Neurocysticercosis is a neglected microbleed mimic. a cautionary note for stroke neurologists

Calcified cysticerci share the morphology and signal properties with true cerebral microbleeds, but this condition is neglected at the time of evaluating MRIs for clinical or research purposes. We report our experience with the MRI reading obtained from the Atahualpa Project, a population-based stroke study, conducted in a village endemic for cysticercosis.

Neuroimaging studies were performed in Atahualpa residents aged ≥60 years identified during a door-to-door survey. Lesions of interest included neuroimaging markers of small vessel disease. Out of 311 residents, 248 (80%) agreed to participate. Two internal readers independently reviewed MRIs blinded to CT findings.

Internal readers achieved good-to-very-good inter-rater agreements for all types of investigated lesions, with the exception of cortical microbleeds (κ = 0.53). After reviewing CTs, six of eight conflicting lesions were cysticercus. Five external experts blinded to CT findings also read those images, reporting conflicting results. Cysticercosis was recognized only in 26% of readings.

Calcified cysticercotic lesions should be included in the list of microbleed mimics. CT should be performed in doubtful cases to avoid overdiagnosis of cerebral microbleeds in large-scale stroke studies and in the clinical practice. Proper recognition of this neglected microbleed mimic may have important therapeutic implications.