Epilepsy surgery in context of neurocysticercosis

The association between neurocysticercosis (NCC) and epilepsy is well known and NCC is an important risk factor for epileptic seizures in many Taenia solium-endemic regions of the world. However, while the relationship between NCC and epilepsy is well known, the association between NCC and medically refractory (or surgically remediable epilepsy) has received little attention in the past. Our experience and review of the sparse literature available suggests that NCC is causally related to surgically remediable epilepsy albeit uncommonly so and that association derives its underpinnings from several different scenarios: (1) Medically refractory lesional epilepsy, in which seizures arise from the vicinity of the calcified neurocysticercus lesion (CNL), (2) Medically refractory epilepsy with dual pathology type of relationship between the hippocampal sclerosis (HS) and CNL in which both have been unequivocally demonstrated to give rise to independent seizures and (3) Mesial temporal lobe epilepsy due to HS with a distantly-located CNL, which is in itself not epileptogenic. A major point of controversy revolves around whether or not there exists a causal association between the CNL and HS. We believe that an association exists between NCC and HS and the most important factor influencing this association is the location of the CNL. Furthermore, NCC is a risk factor for medically-refractory epilepsy and that this might account for a considerable proportion of the intractable epilepsy population in endemic regions; the association has been largely ignored owing to the lack of availability of presurgical work-up facilities in these regions. Finally, from a clinical standpoint of presurgical evaluation, patients with CNL and HS should be evaluated on a case by case basis owing to disparate settings underlying the association.