Often discussed: Although Alzheimer therapy with drugs such as cholinesterase inhibitors and memantine is considered effective, it does not really lead to dramatic improvements with a relevant delay of the disease’s progression. Plenty of other approaches are being explored but unfortunately with little success. The largest beacon of hope – vaccination against beta-amyloid turned out to be too dangerous for the patient in its most effective version. The jury is still out on the follow-up vaccinations but the euphoria has vanished. Scientists also study passive vaccinations with antibodies against beta-amyloid as well as the inhibition of secretase which produce the beta-amyloid as a precursor protein. Here applies as well: Effective but no revolution.
For dementia as well: CPAP is good for the brain!
No wonder that others keep searching – sometimes at completely different places. Physicians at the University of California in San Diego made a find in the sleep lab: They claim that the cognitive performance of Alzheimer patients can be improved with CPAP. As known, CPAP (continuous positive airway pressure) is a form of continuous non-invasive ventilation being used for patients with obstructive sleep apnea (OSA) among other things. The Californians now made a randomized-controlled study with 52 men and women suffering from mild to moderate Alzheimer and OSA. The results were published in the Journal of the American Geriatrics Society. In the beginning of the study, half of the patients were treated with CPAP, the second half did not get this treatment. After three weeks those patients of the second half of the originally placebo patients received CPAP as well for another three weeks. At the end of the placebo controlled phase, diverse parameters showed a trend in favour of the ventilation. When at the end of the study the entire group was analyzed comparing to the beginning of the study, the improvement of the cognitive parameters statistically reached the significance level.
Sonia Ancoli-Israel, head of the studies, explains the lack of reaching significance despite the positive trend after three weeks with the size of the group being too small: “The test results show that we have an improvement in verbal learning and in memory as well as in the executive functions such as cognitive flexibility and mental processing”.
CPAP is no anti-dementia drug
So CPAP seems to work. The question is: How? To start with clearing the role of obstructive sleep apnea in this correlation. Anconi-Israel estimates the OSA quote in dementia patients at about 70 to 80 percent making CPAP no exotic type of therapy for a minority of little relevance. “It is not likely that OSA causes dementia” says the expert. She rather believes that the low oxygen level coming along with OSA and the sleep disorders impair the already limited cognitive function additionally: “At least the study suggests considering a trial therapy with CPAP for patients suffering from dementia and sleep apnea at the same time.”
Less somnolence during the day
Another observation also speaks for co-symptomatic instead of causal coherences. “The study has also shown that CPAPA improves the somnolence during the day” says Professor Jody Corey-Bloom at the department of neurosciences at the UCSD. But Alzheimer patients frequently suffer from sleepiness during the day. And it is also a typical symptom of obstructive sleep apnea. The scientists point out that it is common knowledge for a while now that CPAP ventilation effects the cognitive abilities of healthy people as well. But foremost they warn of the reflex to ignore a potential sleep apnea of Alzheimer patients because the non-invasive ventilation would be out of question. In an earlier study, Anconi-Israel and Corey-Bloom showed that the majority of ambulant Alzheimer patients tolerated a permanent CPAP therapy very well.