Antiparasitic treatment of neurocysticercosis - The effect of cyst destruction in seizure evolution

Abstract

Antiparasitic agents against Taenia solium cysticercosis are in use since 1979, although its use has been questioned on the basis that cysts would die naturally and thus treatment-induced inflammation is unnecessary. In addition, isolated reports have also questioned whether neurocysticercosis (NCC) is a cause of epilepsy. After more than three and a half decades, a large body of evidence is available. Little if any doubt exists on NCC as a cause of seizures - NCC is consistently associated with seizures when appropriate groups are compared, and in a large subset of cases, seizure semiology correlates with the anatomical location of lesions. Cyst degeneration and the subsequent inflammatory reaction increase seizure expression, although patients with non-inflamed cysts may show seizures, as do patients with long-standing, not inflamed calcified scars. Assessment of the evidence on cysticidal efficacy, safety, and the impact of cyst destruction in decreasing seizures leads to conclude that the benefits of antiparasitic treatment in parenchymal brain cysticercosis clearly overcome the risks, and have provided substantive evidence of the role of NCC as a cause of seizures and epilepsy. Antiparasitic therapy should be considered a primary option in the management of patients with live or degenerating brain NCC cysts.

Unique Characteristics of Epilepsy Development in Neurocysticercosis

“…However, several imaging findings have shown promise in identifying those at increased risk for treatment-resistant epilepsy, as it occurs in up to 30% of subjects with NCC. 18,21,26,33,51,52 These imaging findings include 1) an increased number of total, degenerating, and calcified lesions at baseline 18 (Figure 2), 2) persistent perilesional edema on follow-up imaging studies 53 (Figure 3), and 3) higher perilesional T2 values (likely indicative of gliosis) 54 on posttreatment magnetic resonance imaging (MRI) scans. One potential drawback of perilesional edema as a predictive factor for persistent seizures is that this finding could either be caused by vasogenic edema from a seizure or could be due to immune-associated inflammation.…”

Carotid Taenia solium Oncosphere Infection: A Novel Porcine Neurocysticercosis Model

“…Typically, steroids are co-administered with antiparasitic drugs to control the inflammatory response secondary to cyst damage by the immune response, and to reduce the risk of seizures. 11 Further studies are necessary for a better understanding of the pathophysiological processes in NCC, host-parasite interactions, and for improving current therapeutic regimens. In this context, the development of an accurate animal model may be valuable for the study of NCC.…”

Taenia solium, Taenia saginata, Taenia asiatica, their hybrids and other helminthic infections occurring in a neglected tropical diseases' highly endemic area in Lao PDR

“…The Sepon region is included in the MDA programs for elimination of parasitic diseases with treatment using praziquantel. The detection of seropositive individuals for cysticercosis leads to a point of concern in this issue: the occurrence of seizures and other collateral effects after treatment due to the inflammation caused by the sudden damage or death of cysts in the brain [ 30 – 33 ]. Side symptoms after treatment, including seizures, were reported by the population submitted to praziquantel MDA in Lao PDR, leading the people to reject subsequent treatments and the stop of the program.…”