Surgery for "Long-term epilepsy associated tumors (LEATs)": Seizure outcome and its predictors

Objectives: “Long-term epilepsy associated tumors (LEATs)” by definition are tumors primarily causing drug-resistant seizures for two years or more. They include low-grade glial and glioneuronal tumors with normal life expectancy. We studied a large cohort of patients with LEATs who underwent surgery through our epilepsy program. Patients & methods: From 1998–2011, 105 patients with LEATs underwent surgery in our center. We utilized their data archived in a prospective registry to evaluate their electro-clinical-imaging characteristics affecting the long-term seizure outcome. Results: Of 105patients (age 3–50 years),meanage at surgery was 20 years andmeanpre-surgicalduration of epilepsy was 10.9 years. 66 (62.8%) had secondary generalized seizures. 82 had temporal tumors, 23 had extra temporal (13 frontal, 3 parietal, 2 occipital and 5 multilobar lesions) and four had associated hippocampal sclerosis. The interictal discharges and ictal onset were concordant to the lesion in 82 (78%) and 98 (93%) patients respectively. Lesionectomy and/or adjoining corticectomy or temporal lobectomy was done. Ganglioglioma was the most dominant pathological substrate in 61 (58%). During a mean follow-up of 7.5 years (range 3–16 years), 78/105 (74.2%) were seizure-free and 45 (57.4%) were totally off drugs. Secondary generalized seizures (p-0.02), temporal location of tumor (p-0.008) and spikes in third month post-operative EEG (p-0.03) caused unfavorable seizure outcome. A pre-surgical duration of epilepsy of more than 6.6 years caused less than optimal surgical outcome Conclusions: Early surgery should be considered a priority in LEATs. Presence of secondary generalized seizures is the single most important predictor of a poor seizure outcome

Keywords

LEATs Seizure outcome Resective surgery

Citation

Radhakrishnan A, Abraham M, Vilanilam G, Menon R, Menon D, Kumar H, Cherian A, Radhakrishnan N, Kesavadas C, Thomas B, Sarma SP, Thomas SV. Surgery for "Long-term epilepsy associated tumors (LEATs)": Seizure outcome and its predictors. Clin Neurol Neurosurg. 2016;141:98-105