Across the globe, stroke is the second most common cause of death. During stroke, there is disruption of blood supply to one or more areas of the brain due to blockage or rupture of the brain artery.
Types of Stroke
A stroke can arise primarily through two mechanisms
Ischemic stroke: which is more common, among the two occurs when there is a reduction in blood flow to the brain due to blood clot resulting in decreased supply of oxygen and nutrients.
Hemorrhagic stroke: occurs when there is a bleed into the brain tissue due to high Blood pressure or aneurysm rupture .
Risk Factors for Stroke
- Diabetes Mellitus
- Elevated cholesterol
- Physical Inactivity
- Atrial Fibrillation
- Family History of stroke
- Illegal drugs such as cocaine
- Aneurysmsor abnormalities in blood vessels in the brain
- Hole in the heart ( Patent Foramen Ovale, Atrial Septal Defect)
Symptoms and Signs of Stroke
A stroke can manifest in a multitude of ways depending on the size and site of the brain affected ranging from ‘silent’ strokes which are asymptomatic to complete paralysis and loss of sensation at the other extreme. Most frequently, the symptoms noted are localised weakness or loss of sensation, abnormal vision and difficulty with speaking or swallowing. Sometimes the individual may have a seizure or experience loss of consciousness.
In the acute setting, it is helpful to remember the mnemonic FAST to look out for stroke
F for Face - facial asymmetry from weakness and vision problems
A for Arm - sudden weakness, numbness or drift in the arms
S for Speech - slurring of words and difficulty speaking
T for Time - it is important to get urgent treatment to increase the chances of saving brain tissue. Call the local emergency services immediately when you notice someone showing the signs described above (911 in the US and Canada)
Diagnosis of Stroke
In addition to reviewing the patient’s history and performing a physical exam, the doctors would require additional tests to diagnose a stroke and to help plan management.
Imaging is performed with Non Contrast CT of the head or MRI brain. These tests help doctors identify if the stroke is secondary to a bleed or a blood clot.
Blood tests are also done to estimate blood glucose, complete blood count including platelets and tests of bleeding and clotting such as Prothrombin Time and INR (international Normalised Ratio).
Echocardiogram: It is ultrasound of the heart to evaluate heart function, blood clot or hole in the heart.
Carotid Ultrasound: To identify any blockage in carotid arteries.