 2 gyri and no post-excision EA distant to the resection border; complete lesion excision is of paramount importance.