Large (≥3-Millimeter) Parenchymal Brain Calcified Cysticerci Are More Often Associated with Hippocampal Atrophy than Smaller Ones in Seizure-Free Individuals with a Single Lesion.

Calcified cysticerci are often associated with hippocampal atrophy (HA). While most studies suggest that repetitive seizures cause HA in these patients, others have demonstrated that HA may also occur in persons without epilepsy. Little is known about mechanisms triggering HA in seizure-free individuals with calcified cysticerci. Here, we aimed to assess whether the size of the calcification is associated with HA. Using a population-based design, we selected apparently seizure-free individuals with a single calcified cysticercus in whom interictal paroxysmal activity and other causes of HA have been discarded. A total of 55 individuals (mean age, 58.3 ± 13 years, 62% women) fulfilled inclusion criteria. Unadjusted and multivariate models were fitted to assess the association between the size of the calcification dichotomized into <3 mm and ≥3 mm (exposure) and the presence of HA (outcome). Sixteen participants (29%) had HA, which was asymmetric in eight (50%) cases. Hippocampal atrophy was noted in 11/20 (55%) participants with large calcifications and in 5/35 (14%) with small calcifications (P = 0.001). A multivariate logistic regression model showed a significant association between the presence of large calcifications and HA, after adjustment for relevant confounders (odds ratio: 7.78; 95% CI: 1.72-35.1). Participants with calcifications ≥3 mm in diameter were 7.8 times more likely to have HA than those with smaller ones. Study results open avenues of research for the use of agents to prevent HA progression.