Factors associated with motor manifestations in older adults with Alzheimer's dementia: a cross-sectional analysis.

Purpose: Motor signs are frequently observed over the clinical course of Alzheimer's disease (AD). We explored the potential clinical associations of motor manifestations in AD.

Methods: Our sample consisted of older adults (≥ 60 years) with AD from NACC. Individuals with Parkinson's disease or other Parkinsonian syndrome or under anti-parkinsonian agents were excluded. UPDRS III was used to assess motor signs in nine domains: hypophonia; masked facies; resting tremor; action/postural tremor; rigidity; bradykinesia; impaired chair rise; impaired posture/gait; postural instability. A global motor variable assessed the presence of at least one motor sign. Binary logistic models were estimated for the global (primary) and individual motor domain variables (secondary outcomes).

Results: A total of 4771 older, predominantly female, well-educated participants were analysed: 3556 without (75.4 ± 7.6 years, 45.6% males) and 1215 with motor manifestations (79.4 ± 7.8 years, 44.4% males). The most influential risk factor for motor manifestations in AD was the Clinical Dementia Rating stage: stage one increased the odds of motor signs by ~ 44%, stage two by ~ 168% and stage three by ~ 437%. Each additional point on the Geriatric Depression Scale elevated the odds of motor manifestations by ~ 5%, whereas each additional point on the Mini-Mental State Examination decreased these odds by ~ 2.5%. Cerebrovascular disease (by ~ 44%), diabetes mellitus (by ~ 25%), traumatic brain injury (by ~ 30%), alcohol abuse (by ~ 33%), anxiolytics (by ~ 36%), antidepressants (by ~ 31%), antipsychotics (by ~ 48%) and β-blockers (by ~ 33%) elevated the odds of motor manifestations. Angiotensin II receptor blockers decreased the odds of motor manifestations (by ~ 33%).

Conclusion: Disease progression constitutes the most crucial clinical risk factor for motor manifestations in AD.