Abstracts

RATIONALE: The contribution of the amygdala to human emotion recognition has been broadly investigated. Bilateral amygdala damage results in impaired recognition of Facial Expressions of Emotion (FEE), with a disproportionate deficit in fear recognition (Adolphs, 1994). Temporal lobe epilepsy (TLE) is the most frequent form of partial epilepsy in adults, and hippocampal-amygdalar sclerosis (HAS) the most common radiologic and neuropathologic finding. This form of human TLE is frequently associated with an history of febrile convulsion in early childhood and with the appearance of drug-resistance seizures durig adolescence. Recent studies raise concerns that it may be associated with a progressive seizure-induced damage to the medial temporal lobe structures beginning during childhood. The aim of this study was to investigate the recognition of facial expressions of emotion in subjects with epilepsy and neuroradiologic evidence of HAS.
METHODS: Three patients groups and one normal subjects group were studied: a) 25 TLE patients with unilateral HAS: 15 subjects with positive history for febrile convulsions. b) 23 TLE subjects with MR evidence of antero-medial temporal lobe lesion other than HAS. c) 33 extra-TLE subjects. d) 50 age matched normal subjects. All epilepsy subjects were right-handed. None of the subjects entered in the study presented a story of major psychiatric illness. All patients were taken anti-epileptic medication.
Emotion Recognition was examined with a task, which required subjects to match a facial expression with the name of the following basic emotions: happiness, sadness, fear, disgust and anger. Pictures from the Ekman & Friesen series were used as stimuli. 10 face stimuli for each emotion were used giving a total of 50 stimuli. A Face Identification task, which required subjects to match a target face with five alternative was used as a control task.
RESULTS: 1. All subjects showed no deficit in the face-identification task. 2. FEE recognition was impaired in patients with right HAS; recognition performances in epileptic patients with left HAS, TLE and extra-TLE with lesions other than HAS, showed no differences respect to normal control subjects. 3. The deficit in FEE recognition was maximum for fearfull faces. 4. The degree of emotion recognition impairment was related to the age of the first seizure and subjects with complicated febrile convulsions (before two years of age) showed the strongest deficit.
CONCLUSIONS: We observed that patients with temporal lobe epilepsy and right amygdalar damage were impaired in FEE recognition, expecially for fear, at variance with patients with other localization-related seizures. The severe and selective impairment of fear recognition in epileptic patients with history of febrile seizures before 2 years of age, suggest that early right amygdala damage can affect the developement of facial expression processing abilities. These data are further supported by preliminary fMRI findings showing that, in patients with right hippocampal-amygdalar sclerosis, the deficit in fear recognition is associated with the absence of a pattern of brain activation specific for the processing of fearful facial expression (Benuzzi et al., New York academy of Sciences 2002).
[Supported by: Grant MURST 2000.]; (Disclosure: Grant - MURST2000)