Linking motor speech function and dementia

Identification and measurement of motor speech impairments is an important part of the diagnostic pathway in dementia. Accurate assessment of speech and language deficits can enhance diagnostic accuracy where clinical syndromes are differentiated by communication profiles, as is the case in primary progressive aphasias. In this review we provide an overview of motor speech disorders and how they manifest in the most common forms of dementia, including Alzheimer's disease, dementia with Lewy bodies, and frontotemporal dementia including primary progressive aphasia. Motor speech disorders are not commonly present in Alzheimer's disease; however, they are frequently observed in the behavioral and nonfluent forms of frontotemporal dementia. Dysarthria may emerge with progression in some cases of dementia with Lewy bodies.