Early and Mild Phases of Primary Progressive Aphasia: A Case Series.

BACKGROUND: The early and mild phases of various neurodegenerative diseases, sometimes described as Mild Cognitive Impairment (MCI), has been characterized as the transitional state between normal cognition and dementia. It is described as having cognitive decline not severe enough to cause functional impairment. MCI has been divided into amnestic and non-amnestic subtypes with the amnestic subtype most commonly progressing to AD. The MCI phase of other dementias such as DLB has also been described. There are very few reports summarizing this early phase of Primary Progressive Aphasia.

AIMS: Our aim is to contribute to the clinical characterization of the early and mild phases of clinically suspect PPA in order to better describe the presenting features and neuropsychological profile.

METHODS: This is a cross-sectional case series abstracted from our memory disorders clinic. We retrospectively queried and analyzed the cases of 9 patients with a primary diagnosis of MCI and secondary diagnosis of progressive aphasia. Acquired (non-degenerative) aphasias (e.g. stroke, mass) were excluded.

RESULTS: Of the 9 cases, 5 were non-amnestic MCI and 4 were amnestic MCI, all with language as the primary domain. All eMCI cases were non-amnestic. Word finding difficulty was observed in 8 of the 9 cases and sentence repetition impairments in 8 of 8 tested.

CONCLUSION: PPA is a syndrome with an underlying progressive neurodegenerative etiology that results in dementia. PPA, like other neurodegenerative conditions, can transition through an early (i.e. MCI) phase prior to the dementia phase. The clinical description of this early stage of PPA is predominantly characterized by word finding difficulty on observation, sentence repetition impairment on neuropsychological testing, and a diagnosis of MCI or early MCI (eMCI) with language as the primary impaired domain ± an amnestic component.