Emily
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Diagnosed Oct 2005. Direct bypasses: Nov 05 Apr 06
Posts: 259
Brisbane, Australia
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Hi Jacquie, I've got MM and have had two direct bypass surgeries, both very successful. I also still have MM problems in an area that cannot be operated on, and I would consider myself fairly knowledgable about the condition, as far as any of us can be anyway. So I would be more than happy to answer any questions you have.
Basically Moyamoya is a condition where the bloodflow and oxygen flow to the brain is restricted. Medically it can be termed the "sponteneous occlusion of the Circle of Willis". The Circle of Willis is the "roundabout" of arteries and blood vessels that supply the brain. Occlusion means progressive narrowing - the degree of narrowing is not the same for everyone though. A stenosis is a narrowed section of a blood vessel, MM is usually diagnosed by a scan of the brain showing a stenosis/stenoses in the internal carotid arteries. These are the "main" arteries that supply the brain at the front of your head.
As these crucial arteries are narrowing, lots of small campilary "Moyamoya" vessels grow, in order to 'beef-up' the supply. And the MM term comes from their appearance on the scan.
There is no [known] cure for MM - meaning that the narrowing cannot be reversed. This is because the artery walls become weak and brittle as they narrow (for unknown reasons). Some doctors prescribe cerebrovascular (brain blood vessel) dilators, such as some anti-hypertension medications (blood pressure lowering), is is unsure yet as to whether this helps.
MM is manageable, relatively easily, by surgery. Introducing new bloodflow to the brain by either direct or indirect bypasses. A direct bypass uses an artery from outside the skull (extra-cranial) and attaching it to another main artery on the brain (inter-cranial) and then an immediate blood supply is formed. Results are usually instantenous. The most common artieries used are the Superficial Temporal Artery to the Middle Cerebral Artery. So this type of surgery is termed EC-IC or STA-MCA. An indirect bypass uses a muscle from outside the skull, transplanted onto the brain, then the blood supply from the muscle can take anywhere from 6-12 months to grow into the brain. This is called and EDMS [usually].
The type of surgery performed will vary patient to patient & surgeon to surgeon. The direct bypass is more complicated and therefore more risky. It is usually used when there is a very urgent need for blood - for example if one or both internal carotid arteries are completely blocked. AND when there is a proficient surgeon. An indirect bypass will often be used if the narrowing has not yet progressed very far.
Due to restricted bloodflow, strokes and TIA's are common with MM patients. Most people think strokes are caused by blood clots, but the definition of stroke is "failure of blood supply" so they can also be the result of the bloodflow not being able to reach it's destination [in time] due to narrowed and/or blocked arteries. The moyamoya vessels do help a lot with getting the blood supply there, and that's why a lot of people with MM can have a small stroke, then recover completely within short times. If the arteries are very narrow, there can be a lot of pressure on the tiny little MM vessels to get the blood pumping around and it is therefore also 'common' for them to burst and bleed into the brain. These two reasons are why it is very dangerous to leave MM un'treated'. -> ** When treated, you will barely [maybe even completely] know you have it anymore, cept from maybe an aspirin a day and looking after your fluid intakes. So it's good to keep in mind that it's a completely manageable condition. Many people on this board have their surgeries out of the way and cruising through life just like everyone else without special roadwork detours in their brains.
Apart from scary sounding episodes like strokes and bleeds, having MM is likely to cause symptoms such as fatigue, fogginess, reactions to extreme heat, headaches, tingling, confusion [esp when doing many things at a time - easily distracted] etc... this is all due to the body having such a hard time getting the blood around your brain, due to all the roadworks. Things move much slower.
Um that's enough of a speil for now... Do some research but mostly it's important to know YOUR CASE... And find a doctor with experience and one that you're comfortable with.
And ask questions here, everyone's wonderful!
XO Emily
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