Characterising the Neuromuscular Function of Post Stroke Patients

Characterising the Neuromuscular Function of Stroke Patients During Recovery

Strokes are a leading cause of death and disability in developed countries, with significant economic and social impacts. Defined by the WHO, strokes cause rapid and lasting disturbances in cerebral function. In the UK, strokes occur every five minutes, affecting 100,000 people annually and resulting in substantial physical impairments and financial costs. Although stroke-related deaths have decreased due to improved treatments and awareness, strokes remain a major cause of death and disability worldwide, especially in lower-income countries. Strokes typically cause unilateral deficits, leading to significant daily challenges and necessitating tailored rehabilitation strategies such as CIMT, FES, and VR Rehab. As the population ages, innovative neurorehabilitation approaches are essential to enhance functional recovery post-stroke. This pilot study aims to better understand the neuromuscular deficits caused by stroke to inform and improve future rehabilitation interventions, including the potential use of force accuracy training (FAT)

In developed countries, strokes are the third most common cause of death and disability. Stroke is defined by the World Health Organization (WHO) as "rapidly developed clinical signs of focal (or global) disturbance of cerebral function, lasting more than 24 hours or leading to death, with no apparent cause other than of vascular origin. In 2013, the American Heart Association added the term "silent pathology" to the definition, which includes silent haemorrhage and infarctions of the brain, spinal cord, and retina. A transient ischemic attack (TIA) is considered a "warning stroke" because although it has similar symptoms to a stroke, the symptoms last for less than 24 hours. Furthermore, approximately 50% of strokes happen within 24 hours of a TIA.

The National Institute for Health and Care Excellence (NICE) estimates that in the UK a stroke occurs once every five minutes, and 100,000 people suffer from strokes annually. Further, over 1.3 million individuals in the UK have survived a stroke, with two-thirds of these survivors leaving the hospital with some physical impairment. There are 32,000 stroke-related fatalities annually in England alone, and stroke results in an annual expenditure in the region of £26-billion across the UK. In the previous 15 years, there has been a 49% decrease in the number of deaths caused by stroke in the UK despite an ageing population and that advancing age is a clear risk factor for stroke. This is likely due to advancements in both clinical treatment pathways and public awareness.

Despite this reduction in deaths, in terms of disability-adjusted life-years lost (DALY's), stroke is still the second-highest leading cause of death and is considered to be the third-leading cause of disability globally. In 2020, one in six cardiovascular disease-related deaths were caused by strokes. Global costs associated with stroke are projected to exceed 721 billion dollars (0.66 % of the global GDP). The burden (in terms of the absolute number of cases) grew dramatically from 1990 to 2019, with the bulk of worldwide stroke burden lying in lower and lower to middle-income countries (86.0% of fatalities and 89.0% of DALY's). This rise may be linked to a 70 % increase in incident of strokes, a 44 % increase in stroke-related mortality, a 102 % increase in general strokes, and a 143 % increase in prevalent strokes. Therefore, stroke is a disease of immense importance to the global population's health, with significant repercussions for individuals, the economy and society. In the past, it was believed that stroke primarily impacted wealthy nations. In contrast, the burden of stroke has fallen dramatically in many developed countries due to the use of evidence-based management techniques.

One hallmark of stroke is its tendency to cause unilateral deficits, affecting one side of the body. This can lead to weakness, paralysis, and sensory disturbances. These deficits pose significant challenges for daily activities and can have profound psychological and social impacts. Addressing these unique features is vital in rehabilitation, where tailored interventions can improve outcomes and quality of life for stroke survivors. Some of the current stroke rehabilitation strategies include Constraint-Induced Movement Therapy (CIMT), Task-Specific Training, Functional Electrical Stimulation (FES), Robot-Assisted Therapy, Virtual Reality (VR) Rehab, and Cognitive Rehabilitation. These approaches all aim to maximize recovery and improve functional outcomes post-stroke.

As the number of stroke survivors grows due to demographic shifts in our ageing societies, novel strategies for neurorehabilitation are required. Neural reorganisation is the most important driver of functional recovery after a stroke. An enhanced knowledge of the mechanisms that enable plasticity and recovery is required for the development of novel, neurobiologically informed techniques to promote functional recovery.

In sum, a better understanding of the neuromuscular deficits caused by stroke, which will be gained from this pilot study, will allow enhanced future design of rehabilitation interventions, and will inform the consideration of force accuracy training (FAT) as a potential intervention to improve the neuromuscular and physical function of stroke patients.

Inclusion Criteria:

• • Aged between 40-85 years

  • Willing and able to give informed consent for participation in the study
  • Had a confirmed stroke within the last 5 years
  • Self-reports persisting post-stroke loss of unilateral limb function

Exclusion Criteria:

• • Diagnosis of cognitive impairment/dementia

  • Current or recent (<2y) malignancy
  • Severe respiratory disease (e.g., uncontrolled asthma, COPD, pulmonary hypertension)
  • Active cardiovascular disease: Uncontrolled hypertension (BP>160/100mmHg); Recent (<12mo) cardiac event; Heart failure (Class III/IV); Significant arrhythmia; Unstable angina
  • Metabolic disease: Untreated hyper/hypoparathyroidism; Cushing's disease
  • Significant musculoskeletal disorders (based on clinical opinion)
  • Dialysis patients
  • Recent steroid treatment within 6 months or hormone replacement therapy
  • Mobility dependant (wheelchair dependency)