Cerebrovascular Accident (CVA) or Stroke

Definition

Stroke or cerebrovascular accident (CVA) is a sudden onset of neurologic deficit lasting more than 24 hours that can either be due to brain ischemia or hemorrhage. There are two main types of strokes; ischemic stroke and hemorrhagic stroke. Clinical manifestation of stroke depends on the blood vessel affected and the size of the portion that has an infarct.

Stroke is the leading cause of neurologic deficit in adults. In UK it is estimated that someone has stroke every 3.5 minutes. In the United States stroke kills about 150 000 people annually. It is the 5^th most common cause of death and the most common cause of neurologic disability in adults.

Half of stroke survivors have permanent disability. Although Stroke has high morbidity and mortality, there are measures that can be taken to prevent the disease.

Transient Ischemic Attack (TIA) is temporary brain ischemia that cause symptoms similar to stroke but with full recovery within 24 hours. Symptoms typically last less than 1 hour. There is no acute cerebral infarction on MRI scans.

Types of Strokes

There are two main types of strokes:

1. Ischemic Stroke: Accounts for about 85% of all strokes, it is due to thrombus (blood clot) or emboli that blocks a brain vessel leading to localized ischemia. An emboli may come from the heart, aortic arc or internal carotids.
2. Hemorrhagic Stroke: It is an intracranial bleed resulting from a vascular rupture which can be intracerebral hemorrhage or subarachnoid hemorrhage. It accounts for only 15% of the cases of stroke.

Risk Factors of Stroke

Several Risk factors of Stroke can be grouped into modifiable and non-modifiable factors.

Modifiable risk factors

1. Hypertension
2. Diabetes mellitus
3. Bleeding disorders
4. Intracranial aneurisms (berry aneurism)
5. Sudden BP drop by > 40mmHg, especially in younger patients
6. Smoking
7. Obesity and Dyslipidaemia
8. Hypercoagulability
9. HIV
10. Use of certain drugs (e.g. amphetamines and cocaine)
11. Heart diseases such as heart failure, cardiac arrhythmias, endocarditis and Myocardial Infraction (MI).
12. Psychosocial stress e.g. Depressive Illness.
13. Head trauma
14. Covid-19

Non-modifiable risk factors

• Older age
• Previous history of stroke
• Family history
• Ethnicity: African Americans and Hispanics have increased risk of stroke compared to Caucasians.
• Antiphospholipid syndrome

Clinical Manifestations of Stroke

The stroke development is usually sudden, symptoms and signs depend on the part of the brain that is affected, a person may not have all of the features listed here. Cerebrovascular accident occurs in most cases in the early hours of morning (around 04:00 am). This is because at this time, the heart rate is at its lowest while the blood pressure is at its highest affected by circadian rhythm.

Symptoms

• Weakness of one side of the body
• Severe Headache
• Loss of speech
• Loss of consciousness
• Dizziness
• Loss of vision on one side
• Seizures (Fits)
• Inability to swallow (Dysphagia) urinary incontinence
• Stool incontinence

Signs

• Hemiparesis
• High Blood Pressure above 180/110
• Low GCS
• Cranial nerve palsy ( any nerve can be affected)
• Dysarthria
• Ataxia
• Meningism signs in the case of subarachnoid hemorrhage (hemorrhagic stroke).
• Loss of anal sphincter tone.
• Affected limb become flaccid initially but later spastic (feature of upper motor neuron lesion).

Clinical features are worse at the onset of stroke and get better with time, especially is there is early involvement of rehabilitation team (physio, speech and occupational therapy).

Recognizing Stroke

FAST mnemonic is a group of symptoms of stroke that everyone should be aware of and call emergency help line if they have any of them. The mnemonic stands for:

• F-facial asymmetry
• A-arm/leg weakness
• S-speech difficulty
• T-time to call 911 or 112.

Investigations

In any patient with suspected stroke, an urgent CT scan or MRI of the brain should be done within 1 hour in order to determine whether it is a hemorrhagic stroke or ischemic stroke. This can be done while emergency management is initiated e.g. protecting the airway if GCS is low and correction of blood glucose levels.

• Arterial Blood Gas (ABG)
• Blood: Full Blood Count (FBC), LFT, U&Es, Clotting profile (INR, aPTT,PT), Lipid profile (Total cholesterol, HDL & Triglycerides), Anticardiolipin antibodies, ANA, HIV ELISA, Syphilis Serology, ESR, protein S.
• Lumbar Puncture: Can help diagnose subarachnoid hemorrhage and other infectious causes of stroke.
• ECG: May reveal cardiac arrhythmia or other heart pathology that increase risk of stroke
• CT scan or MRI: They give details about type of stroke and location of the brain infarct. Brain imaging can also diagnose tumors and raised intracranial pressure.
• Chest X-ray: To exclude any lung infection and aspiration as most patients have issues with swallowing.

Most of the tests mentioned above are done to determine the cause of stroke in order to treat reversible causes.

Treatment of Stroke

Emergency Management

1. Ensure the airway is protected, incubate if GCS is 8 or less.
2. Check glucose and treat hypoglycaemia
3. Secure IV line access and treat dehydration if present
4. Urgent brain imaging within an hour if possible
5. Give oxygen if hypoxic (SpO2<92% on room air)
6. Urinary catheter to monitor urine output
7. Do not lower Blood pressure unless it is >220/120
8. Nasogastric tube can be inserted for those unable to swallow, otherwise keep nil per os.

When haemorrhagic stroke has been ruled out and 3 hours has not passed since onset of symptoms:

• Give Thrombolytic therapy: Alteplase IV 0.9mg/kg. 10% is given as bolus and remainder as infusion over an hour. This should be done by an experienced professional.
• Contraindications to Alteplase: Haemorrhagic stroke, Severe Liver Disease, Stroke in the past 3 months, anticoagulant therapy, Blood sugar <3 or > 22, Recent Surgery.

When more than 3 hours has passed and hemorrhagic stroke has been ruled out give:

1. Aspirin 300mg oral stat
2. Follow with aspirin 150mg oral daily

If patient is unable to swallow, an NG tube can be used.

Simvastatin 40mg oral nocte should be given as part of secondary prevention.

If blood pressure is >220/120, long acting calcium channel blocker can be used:

• Amlodipine 5mg oral daily

Long Term Management

Stroke treatment requires multidisciplinary approach in order to improve outcomes. Patients should be referred to all relevant allied teams as soon as possible following emergency treatment. These include:

• Dietician
• Speech therapy
• Physiotherapy
• Psychologist
• Occupational Therapy
• Family Members involvement

Prevention of Stroke

Cerebrovascular Accident can be prevented through changes in lifestyle and management of medical conditions that are listed as risk factors.

Patients should be advised to stop drinking alcohol and smoking. Contrary to the popular belief that drinking in moderation has benefits, recent studies and WHO article reveals that there is no benefit from drinking alcohol regardless of the volume.

Management of the following lifestyle diseases:

• Hypertension
• Obesity
• Diabetes Mellitus

Use of anticoagulants in patient at risk of developing thromboembolism e.g. (Atrial Fibrillations). Psychological stress management, which can help people with migraine as well.