Hippocampal volume in children with temporal lobe epilepsy compared to healthy children: a magnetic resonance imaging study.

Context : There are currently few published studies that compare hippocampal volume (HCV) in children with temporal lobe epilepsy (TLE). Aims : T0 o compare HCVs in children with TLE and in relation to normal controls (NC), and to analyze HCV change in the acute phase in pediatric subjects using magnetic resonance imaging (MRI). Setting and Design : T0 he case group (n=24) was matched in gender and age range with NC subjects (n=24). Subjects were divided into three groups according to age: 2-5.9 years, 6-8.9 years and 9-13 years. Materials and Methods : M0 anual measurements were used to obtain HCVs on oblique coronary MRI images obtained by three-dimensional magnetization-prepared rapid gradient-echo (3D-MPRAGE) sequence. Statistical Analyses : T0 he HCV was calculated and normalized. Paired t-tests were used to compare the right and left HCVs within each study group. Analysis of covariance (ANCOVA) was used to consider the impact of age and gender on HCVs. Results : T0 wenty-two patients were diagnosed with definite/probable TLE, and two were non-syndromic focal epilepsy which was distributed in the 2-5.9 years group. The range of left to right mean HCVs of the case and NC group aged 2-13 years was 2014.14 54.32 mm (3) to 2165.31 80.99 mm (3) and 2015.46 26.97 mm (3) to 2100.93 57.33 mm (3) respectively. There were age-related differences in left and right HCV, but no effect of gender. Relative to NC subjects, cases group aged 2-5.9 years had significantly different HCVs, while no significant difference was found in the other two groups. There was significant difference in the right to left HCVs in the case subjects aged 2-5.9 years, but not in the other age groups. Conclusions : T0 he heterogeneity in the 2-5.9 years age cohort may relate to the increased HCVs. The HCV data from NC subjects may be used as a reference to assess hippocampal abnormalities in clinical practice.