Stroke as a neurological disease

Stroke has been misplaced in the International Classification of Disease (ICD) since 1955, but is now classed as a neurological disease in the new ICD-11. The reclassification required a bureaucratic struggle between clinicians and the World Health Organization, but will bring great benefits.

The past year saw advances in endovascular treatment for acute stroke, speech therapy for aphasia after stroke, and cardiac disease management to prevent stroke. These treatments were characterized by more intensive or more extensive effects than standard care, necessitating thoughtful translation of the clinical trial findings into routine clinical practice.

In recently published guidelines on the diagnosis and treatment of cerebral venous thrombosis, the European Stroke Organization has applied a rigorous evidence-based methodology, following the GRADE system. However, the guidelines provide many weak recommendations, reflecting the fact that more high-quality evidence from multicentre observational and experimental studies is needed.

In patients with acute ischaemic stroke resulting from anterior circulation occlusion, endovascular therapy provides greater long-term benefits than does intravenous tissue plasminogen activator. However, further improvement of systems of care and research regarding adjunct therapies is still needed.

Two studies have shown no added benefit of intravenous thrombolysis in patients with acute stroke who are treated with mechanical thrombectomy. We review the importance and interpretation of these findings, compare them to the current guidelines on stroke thrombectomy, and discuss how these studies can change our daily clinical practice.

Despite advances in the treatment of ischaemic stroke, functional outcomes are still suboptimal in many patients. Baron discusses approaches to further limit the spread of brain ischaemia by ‘freezing’ the penumbra — that is, the at-risk but not yet infarcted tissue.

The epidemiology, risk factors, causes, treatment and outcomes of intracerebral haemorrhage (ICH) in young adults (aged ∼18–50 years) can differ markedly from those in elderly patients with ICH. Challenges in this setting include high early mortality and long-term mortality as well as long-term disability and ICH recurrence in survivors.

The prevalence of stroke in women is predicted to increase rapidly in the near future. Yet, despite the presence of numerous female-specific risk factors for stroke, women remain under-represented in stroke clinical trials. Here, members of the Women Initiative for Stroke in Europe (WISE) group summarize new advances and future research priorities in the research of stroke in women.

Cerebral venous thrombosis (CVT) is a prominent cause of stroke, particularly in young adults. Knowledge of this condition has greatly increased in the past two decades, primarily owing to new data from international patient registries. This Review provides an overview of the epidemiology, pathophysiology, diagnosis and treatment of CVT, with a focus on new advances in the field.

Effective drug treatments for intracerebral haemorrhage (ICH) are still lacking. However, therapies that target microglial phenotype switching might soon become available for affected patients. Here, Wang and colleagues summarize key advances in understanding of microglial function after ICH, including modulators of microglial function and interactions with other cells.

Although our understanding of the biological mechanisms of stroke have advanced considerably in animal models, this progress has not been translated into improvements to restorative therapies following stroke in humans. Here, Nick Ward discusses the reasons behind this lack of benefit, and the prospects for understanding poststroke plasticity in humans, with a focus on the development of biomarkers that can reconcile preclinical and human studies.

Proinflammatory conditions have been associated with an increased risk of stroke. In this Review, Esenwa and Elkind look at the association between infection, inflammation and ischaemic stroke, and discuss recommended approaches to reducing the risk of stroke associated with inflammation.

Drawing on data from the Global Burden of Disease 2013 Study, Feigin and colleagues highlight the increasing global stroke burden, which indicates deficiencies in current primary prevention strategies. The authors present a four-point plan to improve primary stroke prevention, which includes a shift in emphasis from a high-risk approach to a more comprehensive approach that targets people at all levels of cardiovascular disease risk.

In addition to the functional impairments that can arise after stroke, about one-third of stroke survivors experience neuropsychiatric disorders such as depression, anxiety or apathy. In this Review, Ferro and colleagues provide an update on the diagnosis and pathophysiology of the acute and long-term psychiatric consequences of stroke, and discuss available treatments and management strategies for these stroke-associated disorders.

The most-established risk factors for intracerebral haemorrhage (ICH) are lifestyle-related, but several studies have reported familial aggregation of ICH. An understanding of the role of genetic risk factors in ICH could provide insight into ICH aetiopathogenesis, and improve prevention and patient-tailored management of ICH. This Review discusses the evidence for a genetic component in ICH, taking into account the strength of evidence and functional relevance to ICH for each genetic variant.

2015 saw the publication of five randomized controlled trials of endovascular treatment for acute stroke caused by vascular occlusion, with huge implications for the future of patient management. Mokin and colleagues consider the findings of these trials in the context of their designs, in particular the criteria for patient selection, and their likely impact on future management of acute stroke.