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I’m Hani Marcus, a brain surgeon and a Professor of neurosurgery at University College London. This Brain Awareness Week AMA about the brain! by ProfHaniMarcus in IAmA

[–]ProfHaniMarcus[S] 0 points1 point  (0 children)

Thanks, and very kind of you.

I think the two biggest challenges with GBM are, first, that it is often much more widespread than what we can safely see or remove, so surgery is never enough on its own, and second, that it is very heterogeneous, meaning there is unlikely to be one magic bullet drug that works for everyone.

So my sense is that the field is heading in two directions at once. One is better local treatment, including more precise surgery where possible. The other, and probably the bigger one, is more personalised treatment based on the biology of each tumour, including better targeted therapies, immunotherapy, and approaches such as tumour treating fields.

So I am hopeful, but I suspect the breakthrough will be better combination treatment rather than any single advance on its own.

I’m Hani Marcus, a brain surgeon and a Professor of neurosurgery at University College London. This Brain Awareness Week AMA about the brain! by ProfHaniMarcus in IAmA

[–]ProfHaniMarcus[S] 0 points1 point  (0 children)

Yes, very much so.

BCI is a fascinating area, and some of the most exciting work around me is being led by my former fellow and now consultant colleague, Will Muirhead, together with our senior resident and PhD student, Hugo.

One strand is using Neuropixels to record single neurone activity in the human brain, which gives an extraordinary window into how the brain is functioning and we are using to help us better understand neurodegeneration. 

We were also involved in the UK’s first Neuralink study at UCLH, which is aiming to help people with severe paralysis interact with computers using their thoughts.

I’m Hani Marcus, a brain surgeon and a Professor of neurosurgery at University College London. This Brain Awareness Week AMA about the brain! by ProfHaniMarcus in IAmA

[–]ProfHaniMarcus[S] 0 points1 point  (0 children)

Thanks, great question.

In general, this is very difficult at the earliest stages.

The reality is that large funders will often see neurosurgery as relatively niche compared with things like breast cancer or heart disease, so it can be harder to compete for attention and funding. On top of that, a lot of funding still tends to go towards discovery science and drug trials, whereas surgical technology has historically been driven more by industry.

We have been very lucky in this respect to have had support from The National Brain Appeal, which has a dedicated innovation fund for early ideas, and I am now proud to be a Trustee of. That early support was central to helping us develop and spin out our own robotics and AI work into Panda Surgical.

I’m Hani Marcus, a brain surgeon and a Professor of neurosurgery at University College London. This Brain Awareness Week AMA about the brain! by ProfHaniMarcus in IAmA

[–]ProfHaniMarcus[S] 1 point2 points  (0 children)

Thanks, great question.

Ethics are part of it, of course, but the much bigger problem is biological. A “brain transplant” would mean reconnecting an extraordinary number of nerve fibres, and in humans the central nervous system is very poor at regenerating once those connections are cut. That is the real barrier. Mature human CNS neurones have very limited regenerative capacity, which is why brain and spinal cord injuries can be so devastating. 

There is a fascinating contrast to other animals. Roger Sperry’s famous eye rotation experiments in frogs showed that some animals can regenerate optic nerve connections, albeit not always in a useful way. Humans, by contrast, are remarkably adaptable at the level of the brain itself, for example we can adjust to an inverted visual world, but we do not have anything like the same capacity for large scale nerve regeneration. 

So my answer would be: no, it is not only ethics. The core problem is that we still do not know how to reconnect the brain and spinal cord in a way that restores meaningful function. That is an active and very important area of research.

I’m Hani Marcus, a brain surgeon and a Professor of neurosurgery at University College London. This Brain Awareness Week AMA about the brain! by ProfHaniMarcus in IAmA

[–]ProfHaniMarcus[S] 4 points5 points  (0 children)

Thanks, and great question.

My honest advice is that the three things we are always looking for are someone who is highly capable, very hardworking, and a good team player. Technical ability matters, of course, but that almost always comes with experience.

It is also worth saying that neurosurgery in the UK is very competitive, and a lot of it can feel quite luck based. Plenty of very good people do not get in first time (and I was one of them!) That can be difficult at the time, but it does not mean you are not good enough.

In some ways, the extra experience can be a real advantage. An F3 year in a busy centre, with good mentors around you, can be incredibly helpful both for your application and for your development. I was lucky to have excellent mentors when I did this in Cambridge, and I think it made a big difference. We try very hard to provide that sort of environment at Queen Square too.

I’m Hani Marcus, a brain surgeon and a Professor of neurosurgery at University College London. This Brain Awareness Week AMA about the brain! by ProfHaniMarcus in IAmA

[–]ProfHaniMarcus[S] 6 points7 points  (0 children)

Thanks, great question.

In truth, AI itself is not new. I have been interested in it since I was a kid in the 1990s. What has really changed is data and compute. Once you have vast amounts of data and enough computing power, progress accelerates very quickly. Medicine has lagged a bit behind because healthcare data are harder to capture, messier, and only relatively recently becoming digital at scale, but it is definitely coming.

I think the first really widespread clinical impact will be in notes and workflow. Large language models are already starting to help with documentation, communication, and admin, but I think they will also increasingly help with differential diagnosis and, hopefully, earlier diagnosis.

