Functional decline in the aphasic variant of Alzheimer's disease

Abstract

Introduction: Primary progressive aphasia (PPA) is a clinical dementia syndrome associated with frontotemporal lobar degeneration (FTLD) or Alzheimer's disease (AD). Impairment in activities of daily living is essential for dementia diagnosis, yet less is known about the neuropathologic impact on functional decline in PPA, especially over time.

Methods: Activities of Daily Living Questionnaire (ADLQ) ratings were compared by suspected underlying pathology between 17 PPA^Aβ+ and 11 PPA^Aβ- participants at 6-month intervals for 2 years using a linear mixed-effects model. A general linear model examined associations between functional decline and cortical thickness at baseline.

Results: Groups did not differ in demographics or aphasia severity at baseline, yet overall and subdomain scores of the ADLQ were significantly worse for PPA^Aβ+ compared to PPA^Aβ- (P = .015) at each interval across 18 months.

Discussion: Functional decline appears more pronounced and disrupts more aspects of life activities for individuals with non-semantic PPA with suspected AD versus non-AD neuropathology.

Keywords: activities of daily living; dementia; frontotemporal dementia; primary progressive aphasia.

Figure 1.

Daily function is significantly more impaired for PPA^Aβ+. NOTE: Group averages of the overall ADLQ are featured with standard errors. Open circles indicate significance and closed circles indicate that analysis yielded no significant differences between groups at that time point. The PPA^Aβ+ group has a higher group mean at baseline and this difference remains throughout all visits.

Figure 2.

PPA^AB+ shows unique patterns of decline across functional subdomains. ADLQ subscales by group over time. Darker shades represent the PPA^Aβ- group and lighter shades represent the PPA^Aβ+ group. The most notable difference between the two groups is in the area of Shopping and Money (p<.0001) followed by Travel (p<.001), Employment and Recreation (p=0.013) and Household Care (p=0.014).

Figure 3.

Baseline atrophy is more widespread in PPA^Aβ+. Red/yellow indicates vertices with significant cortical thinning at baseline for the PPA^Aβ- and PPA^Aβ+ groups compared to healthy individuals. NOTE: LH=Left hemisphere. RH=Right hemisphere.