Primary progressive aphasia

Abstract

When a patient presents with acute aphasia, today's neurologist takes swift action to characterize the clinical syndrome and use neuroimaging and other tools to identify its pathophysiologic basis. One goal of these urgent efforts is to determine whether the patient has an ischemic process that merits thrombolytic intervention. We can only hope that tomorrow's neurologist is as well-equipped with clinical and pathobiologic assessment tools when faced with a patient with progressive aphasia. Three articles in the current issue move us in this direction. Patients with primary progressive aphasia (PPA) may exhibit impairments spanning the spectrum of speech and language function,1 with 3 major subtypes currently recognized and ongoing efforts to reach consensus regarding diagnostic criteria.2 Although the classification of patients with aphasia as fluent or nonfluent may be difficult because of the multifaceted nature of fluent speech,3 it has been obvious for many years that some patients with PPA mostly exhibit difficulties understanding the meaning of words but are generally able to speak fluently—this is semantic dementia (SD),4 or the PPA-semantic variant. Other patients may be able to understand word meaning well but have difficulty with the rate, rhythm, grammatic structure, or articulation of speech. Originally termed nonfluent or progressive nonfluent aphasia (PNFA), many clinicians are now classifying these patients as agrammatic or logopenic5 based on their language characteristics. Patients with logopenic PPA may be variably fluent depending on the type of conversational exchange or test being undertaken.1 Partly because of …