Association Between the Prevalence of Learning Disabilities and Primary Progressive Aphasia

Primary progressive aphasia (PPA) is a syndrome that arises when the language-dominant (usually left) hemisphere is selectively targeted by a neurodegenerative disease. The underlying neuropathology can be either frontotemporal lobar degeneration (FTLD) or an atypical form of Alzheimer disease (AD).¹ The factors that make the language network selectively susceptible to these neurodegenerative diseases remain unknown. One potential clue emerged from our previous report, which showed a history of learning disability (LD), including developmental dyslexia, to be significantly higher in patients with PPA (n = 108) and their first-degree relatives than in cognitively healthy control individuals (n = 353), as well as dementia of the Alzheimer type (n = 154) or the behavioral variant of frontotemporal dementia (n = 84).²