Progressive Nonfluent Aphasia

Aphasia is the inability to vocalize or understand the spoken or written language. Primary progressive aphasia (PPA) refers to the group of neurodegenerative diseases showing gradual speech and language impairment as the primary presenting symptom without significant cognitive, physical, or behavioral components. Although aphasia itself is usually the sudden onset of deficits in expressing or understanding language, such as in stroke, PPA involves the gradual impairment of these functions.Fluent aphasia refers to deficits related to comprehension and is usually associated with Wernicke's brain area pathologies. In contrast, nonfluent aphasias produce a failure in the expression of language, written or verbal, and are often associated with pathologies in the Broca's area of the brain. Although the general concept of a primary progressive language impairment disease process without cognitive effects was first described in the 1890s by Pick and Serieux, it wasn't until the 1980s that PPA was coined and was further explored by Mesulam. It was initially called slowly progressive aphasia but later replaced by the PPA name.Because of its close relation to Alzheimer disease and Pick disease, the classification and diagnosis of PPA can sometimes be controversial. However, PPA is primarily broken up into three main variants: nonfluent/agrammatic variant, semantic variant, and logopenic variant. There also exists the disorder of primary progressive apraxia, which is a similarly gradual, degenerative disorder affecting the planning, programming, and sensorimotor commands required for the actual production of speech.The nonfluent/agrammatic and semantic variants are often grouped under the frontotemporal dementia syndromes, and the logopenic variant is frequently classified as an atypical variant of Alzheimer's disease. This article aims to review the nonfluent/agrammatic variant of PPA (nfvPPA).