Clinical use of SAND battery to evaluate language in patients with Progressive Supranuclear Palsy

Background Progressive Supranuclear Palsy (PSP) patients present language disturbances in tasks like naming, repetition, reading, word comprehension and semantic association compared to Parkinson's disease (PD) and healthy controls (HC). Objective In the present study we sought to validate a Screening for Aphasia in NeuroDegeneration (SAND) battery version specifically tailored on PSP patients and to describe language impairment in relation to PSP disease phenotype and cognitive status. Methods and results Fifty-one PSP [23 with Richardson's syndrome (PSP-RS), 10 with predominant parkinsonism (PSP-P) and 18 with the other variant syndromes of PSP (vPSP)], 28 PD and 30 HC were enrolled in the present study. By excluding the tasks with poor acceptability (i.e., writing and picture description tasks) and increasing the items related to the remaining tasks, we showed that the PSP-tailored SAND Global Score is an acceptable, consistent and reliable tool to screen language disturbances in PSP. However, we failed to detect major differences in language involvement according to disease phenotype. Differently, we showed that patients with dementia present worse language performances. Conclusions Taking into account specific disease features, the combination of the SAND subscores included in the PSP-tailored SAND better represents language abilities in PSP. Furthermore, we showed that language disturbances feature PSP patients irrespective of disease phenotype, but parallels the deterioration of the global cognitive function.