Struggling to think about risks

Hi there,

I am a new member from the UK. Back in November 2023, I was told of an incidental finding of a right superior parasagittal AVM. Had an angiogram in Feb 2024, and consulted with my neurosurgeon in May. Neurosurgeon said there is a 3-5% per year risk of AVM bleed. Given I’m only 57, the likelihood is therefore high that the AVM will bleed before I die (assuming I live another 20-30 years). Given the eloquent position location of the AVM, he recommends GK. I then spoke with the GK neurosurgeon, who explained the risks of GK to me: swelling, epilepsy and the one I’m most scared of: 3-5% risk of sensory and motor deficit and weakness on the left side of my body.

I am so scared that I am really struggling with the various risk percentages. Especially the 3-5% risk of sensory/motor deficit and weaness on the left side of my body. Has anyone been told of this risk? What does that deficit / weakness look like? Will I still be able to live independently. He characterised the 3-5% risk as very low risk, but somehow in my head, it is huge.

I really at this point don’t know how to think about whether to go for the GK. Friends keep saying if I’ve lived with it for 57 years, surely it wouldn’t bleed. I don’t know. How many doctors did you talk to before deciding on a way forward?

Sorry if I’m rambling a bit, but I am so terrified at the moment.

Thank you for any advice,


Hey @josie1 this is exactly the problem!

It is the most difficult decision to take.

When I was first diagnosed, I decided to myself that the time to take action was when the percentages had swapped round the persuading way: so at the point that I was either told that my risk of a bleed had increased or that I perceived myself that it was higher than it had previously been. It seems like the right thing to negotiate with yourself in this way.

I don’t remember my doc giving me a percentage risk of rupture but I do remember him telling me that the risks involved in my surgery were “5% risk of something bad happening, including death” :scream: I mean, how do you choose to take that route?

Now, in my case, I took the view that the 5% included a risk of dying rather than the risk of dying being one patient in twenty, so I persuaded myself that the actual death risk was probably much lower. I didn’t attribute a number to it.

What happened with me was that I was getting pretty rapid changes in symptoms from my AVM. I could hear the erroneous flow, so that was extra perturbing, I think, and it got louder and louder and I got dizzier and dizzier. So as my symptoms progressed, I got much clearer on my need for intervention.

So I think that choice was much easier for me. I’d still say that it’s a hard decision to make, real dice-rolling stuff. I think the most important thing to do is to rationalise with yourself however you want to make your decision.

I’d also say that there are occasions when a doctor’s recommendation is to leave well alone. Some people have their doctor baulk at the idea of surgery or embolization or radiotherapy because it is clear to them that they are likely to do more damage than good by attempting to intervene. So not doing an intervention can be the right choice, too. There is no nice, controlled study that clearly indicates when to act and when to abstain, mostly because in order to do so, you have to do the placebo thing and pretend to a bunch of people that you’ve done something when you haven’t and see how long everyone stays healthy. That’s not an ethical choice, so there’s no such study.

So I think rationalise with yourself when that crossover point would come. Share your thoughts, if it helps, and without persuading you one way or the other, I hope we might help you with that rationalising.

Hope something I share might help.

Very best wishes,


Richard, thank you so much for sharing your thoughts.

At the moment, because I don’t have any symptoms at all, the 3-5% risk of motor/sensory deficit and weakness feels like a huge risk. But both neurologists I’ve spoken to are adamant that given the position of the AVM, they don’t recommend leaving it alone. I’m thinking perhaps I should talk to a couple more neurologists, see what they say. Also, maybe I should have the GK later in life, again both neurologists think it’s pointless to wait. I really wish that I never found out about my AVM



I’d always suggest to people that there’s often no need to rush into a decision – it took me months and months to get to surgery: if I had been urgent, my assumption is that I would have been seen much more urgently than I was. So, yes, getting a second opinion sounds like a good step.

I’m not sure this next thought is going to help but I said that initially I was of the view that waiting for the numbers to change round the right way was how I approached it. Can I say that (other than the fact that mine appeared to be changing rapidly) I pretty quickly came to the opinion that waiting for the risk to increase didn’t make any sense to me.

Now, where you’ve got a risk of deficits, it may make more sense, but as I reasoned with myself, I decided that delay was just increasing my risk overall, not reducing it. I guess I decided that I had plans to live at least another 20 years and therefore having the op was going to be necessary at some point.

Having that increasing feeling of illness, the rationale that I would need it at some point and no focus on deficits(!) led me to get on with it.

The choice for you needs to be yours. However you rationalise it, that’s what matters.

My neurologist’s view is that given where the AVM is located, if it bleeds, it would paralyse me. So I don’t really have the option of doing something about it after it bleeds. Feels really scary. And yet, I can’t help thinking, if it hasn’t bled for 57 years, will it?

It feels like this risk of deficit and weakness is specific to me, rather than a generic risk of GK?

