Etidronate May Reduce Residual Calcification in Porcine Neurocysticercosis

Residual brain calcifications that occur after antiparasitic treatment in neurocysticercosis (NCC) can serve as foci of enduring neuroinflammation and associated seizures. Etidronate, a first-generation bisphosphonate, has exhibited efficacy in reducing the formation of ectopic brain calcification. In the present proof-of-concept study, its effects on post-treatment calcifications were evaluated in 12 pigs naturally infected with NCC, confirmed via magnetic resonance imaging. All animals received albendazole plus praziquantel for 5 days, either alone (n = 6) or with etidronate (20 mg/kg/day for 2 weeks, then 10 mg/kg/day for 8 weeks; n = 6). Eight months post-treatment, the animals were euthanized for ex vivo brain computed tomography, histology, and scanning electron microscopy of calcified lesions. Etidronate reduced the risk of calcification by 21% (risk ratio = 0.79; 95% CI: 0.65-0.90; P = 0.020); however, there was considerable individual variability in the magnitude of this risk reduction, as well as significantly decreased calcium and phosphorus content in granulomas. Etidronate was well tolerated and may serve as an adjunctive therapy to reduce residual calcification after antiparasitic treatment in NCC.