A road map for transforming stroke recovery

As neurologists, we have always been told (by those in other fields) that we work in a speciality that has no treatments and is obsessed by clinical diagnosis and little else. The advent of biological therapeutic targets in neurological disease is of course changing all that. The popular view of neurorehabilitation on the other hand is that it is falling behind because there are no ‘recovery’ drugs, only physical, behavioural or adaptive therapies that are not particularly effective. As illustration, many years ago a recently appointed consultant neurologist was asked why he had an interest in neurorehabilitation when it amounted to nothing more than the provision of a walking stick or a wheelchair. That behavioural interventions are generally overlooked in neurology is curious for a speciality that deals with the brain, whose very structure and therefore function can be changed through experience. The naive reader of Broken Movement might be surprised to find that when it comes to recovery from hemiplegic stroke there are a wide range of treatments, from behavioural to pharmacological. What Krakauer and Carmichael show us is that with a little clear thinking and honest critical appraisal, we will be on the threshold of some remarkable breakthroughs in a field that has proven stubborn to crack. However, the crisis in confidence in neurorehabilitation that currently grips us is not because existing therapies have been inadequately tested in randomized controlled trials, but because these therapies are ill-conceived from a neurobiological perspective in the first place. The message is clear—develop therapeutic approaches from a mechanistic perspective. The book is divided into chapters that deal with behavioural or molecular and cellular consequences of stroke. We are provided with a detailed insight into the natural history of poststroke events, how these provide opportunities for therapies and importantly, where we have gone wrong so far. In clinical practice, there is undoubtedly a nihilistic view towards recovery after stroke and this is reflected in the ever-dwindling provision of support for stroke survivors around the world. Discussion amongst healthcare providers has turned to improving support for life after stroke, as if all we can do is palliate the often devastating effects. There is a lack of faith in the prospects for promoting brain repair and recovery. Although this book starts out by bluntly telling us that nothing that we are doing right now to reverse the effects of hemiplegic stroke is having much effect, reading it leaves you with an overwhelmingly optimistic sense that we are not so far from some major advances. What is made absolutely clear though is that this will not happen if we base our future work on a ‘hotchpotch’ of ‘half-baked’, ‘conceptually flawed’ and (my favourite) ‘neuroscientifically flavoured’ ideas. The authors pull no punches. Their obvious frustration comes about because looking back through the literature, in other words what we should already know, tells us in no uncertain terms that we ought to be doing things very differently. In a sense, it is a road map for transforming the field of stroke recovery. Broken Movement shows us that we know a great deal about the neurobiology of stroke recovery from experiments performed in preclinical animal models over many decades. What this work has told us is that there is a continuum of biological responses to brain injury that appear both in the ischaemic core, the penumbral peri-infarct cortex and in more distant (but connected) brain regions. This is exciting because each of these processes is amenable to pharmacological manipulation in a way that could support brain repair and recovery. The prospects for stem cells, blockers of axonal growth inhibition, and pharmacological agents that may enhance post-stroke plasticity, such as amphetamine, selective serotonin reuptake inhibitors, dopamine antagonists and drugs that reverse post-stroke increased tonic GABAergic inhibition, Broken Movement: The Neurobiology of Motor Recovery after Stroke By John W. Krakauer and S. Thomas Carmichael MIT Press, Cambridge, MA, USA ISBN: 9780262037228 50 USD doi:10.1093/brain/awy248 BRAIN 2018: 0; 1–2 | 1