Optical sensor light leak under wrist
Wearing a fitness tracker on the underside of the wrist introduces noise because tendons running to the fingers cause light leak in the optical sensor.
Similar snapshots
Data point
2-3 decades
Amyloid deposition can begin two to three decades before the onset of clinical cognitive symptoms.
Data point
25%
About 25% of community-dwelling people in their seventies have amyloid in their brains without any symptoms of dementia.
Data point
44%
By age 90, approximately 44% of community-dwelling people have brain amyloid without dementia symptoms, undermining blood-test specificity.
Data point
4%
Gayatri Devi's slow-titration protocol for APOE4 carriers on anti-amyloid monoclonal antibodies yields only a 4% rate of ARIA, far below standard protocols.
Data point
98-99%
Autopsy studies show that between 98% and 99% of Alzheimer's patients have some form of concomitant primary brain pathology, most commonly vascular disease.
Data point
40%
About 40% of Alzheimer's patients eventually develop some level of Lewy body pathology, illustrating significant dementia overlap.
Data point
0.3–0.4 pts
Anti-amyloid therapies like lecanemab and donanemab show only 0.3–0.4 point improvements on the 18-point CDR Sum of Boxes scale, a modest but potentially meaningful shift.
Data point
30%
Approximately 30% of patients enrolled in Alzheimer's drug trials did not actually have Alzheimer's by pathology, having been misdiagnosed clinically.
APOE4 homozygous risk: +60% vs wild type
Carrying two copies of the APOE4 allele increases Alzheimer's risk by approximately 60% compared to the APOE3/3 wild type, analogous to carrying the BRCA gene for breast cancer.
