LAUSR

Abstract Background Supplementary motor area (SMA) plays a complex role in language. Language disturbances associated with SMA pathology have some times been named as “aphasia of the SMA” or simply “SMA aphasia”. However, this type of aphasia is extremely unusual, that it is not even included in classical aphasia classifications. Aims To review the involvement of the SMA in language, in order to suggest if the language disorders observed in SMA pathology should be considered as an aphasia subtype. Methods & procedures An extensive literature review was performed using PubMed and Google Scholar. Outcomes & results It was found that 45 papers refer to the speech and language disorders associated with SMA damage. Only three of them name this disorder as “aphasia”. It is reported that damage in the SMA results in both speech (posterior SMA, including speech automatization, initiation, timing control, and monitoring speech) and language disorders (pre-SMA, including working memory, word production, lexical disambiguation, context-tracking, monitoring, inhibition of erroneous language representations, and inner language). Conclusion Regardless of its rarity, it is evident that damage in the left SMA usually results in a clinical syndrome that clearly corresponds to aphasia. Interpreting this as an aphasia can aid in overcoming the limited idea of a “language zone” located in the perisylvian area of the left hemisphere, that was proposed over one century ago.