Drug treatment of neurocysticercosis.

Neurocysticercosis, the most common parasitic disease of the central nervous system, was treated surgically for a long time. Praziquantel (an isoquinolone) and albendazole (an imidazole) are anticysticercal drugs that are currently being used for the treatment of neurocysticercosis. Both have been reported to eliminate or markedly reduce the number and size of cysticerci. Albendazole is less expensive than praziquantel, and is as effective when given for 8 days as compared to longer periods. In a small number of comparative trials, albendazole appeared to be slightly more effective than praziquantel for the treatment of parenchymal cysticercosis. Albendazole has also been found effective in ventricular, subarachnoidal and racemose forms of the disease. However, the response to treatment is not universal. Treatment with these drugs has been associated with a high frequency of adverse reactions, probably due to the host's inflammatory reaction to the dying parasites. Headache, nausea and seizures are common but usually transient. Steroids appear to ameliorate these effects and their concomitant administration has been advocated. However, no data are available to support this view. The rationale of medical therapy in spinal cysticercosis is presently based on the reported efficacy of anticysticercal drugs in cerebral cysticercosis. A marked improvement in an associated seizure disorder following anticysticercal therapy has been observed. Though seizure control is better, the total duration of anti-epileptic drug therapy has not been determined. Some single enhancing computed tomography lesions in patients of epilepsy may be benign forms of neurocysticercosis. The spontaneous resolution of a majority of these lesions has led to doubts of them being merely infective in aetiology. Also, a controlled trial could not demonstrate any beneficial effect of albendazole on such lesions. Hence, most authors recommend that these patients should be treated with anti-epileptic drugs only. Doubts persist about the efficacy of anticysticercal drugs in altering the natural course of the disease and the reported tendency of cysticercus lesions to resolve.