Left Parietal AVM

Contributor:

Dr. Chris Ekong

Consultants:

Dr. Mike Tymianski
Dr. Fred Gentili
Dr. John Wong
Dr. J Max Findlay
Dr. Michael Schwartz
Dr. Christopher Wallace
Dr. Michael West
Dr. Renn Holness
Dr. Gary Steinberg
Dr. D Sutherland
Dr. Karel terBrugge

Case 33

Age: 48

Sex: Female

History: August 2006. Presented with headaches. Examination showed no neurological deficit. CT head done and showed Left Parietal calcification which enhanced with contras

Impression: Left Parietal AVM

Now what?

- Leave alone and repeat studies from time to time?

- Embolization + Surgery?

- Embolization + Radiation?

- Surgery?

Dr. Chris Ekong, Neurosurgeon, Regina. September 22, 2006

Dear Gary, Fred, Mike, Bob, John, Max, etc.:

Welcome back from holiday.

What do you think of this case ?

Chris

Dr. Ian Fleetwood, Neurosurgeon, Halifax, September 23, 2006

Hi Chris:

Can we presume she is right handed? I don't see convincing evidence of SAH or ICH on non-contrast CT. Wouldn't mind seeing an MRI - might help nail down nidus size and could show any old changes if she had a subclinical bleed in the past.

Regardless, based on her age, incidental presentation, angiographic

findings and "old" natural history data, I would offer her treatment rather than conservative management with the indication being prevention of future ICH and no guarantees about her headache.

Best treatment option here is radiosurgery with marginal dose 18 - 20 Gy. Nidus is reasonable size so no role for embolization pre-SRS. Not convinced that the left PCoA lesion is an aneurysm - looks infundibular on the 2 views provided, so no need for clipping/coiling there. No other flow-realted aneurysms.

I mention "old" natural history data because according to recent review paper from Columbia group (Current Opin Neurol), any treatment here would be "experimental therapy", so other option would be randomization into ARUBA trial.

Ian

Dr Garnette Sutherland, Neurosurgeon, Calgary, September 23, 2006

Dear Chris:

Interesting case. If I understand the clinical history she is a 48 year

old woman presenting with only headache. Her AVM is left sylvian fissure -parietal lobe in location. While the nidus is relativeely compact it has a number of small MCA and to a lesser extent PCA feeders. This will make dissection difficult and put at risk adjacent cortex. Although from the data provided I am uncertain, suspect her speech cortex is not far from the AVM. Functional MRI would be a non invasive way to asses such a relationship.

I suspect her surgical risk would be as high as 30%. As the AVM is

unruptured I would recommend observation only. It would be important that her blood pressure be monitored and controlled if elevated. I would provide her a prescription for atenolol (25 mg PO, OD) on the belief that this reduces turbulence and thus the risk of AVM rupture - obviously not proven.

Best,

Garnette

Dr. M Christopher Wallace, Neurosurgeon, Toronto. September 23, 2006

Hello Chris:

Patient is very young. Would try to treat because of long annual risk of bleed options watch... ok if she appreciates risk but repeat imaging not very helpful.

Embo... no aneurysms or ectasias... cure not likely due to PCA and MCA

supply... but could help pre-op by taking out PCA supply rads... sure... size fits and decent chance of cure at three years (70%) surgically accessible, compact nidus....dominant but posterior my preferred option; Surgery.

Second choice: rads

Chris

Dr. Max Findlay, Neurosurgeon, Edmonton. September 23, 2006

Hi Chris,

I would have a neurointerventionalist take a good look at this but I think they could achieve a considerable reduction in supply to facilitate surgery, which would be a major undertaking of course but entirely feasible (and satisfying).

Radiosurgery is to me the obvious and attractive option; I

would really need to talk to the patient--Chris you have provided us what I think is the major question we face today to unruptured AVM treatment. It used to be so much easier when it was surgery or nothing!

In this case I would recommend treatment, but honestly let the patient decide after being given all the facts.

Best,

Max

Dr. Mike Tymianski, Neurosurgeon, Toronto. September 24, 2006.

Compact, relatively small nidus.

Would favor treatment as she has a 4% per year hemorrhage risk.

Would rank surgery above rads due to immediacy of the effect.

Not likely to be curable by embo. Pre-op embo a consideration.

Mike Tymianski

Dr. Gary K. Steinberg, Neurosurgeon, Stanford. September 25, 2006

Chris:

Although some of the AVM and venous drainage involves the parietal area, I'm somewhat concerned this AVM also involves the dominant superior temporal gyrus, so would like to see MR for better localization and maybe functional MR. However, I would lean towards embolization followed by surgical resection, because of patient's young age and relatively small, compact nidus.

Thanks,

Gary

Dr. Karel terBrugge, Interventional Neuroradiologist, Toronto. September 25, 2006.

There is a discrepancy between the slightly diffuse moderate size AVM nidus and the relatively large feeding MCA branches. I suspect there are some fistulas hidden in the nidus. While embo is unlikely to cure it may make things easier for the other team members.

KTB

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