I took a day off from work and I spent 20 hours straight digging deeper and deeper into it - going through wiki, popular medical sites, reading research papers with sometimes conflicting statistics, youtube videos (thats right, youtube is a fantastic educations tool for any and every possible topic), and AVM related patient support forums.
And my thirst for more information will continue for sometime to come, but here is the distilled version of what I have understood so far about AVMs.
Now, the details:
First, the good news:
- AVM is not immediately serious or life threatening, especially for me since it hasn't bled yet
- It doesn't grow like a tumor
- Nor does it spread like cancer
- And a very high percentage of these are completely treatable
Now, the details:
What It Is:
We know arteries carry oxygen rich blood from the heart to various parts of the body and veins carry the oxygen depleted blood back to the heart. And the arteries will normally branch off into smaller and smaller tubes until they become capillaries. From the capillaries, blood will be used by the cells and the oxygen depleted blood will be collected by veins and sent back to the heart.
In the case of AVM, arteries and veins will be connected abnormally (directly without capillaries), and usually in a cluster of abnormal connections. Basically a tangle of arteries and veins. Hence the name ArterioVenous Malformation. They can happen in few different places in the body, including the brain and spine. In my case, it is in the brain (Cerebral AVM).
Why Does It Happen:
No one knows. It is usually congenital (birth defect), but thankfully not hereditary, (so my lovely daughter and brothers have nothing to worry about). So I may have pretty much lived with it for 40 years already. So I shouldn't have to worry about it much then right?. Not so fast.
Effects & Symptoms:
The biggest issue is that these abnormally formed arteries have weak walls and may rupture and leak blood inside the skull (intracranial hemorrhaging). And that hemorrhaging can result in seizures, stroke, paralysis, loss of vision, speech, movement, or even coma or death. Sounds like a party right.
Even without hemorrhaging, an AVM can cause issues like sever headaches, seizures or other problems since they are diverting some blood from reaching their intended areas, and sometimes the malformation could put pressure on parts of the brain.
AVM Grades:
AVMs are graded from 1 to 5 (called Spetzler-Martin scale) based on 3 things:
- their size
- their location in the brain
- and their draining veins
Grade 5 AVMs are too complex and are usually left alone. Any attempts to fix these may cause the same damage to the brain that could be caused if and when an AVM bleeds. Simply put, its not worth the risk. And patients with these AVMs may have to resign to the fact that there is a ticking time bomb in their head that could go off anytime.
Grades 1 - 3 AVMs are usually treatable. And the good news is the success rate of these treatment (in removing the AVMs completely) is very very high. But there is always a chance for side effects. When it comes to brain, nothing is simple, nothing is risk free.
AVM by the numbers:
Thanks to University of Toronto, and UCLA medical school websites, here are some key stats:
- In the US, AVMs appear in about 1 in every 1000 people.
- Typical time of discovery is between ages 20 and 40.
- A majority of them of become symptomatic by age 50.
- Risk of hemorrhage from an AVM is about 2 - 4 percent in any given year.
- Cumulative risk of hemorrhage is about 33% in 10 years, 55% in 20 years and 70% in 30 years.
- And if and when it bleeds,
- there is a 30% chance of death and
- there is a 25% chance of serious long term (permanent) effects (seizure, stroke, etc.)
- If the AVMs are treatable, more than 90% of treatments succeed in removing the AVMs completely (but there may be side effects of varying degree).
In My Case:
I went to the lab and picked up my report and MRI images (in a CD). Came home, installed OsiriX program on my MacBook and copied all data (about 900 images) and looked at the animation. It was super cool. It was a bit like watching the gender scan with my wife before our daughter was born - only a lot less exciting. After all, I don't need to argue with my wife to pick a name for this one. ;)
According to the radiologist's report, my AVM is about 4 cm x 4 cm x 3 cm and is in my Right Occipital Lobe in the back of my head. Thankfully it hasn't bled yet. Occipital lobe is responsible for our vision, hence my partial peripheral vision loss on the left side of both my eyes. (Remember Biology 101, right part of the brain controls the left side of our body and vice versa? ). I don't know what grade my AVM is yet, but my educated guess is Grade 3. When it comes to AVM grades, lower is better, like hurricanes or earthquakes ;) In addition, the report mentioned something about a couple of enlarged arteries and veins. Not sure what they mean.
This is just a random image I found on the internet that seemed close enough. I will post a frame from my actual scan after I visit with my surgeon.
I have also been suffering from migraine headaches for the last several years. Every episode will start gradually with partial vision loss on the left side of my eyes for about 30 minutes followed by severe headache on the right side. And all will be back to normal in a few hours. But now I think the headaches weren't actually headaches at all, instead they may be mini seizures caused by epilepsy of the occipital lobe. How do I know this? Coz' I stayed in a Holiday Inn Express. And also based on some research papers I found on nih.gov that talks about how patients with AVMs in Occipital lobe often get their seizures misdiagnosed as migraine headaches. Anyway, that is my theory and I am sticking with it until my neuro slaps me silly.
Treatment Options:
3 main options are available when it comes to treating brain AVMs:
- Craniotomy - Your plain vanilla brain surgery - open the skull, pull the weeds out, and put the lid back on. Results are immediate.
- Stereotactic Radiosurgery - Use radiation (gamma knife) and precisely zap the AVM. This is especially effective for small AVMs (under 3cm). It my take more than one sitting, and it may take up to 3 years for the AVMs to completely disappear. But it is a lot less messy compared to craniotomy.
- Embolization - This is a minimally invasive surgery, where a catheter is pushed up the artery (usually using the femoral artery in the inner thigh) all the way up to the AVM and a special glue will be squirted into the AVM to seal it off. Again less messy, but not always very effective. More often than not, embolization will be used in conjunction with craniotomy or radio surgery. Usually embolization will be done few days ahead of the surgery to minimize blood loss during the surgery.
Now, I can't wait to visit my neurosurgeon to find out my grade and treatment options. Something to look forward to :)
