Poster A6, Tuesday, August 20, 2019, 10:15 am – 12:00 pm, Restaurant Hall
Language disorders after adulthood cerebellar lesions: systematic review of 91 cases
Emilia Malinen1, Matti Lehtihalmes1;1University of Oulu, Finland
Introduction There has been a growing interest of discovering the role of the cerebellum in cognitive functions, such as language (van Dun et al., 2016). Despite of several reviews of cerebellum’s connection to linguistic processing (see e.g. De Smet et al., 2007; van Dun et al., 2016), to our knowledge, no comprehensive systematic review of linguistic disorders after adulthood cerebellar lesions including single cases have been published. Methods Our objective was to evaluate systematically the type of language disorders after adulthood cerebellar lesions, and the association between symptom severity and time since injury. Systematic literature search was conducted on seven electronic databases. Manual and reference search were also conducted. Total of 91 cases with a cerebellar lesion published in 35 articles (out of 1317) between 1994-2017 met the inclusion and exclusion criteria. Results Studies included in this systematic review were methodologically highly heterogeneous. Only limited number of studies were high-quality and reliable. Results showed a large variation in linguistic disorders after cerebellar lesions. There was no clear laterality effect between language disorders and damage location. Language symptoms mentioned most often were disorders in verbal fluency (VF) and in verbal working memory. In addition, disorders in naming and word finding, higher level language deficits and agrammatism were also mentioned frequently. However, disorders were mainly restricted, affecting only single language functions, which can be partially explained by limitations of language assessments in the studies included. Only in five cases the symptoms were defined as aphasia. Because of the limitations in studies, we could not comprehensively conclude the severity of all language disorders. Language disorders often seem to have improved over time and, in some cases, the full recovery of symptoms was observed. Relationship was found between the severity of VF and naming disorders and time since lesion as the degree of most prominent impairments decreased over time. Notably, VF impairments seems to improve slower than naming. In some cases, language disorders were observed even years after damage. However, after one year or more post onset, disorders were mainly restricted, specific and were related to other cognitive impairments. Functional abnormalities in cortical and subcortical regions outside the cerebellum seem to be a potential mechanism explaining the phenomenon. Conclusion In most of the cases included to this systematic review, language disorders related to adult cerebellar lesions seem to be mild or restricted. Noteworthy, language symptoms can show high individual variation among patients with a cerebellar lesion. This systematic review confirmed earlier findings (De Smet et al., 2007) of connection between cerebellar lesions and language disorders. However, according to previous view (van Dun et al., 2016), co-existing cognitive disorders and functional abnormalities in cortical and subcortical areas seem, at least partially, to explain this connection. References De Smet, H. J., Baillieux, H., De Deyn, P. P., Mariën, P., & Paquier, P. (2007). The cerebellum and language: The story so far. Folia Phoniatrica et Logopaedica, 59, 165–170. van Dun, K., Manto, M., & Mariën, P. (2016). The language of the cerebellum. Aphasiology, 30, 1378–1398.
Themes: Disorders: Acquired, Language Production
Method: Other