investigation of semantic system defects in adult aphasic patients following stroke

Introduction: semantic system plays a key role in all areas of language including understanding and expression of language. based on a traditional view, the left hemisphere is dominant for processing of various linguistic information, including semantic information. it is believed that lesions in the left hemisphere impair the semantic component of language. in this study, we aim to study different types of semantic impairment in patients with aphasia; so that with early diagnosis of these sematic impairment we can identify patients who need treatment.materials and methods: this is a cross-sectional, descriptive-analytic study. a total of 39 subjects, comprising 13 patients with left cerebral ischemic stroke in the temporoparietal region and 26 healthy subjects, were evaluated using pyramids and palm trees test, concrete and abstract word synonym test, and bilingual aphasia test (bat).results: in concrete and abstract word synonym test, patients with left hemisphere damage had lower performance than the normal group. only in the verbal version of the pyramids and palm trees test, patients with left hemisphere damage obtained significantly lower scores than the normal participants. in the bat test, patients with left hemisphere had a heterogeneous performance.conclusion: based on these findings, although a large part of semantic processing is performed by the dominant hemisphere of the brain, the right hemisphere has a complementary role in semantic processing.