As part of the 2019 update, the guideline committee retained the research recommendations on avoidance of aspiration pneumonia, aspirin and anticoagulant treatment for acute ischaemic stroke, aspirin treatment in acute ischaemic stroke, early mobilisation and optimum positioning of people with acute stroke, blood pressure control, and safety and efficacy of carotid stenting. The committee made an additional research recommendation on MRI brain scanning.
Does early MRI brain scanning improve outcomes after suspected transient ischaemic attack (TIA)? 
For a short explanation of why the committee made this recommendation see the rationale section on imaging for people who have had a suspected TIA or acute non-disabling stroke.
Full details of the evidence and the committee's discussion are in evidence review C: TIA imaging.
Does the withdrawal of oral liquids or the use of modified (thickened) oral fluids prevent the development of aspiration pneumonia after an acute stroke?
People with dysphagia after an acute stroke are at higher risk of aspiration pneumonia. The GDG considered how best to reduce the likelihood of people with acute stroke developing aspiration pneumonia, but there was insufficient evidence on which to base a recommendation. Current clinical practice dictates that those people with clinical evidence of aspiration are given 'nil by mouth' or are given modified (thickened) oral fluids. However, there is little evidence to suggest that withdrawal or modification of fluids reduces the incidence of pneumonia. Oral hygiene is impaired by the withdrawal of oral fluids, and aspirated saliva (up to 2 litres/day) may be infected as a result. Medications are not given orally, and patients may be distressed by the withholding of oral fluids. The research question is whether allowing people with evidence of aspiration free access to water predisposes them to the development of aspiration pneumonia compared with withdrawal of oral liquids or the use of modified (thickened) oral fluids. 
Does modified-release dipyridamole or clopidogrel with aspirin improve outcome compared with aspirin alone when administered early after acute ischaemic stroke?
Aspirin administered within 48 hours of acute ischaemic stroke improves outcome compared with no treatment or early anticoagulation. In the secondary prevention of stroke, the combination of modified-release dipyridamole with aspirin improves outcome compared with aspirin alone. Clopidogrel, administered with aspirin, improves outcome after myocardial infarction. It is not known whether antiplatelet agents other than aspirin (alone or in combination) may be more effective than aspirin alone in the acute phase of ischaemic stroke. The research question to be addressed is whether modified-release dipyridamole or clopidogrel with aspirin improves outcome compared with aspirin alone when administered early after acute ischaemic stroke. 
Should a person who has a stroke or a TIA and is already taking aspirin be prescribed the same or an increased dose of aspirin after the stroke?
Many people take aspirin routinely for the secondary or primary prevention of vascular disease. When a person who is taking 75 mg aspirin daily has a stroke or TIA, there is no evidence to guide clinicians on whether to maintain or increase the dose. The research question to be addressed is whether a person already on aspirin who has a stroke or TIA should be offered the same or an increased dose of aspirin. 
How safe and effective is very early mobilisation delivered by appropriately trained healthcare professionals after stroke?
Most people with stroke are nursed in bed for at least the first day after their admission to the stroke unit. The severity of limb weakness or incoordination and reduced awareness or an impaired level of consciousness may make mobilisation potentially hazardous. There are concerns about the effect of very early mobilisation on blood pressure and cerebral perfusion pressure. However, early mobilisation may have beneficial effects on oxygenation and lead to a reduction in complications such as venous thromboembolism and hypostatic pneumonia. There could be benefits for motor and sensory recovery, and patient motivation. The research question to be addressed is whether very early mobilisation with the aid of appropriately trained professionals is safe and improves outcome compared with standard care. 
How safe and effective is the early manipulation of blood pressure after stroke?
Many people with stroke have pre-existing hypertension, for which they may be receiving treatment. After stroke, even apparently small changes in blood pressure may be associated with alterations in cerebral perfusion pressure, which may affect the ability of damaged neurones to survive. A sudden drop in blood pressure to an apparently 'normal' level may have very marked effects on the damaged brain in a person who had elevated blood pressure before the stroke. The effect of raised blood pressure may differ between people with ischaemic stroke and those with haemorrhagic stroke. It is not known whether a reduction in blood pressure after stroke is beneficial or harmful, and whether elevation of blood pressure under certain circumstances might be associated with better outcome. The research question to be addressed is whether early manipulation of blood pressure after stroke is safe and improves outcome compared with standard care. 
What is the safety and efficacy of carotid stenting compared with carotid endarterectomy when these procedures are carried out within 2 weeks of TIA or recovered stroke?
Carotid stenting is less invasive than carotid endarterectomy and might be safer, particularly for patients very soon after a TIA or stroke, for whom the risks of general anaesthetic might be high. However, neither the risk of stroke nor long-term outcomes after early carotid stenting are known. A randomised controlled trial comparing these interventions early after stroke would determine which of them is associated with the best outcome, as well as comparing their relative safety and cost effectiveness.