At what age does dementia set in for Down's syndrome patients?

Down syndrome patients generally experience dementia and cognitive decline. William Mobley, MD, PhD, describes the onset of symptoms and when they usually occur.

Transcript

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It's quite clear the pathology begins well before the onset of dementia, that the pathology

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is likely to be much more subtle than the typical Alzheimer's disease pathology. [SOFT UPBEAT MUSIC]

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If you look between ages 35 and 40 at the brain postmortem, it has all this pathology that you expect

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to see in Alzheimer's disease. If you ask, what's the average age at which those people begin to show

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cognitive decline over their baseline, from their baseline, 53. If you ask how many have dementia

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by age 60, more than 60%. If you ask at what point do 90% of those people,

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if they survive, have dementia, and it's 73. So it's quite clear the pathology begins well

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before the onset of dementia, that the pathology is likely to be much more subtle than the typical Alzheimer's disease pathology, meaning that the onset of early changes

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probably predates by a decade, the pathological findings you see on postmortem examination, and that both of those precede,