Sleep apnea and Alzheimer's are not commonly known to be associated, but a recent study in the Journal of Clinical Sleep Medicine reported that the greater the severity of one's sleep apnea, the greater the chance that you'll have what are called lacunar infarcts in your brain on an MRI study. Lacunar strokes (or infarcts) occur when small vessels supplying a specific part of the brain gets blocked and can show up on an a CAT scan or MRI as multiple small lesions. These areas correlate with small areas of dead brain tissue in the distribution of small arteries. In the study, 54% of people with severe OSA, and 12% with mild OSA, were found to have lacunar infarcts. All these people were asymptomatic neurologically at the time of testing. Their conclusion was was people with severe OSA have a higher incidence of silent cerebrovascular lesions than their counterparts with less severe OSA.
An interesting finding, in light of the fact that Alzheimer's is now thought to be a disease of small vessels in the brain. There's still a lot of controversy about the clinical significance of incidental lacunar infarcts on an imaging study, but I think you would agree with me that having dozens or hundreds of these small areas of dead brain tissue is not good for your memory. Add to this all the research studies that show that people with OSA are more likely to clot due to increased inflammation in general. Others studies have shown that people with lacunar infarcts have a higher incidence of heart disease. Over 80% of people with OSA are not diagnosed in this country. OSA is known to be strongly linked to heart disease. The links go on and on.
Do you think this is a valid association that's worth further research, or am I taking the sleep-breathing paradigm a little too far?