Hippocampal atrophy and neurocysticercosis calcifications

OBJECTIVE To determine the relationship between hippocampal atrophy (HA), neurocysticercosis calcifications (NC) and seizure semiology in patients with partial epilepsy. METHODS We identified two groups of patients: mesial temporal lobe epilepsy (MTLE) and extra-temporal epilepsy (ETE) patients. Each group was subdivided according to CT findings: normal, NC in the temporal regions, and NC in extra-temporal regions. MRI was obtained in a 2-T scanner and hippocampal volumetry was performed using 3-mm coronal T1-IR images. Hippocampal volumes below 2 standard deviations from the mean of the control group determined the presence of HA. RESULTS We studied 89 consecutive patients: 63 with MTLE and 26 with ETE. HA was found in 43/89 (49.5 %) patients, 42 of them with MTLE. There was no difference in frequency of HA in the comparison between patients with (25/50) and without NC (18/39) (chi(2), p=0.71). Furthermore, there was no relationship between localization of NC (temporal or extra-temporal) and seizure semiology (MTLE or ETE). CONCLUSIONS HA was more frequent and more severe in patients with MTLE, with no differences regarding the presence and localization of NC. These findings further support the concept that NC on CT not necessarily indicate the etiology of epilepsy and may represent only a co-existent pathology.