Map of broken brain networks shows why people lose speech in language-based dementia

Researchers have identified the location of dysfunctional brain networks that lead to impaired sentence production and word-finding in primary progressive aphasia (PPA). PPA can occur in those with neurodegenerative diseases, such as frontotemporal dementia and Alzheimer's disease. Mapping the networks allows clinicians to apply non-invasive brain stimulation to potentially improve speech in those with PPA.