The physiology of stroke neurorehabilitation

The Cochrane network, in its definition of rehabilitation, refers to “interventions targeting a person's” capacity (by addressing body structures, functions, and activities/participation) … with the goal of “optimizing” the “functioning” … of “persons with health conditions currently experiencing disability or likely to experience disability …” (Negrini et al., 2022). In respect of the significance accorded to ‘capacity’ and ‘functioning’, rehabilitation lies squarely within the purview of physiology, with its emphasis on the integration of molecular, cellular, systems and whole-body function. Neurorehabilitation (a.k.a. neurological rehabilitation) deals more specifically (e.g. National Institute for Health & Care Excellence, 2021) with neurological impairments that arise from injury to the brain, spine or peripheral nerves, caused by disease, trauma, tumours, infections, metabolic insults and disorders of the blood supply – such as stroke. In terms of its ramifications, stroke ranks as the second highest cause of death (Roth et al., 2018), and follows only neonatal disorders and ischaemic heart disease as an agent of long-term disability (Kyu et al., 2018). Most notably, stroke has a disability impact – in terms of severity, greater than any other chronic disease (e.g. Adamson et al., 2004). It is estimated that approximately 15 million strokes occur worldwide every year (World Health Organization, 2024). Of those who survive, half will be left with a disability that demands neurorehabilitation. With the lethality of stroke falling, and the incidence of stroke rising – especially in low-income and middle-income countries (Prust et al., 2024), there is a renewed imperative to direct research towards life after stroke, particularly since targets for neurorehabilitation feature prominently among the priorities identified by stroke survivors and their carers (Pollock et al., 2012).

It seems self-evident that physiological knowledge should inform stroke neurorehabilitation, particularly when there is an aspiration to increase the efficacy and efficiency of its delivery. In this context, such knowledge might extend to mechanisms that mediate adaptation to, or recovery from, brain damage. It may also encompass means through which a neurorehabilitation technique exerts an effect. Writing in this collection, Carson and Hayward (2025) point out that these strands of knowledge are integrated less frequently than one might suppose. In addition, and unlike in many other areas of clinical science, knowledge of the relevant physiology is frequently sought (if at all) following the concoction of a novel neurorehabilitation therapy, rather than as a precursor. Perhaps this is due to lack of appreciation of an existing corpus of physiological knowledge that is directly relevant to stroke neurorehabilitation. This special issue of The Journal of Physiology has been devised with the aim of highlighting recent empirical contributions to this corpus, along with the key theoretical concepts with which the relevant information can be parsed.