Neurocysticercosis: the good, the bad, and the missing

Abstract

Neurocysticercosis (NC) is a neglected disease that contributes substantially to neurological morbidity/mortality in lower-income countries and increasingly among high-income countries due to migration. Many advances have been made in understanding NC, but unanswered questions remain Areas covered: This review discusses the epidemiology, pathophysiology, immunology, diagnosis, treatment, and eradication of NC. Expert commentary: The global NC prevalence remains unknown and needs proper ascertainment. Further understanding of the pathophysiology of extraparenchymally located cysts is needed to improve management. The role of inflammation, which is required for parasite death and reabsorption, but may lead to severe complications, must be better understood. Valid screening tools including immunological and molecular tests need to be developed to reduce the reliance on neuroimaging which is not usually accessible in endemic areas. Prognosis for people with parenchymal NC is generally good after treatment, but there are no sufficiently powered randomized trials evaluating antiparasitic treatment for extraparenchymal NC. Most people with seizures do not develop epilepsy. Overemphasizing NC as the main cause of epilepsy could increase stigmatization with potential medico/social implications. Several tools for prevention and control of taeniasis/cysticercosis are available, but strategies to eradicate NC must be created with the involvement of all stakeholders.

Exploring the complex associations over time among albendazole treatment, cyst evolution, and seizure outcomes in neurocysticercosis

“…Unfortunately, cross‐sectional studies cannot answer the question about NC as a cause of epilepsy, because temporality cannot be determined. Prospective studies enrolling participants with new onset NC‐related seizures are necessary to assess the proportion of individuals with NC who develop epilepsy . Two participants with only residual calcifications continued to have seizures, with two seizures each.…”

“…Neurocysticercosis (NC) is infection of the central nervous system (CNS) with the larval stage of the pork tapeworm Taenia solium, and seizure is the most common presenting symptom, with about one‐third of patients having seizure recurrence . Seizure outcomes with NC are unpredictable and are likely to be related to the location, number, and stage of the cysts, as well as other factors that impact the host immune response .…”

“…Some authors have argued that faster resolution of the cysticerci with anthelmintic treatment (AHT) should lead to improved seizure control . However, although AHT is somewhat effective in eliminating viable parenchymal cysts, its effect on degenerating parasites is not well understood . Furthermore, among those with multiple viable cysticerci, not all cysts resolve simultaneously after AHT; consequently, there might still be some viable cysts remaining that cause seizures even after other cysts have resolved or developed into calcifications .…”

“…6,7 However, although AHT is somewhat effective in eliminating viable parenchymal cysts, 6,8 its effect on degenerating parasites is not well understood. 1 Furthermore, among those with multiple viable cysticerci, not all cysts resolve simultaneously after AHT; consequently, there might still be some viable cysts remaining that cause seizures even after other cysts have resolved or developed into calcifications. 6,8 Perhaps because of the complicated impact of AHT on cyst stage, the effect of AHT on seizure outcomes over time is not well understood.…”

Neurocysticercus: Diagnosis on intraoperative squash smear

“…Seizures are the most common presenting symptom accounting for 80%, children being more affected than adults. 2,3 Headache and intracranial hypertension is diagnosed in one-third and one-fifth of patients, respectively.…”