Acute symptomatic seizures due to single CT lesions: how long to treat with antiepileptic drugs?

The duration of anti epileptic drug therapy for single small enhancing CT lesions (SSECTL) presents a major dilemma. We studied the efficacy of short duration (6 months) antiepileptic drug therapy as compared to long duration (2 years) drug therapy. Seventy three patients presenting with seizures and showing SSECTL on cranial CT scans (plain and contrast) were randomized into group A (6 months therapy) and group B (2 years therapy). There were 47 patients in group A and 26 patients in group B. Patients were followed up for one year after withdrawal of anti epileptic drugs. CT Head (plain and contrast) was repeated after 3 months, or earlier in cases of recurrence to rule out reinfection. 53.2% in group A and 53.8% in group B showed complete resolution and were seizure free on one year follow up. Punctate residual calcification was seen in 46.8% in group A and 46.2% in group B. Eight patients (17%) in group A and three (11.5%) in group B had a recurrence. The difference in recurrence of seizure between the two groups was not statistically significant (p<0.77) in the calcified lesion subset. Since none of the patients in total resolution subset showed recurrence, the difference between calcified and total resolution subset was highly significant. The study shows that a short duration (6 months) AED therapy in patients with total resolution of lesion on follow up scan, may be adequate in comparison to those who have calcific speck as a residue. However, a longer duration of therapy in case of calcific group probably does not alter their chances of recurrence.