Single-word, sentence, and discourse comprehension in individuals with temporal lobe epilepsy

The purpose of this study was to systematically investigate language comprehension in individuals with left and right temporal lobe epilepsy (TLE) at different language levels - single word (noun and verb), sentence, and discourse. Neither of the groups with TLE showed difficulties with noun comprehension, whereas verb comprehension performance was significantly lower in individuals with left, but not right TLE as compared to healthy controls. In contrast, sentence and discourse comprehension was overall impaired, irrespective of the lateralization of the epileptogenic focus. Education level and age at seizure onset were also found correlating with language comprehension in our tested cohort. The results, firstly, confirm that the verb comprehension task is more sensitive for assessment of single-word comprehension in individuals with TLE. Secondly, they indicate that language comprehension in left and right TLE is mostly impaired at the sentence and discourse levels, which may be associated with low working memory capacities.