Neurocisticercose: diagnóstico tomográfico em pacientes neurológicos

Abstract

Neurocisticercose (NC) é a parasitose mais comum do sistema nervoso central no nosso meio. Foram analisadas 3093 tomografias computadorizadas (TC) de 2554 pacientes neurológicos durante o período de um ano. A maioria dos pacientes era procedente de Curitiba (77,3%). 1821 (58,9%) das TC foram normais. Do total destes pacientes, 236 (9,2%) possuíam achados tomográficos compatíveis com NC; a proporção feminino:masculino foi 1,6:1. Duzentos e dezenove casos (92,8%) apresentavam a forma inativa, 13 (5,5%) ativa, 3 (1,3%) ambas, e apenas 1 caso a forma racemosa. Calcificações intraparenquimatosas foram o achado mais comum (89%). Cefaléia foi o achado clínico mais frequente (35,5%), seguida de epilepsia isolada (20,9%) ou associada a outros achados neurológicos (9%). Achados tomográficos compatíveis com NC, especialmente a forma inativa, são achados relativamente comuns em uma população não selecionada de pacientes neurológicos. Com exceção parcial dos pacientes epilépticos, a relação destes achados com o quadro clínico neurológico deve ser cuidadosamente analisada individualmente, pois a presença casual de calcificações isoladas intraparenquimatosas ocorre em uma proporção significativa de pacientes com queixas ou doenças neurológicas sem relação com a NC.Neurocysticercosis (NC) is the most common parasitic disease of the central nervous system and accounts for a significant proportion of morbidity and mortality, in special epilepsy. The authors reviewed 3093 computed tomography scans out of 2554 randomized neurological patients evaluated during a one year period. Most patients (77.3%) were living in Curitiba, Paraná, Brazil. 1821 (58.9%) CT scans were normal. NC was diagnosed in 236 patients based on tomographic criteria; the sex ratio was F:M 1.6:1. 219 (92.8%) patients had the inactive form of NC: 195 (89%) had only isolated intraparenchymal calcifications, and 24 calcifications plus hydrocephalus. Active forms were observed in 14 patients: 8 with degenerating cysts, 4 with viable cysts, 1 with intraventricular cyst, and 1 with racemose form. Three patients had both forms, active (cysts) and inactive (calcifications). The most common clinical finding among patients with tomographic diagnosis of NC was headache alone (35.5%), followed by epilepsy (20.9%). There is a potential role of NC as a causal factor of epilepsy in most of our patients, but surely not in all of them. On the other hand, the finding of inactive NC (calcifications without hydrocephalus and/or meningitic reaction) in patients with headache is probably fortuitous in most cases. In fact, the occasional finding of isolated calcifications in general population is not quite rare, as it was observed in 3.3% of another series of 973 patients with head trauma submitted to CT scan and without epilepsy previous history. The presence of CT findings compatible with NC, especially calcifications, must be carefully correlated with the clinical context in each case. Only then, an unequivocal cause-effect with all its medical and epidemiological implications role can be established.