Stroke Notes

What is a Stroke?

  • Hippocrates referred to sudden death or paralysis as Apoplexy, meaning 'strike down'.

  • In the 1500s, sudden death or paralysis became known as 'stroke'.

  • The World Health Organization (WHO) defined stroke in 1978 as "rapidly developing 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 that of vascular origin."

Key Aspects of the WHO Definition

  • Rapidly developing: Symptoms appear suddenly.

  • Focal disturbance of cerebral function: A specific part of the brain stops working, leading to clinical features such as leg weakness.

  • Lasting more than 24 hours or death: Distinguishes stroke from transient, non-permanent brain insults.

  • Vascular origin: Caused by blood supply problems.

    • Ischemia: Blood supply is cut off, leading to a lack of blood supply.

    • Infarction: Cell death due to ischemia.

    • Hemorrhage: A blood vessel bursts, causing bleeding into the brain.

More Recent Definitions

  • International Statistical Classification of Diseases and related health problems (ICD) number 11 (2018) definitions of stroke include:

    • Cerebral ischemic stroke: Acute focal neurological dysfunction caused by focal infarction of the brain. Evidence is based on symptom duration > 24 hours or imaging.

    • Intracerebral hemorrhage: Acute neurological dysfunction caused by hemorrhage within the brain.

  • Other definitions, such as from the AHA (2013), also exist.

Stroke Incidence

  • In the UK, over 100,000 people have a stroke each year.

  • Currently, 1.2 million stroke survivors are living in the UK.

  • Stroke is the 4th most common cause of death.

  • Ischemic stroke (85%) is more common than hemorrhagic stroke (15%).

  • The average age for stroke is 74 for men and 80 for women.

Causes of Stroke

Ischemic Stroke

  • Atherosclerosis and Thrombosis: Narrowing of blood vessels followed by occlusion by a clot.

  • Embolism: A clot from the heart or a large blood vessel breaks loose and blocks a smaller artery downstream.

Risk Factors for Atherosclerosis

  • Smoking

  • Hypertension

  • Diabetes

  • High cholesterol

  • Physical inactivity

  • Poor diet

  • Age

  • Gender

  • Family history

  • Previous stroke

  • Heart disease

Causes of Embolism

  • Blood clots in the heart

  • Atrial fibrillation

  • Myocardial infarction

  • Ventricular aneurysm

  • Valve disease

  • Atherosclerosis in the aorta

  • Atherosclerosis in the blood vessels in the neck

Hemorrhagic Stroke

  • Hypertension

  • Cerebral aneurysms

  • Arteriovenous malformations

  • Blood clotting disorders

  • Anticoagulant (blood-thinning) drugs

Clinical Features of Stroke

  • Symptoms depend on the affected brain area.

  • Symptoms usually appear on the opposite side of the body from the brain injury.

FAST Acronym

  • Face: Drooping.

  • Arms: Weakness.

  • Speech: Difficulty.

  • Time: Call emergency services immediately, as some treatments must be administered rapidly.

Common Clinical Features

  • Face, arm, leg weakness, and/or sensory loss.

  • Speech disturbance.

  • Visual disturbance.

  • Loss of coordination.

Weakness and Sensory Loss

  • Weakness affects one side of the body; patients may describe heaviness, clumsiness, or weakness.

  • Sensory symptoms also affect one side, often described as numbness, tingling, or a dead feeling.

Speech Disturbance

  • Dysarthria: Slurred speech due to disordered articulation.

  • Dysphasia: Difficulty understanding speech or producing sentences, words, or using non-words.

Visual Disturbance

  • Patients struggle to describe visual symptoms.

  • Homonymous hemianopia: Visual loss affecting the same half of the visual field in both eyes; patients may describe visual loss, blurred vision, or a shadow in their vision.

Loss of Coordination

  • Difficulty describing symptoms.

  • Difficulty walking, may stagger as if drunk.

  • Vertigo (the illusion of movement) can occur.

Clinical Features and Blood Supply

  • Anterior Circulation (Carotids): Disruption mainly results in face, arm, leg, speech, and visual problems. More common.

  • Posterior Circulation (Vertebrobasilar): Disruption mainly results in coordination, vertigo, and sometimes visual problems.

Making a Diagnosis

Stroke Mimics

  • Seizures

  • Syncope (low blood pressure)

  • Hypoglycemia (low blood sugar)

  • Sepsis (+ previous stroke)

  • Severe migraine (if painless)

  • Space-occupying lesions (tumors)

Diagnostic Procedures

  • Confirmed at the hospital.

  • Brain imaging, typically CT scan, sometimes MRI scan.

  • Hemorrhage is always visible on CT, but infarcts take time to appear, making early diagnosis of ischemic stroke challenging.

Rapid Investigation

  • Suspected stroke patients need rapid investigation.

  • Paramedics pre-alert the hospital.

  • Hospitals target CT scan within 1 hour.

  • Specialized treatments mean only certain hospitals with a hyperacute stroke unit (HASU) can accept suspected stroke patients.

Treatments

Stroke Treatment Overview

  • General acute care for all strokes.

  • Specific acute treatment: Reversing/minimizing brain damage.

  • Stroke rehabilitation.

  • Prevention of recurrent stroke.

General Care for All Strokes

  • Specialization in stroke.

