Neurocysticercosis and seizures: updated estimates from a systematic review

What was studied

This systematic review examined how often neurocysticercosis was found among people with epileptic seizures from 1990 through May 2023. Neurocysticercosis is an infection of the central nervous system caused by the larval stage of the tapeworm Taenia solium.

Researchers searched 20 databases and included 77 studies that diagnosed the infection using neuroimaging, biopsy, or autopsy. The main pooled estimate came from 35 studies that included children and adults of both sexes and used clear definitions for neurocysticercosis and epileptic seizures.

What they found

Across the 35 studies with clear definitions, the estimated pooled proportion of people with epileptic seizures who had neurocysticercosis was 25.2%. The 95% Bayesian credible interval was 19.5% to 32.2%.

The estimated proportion did not vary by age or sex. It declined in the June 2008 to May 2023 period across studied regions of Africa, the Americas, and Southeast Asia. Studies without clear definitions reported considerably lower proportions, suggesting possible misclassification error.

Limits of the evidence

Results varied substantially among studies, indicating context-specific differences. The pooled estimate therefore should be interpreted cautiously and should not be treated as applying universally to every country, community, or person with seizures.

The review cannot determine whether the observed decline represents a true decrease in neurocysticercosis or an apparent reduction related to changes in case definitions, study populations, neuroimaging technologies, or underlying causes of epileptic seizures. The abstract does not provide participant totals or detailed results for individual countries.

For families and caregivers

Neurocysticercosis was found in a substantial pooled proportion of people with epileptic seizures in the included studies. However, the 25.2% figure is a combined estimate from multiple studies in endemic regions, not an individual person's probability of having the infection. The review does not determine whether any particular person should be tested or diagnosed.

What to watch next

Further research should determine whether the observed decline in neurocysticercosis among people with epileptic seizures is real or instead reflects changes in case definitions, study populations, neuroimaging technologies, or underlying causes of seizures.

Terms in this summary

neurocysticercosis

An infection of the central nervous system caused by the larval stage of Taenia solium, a tapeworm.

systematic review

A structured search and assessment of studies that meet predefined criteria for a research question.

meta-analysis

A statistical approach that combines results from multiple studies.

Bayesian credible interval

A range that, under the statistical model and available evidence, has a specified probability of containing the estimated value.

heterogeneity

Variation in results among studies, potentially related to differences in populations, settings, definitions, or methods.

misclassification error

An error that occurs when a person or condition is placed in the wrong diagnostic category.

endemic region

An area where an infection is regularly present.