Non-Fluent Variant Primary Progressive Aphasia (nfvPPA)

Non-fluent/agrammatic variant primary progressive aphasia (nfvPPA) is one of three primary progressive aphasia subtypes alongside semantic and logopenic variants. Patients present with effortful, halting, distorted speech, agrammatism in production and comprehension of complex syntax, apraxia of speech, and relatively preserved single-word comprehension and object knowledge. Cognitive function in non-language domains is initially preserved but gradually declines.

Underlying pathology is most often tauopathy (corticobasal degeneration, progressive supranuclear palsy, Pick's disease) in 70 percent, with TDP-43 type A pathology in a minority. The clinical phenotype frequently overlaps and progresses to corticobasal syndrome with limb apraxia and parkinsonism, or to progressive supranuclear palsy with vertical gaze palsy and falls. Brain MRI shows asymmetric left posterior frontoinsular and dorsolateral frontal atrophy.

Diagnosis is clinical (Gorno-Tempini criteria 2011) supported by speech-language pathologist evaluation, brain MRI showing left frontal atrophy, FDG-PET showing left frontoinsular hypometabolism, and amyloid/tau PET to identify underlying proteinopathy. Management is symptomatic: speech therapy with augmentative and alternative communication, dysphagia evaluation, caregiver education, fall prevention, and palliative planning. Disease-modifying therapies are limited; future tau-targeted therapies are in trials.