Spend 24 hours in the company of a couple of hundred brain surgeons and you’d have a sense of unease too. I’m at a conference where “minimally invasive neurological therapies” are being discussed. My take-home message? No one knows anything for sure. Until it’s too late, that is.

Not that they aren’t good at their job – they’re the best in the world at getting at blockages and other problems inside your brain. But they are here to discuss the things they don’t know. And those are conversations you’d rather not overhear.

The typical presentation goes like this. “So, we went to perform an angioplasty on patient A, who was suffering from acutely reduced vision” (I may be paraphrasing badly). “Here’s the imaging.”

On the screen appears a picture of some loopy, tangled-looking blood vessels. There are murmurs and sharp intakes of breath. A voice just behind me mutters “ay-ay-ay”.

I have no idea what I’m looking at. I’m only here to give a talk about more general issues in scientific research. But I have that sinking feeling, like in the first five minutes of an episode of Casualty, that something bad is about to happen.

“I’d like to know: what would you have done?” the presenter asks. She offers two options. The room votes. The split is even, an observation that makes me hugely uncomfortable. There is no consensus. Why is there no consensus? Surely there’s a right thing to do in any situation? The presenter goes on to explain what she did. There is another round of murmuring in the room. Clearly, many people – approximately half – think this was a very bad idea.

The next presenter describes a surgery that started to go wrong 4 hours into an operation. He talks like it’s Who Wants To Be A Millionaire. “What do you think?” he asks the audience. “Shall I go on or stop now?” A voice from the back shouts, “No, no, no. Stop. You have to stop!”

He did go on, as it happened. He describes how the procedure progressed, blow by blow. “No, no, don’t do that!” comes an anguished shout, like this is Surgery Live. It’s not: this all happened last year. “Yeah,” the presenter mutters. “Thanks, I know that now.”

The next presentation ends with, “Well, I’ll never do that again.” Then comes another: “So, I’d like your opinions – should I treat this? If so, how?” The audience is calling out answers like a classroom full of show-offs. The session chair asks for calm.

Not all the answers are helpful. “If you get bleeding there, that’s going to be catastrophic.” The presenter furrows his brow. “I know,” he says. “That’s why I’m asking.”

This one is not a done deal, as it turns out. “Thanks,” the presenter says as the deluge of conflicting answers abates. “I’m due to see her again in ten days, so that’s really helpful.”

Here’s hoping she’s not reading this.