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

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.

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).

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%).

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