ADAS-Cog Trajectories Differ from Expected Decline in Dementia Following Repeated Non-Invasive Interventions over 3...

Area of Science:

• Neuroscience
• Gerontology
• Clinical Neurology

Background:

• Non-pharmaceutical interventions, including cognitive training, transcranial electrical stimulation (tES), and repetitive transcranial magnetic stimulation (rTMS), show potential for improving cognitive function in Alzheimer's disease (AD) and dementia.
• The long-term efficacy and impact of repeated non-invasive interventions on cognitive trajectories in dementia patients remain largely unknown.
• This study addresses the need to understand the sustained effects of these interventions over extended periods.

Purpose of the Study:

• To investigate if repeated non-invasive interventions administered over 1 to 3 years are associated with slower cognitive decline compared to typical Alzheimer's disease progression.
• To determine if longer intervals without treatment predict greater cognitive decline after intervention periods.
• To evaluate the long-term effectiveness of non-pharmaceutical interventions in managing cognitive decline in dementia.

Main Methods:

• Seventy-three participants with dementia or AD underwent 2 to 9 blocks of non-invasive treatments (tES, rTMS, cognitive training).
• Cognitive decline was tracked longitudinally using Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) scores for up to 36 months.
• Mixed-effects models were used to compare the observed rate of cognitive decline to established AD progression rates, adjusting for baseline factors.

Main Results:

• Participants exhibited a significantly slower rate of cognitive decline than the reference AD progression rate (p < 0.001).
• Many participants maintained stable ADAS-Cog scores during treatment periods lasting 1 to 3 years.
• Longer no-treatment intervals were significantly linked to increased post-treatment cognitive decline (p < 0.001), while AD medications showed no significant impact.

Conclusions:

• Repeated non-invasive interventions, when applied consistently over extended periods, appear to mitigate cognitive decline in individuals with dementia.
• The findings support the feasibility and effectiveness of personalized, long-term non-invasive treatment strategies for managing dementia.
• Sustained intervention delivery is crucial, as extended breaks correlate with accelerated cognitive decline.