Rs. Briellmann et al., ONSET-AGE DEPENDENT MRI BASED HIPPOCAMPAL VOLUME ASYMMETRIES IN INTRACTABLE PARTIAL COMPLEX TEMPORAL-LOBE EPILEPSY, European journal of neurology, 4(5), 1997, pp. 453-459
The purpose of this study was to determine whether the age at onset of
temporal lobe epilepsy influences hippocampal volume. Fifteen right-h
anded patients with medically intractable partial complex epilepsy of
temporal origin were studied in quantified magnetic resonance imaging
(MRI) and neuropsychological tests. In seven patients (mean age: 24 ye
ars) epilepsy began before the age of three (= YOUNG), in eight patien
ts (mean age: 29 y) after the age of three (= OLDER). Education, socia
l integration, duration of epilepsy and seizure frequency were equal i
n YOUNG and OLDER. The mean hippocampal volume, after normalization to
total intracranial volume was for the right and for the left side sma
ller in YOUNG than in OLDER (p less than or equal to 0.02). The side-t
o-side asymmetry of absolute hippocampal volume was in patients with l
eft-side focus more pronounced in YOUNG than in OLDER (p < 0.03). The
number of patients with right-side focus was too small for statistical
analysis. Results of neuropsychological testing showed no significant
differences between YOUNG and OLDER. Onset-age of epilepsy before thr
ee Sears is associated with a higher risk of bilateral hippocampal hyp
otrophy and unilateral hippocampal asymmetry. Performance in neuropsyc
hological testing seems not to be significantly influenced by hippocam
pal volume or age at onset.