  • Coordinated multidisciplinary care.

  • Emergency treatments.

  • Prevention and early recognition of complications (e.g., pneumonia).

  • Rehabilitation.

  • Prevention of another stroke.

  • Education.

  • Research to reduce mortality and morbidity

  • Stroke Units.

Specific Treatment for Ischemic Stroke: Thrombolysis

  • Thrombolysis: Breaking up the clot with a drug (e.g., alteplase) to restore blood flow.

  • First research appeared in the 1990s; widely available in the UK by the mid-2000s.

  • Benefit is time-dependent; typically given within 4.5 hours of symptom onset.

  • Wardlaw \JM, Murray \V, Berge \E, del Zoppo \G, Sandercock \P, Lindley \RL, et al. Recombinant tissue plasminogen activator for acute ischaemic stroke: an updated systematic review and meta-analysis. Lancet. 2012 Jun 23;379(9834):2364-72

Complications of Thrombolysis

  • About 3% of patients experience intracerebral bleeding, worsening their condition.

  • Diagnosis of ischemic stroke can be challenging, and determining the exact onset time can be difficult.

  • Stroke specialists weigh up risks vs. benefits.

  • Variation between hospitals in treatment rates and time to treatment exists.

Improving Access to Thrombolysis

  • Public health campaigns (e.g., FAST TV advert).

  • Hospital service reorganizations (e.g., urgent imaging availability).

  • Pre-hospital initiatives (e.g., pre-notification of suspected stroke).

  • Mobile stroke units.

Specific Treatment for Ischemic Stroke: Thrombectomy

  • Thrombectomy: Removing the clot surgically.

  • For severe stroke due to blocked middle cerebral artery (“large vessel occlusion”).

  • A fine guide-wire is inserted to grab and remove the thrombus.

  • Evidence emerged in 2015 that it is beneficial.

  • Like thrombolysis, benefit is time-dependent.

Access to Thrombectomy

  • Requires specialist technology and trained staff.

  • There are 24 NHS thrombectomy services in the UK, compared to 127 HASUs.

  • Access is an issue.

  • Improving access is a topical research area.

Selective Redirection for Thrombectomy

  • Clinical scales alone do not provide accurate identification of large vessel occlusion (LVO).

  • Combining clinical scales with remote assessment may improve accuracy.

SPEEDY Clinical Trial

  • Specialist Pre-hospital Redirection for Ischaemic Stroke Thrombectomy: SPEEDY.

  • On-going clinical trial led by Newcastle University Stroke Research Group.

  • Due to run until late 2025, involving up to 80,000 patients.

Selective Redirection for Thrombectomy – Blood biomarkers

  • Blood biomarkers measured via fingerprick are of increasing interest.

  • Newcastle University Stroke Research Group is leading the ‘RADAR’ study.

  • Lateral flow technology is used to measure d-dimer and GFAP when patients arrive at the hospital.

  • The study will determine whether measuring d-dimer and GFAP can accurately identify large vessel occlusion stroke.

  • If so, the lateral flow tests could be used in ambulances in the future.

Selective Redirection for Thrombectomy – Technology

  • Radiowaves, EEG patterns, and Ultrasound have been tested to recognize LVO,

  • All remain research tools; none are sufficiently developed for use.

Treatments for Hemorrhagic Stroke

  • Blood pressure lowering.

  • Anticoagulation reversal.

  • Supportive care.

  • Little benefit from surgery.

  • Pro-clotting drug (tranexamic acid) under research evaluation.

Rehabilitation

  • Despite acute treatments, 2/3 of people have remaining disability at hospital discharge.

Effects of Stroke

  • Physical effects: Immobility, dependence on others, visual impairment, communication problems.

  • Psychological effects: Depression, anger, fear of further stroke, emotional lability.

  • Social effects: Driving restrictions, employment, relationship challenges.

Stroke Rehabilitation Definition

  • “Minimising the impact of stroke and helping people to live with its consequences.”

  • Encompasses specific interventions to complex care systems involving teams of professionals.

  • Typically delivered by physiotherapists, occupational therapists, and speech and language therapists.

  • Many treatments lack strong research evidence.

Stroke Rehabilitation: Services

  • Early Supported Discharge (ESD): Multidisciplinary service providing rehabilitation at home after stroke unit care, enabling earlier hospital discharge. Backed by evidence, improves disability compared to longer hospital stays.

Stroke Rehabilitation: Specific Interventions

  • Newcastle WAVES: Pilot study to determine if patients would wear and respond to a buzzing wristband to move their arm – they would.

  • RATULS: Big trial to determine if using a robot would improve arm function – it did not.

  • ACTIVATE: Pilot study to determine if patients could undertake walking exercises using a metronome - bigger study planned.

Recurrent Stroke Prevention

  • Treat risk factors.

Prevention Strategies

  • Hypertension (medication: antihypertensives).

  • Hypercholesterolemia (medication: statins).

  • Stop smoking.

  • Optimize treatment of diabetes.

  • Improve diet and lifestyle.

  • Aspirin or other antiplatelet for ischemic stroke.

  • A cardiac source of emboli may need other specific treatment – e.g., atrial fibrillation is treated with warfarin or new anticoagulant.

  • Carotid stenosis may be offered carotid endarterectomy.