Cerebral Amyloid Angiopathy and Alzheimer's Disease: Evil Twins?

A couple of posts ago, I mentioned that my father had both cerebral amyloid angiopathy (CAA) and Alzheimer's disease.  This isn't unusual - one study estimates 25% of people with Alzheimer's have moderate to severe CAA.

It turns out that the protein in the deposits on CAA patients' blood vessel walls is closely related to the protein seen in the plaques associated with Alzheimer's.  Researchers don't understand why excess levels of these proteins build up in some people's brains, or exactly what the connection is between CAA and Alzheimer's.

One recent study shows that a kind of CAA concentrated in small capillaries, rather than in larger blood vessels, is linked to Alzheimer's disease.  But Dad's CAA was not concentrated in his capillaries.  In fact it seems his CAA and Alzheimer's were not really connected.  "The burden of CAA in the brain vastly exceeds that seen in even the most severe and advanced cases of AD [Alzheimer's disease], indicating that this is likely to have been an independent disease process," Dad's autopsy report says.

There's growing recognition that CAA can cause or contribute to dementia, as well as cause hemorrhagic strokes like the one my dad had.  The fact that cerebral microbleeds, which can be caused by CAA, were common in Dutch memory clinic patients in a recent study seems to support this.

Whether or not CAA and Alzheimer's disease are evil twins, they were double trouble for Dad.

Comments

[Roy E. Bonwick]

A good friend of mine has had two hemorraghic strokes due to "cerebral amyloid angiopathy" (CAA). I am looking for clinical trials of drugs and other treatments targeted at CAA and for CAA support groups (if such exist). So far, the closest I have come to finding anything relevant is Neurochem's experimental drug Cerebril for which a successful Phase IIa clinical trial (for safety) was completed in 2004. There was mention of a planned Phase IIb clinical trial of this drug for efficacy - but it appears to have been delayed due to competing priorities at Neurochem.

Does anyone have any CAA leads, links, sources etc. that might be useful?

[Mona Johnson]

I'm really sorry to hear your friend has CAA and has had strokes. Awareness of CAA has been growing, but it seems we're in the very early stages of developing treatments for this disease.

I'm not aware of any trials of CAA treatments other than than the Neurochem one. There is a trial of NovoSeven for hemorrhagic stroke, but I think this is used for treatment right after a person has had a stroke, not to treat CAA (http://www.clinicaltrials.gov/ct/show/NCT00426803?order=11). I don't think the results have been published yet.

You might check in with the office of Dr. Steven Greenberg (http://neuro-oas.mgh.harvard.edu/caa/research_studies.html) to see if there are any other trials your friend could participate in. There's also a conference on CAA in Iceland this summer - you might look at the program to get some ideas about where the research is - see http://www.yourhost.is/content/view/53/68/lang,en/

I have found a study on minocycline (an antibiotic) for mice bred to have CAA (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17376966&query_hl=6&itool=pubmed_docsum), but of course results could be very different in humans. I can't address what this study means - your friend should check with his doctor about this research if he's interested.

I wish the very best for you and your friend...

Mona

[Dave Osborne]

Hi. I wrote in about three months ago. My mother who is 78 was diagnosed with CAA after her first hemorrage. She is still alive today and has probably experienced at least ten. With each one, she loses a little more. Two weeks ago she seemed to have lost her depth perception. Last week, it seems she is susceptible to seizures and we now have her on an anti-seizure medication. She still eats and does recognize me when i see her. She remains at hospice where she has been since March 4. We are so grateful to have moved her there.
My question to you is do you know of many patients who have been diagnosed with CAA that have left this long and can give us any indication of some of the things we are experiencing with mom. I thought to contact a clinic. We are close to Cleveland and I know UH is doing some work in this area.
Well, that is it. Thank you for listening.
Dave

[Mona Johnson]

Dave,

Thanks for the update. I know how hard this must be for you and your family.

Of course, I'm not a doctor, and don't really know what the typical course of CAA is. I doubt that there's an "average" patient. Dr. Steven Greenberg (see my comment above) may be able to help you and/or refer you to someone in Cleveland.

I wish there were more information available on CAA, and that I could be more helpful.

Mona

[JANE BROADHEAD]

COULD YOU TELL ME HOW QUICKLY CAA PROGRESSES AT THE AGE OF 81? A SIGNIFICANT BLEED TO THE HEAD HAS ALREADY OCCURRED AND A STROKE HAS BEEN EXPERIENCED.THIS WAS WHEN CAA WAS DIAGNOSED AFTER AN MRI.
HOW DESTRUCTIVE IS THE DISEASE WHEN TAKING BLOOD PRESSURE CONTROL?
IS IT ALWAYS NOTICABLE WHEN PROGRESSIVE DAMAGE NEWLY OCCURS SO THAT ONE CAN PIN POINT EXACTLY WHAT IS GOING ON TO DIFFERENTIATE BETWEEN DEMENTIA,DRUG SIDE EFFECTS, THE DISEASE ITSELF AND PROGRESSION OF THE DISEASE? IT'S SO HARD!

[Mona Johnson]

Jane, I wish I could answer your questions - I'm not qualified to give medical advice.

These are the kinds of questions I had when my father was alive, and I'm not sure anyone can answer them at this point. You might look at a related post from this past February to get an idea of where research on CAA is:

http://www.tangledneuron.info/the_tangled_neuron/caa-microbleeds-and-dementia-an-update.html

I hope this is at all helpful...