There are an estimated 1.4 million stroke survivors in the UK, more than half of whom have been left with a life-limiting disability.
In this project, Professor Nick Ward set out to ascertain why some stroke patients recover function more easily than others, to understand what factors are important in the recovery process itself and unveil opportunities for - and barriers to - better outcomes.
In the UK, around 100,000 people have strokes every year, and the number of stroke survivors is estimated to be as many as 1.4 million. More than two-thirds of these survivors leave in-patient care with a disability [i]. This may include limb weakness, impaired mobility, or problems with speech, balance and co-ordination – all of which seriously affect people’s ability to live productive, independent lives.
In addition to the huge personal impact on the lives of stroke survivors and their carers, the impact on society is enormous. The economic burden of stroke in the UK is estimated at £26 billion a year – including health and social care costs, informal care, productivity losses and benefit payments [ii].
Improving stroke recovery is therefore a key goal.
Nick Ward is Professor of Clinical Neurology and Neurorehabilitation at UCL Queen Square Institute of Neurology, and a consultant neurologist at the National Hospital for Neurology and Neurosurgery. His special clinical interest is in stroke and neurorehabilitation, with a particular focus on recovery of arm and hand function. His Upper limb neurorehabilitation programme is the first of its kind, offering high quality, high intensity, high dose upper limb rehabilitation to people with stroke.
In their own clinic, Professor Ward and team had observed that about half of patients whose arms and hands are quite severely affected after stroke have a good early recovery (commonly referred to as spontaneous biological recovery), whilst the other half do not. They wanted to understand the reasons for this, in order to identify opportunities to improve recovery in those patients with poor recovery.
They hypothesised that structural damage to the brain would be the main determinant of the immediate severity of stroke symptoms but that brain function would be the main determinant of how much recovery occurs in subsequent months.
They set out to compare the two groups of patients - i.e. good early recovery vs poor early recovery - using advanced brain imaging techniques to study differences in the pattern of anatomical brain damage and differences in brain repair mechanisms.
Magnetic resonance imaging (MRI) was used to assess structural brain damage whilst an imaging technique called magnetoencephalography (MEG), which maps electrical activity in the brain, was used to assess brain function.
The team collected neuroimaging and clinical data from acute (first three months post-stroke), and chronic (beyond six months) as well as healthy controls. Impacted by the Covid pandemic, which meant there were periods when they were unable to carry out imaging, they also took advantage of some previously-collected datasets to carry out additional analyses.
Their hypotheses proved largely correct, with their findings suggesting that in the early post-stroke phase, structural brain damage is associated with initial severity of impairment, whereas measures of brain function are more predictive of subsequent recovery.
These results have important consequences. Stroke recovery remains a huge clinical problem and being able to predict outcomes for individual patients is important because it helps guide treatment and rehabilitation, enabling personalisation of therapy and determining the ‘who’ and ‘when’ to treat with current therapies.
There is currently a reliance on structural brain imaging to predict outcomes after stroke but this work Prof Ward and team has shown that structural metrics alone do not accurately predict long-term outcomes, and that it is necessary to include measures of both brain structure AND brain function.
They have also shown that the way the brain’s activity changes after stroke is very likely connected to how well the brain can subsequently rewire and adapt after a stroke. This points to possible new targets for “recovery” drugs, which should be tested in future clinical trials of drugs promoting recovery after stroke.
[i] Stroke Audit 2024: https://www.strokeaudit.org/Documents/National/Clinical/Apr2023Mar2024/Apr2023Mar2024-AnnualReport.aspx
[ii] Estimated societal costs of stroke in the UK based on a discrete event simulation. Patel A, Berdunov V, Quayyum Z, King D, Knapp M, Wittenberg R. Age Ageing.2020 Feb 27;49(2):270-276. doi: 10.1093/ageing/afz162. PMID: 31846500; PMCID:PMC7047817.
Post-stroke changes in brain structure and function can both influence acute upper limb function and subsequent recovery; Zich C, Ward NS, Forss N, Bestmann S, Quinn AJ, Karhunen E, Laaksonen K. Neuroimage Clin. 2025;45:103754. doi: 10.1016/j.nicl.2025.103754. Epub 2025 Feb 13.PMID: 39978147
Acquired brain and spinal cord injury (including stroke) is one of our current research priorities, reflecting the large unmet need in this area. Our aim is to fund research to advance understanding of how to promote repair of the brain and spinal cord following injury.
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