MRI as a prognostic factor in epilepsy

DAMIAN E CONSALVO, ROBERTO E SICA, SILVIA ODDO, BRENDA GIAGANTE, WALTER H SILVA, PABLO A SALGADO, SILVIA KOCHEN

New Orleans, USA

Congreso; Annual Meeting of the American Epilepsy Society; 2004

The aim of the study was to analyze prognostic factors in epileptic patients in relation to the response to the pharmacological treatment. We studied 378 patients with a previously defined epileptogenic zone who have been submitted to MRI studies. They were classified into 2 groups: Refractory (G1) and Non Refractory (G2) to the drug therapy. We analyzed the variables: age, age at onset (AO), epileptogenic zone, MRI results (normal or abnormal defined by the presence of an epileptogenic lesion) and the predictive value of the MRI. G1: n=171, average age 30.8±12.1 years, AO 10.7±10.2 years. Temporal 93 (54.4%); Extratemporal 69 (40.3%); Generalized 9 (5.3%). Abnormal MRI: 113 (66.1%). G2: n=207, average age 34±15.8 years, AO 19.2±16.7 years. Temporal 66 (31.9%); Extratemporal 93 (44.9%); Generalized 48 (23.2%). Abnormal MRI: 72 (34.8%). There were differences in age (p<0.02) and AO (p<0.01) less in G1. Generalized epilepsy was more frequent in G2 (p<0.01) and temporal lobe epilepsy (TLE) more frequent in G1 (p<0.03). Abnormal MRI was more frequent in G1 (Odds Ratio: 3.65 [2.33-5.73], p<0.001). The positive predictive value of the MRI was 61.1%. The negative predictive value of the MRI was 69.9%. Younger age and TLE were related to a bad response to the pharmacological treatment. Generalized epilepsy was related to a good outcome. MRI seems to be the most powerful tool to define a prognosis in epilepsy patients.