Cognitive and metabolic correlates of emotional vulnerability in patients with temporal lobe epilepsy.

BACKGROUND: Recent investigations have suggested that the occurrence of epileptic seizures is not completely random. In particular, various types of psychological changes or life events may act as triggering factors.

OBJECTIVE: To identify a possible link between self-perception of the impact of affective precipitants, cognitive responses modulated by aversive information and brain metabolic modifications in patients with temporal lobe epilepsy (TLE).

METHODS: The extent to which seizures were elicited or not by emotional precipitants was estimated using a self-reported scale, allowing distinction of two groups: 'Emo-TLE' group (patients reporting to have seizures triggered by emotional events) and 'Other-TLE' group, which were compared with healthy individuals ('control' group). Attentional biases were investigated using the probe detection paradigm, using negative and neutral stimuli. Interictal brain metabolism was studied using FDG-PET, and comparison was made between controls, Emo-TLE and Other-TLE groups.

RESULTS: Patients with emotional vulnerability (Emo-TLE) disclosed specific attentional biases towards negative stimuli compared with the Other-TLE and control groups. Patients with Emo-TLE also exhibited specific hypometabolism in the anterior temporal lobe, including amygdala and hippocampus. The degree of attentional biases correlated with decreased metabolism in these regions.

CONCLUSIONS: This investigation shows that the impact of affective events is the result of self-perception and also that it might be determined by specific cognitive and brain metabolic modifications in TLE.