Acute Stroke
Introduction
Stroke is an acute neurological deficit of vascular origin and is a time critical neurological emergency. It is the third most common cause of death and the leading cause of disability in the UK. It requires prompt recognition, investigation, and management to maximise chance of recovery.
The underlying pathology is;
80% Ischaemia
17% Haemorrhagic
3% Other
e.g. arterial dissection, venous sinus thrombosis, vasculitis, vasospasm (e.g. cocaine, post SAH)
The blood supply to the brain has two supplies: the internal carotid and the basilar arteries. The internal carotids supply the anterior and middle cerebral artery ( the anterior circulation) and the basilar artery supplies the posterior cerebral artery (the posterior circulation). Anterior and posterior circulation strokes present in different ways.
Risk Factors for Stroke
Age
70% of strokes occur in over 70s
Atherosclerotic Risk Factors
Diabetes, HTN, hyperlipidaemia, smoking, obesity, family hx, sedentary lifestyle
Embolic Risk Factors
Atrial Fibrillation, valvular disease, cardiomyopathy, ventricular aneurysm, PFO, long bone fracture
Risk Factors for haemorrhage
Hypertension, bleeding disorders, anticoagulants, AVM
Clinical Features
Establishing the time of ischaemic stroke symptom onset is critical because it, along with CT findings, is the main determinant of eligibility for treatment with intravenous thrombolysis and endovascular thrombectomy.
Patients with stroke present in different ways depending on the area of the brain affected and the extent.
Anterior Circulation Stroke
Think FAST – Facial Drooping, Arm Weakness, Speech Difficulties, Time Critical
Facial droop
Arm Weakness on the opposite side of the infarct
Speech difficulties, especially if affecting the dominant (usually left) side of the brain. Dysarthria, receptive and expressive dysphasias.
Visual Field deficits – Hemianopia/Quadrantanopia, diplopia, or blindness
Neglect: inability to track to one side, ignoring one side, unable to identify own arm, sensory neglect
Posterior Circulation Stroke
Cerebellar signs - PINARDS
Pass pointing, intention tremor, nystagmus, ataxia, rebound, dysdiadochokinesia, staccato speech.
Diplopia, vertigo, nausea, vomiting,
Visual Defects
Other
Headache
Preceded by neck pain: consider carotid/vertebral artery dissection
Stroke severity is calculated and tracked by using the National Institute of Health Stroke Scale (NIHSS).
Differential Diagnosis
Sudden loss of focal brain function is the core feature of the onset of acute stroke. However, patients with conditions other than brain ischaemia may present in a similar fashion. These conditions are referred to as “stroke mimics”.
CNS
Hemiplegic migraine
Space occupying lesion
Brain abscess
Subdural haematoma
Intraparenchymal haematoma
Multiple sclerosis
Menigo-encephalitis
Todd’s paralysis
Other
Hypoglycaemia
Hyponatraemia
Hepatic encephalopathy
Hypertensive encephalopathy
Clinical Investigations
Time is of the essence in evaluating a patient presenting with symptoms consistent with acute stroke. If the patient is stable the initial priority is to obtain IV access, check their blood sugar and transfer to CT as soon as possible. No other investigation should delay transfer to CT. CT findings along with certain patient factors will determine whether a patient is a candidate for thrombolysis or thrombectomy. As the benefit of these treatments is time dependent, it is critical to diagnose and treat patients as quickly as possible
Bedside
Rapid finger stick blood sugar
Hypoglycaemia is a common stroke mimic
VBG
pH, lactate, blood glucose, an estimate of Hb, and electrolytes.
ECG
Looking for Atrial Fibrillation
Urine Toxicology
if concerned drugs of abuse such as cocaine could be implicated
Laboratory
FBC
signs of infection, haemoglobin, platelets
Biochemistry
Urea and electrolytes, CRP (Infection), LFTs (clotting)
Coagulation
Bleeding tendency, INR if on warfarin
Group and Hold
if thrombolysis is a possibility.
Radiology
Immediate, emergency, non-contrast CT Brain in the following patients with focal neurology
patient presents within 4 hours of onset and symptoms are ongoing, patient is on an anticoagulant, known bleeding disorder, GCS < 13, Unexplained progressive or fluctuating symptoms, papilloedema, neck stiffness, fever, or severe headache at time of onset.
CT Angiogram + CT Perfusion
may be indicated depending on patient factors and non-contrast CT Brain findings
MRI Brain
posterior circulation and small lacunar infarcts may only be visible on MRI
Management and Disposition
Initial Resuscitation
As soon as diagnosis of acute stroke is considered “Stroke Call” should be initiated.
this involves attendance of ED medical and nursing staff and stroke medical and nursing staff at the patients bedside. It should also put radiology and CT radiographer on standby
Stroke patients should be managed in resus with full non invasive close monitoring
Attention to airway, breathing & circulation as clinically indicated
Give supplemental O2 if SpO2<95%
Seek and treat hypoglycaemia
Keep patient NPO until swallow can be assessed
Specific Treatment
Assess for presence of any contraindications to tPA/thrombectomy (opposite)
Different treatment options will be determined by patient factors, time of onset, NIHSS, and imaging. NB: There should be involvement of senior decision maker i.e. ED or stroke consultant
Within 4.5 hrs of onset, and haemorrhage has been excluded, thrombolysis can be administered by specially trained staff.
Within 6 hours of onset, thrombectomy is offered along with thrombolysis, to people who have acute ischaemic stroke and confirmed occlusion of the proximal anterior circulation on CT angiogram
Between 6 – 24 hours thrombectomy can be offered in patients who have acute ischaemic stroke and there is potentially salvageable brain tissue as shown by CT perfusion.
Aspirin 300mg PO/NG/PR
If patient is not being thrombolysed give asap
Do not give until > 24 hours post thrombolysis.
Disposition
Depending on service configuration patient may need to be transferred to a neuro-radiology centre to facilitate thrombectomy
Where possible the patient should be admitted to a designated stroke unit for ongoing monitoring and early MDT input and rehabilitation
References
Helman, A, Himmel, W, Dushenski, D. ED Stroke Management in the Age of Endovascular Therapy. Emergency Medicine Cases. January, 2019. https://emergencymedicinecases.com/stroke-update-endovascular-therapy/. Accessed 15/11/20
Wyatt, J., Illingworth, R., Graham, C., Hogg, K. 2018. Oxford Handbook of Emergency Medicine. 4th ed. Oxford: Oxford University Press.
National Institute for Health and Care Excellence (2019) Stroke and transient ischaemic attack in over 16s: diagnosis and initial management. Available at: https://www.nice.org.uk/guidance/ng128/chapter/Recommendations#rapid-recognition-of-symptoms-and-diagnosis [Accessed 16/11/20]
Case courtesy of Dr Heba Abdelmonem, Radiopaedia.org, rID: 51593
SJH Stroke (Hyper-Acute) - Assessment and Treatment Protocol. Oct 2018
This blog was written by Dr James Morris and was last updated in December 2020