Characteristics of mesial temporal lobe epilepsy associated with hippocampal sclerosis plus neurocysticercosis

•We compared patients with hippocampal sclerosis with or without neurocysticercosis.•Neurocysticercosis was more common in women or without classical initial precipitating injury.•Neurocysticercosis lead to increased EEG abnormalities in these patients.•Hippocampal sclerosis occurred more often ispilateral to neurocysticercosis.•Neurocysticercosis may lead to temporal lobe epilepsy with hippocampal sclerosis.

SummaryRecent observations suggest that neurocysticercosis (NCC) might act as an initial precipitating injury (IPI) causing mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS). A total of 191 patients from Brazil, a country in which NCC is endemic, were surgically treated for MTLE-HS, and subsequent findings for patients with MTLE-HS were compared with those of patients with MTLE-HS plus NCC. Seventy-one patients (37,2%) presented chronic findings of NCC (cNCC). MTLE-HS plus cNCC was significantly more common in women (O.R. = 2.45; 95%CI = 1.30-4.60; p = 0.005), in patients with no history of classical forms of IPI (O.R. = 2.67; 95%CI = 1.37-5.18; p = 0.004), and in those with bi-temporal interictal spikes on video-EEG (O.R. = 2.00; 95%CI = 1.07-3.73; p = 0.03). Single cNCC lesions were observed to occur significantly more often on the same side as hippocampal sclerosis, a finding suggesting an anatomical relationship between NCC and MTLE-HS. Taken together, our results suggest that NCC may be a marker, or contributes to or even causes MTLE-HS. Based on our findings, we propose two distinct, non-excluding, and potentially synergistic mechanisms involved in the development of MTLE-HS in NCC, one of them being inflammatory-mediated, while the other is electrogenic-mediated. Taken together, our observations may provide further evidence suggesting a role of NCC in the genesis or development of MTLE-HS.