Predictors of Seizure Recurrence in Solitary Calcified Neurocysticercosis in Relation to Computed Tomography Scan: Prospective Observational Study.

Background and purpose: Solitary calcified neurocysticercosis (NCC) on the computed tomography (CT) scan of brain in patients of epilepsy is common finding in endemic regions. Factors causing seizures in such cases are debatable. Immature calcification may be the causative factor for seizure recurrence. Thus, we aimed to study predictors of seizure recurrence specific to morphological characteristics on CT scan.

Methods: Patients with solitary calcified NCC on CT scan brain and active seizures were prospectively included. The protocol included clinical evaluation, contrast-enhanced CT scan of the brain, and electroencephalogram (EEG) at baseline and 9th month of 1-year follow-up in all patients. Seizure recurrence after 1 week of enrolment was recorded.

Results: One hundred twenty patients with a mean age of 23.33±12.81 years were included with a final follow-up of 109 patients and 35 patients had seizure recurrence. On univariate analysis, seizure frequency of more than 1 episode/month (45.7% vs. 25.7%, p=0.037; odds ratio [OR], 2.06; 95% confidence interval [CI], 1.05-5.68), perilesional edema on CT head (45% vs. 10.8%, p<0.001; OR, 6.95; 95% CI, 2.58-18.7), lower density (HU) of lesion on CT head (139.85±76.54 vs. 204.67±135.9 HU p=0.009) and abnormal EEG at presentation (p<0.001; OR, 18.25; 95% CI, 2.15-155.13) were significantly associated with seizure recurrence. On multivariate analysis, presence of perilesional edema on CT head (p=0.001; OR, 6.854; 95% CI, 2.26-20.77), density of lesion on CT (HU) (p=0.036; OR, 0.995; 95% CI, 0.99-1) and abnormal EEG (p=0.029; OR, 12.125; 95% CI, 1.29-113.74) were independently associated with seizure recurrence.

Conclusions: The presence of perilesional edema, HU of calcification on CT brain, and abnormal EEG suggest an increased risk of seizure recurrence in patients of epilepsy with solitary calcified NCC.