Abstracts

Neurocysticercosis (NCC) is a major cause of seizures in many less developed countries. Although less common, NCC is becoming a significant health concern in developed countries as well, mostly due to migration of infected persons.
The main causes of intractable epilepsy (IE) are mesial temporal sclerosis (MTS), brain tumors (BT), and malformations of cortical development (MCD). Although studies in endemic regions have indicated that NCC is the leading cause of symptomatic epilepsy, there is no study investigating the relationship between calcified cysticercotic lesions (CCL) and intractable epilepsy (IE) in general. Here we carry out a cross-sectional study investigating the etiological profile of IE in our country, an endemic region for NCC, with attention to the presence of CCL. From 2002 to 2003, 512 consecutive patients (273 women) evaluated at Ribeir[atilde]o Preto School of Medicine Hospital, aged [gt]18 years, were included in the survey. Intractability was defined as: 1) one or more seizures every 3 months during the last year of follow-up review or until successful seizure surgery, and 2) failure of two or more first-line AEDs at maximum tolerated doses. Neuroimaging included brain CT scans with contrasted and noncontrasted phases, high-resolution MRI with special protocols to epilepsy for all patients. Five hundreds and twelve patients met our inclusion criteria. The mean age at enrollment was 38.66 +/- 10.6 years. The mean age at epilepsy onset was 11.9 [plusmn] 7.4 years (range 1-36 years). The epilepsy duration was 21 years [plusmn] 11.3 years (range 3-48 years). The mean seizure frequency was 4.3 +/- seizures per month. The most frequent epileptogenic lesion was MTS (52,6%), followed by MCD (13.8%), and BT (10.5%). cNCL were found in 38% of cases, but, in most cases, associated with another epileptogenic lesion. Isolated CCL were found in only 1,8% of cases. In addition, we found a very higher prevalence of CCL in MTS cases (36,7%), in comparison with extratemporal epilepsy (16,8%)(p[lt]0.01, Fisher[acute]s exact test). We found evidence that the etiological profile of medically IE is very similar to those from developed countries, and that neurocysticercosis, even in an endemic region as Brazil, is a rare cause of IE. We found that CCL were twice more frequent in patients with MTS than in those with extratemporal epilepsy, suggesting either a potential role of NCC in the development of MTS or that CCL and MTS covariate with another variable, such as socioeconomic status. (Supported by Fapesp/CINAPCE program, CAPES, and CnPq.)