Background: The timing of progression of logopenic variant primary progressive aphasia (lvPPA) to severe dementia has not been elucidated. To address this shortcoming, 10 patients with lvPPA were continuously followed.
Methods: Patients were assessed with the annual rate of change in the Clinical Dementia Rating (CDR) sum of boxes and period from lvPPA onset to the onset of benchmark signs, including mild, moderate, or severe dementia, episodic memory deficits, topographical disorientation, difficulties with using controls for electronic appliances, and conceptual apraxia. When severe dementia was evident, we also investigated the incidence of severe cognitive and behavioral signs such as neologistic jargon, difficulties in recognizing family members, pica, and mirror sign.
Results: The mean time for patients to reach a particular CDR was as follows: CDR of 1, 4.1 ± 1.3 years post-onset; CDR 2, 5.7 ± 1.6 years; CDR 3, 7.3 ± 1.6 years. The annual rate of change in the CDR sum of boxes was 3.4 ± 1.1, corresponding to 1.7 years for the CDR to increase by 1.0. Difficulties with using electronic controls began at 3.3 ± 1.6 years, episodic memory deficits at 4.0 ± 2.0 years, topographical disorientation at 5.2 ± 2.1 years, and conceptual apraxia at 5.5 ± 2.1 years. For patients who progressed to severe dementia, six could not recognize family members, five exhibited pica, three experienced mirror sign, and one developed neologistic jargon.
Conclusions: Our results suggest that patients with lvPPA progress rapidly to dementia and develop conceptual apraxia, episodic memory deficits, visuospatial deficits, and semantic memory deficits.
Keywords: Conceptual apraxia; Episodic memory deficits; S: Logopenic variant primary progressive aphasia; Semantic memory deficits; Visuospatial deficits.