Neurocysticercosis
Neurocysticercosis (NCC) is not necessarily a tropical disease, it is related to unsanitary conditions, poverty and poor health-care systems of a country, regardless of its geographical location. Studies of highly selected patients with epilepsy (or seizures?) in neurologic services of hospital settings from some developing countries report NCC as the main cause of epilepsy, accounting for 30% to 50% of patients.16,31
However, in the recent prospective multicenter study carried out in Ecuador, NCC was the putative risk factor for epilepsy in 8.3% of newly diagnosed patients with epilepsy.15 In other studies in which acute symptomatic seizures were excluded, only 5.3%34 and 11%35 of patients with epilepsy had NCC It seems that most of the patients with NCC have acute symptomatic seizures which do not evolve into epilepsy. High incidence of epilepsy related to NCC, reported in some studies, probably related to failure to differentiate between epilepsy and seizures.36,37 Although NCC is one of the most frequent antecedents among the symptomatic group, this disease is not the main cause of epilepsy.
Surprisingly, the proportion of epilepsy cases associated with cysticercosis using immunological tests as diagnostic tools is considerably lower than the proportion of NC using CT. Only 12% of patients with epilepsy attending an outpatient clinic in Peru had serological evidence of T. solium by enzyme-linked immunotransfer blot (EITB) test.36 There are also clinical inconsistencies in the link between epilepsy and NCC. Parasite location may be remote from the apparent epileptogenic region.38 There is no correlation between the NC burden of lesions and the severity of the epilepsy. Patients with severe refractory seizures may have only one calcified lesion. On the other hand, there are patients with multiple cysts or calcifications but no epilepsy. NC and epilepsy are common diseases in most developing countries. Because of their high prevalence, a causal as well as fortuitous relationship between the two conditions might independently exist.35,39,40
Post a comment