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I think the risks are to do with the location of it in each case, so the doc is assessing where he or she is working and the impact on surrounding tissue, so yes, I think the risk you’ve been given is to do with the area of work. I’m pretty sure everyone gets a similar assessment of the risk of operating wherever the AVM is.

My AVM was classified as a DAVF, which is very much on the surface of the brain, so the risks are different from a classic AVM such as yours and a different classification is used. I’ve come away with zero deficits, which may be why there was no conversation that I remember about potential deficits for me.

So this is definitely something to discuss with the doc. What I can tell you from reading round here is that a lot of people are told by their doctor that the risk of a bleed increases over time. I guess the features of each of our own AVM give clues as to the rate of change and I’m sure it will vary.

The basic risk associated with a brain AVM is that you have arterial pressure blood flowing directly into a vein. Arteries are high pressure blood vessels, whereas veins are not, so the risk of a bleed is to do with how strong the flow is (I suppose) and how the vein is impacted by that. If the doctors can see the vein bagging out, then it would seem more likely that a rupture is close by. If there’s little apparent impact on the vein, maybe there’s much longer before the risk rises to imminent. However, I’m no doctor, I’m just a patient like you, so I’m supposing how these things are assessed.

If you want to understand your risk more, I’d say talk to the doctor. That they are of the view that an operation is appropriate might be as much of an indication that you’ll get, I don’t know. Or, do get a second opinion and ask the same questions there: I guess the question really is “how imminent” does your risk appear to be?

I think you could also ask for more views on what deficits are likely (and how significant a deficit does the doctor anticipate). I think we’re taking detail on what you’ve already been told but maybe understanding that detail might help you balance the impossible. It is always as difficult as this, I feel. All of us who’ve not had a bleed find this to be near impossible.

It is also fair to say that some people are advised to “watch and wait”. I guess those people have an MRI or other scan every year or two to see how the AVM is developing, with a view to taking action when it appears to be important to do so. There are obviously risks associated with every approach to this problem. I very much take the view that we find ourselves with a bunch of risks in every direction that we look.

However, we take risks every day: we cross the road, we walk down stairs. In these cases, we are used to the risks and we take mitigations to reduce the likelihood or impact. With an AVM, we have to trust someone else to mitigate the risks. That’s part of the difficulty of it.

I hope that some of my thoughts will help. I do not want to nudge you one way or the other, just help to rationalise the decision.

Very best wishes,


Richard, your thoughts are certainly helpful. They have been especially helpful in formuating for me the questions I need to ask. I’ve now had conversations with two neurosurgeons and both times, I had been so terrified that I drew a blank and couldn’t think of any questions to ask. I will take my time, talk to more people. At the moment, I’m waiting for my angio images so I can take them to get a second opinion.

Thanks again for being so helpful


Hi @josie1 & welcome to the family… sorry to hear about your diagnosis & it’s never an easy decision in these circumstances… I was diagnosed with a right frontal AVM in December 2010 & told 1-2% chance of a bleed every year but had a bleed January 2011 at the age of 30 & underwent surgery a month later with no time for second opinions etc - had no symptoms my entire life.

I think getting second opinions helps as we rely on the advice provided by the medical experts… you need to weigh up the risks associated with a bleed vs treating/not treating it, as you see these things are unpredictable.

Rest assured that technology has advanced so much in the medical field & continuously advances daily, which should put you at ease once you have the right medical team treating you… is it possible to take a support person with you when going to such appointments as this could help you get a better picture of your situation & minimising stress levels… I would write questions down before my consultations so that I didn’t forget.

As tough as this is now I can honestly say that there is light at the end of the tunnel & life does go on… you just need to be comfortable with your decision at the end of the day as we are all different… please continue to keep us updated on your journey… God bless!


@Adrian1 thank you for your kind words. My surgeon was telling me too about how unpredictable a bleed is. I am on blood thinner for the next three months because of a blood clot created during my angio, so there is the added fear of a bleed happening during this time. I am trying to stay positive, some days are better than others.

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@josie1 it’s a horrible decision isn’t it? For my part, I was told that I had a 20% chance of having speech deficits if they operated. That would mean having to leave my job and career, and changing every aspect of my family’s life. I wasn’t told the chance if the AVM bled, I would imagine higher than that. It’s so strange because we’ve been walking around with these things our whole lives, and yet the knowledge of having them has turned everything upside-down. I think I’m pleased I had an MRI for my migraines and so found out about my AVM now, before rupture, but I certainly miss not knowing and not worrying about it. God bless you.

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@EverlastingHills I too miss the days when I didn’t know. I found out because I had eczema on my ear, one thing led to another, and here I am. I sometimes think there must be a reason God wants me to find out. Anyway, for now, I’m taking the advice to not rush, talk to experts and think carefully. I’m also not sure I want to have GK while I am on blood thinner.

Because of the blood clot, I am not able to fly. But I didnt want the family to cancel their holiday, so have sent them off on their holiday while I stayed in the UK. Almost feels a bit like I’m getting them ready for life without me. So today is a day of not feeling very positive. But I know tomorrow I will be better.