One of the most extraordinary stories in Norman Doidge's new book, The Brain's Way of Healing, is that of the Broadway singer, Ron Husmann. Husmann developed multiple sclerosis (MS) and, over a 30-year period, the disease robbed him of his rich baritone voice and most of the function of his limbs. A friend of Husmann's, who had also developed MS, told him about a laboratory at the University of Wisconsin-Madison where they were testing an electronic device that seemed to be effective at treating a range of neurological disorders, including MS.
Part of the device, called PoNS (Portable Neuromodulation Stimulator), is placed in the patient's mouth, where it painlessly stimulates the tongue with electrical pulses. While the tongue is being stimulated, the patient is instructed to do a therapeutic exercise such as running on a treadmill or standing on one leg or, in Husmann's case, humming. The electrical stimulation helps to reboot the electrically noisy brain so that the therapeutic exercise can form new neural pathways to make up for the lost function.
Husmann's recovery was so dramatic as to be almost miraculous. He arrived at the lab, barely able to walk or talk, but after two weeks of treatment he was able to tap dance and belt out "Ol' Man River".
But Husmann wasn't cured of MS, even if his symptoms had profoundly improved. Indeed, we later read that he's had a relapse. Sadly, Husmann developed arthritis and had to have both knees and shoulder joints replaced. Dealing with arthritis and recovering from surgery gave him little time to use the PoNS device, so the MS symptoms resurfaced.
But many other people are benefiting from the device. So far, more than 200 people have been treated for conditions ranging from Parkinson's disease to traumatic brain injury. As with Husmann, the patients aren't cured, but it does help to improve their symptoms, especially those related to movement.
Norman Doidge's first book, The Brain That Changes Itself, sold more than a million copies and garnered praise from neuro-luminaries such as Oliver Sacks and VS Ramachandran. Sacks called the book "a remarkable and hopeful portrait of the endless adaptability of the human brain".
The endless adaptability of the human brain is summed up by the term "neuroplasticity". A few decades ago, scientists thought the brain was relatively fixed. After a certain age, no new neurons grew and certain neural pathways became fixed. It was also believed that different areas of the brain had their own specialities and didn't veer from these. Now we know that it's a bit more nuanced than that. New neurons do grow, in certain areas of the brain. New neural pathways can be formed and, when disease or damage occurs in one part of the brain, cortical maps can be redrawn to make up for lost function.
Doidge, a Canadian psychiatrist and psychoanalyst, is the master of explaining how the brain's plasticity can be harnessed to improve the symptoms of brain-related disorders, ranging from stroke to autism.
In a telephone interview, Doidge tells me that, after The Brain That Changes Itself was published in 2007, his email inbox became "like Grand Central Station". Doctors, scientists and patients from all over the world got in touch to tell him their stories about brain plasticity. He spent the next seven years travelling the world, meeting these people and turning their stories into The Brain's Way of Healing.
Nobody really knows how the treatment works and that's true of most of the neuroplastic treatments that Doidge expounds in his book. Some people are healed by light, some by sound, some by vibration and others by movement. They're diverse and often eccentric therapies. For example, the Tomatis Method involves playing Mozart, Gregorian chants and the modified voice of the patient's mother to the patient using something called the Electronic Ear.
Doidge has studied each of these techniques in detail and identified stages of healing that they have in common: corrections of general cellular functions of the neurons and glia, neurostimulation, neuromodulation, neurorelaxation and neurodifferentiation and learning.
The first stage, which I'll call brain cell repair, is the only stage that isn't about "rewiring" the brain, it's about restoring brain cell health. Doidge says that he has seen patients with depression, bipolar disorder and attention deficit disorder "make major progress by eliminating toxins and certain foods, such as sugar and grains, that they were sensitive to". Neurostimulation is when "dormant circuits in the hurt brain" are stimulated by light, sound, movement, electrical stimulation and other healing tools and techniques used by "neuroplasticians". This is followed by neuromodulation, where the brain is reset so that it's neither too excited nor too inhibited. Sick brains, we're told, are "noisy".
Brain disorders often leave the person exhausted, so relaxation (or neurorelaxation, as Doidge prefers) is an important part of recovery. People often sleep a lot during this phase.
Neurodifferentiation and learning is probably the least well defined of the stages. Doidge simply states that it's the stage when the brain does "what it does best" which is, apparently, "making fine distinctions".
Creating a framework for how neuroplastic therapies work is all well and good, but I would like to have seen more solid evidence that the treatments actually work and aren't the result of, say, the placebo effect.
For example, Doidge writes that a boy called Jorden Rosen, who underwent auditory integration training (AIT) in which patients are exposed to specially modulated music, had "life-transforming improvements" in his autism, for which "the word cure would be appropriate". The UK's National Autistic Society (NAS) seems to be a bit less assured of the treatment's efficacy. Its website states: "There is some high quality research evidence to suggest that AIT is not helpful in improving symptoms of autism, although we believe it may be of limited use in helping with sensory problems, such as hypercusis [sensitivity to certain sounds]." And in the US, the Food and Drug Administration (FDA) has not given approval for the use of AIT to treat medical, behavioural or emotional disorders. So why is Doidge advocating treatments, some of which have yet to be proven to work?
"I'm writing very much at the cutting edge," says Doidge. "By the time you get huge, randomised controlled studies, you're not at the cutting edge any more." PoNS therapy is cutting-edge, but at least there has been a small study that demonstrated that it may aid physical therapy in people with MS. But some of the healing techniques that Doidge devotes entire chapters to, such as the Feldenkrais method, the Tomatis method and the Bates method, have been around for decades, so where are the studies to back them up?
"One of the reasons there weren't studies of things like the Tomatis work is because nobody believed that the cures or the improvements he claimed were possible," says Doidge. "There wasn't a model of a neuroplastic brain that could explain to people how it was possible that listening to frequencies of sounds could rewire the brain and because the doctrine of the unchanging brain reigned supreme during most of his life, you couldn't get a grant to study plasticity."
Now that we do have proof that the human brain is quite adaptable, perhaps it's time to put these healing methods to the test. But, until the data is in, wouldn't it be giving people false hope to suggest that they can lead to "remarkable recoveries"?
"I'm very, very careful not to do that," says Doidge. "But I'm also careful not to generate false pessimism. It's a delicate thing."
'The Brain's Way of Healing' by Norman Doidge (Allen Lane, £20) is out now