Previous studies of frontal lobe epilepsy (FLE) have documented different impairments of theory of mind (ToM), while the study of frontal lobe (FL) lesion without seizures has produced inconsistent results. Given the role played by the FLs in ToM, we evaluated this and other functions in patients with FLE with and without FL lesions. The main objective was to clarify the salience of ToM impairment in the cognitive pattern of FLE and its capacity to discriminate these patients from healthy subjects. The effects of FL lesions on ToM were also explored.
Seventy‐five adult patients with FLE (40 cases with FL lesions) were compared with 42 healthy controls. The Faux Pas Task (FPT) and other neuropsychological tests were utilized to assess ToM, reasoning, language, memory, praxis, attention, and executive abilities.
The patients obtained lower z scores for the FPT than for other tests. The ToM, Executive, and Verbal factors discriminated patients from healthy subjects. The patients with or without FL lesion showed significant impairments in recognizing and understanding others’ epistemic and affective mental states, but adequate capacity to exclude inexistent mental states was retained. In comparison with controls, the patients with FL lesions obtained lower scores for lexical, memory, praxis, attention, and executive functions, whereas those without lesion only showed attention and initiative deficits. Schooling was the major predictor of ToM, whereas the capacity to exclude inexistent mental states was related to seizure onset age and epilepsy duration. Other cognitive functions were related to schooling, age, or FLE laterality.
Impaired understanding of real mental states is a specific, salient, and discriminating cognitive aspect of FLE. Poor education is a risk factor for ToM deficit, whereas the clinical variables and FL lesions have no impact. These results suggest that impaired ToM may be a marker of FLE neurobehavioral phenotype.