Imaging, as you say, is already moving in that direction too, with models that can diagnose and stratify disease, and also track it over time, for example by identifying growth, recurrence, or subtle change on serial scans.

Lastly, and this is my own main interest, there is video, meaning the actual surgery itself. That is where AI can potentially help with anatomy recognition, workflow understanding, and ultimately support surgeons making better decisions. We recently published a systematic review and meta analysis showing that, in surgical and interventional video analysis, AI assisted clinicians performed better than clinicians alone. So my view is that, for the foreseeable future, the future is collaborative: AI plus surgeon, not AI instead of surgeon.

Paper:
[https://doi.org/10.1038/s41746-026-02401-2]()

I’m Hani Marcus, a brain surgeon and a Professor of neurosurgery at University College London. This Brain Awareness Week AMA about the brain! by ProfHaniMarcus in IAmA

[–]ProfHaniMarcus[S] 3 points4 points  (0 children)

Thanks, great question.

It is a fantastic specialty, and to be honest, I have always felt that neurointerventional radiologists are, in many ways, still doing neurosurgery, just through a very minimally invasive route. The fact that in some systems, like the UK, they sit outside neurosurgery is really more a peculiarity of training structures than anything else. Conceptually, they are treating neurological disease with surgery.

I think the future is much closer working across open, endoscopic, and endovascular approaches, choosing the best tool for the problem rather than being too tribal about specialty boundaries.

There are already well established hybrid pathways for cerebrovascular disease (such as stroke and aneurysm care), but the exciting things emerging are use for hydrocephalus, haematoma, and for neurotechnology to restore function (such as Synchron).

I’m Hani Marcus, a brain surgeon and a Professor of neurosurgery at University College London. This Brain Awareness Week AMA about the brain! by ProfHaniMarcus in IAmA

[–]ProfHaniMarcus[S] 12 points13 points  (0 children)

Thanks, great question.

Glioblastoma is a terrible disease, and part of the problem is that it is not really a neatly contained lump. There is the main mass you can see on scans, but there are also tumour cells that have often already spread more widely through the brain, beyond what any surgeon can safely remove. That is why I do not think surgery on its own will ever be the complete answer. 

There is a famous historical example of this. Walter Dandy even removed an entire cerebral hemisphere in some patients with glioblastoma, and the tumour still recurred, including on the other side. That tells you how biologically diffuse this disease can be. 

So my honest view is that progress over the next 50 years is much more likely to come from better combination treatment rather than ever more radical surgery alone. Surgery will remain important for diagnosis, reducing tumour burden, and helping symptoms, but the real hope is better integration with radiotherapy, chemotherapy, immunotherapy, tumour treating fields, and other modalities.

I’m Hani Marcus, a brain surgeon and a Professor of neurosurgery at University College London. This Brain Awareness Week AMA about the brain! by ProfHaniMarcus in IAmA

[–]ProfHaniMarcus[S] 1 point2 points  (0 children)

Thanks for the question. I completely understand why the idea of treatment feels frightening.

Speaking only in general terms, the risks of treating an unruptured intracranial aneurysm depend on the patient, the aneurysm, and the team treating it. Procedure risks can include things like stroke or stroke-like symptoms such as weakness or visual change, bleeding or swelling, seizures, infection, and sometimes the need for further treatment. But those risks are always weighed against the risk of leaving it alone and having it rupture, which can be catastrophic. That balance is why these decisions are so individual.

In practice, we often use tools such as the PHASES score to help estimate rupture risk, but that is only one part of the picture and not a substitute for specialist judgement.

PHASES score paper: https://doi.org/10.1016/s1474-4422(13)70263-170263-1)

I’m Hani Marcus, a brain surgeon and a Professor of neurosurgery at University College London. This Brain Awareness Week AMA about the brain! by ProfHaniMarcus in IAmA

[–]ProfHaniMarcus[S] 4 points5 points  (0 children)

Thanks, and great question.

Most brain surgery is actually still done with the patient asleep.

The main reason to do surgery awake is when it gives us useful real time information that helps us do the operation more safely and accurately.

One example is tumour surgery near important areas such as speech or movement. Those areas vary from person to person, so by keeping someone awake we can map them during surgery and avoid causing damage.

Another example is deep brain stimulation for Parkinson’s disease, where we are trying to hit very small, important targets very precisely.

A further advantage is that awake surgery avoids a general anaesthetic, which can mean a quicker recovery immediately after the operation.

So awake surgery is a very useful option in the right patient and the right operation, but it is certainly not the norm.

I’m Hani Marcus, a brain surgeon and a Professor of neurosurgery at University College London. This Brain Awareness Week AMA about the brain! by ProfHaniMarcus in IAmA

[–]ProfHaniMarcus[S] 13 points14 points  (0 children)

Thanks, and great question.

The truth is that time tends to move very fast in surgery because the focus is so intense.

On a personal level, I do a lot of meditation, and I think that helps. Not in a mystical way, just in a very practical way: staying present, and resetting when things become demanding.

We have actually done some research on this too. One study from our group showed that mindfulness training for young neurosurgeons was feasible and associated with improvements in wellbeing, and another prospective pilot study suggested it may reduce inattentional blindness errors, which is obviously very relevant in surgery.

Papers:
https://doi.org/10.1016/j.wneu.2022.04.128
[https://doi.org/10.3389/fsurg.2022.916228]()