Language disturbances in bilinguals patients after thalamic lesions.

Three bilingual patients with ischemic or tumoral brain lesions localized in the left thalamus have been submitted to a thorough neurolinguistic analysis by means of the Bilingual Aphasia Test (BAT). They all presented with language impairments which included reduced verbal fluency; phonemic, semantic and verbal paraphasias; grammatical errors (e.g. omission and addition of free grammatical morphemes); greater disruption of comprehension as opposed to repetition; and disorders of written language. In all patients, the most disrupted linguistic levels concerned morphology and syntax, more in L2 than in L1. One patient also presented with several mixing phenomena and major difficulties in translating sentences.