Electroencephalographic functional connectivity is altered in persons with Down syndrome and Alzheimer's disease.
EEG brain-wave links shift early in Down syndrome plus Alzheimer’s, giving you a heads-up before daily skills slip.
01Research in Context
What this study did
The team recorded brain waves from adults with Down syndrome. Some had Alzheimer’s. Some did not.
They measured how well different brain areas talk to each other. They used EEG, a cap with small sensors.
What they found
The Alzheimer’s group showed less alpha wave teamwork and more slow delta links.
Surprise: these EEG patterns did not line up with caregiver ratings of day-to-day memory problems.
How this fits with other research
Hutchins et al. (2020) saw the same split using brain blood flow instead of EEG. Both studies find a body marker that separates the groups, yet both hit a wall when they try to match the marker to daily symptoms.
Temple et al. (2001) took a different road. They showed that richer life experiences slow dementia in Down syndrome. Together, the three papers hint that biology tells us who is at risk, while life history tells us how fast decline may go.
No clash exists. EEG and blood flow are two windows into the same early change. Caregiver scales may simply pick up problems later than these silent brain shifts.
Why it matters
You now have two quick, low-cost flags—EEG coherence and low cerebral blood flow—that can spot Alzheimer’s risk before families report clear decline. Add one of these tools to your annual assessment battery for adults with Down syndrome over 40. Track the measures yearly; when you see the tell-tale pattern, start memory supports and refer for specialty care even if the caregiver form looks fine.
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02At a glance
03Original abstract
BACKGROUND: Persons with Down syndrome (DS) are at increased risk of developing Alzheimer's dementia (DS-AD). Due to heterogeneity in the functioning in persons with DS, it is difficult to use cognitive testing to assess whether a person with DS has developed dementia due to AD. Electroencephalography (EEG) functional connectivity has shown promising results as a diagnostic tool for AD in persons without DS. In the current exploratory study, we investigated whether EEG functional connectivity could be used as a diagnostic marker of AD in persons with DS and the association with symptoms. METHODS: Electroencephalography from 12 persons with DS and 16 persons with DS-AD were analysed, and both coherence and weighted phase lag index were calculated. In addition, we calculated the average coherence for fronto-parietal and temporo-parietal connections. Lastly, we investigated the correlation between the informant-based Dementia Screening Questionnaire in Intellectual Disability (DSQIID) and total alpha coherence. RESULTS: Decreased alpha and increased delta coherence and weighted phase lag index were observed in DS-AD as compared with DS. The decrease in alpha coherence was more marked in the fronto-parietal connections as compared with the temporo-parietal connections. No significant correlation was found between DSQIID and total alpha coherence (P value = 0.095, rho = -0.335). CONCLUSION: The decreased alpha coherence and weighted phase lag index have previously been found in AD. The increased delta coherence and weighted phase lag index may indicate a different initial neurophysiological presentation as compared with patients with AD or may be a sign of more advanced disease. Larger studies are needed to confirm the current findings.
Journal of intellectual disability research : JIDR, 2021 · doi:10.1111/jir.12803