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![\"\"](\"https:\/\/blogs.bmj.com\/jnnp\/files\/2019\/06\/brain-mind.jpg\")
Historically, the descriptive term \u2018apraxia\u2019 was first coined by Heyman Stenthal in 1891 when he noted patients with aphasia incorrectly using objects and failing to perform purposeful actions. The term is now analogous with the presence of higher motor dysfunction in the absence of any elementary\u00a0<\/span>dysfunction in the sensorimotor system or other explainable cognitive impairments (such as language, understanding or recognition). In this study, the authors performed an apraxia screening assessment (the Cologne Apraxia Screening test, CAS) and use a \u2018CAS functional score\u2019 (CAS limb score \u2013 CAS face score) to differentiate between AD versus FTD praxis impairment, based on the reported observation that FTD patients have relatively preserved limb apraxia with more pronounced orofacial apraxia. A CSF biomarker ratio (total tau\/amyloid beta >0.52) was additionally used to indicate the presence of AD pathology. Interestingly, the authors report evidence of potential AD pathology (based on CSF biomarker profiling) in a relatively large proportion of patients with early stage FTD (43%), positively correlating with the presence of an AD-type apraxia on the CAS functional score.<\/p>\n