Description des troubles langagiers suite à un accident vasculaire cérébral ischémique du thalamus : une revue de la littérature.

Abstract

Background: The thalamus is a complex brain structure that has been the subject of numerous scientific studies since its discovery. Its involvement in language processes is currently recognized by the scientific community. Objectives: The aims of this study are to review the latest advances in research in order to clarify the clinical manifestations of aphasia found in ischemic stroke of the thalamus, and to enable speech therapists to assess and manage them specifically. Method: Using the four-stage PRISMA method, we compiled a review of the literature and identified the most relevant articles on the subject under study. Results: A total of 10 articles were included in this literature review. Various tests, more or less exhaustive and specific, were administered to the patient samples in these studies, in order to assess language functions. This review identifies and analyzes information on the frequency, severity, laterality and cognitive-linguistic impairment of thalamic aphasia, depending on the vascular territory affected. The hypothesis that a thalamo-cortical disconnection is responsible for language disorders was also put forward.  Discussion: The results showed that the thalamus is involved in language processes, with left lateralization. Damage to the thalamus may be associated with diaschisis and thalamo-cortical disconnection, leading to impairments in language production and comprehension. The degree of severity tends to be mild, with particular impairment of elaborate language, which can make diagnosis difficult in the acute phase. The frequency of thalamic aphasia therefore varies from study to study, and depends on the specificity of language assessment. Conclusion: Language impairment in thalamic stroke is essentially characterized by fluency disorders, anomia and little or no impairment of repetition, with a good prognosis of evolution. The use of sensitive tools, based on cognitive and neuropsychological models of language, would appear to be necessary to provide a detailed assessment of thalamic aphasia, and enable specific and adapted rehabilitation approaches to be envisaged.