Remote ischaemic conditioning (RIC) triggers endogenous protective pathways in distant organs such as the kidney, heart and brain, and represents an exciting new paradigm in neuroprotection. RIC involves repetitive inflation and deflation of a blood pressure cuff on the limb, and is safe and feasible. The exact mechanism of signal transmission from the periphery to the brain is not known, but both humoral factors and an intact nervous system seem to have critical roles. Early-phase clinical trials have already been conducted to test RIC in the prehospital setting in acute ischaemic stroke, and in subarachnoid haemorrhage for the prevention of delayed cerebral ischaemia. Furthermore, two small randomized clinical trials in patients with symptomatic intracranial atherosclerosis have shown that RIC can reduce recurrence of stroke and have neuroprotective activity. RIC represents a highly practical and translatable therapy for acute, subacute, and chronic neurological diseases with an ischaemic or inflammatory basis. In this Review, we consider the principles and mechanisms of RIC, evidence from preclinical models and clinical trials that RIC is beneficial in neurological disease, and how the procedure might be used in the future in disorders such as vascular cognitive impairment and traumatic brain injury.

We describe the first Danish case of presumed inflammatory and thrombotic response to vaccination with an adenoviral (ChAdOx1) vector‐based COVID‐19 vaccine (AZD1222). The case describes a 60‐year‐old woman who was admitted with intractable abdominal pain 7 days after receiving the vaccine. Computed tomography of the abdomen revealed bilateral adrenal hemorrhages. On the following day, she developed a massive right‐sided ischemic stroke and magnetic resonance imaging angiography showed occlusion of the right internal carotid artery. The ischemic area was deemed too large to offer reperfusion therapy. During admission, blood tests showed a remarkable drop in platelet counts from 118,000 to 5000 per μl and a substantial increase in D‐dimer. The patient died on the sixth day of hospitalization. Blood tests revealed platelet factor 4 reactive antibodies, imitating what is seen in heparin‐induced thrombocytopenia. This may be a novel immune‐mediated response to the vaccine.

Rationale: Remote ischaemic conditioning, applied in the prehospital setting and continued in-hospital, may improve functional outcome in patients with acute ischaemic stroke and intracerebral haemorrhage. Aims: To evaluate whether combined remote ischaemic per-and postconditioning can improve long-term functional outcome in acute ischaemic stroke and intracerebral haemorrhage patients. Methods and design: Danish multicentre, prospective, randomised, patient-assessor blinded, sham-controlled study. Adult patients with a putative stroke identified prehospital with symptom duration <4 h, who are independent in daily activities will be randomised 1:1 to remote ischaemic conditioning or Sham-remote ischaemic conditioning. The treatment protocol will be five cycles, each consisting of 5 min with a blood pressure cuff inflation and 5 min with a deflated cuff placed on the upper extremity. The cuff pressure for remote ischaemic conditioning will be 200 mmHg-285 mmHg according to the individual systolic blood pressure and 20 mmHg sham-remote ischaemic conditioning during inflation. The study is approved as an acute study and consent is waived in the acute phase. Sample size estimation: For a 7% increased odds for a beneficial shift on the modified Rankin Scale at a significance level of 5% and power of 90%, 1000 patients with a target diagnosis of acute ischaemic stroke and intracerebral haemorrhage and a total of 1500 patients with a prehospital presumed stroke will be included. Study outcomes: The primary outcome will be the modified Rankin Scale score measured at three-month follow-up (analysed using ordinal logistic regression). ClinicalTrials.gov Identifier: NCT03481777.

Introduction Only a minority of patients with acute ischaemic stroke receive reperfusion treatment, primarily due to prehospital delay. We aimed to investigate predictors of a primary contact to the emergency medical services, arrival at stroke centre within 3 h of symptom onset and initiation of reperfusion therapy in patients with acute stroke. Patients and methods We conducted a cross-sectional study of consecutive patients with acute ischaemic stroke, intracerebral haemorrhage or transient ischaemic attack. Structured interviews of patients and bystanders were performed and combined with clinical information from the Danish Stroke Registry. Eligible patients were aged ≥18 years and were independent in activities of daily living before the stroke. Results We included 435 patients. Presence of a bystander at symptom onset and knowledge of ≥2 core symptoms of stroke were associated with a primary emergency medical services contact. Higher stroke severity and patients or bystanders perceiving the situation as very serious were associated with a primary emergency medical services contact (ORpatients 2.10; 95% CI 1.12–3.95 and ORbystanders 22.60; 95% CI 4.98–102.67), <3 h from onset to arrival (ORpatients 3.01; 95% CI 1.46–6.21 and ORbystanders 4.44; 95% CI 1.37–14.39) and initiation of reperfusion therapy (ORpatients 3.08; 95% CI 1.23–7.75 and ORbystanders 4.70; 95% CI 1.14–19.5). Conclusion: Having a bystander, knowledge of ≥2 core symptoms and understanding that stroke is a serious event are associated with appropriate help-seeking behaviour, shorter prehospital delay and higher chance of reperfusion therapy in acute stroke patients.