In the section "Controversies in Neurology" of the January issue of the Archives, Kramer1 and Del Brutto2 do a commendable job of defending opposed positions about the role of antiparasitic therapy in the management of neurocysticercosis. We would like, however, to discuss the final statements of the section editor, Dr Hachinski,3 that placebo-controlled therapeutic trials for neurocysticercosis are not plausible for ethical reasons.
The actual knowledge of the evolution of untreated cysticercosis is scarce and based on anecdotal case reports.4,5 Selection bias affects the validity of these reports: cases with more severe symptoms will be more likely to be chosen for study since patients with milder symptoms will be less likely to seek medical attention. "Historical" controls (patients who had computed tomographic studies performed before treatment) have also shown that lesions do not significantly increase in number or size.6,7 These historical controls were selected from