Dysarthria and stroke. The effectiveness of speech rehabilitation. A systematic review and meta-analysis of the studies

INTRODUCTION: Speech difficulties, such as dysarthria or aphasia, in addition to motor impairments are frequently seen in post-stroke patients. EVIDENCE ACQUISITION: Literature searches with the keywords: "stroke" and "dysarthria" and "diagnosis" and "stroke" and "dysarthria" and "assessment" were conducted using PubMed, EMBASE, Cochrane Library, and Web of Science databases to perform the systematic review about the methods used to measure the severity of dysarthria in subjects post-stroke. The search was performed by two authors from 15 January to 22 February 2020. The research identified a total of 402 articles for the search using the keywords "stroke" and "dysarthria," and "diagnosis" and 84 references for the search using the keywords "stroke" and "dysarthria" and "assessment." Sixty-nine selected articles were analyzed by the reviewers. Thirty-seven publications met the inclusion criteria and were included in the systematic review. Thirty-two articles were excluded for several reasons: 1) 12 involved individuals with aphasia or other speech problems different from dysarthria; 2) 12 examined different topics from our aim; and 3) eight did not include post-stroke cases. EVIDENCE SYNTHESIS: The systematic review identified methods for measuring the severity of post-stroke dysarthria. The meta-analysis showed the acoustic parameters affected in dysarthria secondary to stroke and the differences in these parameters after speech therapy. CONCLUSIONS: The alternating and sequential motion rate (AMR- P., AMR-T., AMR-K., and SMR-P.T.K.) and maximum phonation time were significantly improved after speech rehabilitation.