Purpose: Refractory temporal lobe epilepsy (TLE) is often associated with hippocampal sclerosis (HS). Patients with Major Depression (MD) may also show structural abnormalities in the limbic system. Co- occurrence of TLE with HS and MD is not uncommon. We investigate clinical and morphological characteristics of TLE patients in relation to MD.
Methods: Thirty-four TLE patients with HS were assessed at a Comprehensive Epilepsy Program. All relevant clinical data were obtained, including the history of antecedent events to epilepsy. MD was diagnosed based on detailed psychiatric investigation. MRI was used to measure the volume and tissue signal (T2-relaxometry) of the hippocampus and amygdala. The imaging data were expressed as percentage of the values obtained in a series of 55 controls.
Results: A history of MD was present in 15 (44%) of the 34 patients. Patients with MD had a longer duration of their epilepsy (p<0.05), and a lower frequency of antecedent events (13% with MD, 58% without MD, p< 0.05). Both groups had a similar degree of ipsilateral HS (small hippocampal volume, increased hippocampal T2- relaxation time), and demonstrated bilateral amygdaloid atrophy. However, the contralateral amygdala showed lower signal in presence of MD (97 ± 9 msec; no MD: 103 ± 8 msec, ANCOVA, p<0.05).
Conclusion: The integrity of the amygdala may influence mood disturbances in TLE patients with HS, as depression was associated with a relative preservation of the contralateral amygdala. In contrast, hippocampal abnormalities were not related to the presence of depression.
- temporal lobe epilepsy