Marr’s mini miracle: After a stroke left him partially paralysed, Andrew Marr feared he’d never walk normally again. Then a US doctor turned him upside-down – and, as he movingly reveals, it’s sent his spirits soaring

Here are a couple of phrases to consider. ‘One in a million.’ Yes, I am. That is, I am one of an estimated 1.2 million survivors of a stroke living in the UK. ‘Cost me an arm and a leg.’ It did. That is, the tear in my carotid artery, running up the inside of the right-hand side of my neck, more or less paralysed my left arm and hand, and my left leg.

The consequences aren’t generally obvious on television. But there’s very little I can do with my left arm. I can walk for hours at a time and without a stick. But it’s an awkward, slow, lurching walk, almost as if I have a wooden leg.

Now all of this is being laid bare in a TV documentary. I don’t like watching myself struggle with physiotherapy, or walking badly. Who would? But after four years of recovery, it was time to be a bit more open, rather more honest.

What we hope is that the film, which investigates exactly what happened to my brain when I had the stroke, will encourage some of my fellow survivors. If there’s one thing I can do, it is say ‘This happened to me’ and offer to share the experience.

Having a stroke is a terrifying experience. Slowly trying to recover from one can be a lonely one. I know. Apart from my own experience, I’ve been working with stroke organisations around the country.

But there’s a long way to go. It hasn’t got the strange charisma of cancer or even heart disease, yet stroke is the single biggest cause of disability in Britain. So this is me doing my very small bit to help.

Four years on from my family being told (twice) that I was going to die, I haven’t done too badly. I’m working again full-time. Apart from my Sunday morning politics show and Start The Week on Radio 4, I have written a couple of books and am painting.

I go for walks. I go to a gym, though I don’t overdo it any more. I eat out, down the occasional pint, and have passionate discussions about everything under the sun with my close family and friends. Life, by and large, is good.

But over the past year there’s been no getting away from it. My recovery has stalled. However much exercise I do, the fingers on my left hand have remained pretty much frozen and my left ankle paralysed – which severely limits my walking and means I can’t run, cycle or swim.

The jargon word for all of this is ‘plateaued’ and the standard remedy is yet more physiotherapy.

Well, I do a lot of physiotherapy. I have a brilliant neuro-physiotherapist called Jo Tuckey who comes twice a week to put me through my paces. Until recently, I also did specialist weight training with Tom Balchin, an incredibly determined stroke survivor who set up a national charity, ARNI, which I am proud to support. I do the work.

But sometimes, however much you struggle, the missing brain connections simply can’t be worked around.

So at this point we went searching for other answers. The two most mainstream ways of helping stroke survivors medically are a form of electrotherapy, and the implantation of stem cells.

The electrical route involves placing small electrodes on the brain and passing a gentle current through the affected areas. The idea is that this speeds up something that happens, almost miraculously, anyway.

It’s called neuro plasticity. What that means is that the brain, instead of being static, like a piece of computing hardware, is in fact constantly changing and moving.

Whatever you do – if you are playing tennis, or chess, or reading, or having a conversation – affects the delicate wiring of the brain. It rewires and changes all the time, and over time the brain can really change.

How can a ballet dancer spin around on one leg without becoming dizzy and falling over? The answer is that after much practice, his or her brain has changed.

This, by the way, is such a remarkable thing that it ought to change how we think about life generally.

What we do affects our brains just as much as it affects the rest of our bodies. We don’t think it’s OK to spend all of our lives slumped on the sofa or lying around in bed. But a life spent glued to really bad TV, or even online porn, will degrade the brain just as much.

Try to learn a language, or do crossword puzzles or read decent books and your brain will become – to use a non-scientific word – cleverer.

I subjected myself to gentle cranial electrocution for three weeks, while doing fairly basic and rather irritating physiotherapy exercises. And I got no better at them.

So what about stem cells? These are, of course, the basic cells which can develop into all kinds of specialist cells, given the right chemical prompting, when they are in the right part of the body.

They can be ‘harvested’ from embryos or drawn from bone marrow, and are then injected into the damaged part of the brain. I think stem-cell therapies are going to be a very big part of medical advance over the next decade. But right now, this treatment does involve having a hole drilled into the skull, and an injection made deep into the brain. In terms of stroke recovery, this is still a very new therapy.

I’m sorry but, right now, I thought that this treatment was a bit much. It’s an invasive procedure and I think I will wait a while. So, what was left? I had been encouraged to try a bit of radical dieting to help my brain chemistry, and I kept away from booze, caffeine and certain foods for a few months.

It caused no harm at all but nor did I see any new movements in my paralysed areas.

I’d heard of one other possibility. There is a comparatively new drug called Etanercept, developed for inflammatory diseases such as arthritis, and now effective and mainstream in those areas.

But because it targets a protein called tumour necrosis factor, which clusters around damaged areas of the brain and which in excess can stop cell regrowth, it is now being used in America for stroke victims as well.

Etanercept is a large molecule and it cannot pass the blood-brain barrier – the natural defensive system around the brain – if it is injected normally.

However, a Florida-based doctor, Ed Tobinick, discovered that if it was inserted into a cluster of veins around the top of the spine, and the patient is gently tilted upside down for a few minutes, gravity can take it into the brain.

I tried to follow the science behind this as far as I could, and thought it made some sense. I read papers from Tobinick’s organisation, and other papers from people who vehemently disagree with him.

I watched some miraculous-seeming videos of patients being transformed by the treatment. I took a pinch – nay, a handful – of salt.

But then I realised that, so far, he has treated about 2,000 stroke victims, and while by no means everybody had a successful outcome, nobody seemed to have been harmed by the treatment. It costs about £5,650 a pop – and I plucked up my courage and decided to give it a go.

Much medical advance begins with an outsider, ridiculed by the mainstream. Tobinick hasn’t had the backing to do a big, proper, expensive double-blind trial of the kind authorities would like to see. I hope he gets the chance.

So, with my wife riding shotgun, we went to Boca Raton and took the medicine. I was measured, assessed, strapped into a chair, injected and tilted upside down – twice. And then… Great disappointment.

Not much seemed to have changed. Perhaps a very slight extra strength here or there? Not really. I didn’t want to fool myself. Maybe this was another therapy that worked for other people, but not for me. Tobinick himself had worried that my recovery had already gone too far to see much of a change.

I limped off to our hotel room, rather deflated. But then I noticed in the middle of the night that my paralysed forefinger was moving much more clearly. And I felt a strange tremor in my foot. I padded around the bedroom.

My foot seemed to be holding up very slightly better than usual. The following morning, I walked down to the beach without the metal brace I have been using for three years. The walking wasn’t very good, but I didn’t fall over – and even went for a very gentle splash in the Atlantic.

Well, I’ve been home now for more than a month, and I have had a change. I am very wary about self-assessing because I am so naturally optimistic that it might simply be placebo effect.

So I asked my physiotherapist Jo, who had been sceptical about the whole thing. She confirmed that I was getting movement in my foot that I hadn’t had before.

This means that I start 2017 in a very different place. I have a ferociously hard amount of physiotherapy still to do. If I don’t work hard enough then these tiny changes won’t alter my life.

But I have the possibility, at least, of learning to walk properly again. And one day, who knows, getting back on a bicycle.

I’d like many more people who have had my horrible condition to get the opportunity to try new therapies. But I’m sure of one thing: we are living through a remarkable age of medical progress, a scientific renaissance. And that means none of us – none of us – should ever give up.