The Association Between Neurocysticercosis and Hippocampal Atrophy is Related to Age

Abstract

Abstract. Neurocysticercosis (NCC) has been associated with hippocampal atrophy, but the prevalence and pathogenic mechanisms implicated in this relationship are unknown. Using a population-based, case-control study design, residents in a rural village (Atahualpa) aged ≥ 40 years with calcified NCC were identified as cases and paired to NCCfree individuals (control subjects) matched by age, sex, and level of education. Cases and control subjects underwent magnetic resonance imaging for hippocampal rating according to the Scheltens' scale for medial temporal atrophy and were interviewed to identify those with a clinical seizure disorder. The prevalence of hippocampal atrophy was compared between cases and control subjects by the use of the McNemar's test for correlated proportions. Seventy-five individuals with calcified NCC and their matched control subjects were included in the analysis. Hippocampal atrophy was noted in 26 (34.7%) cases and nine (12%) control subjects (odds ratio: 4.4; 95% confidence interval: 1.6-14.9, P < 0.0021). Stratification of pairs according to tertiles of age revealed an age-related trend in this association, which became significant only in those aged ≥ 68 years (P = 0.027). Only five cases and one control had recurrent seizures (P = 0.221); three of these five cases had hippocampal atrophy, and the single control subject had normal hippocampi. This study confirms an association between NCC and hippocampal atrophy, and shows that this association is stronger in older age groups. This suggests that NCC-related hippocampal atrophy takes a long time to develop.

On the relationship between calcified neurocysticercosis and epilepsy in an endemic village: A large‐scale, computed tomography–based population study in rural Ecuador

“…22,29,30 As detailed elsewhere, MRIs were performed with a Philips Intera 1.5T (Philips Medical Systems, the Netherlands) at Hospital-Clínica Kennedy, and included two-dimensional multi-slice turbo spin echo T1-weighted, fluid attenuated inversion recovery (FLAIR), T2-weighted, and gradient-echo sequences in the axial plane, as well as a FLAIR sequence oriented in the sagittal plane; slice thickness was 5mm with 1mm gap between slices. 29 A total of 452 MRIs, all performed in Atahualpa residents aged ≥40 years, were reviewed.…”

“…Due to the potential lack of resolution of CT to detect small cystic lesions in the brain parenchyma, subarachnoid space, or ventricular cavities, we used information provided by brain magnetic resonance imaging (MRI) performed in the same population for other research purposes, as part of the Atahualpa Project. 22,28,29 As detailed elsewhere, MRI was performed with a Philips Intera 1.5T (Philips Medical Systems, The Netherlands) at Kennedy Hospital-Clinic, and included two-dimensional multislice turbo spin echo T 1 -weighted, fluid attenuated inversion recovery (FLAIR), T 2 -weighted, and gradient-echo sequences in the axial plane, as well as a FLAIR sequence oriented in the sagittal plane; slice thickness was 5 mm with a 1-mm gap between slices. 28 A total of 452 MRIs, all performed in Atahualpa residents aged ≥40 years, were reviewed.…”

“…Atahualpa is a rural village located in coastal Ecuador, known to be endemic for NCC. 15,21,22 Atahualpa residents are homogeneous regarding race (95% belong to the native/ mestizo ethnic group), living conditions, socioeconomic status, and dietary habits, as detailed elsewhere. 20 Atahualpa is a closed village with a low migration rate (<30 adults leave the village every year), making it an optimal setting for conducting population-based studies.…”

The Association between Calcified Neurocysticercosis and Cognitive Performance: A Case–Control Study Nested to a Population-Based Cohort

“…11 Given the major role of the hippocampus in memory and other cognitive functions, it is plausible to hypothesize that hippocampal atrophy could be the link to explain cognitive impairment in NCC patients. In addition, previous studies from our group have shown a significant association between NCC-related hippocampal atrophy and increasing age, 12 which, in turn, is also associated with worse cognitive performance. None of the aforementioned studies investigated the role of hippocampal atrophy or age to explain the cognitive performance of NCC patients compared with controls.…”

Neurocysticercosis and hippocampal damage: a causal link favored by epileptogenesis or neuroinflammation?

“…[16] In the same population, it was demonstrated that this association is strongly related to age, suggesting that NCC-related hippocampal atrophy takes a long time to develop. [17] Interestingly, many of the studied individuals do not had epilepsy or electroencephalography evidence of paroxysmal abnormalities, showing that the association between NCC and hippocampal atrophy may occur irrespective of seizure activity (unpublished data).…”