To provide an in-depth longitudinal cognitive and neuroimaging description of a case of progressive dynamic aphasia.

In 1966 Luria detailed a group of patients with left-sided prefrontal lesions who exhibited dramatic reductions in verbal output, despite preserved naming, comprehension and repetition, which he termed dynamic aphasia. Most often the result of tumor or ischemic disease, rare reports of progressive, neurodegenerative presentations have been detailed.

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We present a 48-year-old, right-handed woman, referred to the UCSF Memory and Aging Center for 3-years progressive reduction in spontaneous speech output and a diagnosis of non-fluent primary progressive aphasia (nfvPPA). On examination, she showed no evidence of motor speech hesitation, repetition difficulties, grammar changes or loss of semantic knowledge and thus did not meet formal nfvPPA criteria. Instead, her presentation was notable for a gradual lack of motivation in generating speech and difficulty in organizing verbal propositions (confirmed by formal speech-language assessment). Her apathy for verbal information, did not extend into other behavioral domains, nor was there any evidence of disinhibition, loss of empathy, repetitive behaviors, or executive dysfunction. Brain imaging revealed asymmetric, L>R atrophy within the dorsal-medial prefrontal cortex and supplementary motor area. By the third visit, her speech was now sparse and stereotypic, but remained without effort or groping. Her symptoms of restricted verbal apathy had now expanded into naming and single-word comprehension deficits, she developed symptoms of hyperorality, loss of empathy, disinhibition, and executive dysfunction. Atrophy on imaging progressed bilaterally, L>R, into cingulo-insular, orbitofrontal and hippocampal regions.

This individual’s clinical profile, characterized by striking reduction in propositional voluntary speech with relative sparing of naming, comprehension and repetition does not meet criteria for a specific PPA variant. Her presentation most closely approximates that of a progressive dynamic aphasia and argues for an expansion of current clinical subtypes within PPA.