Abstracts

RATIONALE: The amygdala has been implicated as a key structure within a brain system involved in the perception of emotion in others and social cognition. There is also evidence that the amygdala may be atrophied as a result of chronic temporal lobe epilepsy (TLE). This paper reports the outcome of a longitudinal study to explore the impact of unilateral temporal lobe surgery on key measures of emotion perception, social cognition and quality of life (QOL) in TLE sufferers.
METHODS: 17 left (L) TLE and 21 right (R) TLE patients were tested prior to and, where possible, six months following surgery for temporal lobe epilepsy using measures to assess perception of emotion in faces and voices, social judgement and QOL. Duration of epilepsy was also recorded for all patients and MRI amygdala volumes were available for 18 participants.
RESULTS: Pre-operative data indicated that the amygdala was smaller in the side affected by TLE (p[lt]0.05). The MRI index was also found to correlate with a number of measures including perception of facial expressions and suggested that the left amygdala may be particularly important for emotion perception (p[lt] 0.05). Duration of epilepsy was also found to be negatively correlated with some pre-operative scores on the Facial Expression task, voice tasks (p[lt]0.05) and a video task (p=0.057). Post-operative data suggested that outcomes for some Facial Expression tasks may be worse if the left amygdala was intact pre-operatively and the duration of epilepsy was shorter before surgery. For the QOL measures, prior to surgery some scales had higher scores when the right amygdala was intact (p [lt]0.05). QOL scores were unaffected by duration of epilepsy in this sample. Post-operatively, QOL measures showed improvement, but analysis of difference scores showed that this improvement was in fact confined to the RTLE group (p[lt]0.05).
CONCLUSIONS: The pre-operative data showed that the volume of the amygdala tended to be smaller on the side affected by TLE. In addition, prior to surgery, both the amygdala volume and duration of epilepsy were found to influence performance on key measures of emotion perception and social judgement, with a suggestion of a particularly important role for the left amygdala. Post-operative data suggested that performance was worse for some emotion perception measures after surgery if the left amygdala was intact prior to surgery and duration of epilepsy was shorter. For QOL, the pre-operative data suggested that the right amygdala was particularly important and the post-operative data demonstrated that improvement in QOL scores occurred only for RTLE patients.