Brain Scans: Stroke Diagnosis And Treatment Revolutionized

Strokes are a medical emergency that can have debilitating and deadly consequences. Therefore, it is crucial to diagnose strokes early and accurately to increase the chances of recovery and reduce the risk of long-term disability. Brain scans, such as computed tomography (CT) and magnetic resonance imaging (MRI), are essential tools used by doctors to diagnose strokes and determine the appropriate treatment. These imaging tests provide detailed visuals of the brain, helping doctors identify the type of stroke, its location, and the underlying cause, which is vital for effective treatment.

CT scans can detect brain bleeds and blood clots

CT scans are a crucial tool for diagnosing strokes and identifying their type. They are often the first imaging test performed when a stroke is suspected, as they can reveal bleeding in the brain, blood clots, or damage to brain cells caused by a stroke.

Computed tomography (CT) scans use X-rays to capture multiple images of the brain from various angles, creating a cross-sectional view. This provides doctors with a three-dimensional perspective, allowing them to assess the size and location of any abnormalities, such as tumours, blood clots, or infections. CT scans can also help rule out other brain conditions that may be causing similar symptoms.

One significant advantage of CT scans is their ability to detect brain bleeds. They can identify bleeding in the brain, which is crucial for diagnosing haemorrhagic strokes, where a blood vessel bursts and bleeds into the brain. This information guides treatment decisions, as haemorrhagic strokes require different management compared to ischaemic strokes, where a blood clot blocks blood flow to the brain.

Additionally, CT scans are valuable in detecting blood clots. Ischaemic strokes, the most common type of stroke, are caused by blood clots blocking blood flow. CT scans can identify these clots and help determine the best treatment approach, such as thrombolytic therapy, to break up the clots and restore blood flow.

Doctors may repeat CT scans during treatment to monitor the progress and effectiveness of clot-busting interventions. They may also administer intravenous dye or "contrast agents" to enhance the visibility of blood vessels and blocked areas, aiding in treatment planning and evaluation. CT scans are widely available, providing quick results, which is essential for timely stroke diagnosis and treatment.

MRI scans can identify brain tissue changes

Magnetic resonance imaging (MRI) scans can identify changes in brain tissue. MRI scans are a diagnostic procedure that uses a combination of a large magnet, radio waves and a computer to produce detailed images of organs and structures within the body. The MRI machine creates a strong magnetic field around the patient, altering the hydrogen atoms' natural alignment in the body.

MRI scans are often used to diagnose strokes, as they can show bleeding in the brain or damage to brain cells. They can also reveal other brain conditions that may be causing the patient's symptoms. MRI scans can identify abnormalities in the brain and surrounding tissues, including inflammation, swelling, abnormal growths or masses, and haemorrhaging.

In the context of stroke diagnosis, MRI scans can detect blood clots in the brain, which are the most common cause of ischaemic strokes. They can also identify haemorrhagic strokes, which occur when a blood vessel bursts. MRI scans can further help determine the specific location of a functional centre of the brain, such as speech or memory, to assist in the treatment of a stroke.

Additionally, MRI scans can be used to monitor existing conditions and detect other neurological issues, such as multiple sclerosis, dementia, brain tumours, and traumatic brain injuries.

Ultrasound scans can check inside and around the brain

Ultrasound scans are a non-invasive diagnostic technique used to image inside the body. Ultrasound probes, called transducers, emit sound waves at frequencies above the threshold of human hearing (above 20 kHz). These sound waves bounce off the boundaries between tissues in the body and are reflected back to the transducer, which generates electrical signals that are sent to the ultrasound scanner.

Ultrasound scans can be used to check inside and around the brain. Cranial ultrasounds are imaging tests that use sound waves to create pictures of the brain. There are two types: head ultrasounds and transcranial Doppler. During the test, a machine sends sound waves into the head, and a computer records the images they make. These pictures show the inside structures of the brain and the fluid that flows within the hollow spaces deep inside the brain, known as ventricles.

In adults, the bones of the skull block sound waves, so cranial ultrasounds are typically performed on infants younger than six months old. This is because infants have a soft spot on top of their heads where the skull hasn't yet grown together, allowing the ultrasound to pass through. However, cranial ultrasounds can also be performed on adults during brain surgery to locate masses or tumors.

The transcranial Doppler is another type of ultrasound used to check how blood moves through the brain. It can help assess conditions that affect blood flow, such as stenosis and vasospasm, which can narrow blood vessels in the brain. It can also help evaluate the risk of stroke in adults and children with sickle cell disease.

Electrocardiograms can check for heart problems

A stroke can be diagnosed through brain scans such as CT, MRI, and ultrasound scans. In addition to these brain scans, doctors may also use an electrocardiogram (ECG or EKG) to check for heart problems.

An electrocardiogram is a simple, painless, and quick test that measures the electrical impulses of the heart to check for signs of heart disease. It is often the first test performed if a doctor suspects a heart condition. The test is done by attaching small electrode patches to the skin on the chest, arms, and legs. The computer then translates the electrical signals from the heart into a pattern of wavy lines that a doctor can interpret.

An ECG can help diagnose several heart conditions, including:

• Abnormal heart rhythms (arrhythmia)
• Enlarged heart chambers
• Blocked or narrowed arteries in the heart
• Poor blood flow to the heart muscle (ischemia)
• Heart attack
• Heart inflammation (pericarditis or myocarditis)

There are different types of ECG tests, including:

• Resting ECG: The standard type of ECG where the patient lies down and rests.
• Exercise stress test: The patient exercises on a stationary bike or treadmill while gradually increasing the intensity to observe the heart's reaction.
• Holter monitor: A portable EKG that records the electrical activity of the heart for 1-2 days while the patient goes about their daily activities.
• Event monitor: A device that records the heart's electrical activity for weeks or months, either manually by pressing a button or automatically when it detects an irregular heartbeat.
• Implantable loop monitor: A type of event monitor implanted just under the skin of the chest that records the heart's electrical activity continuously for up to 3 years.

Lumbar punctures can collect fluid from the spine

A stroke can be diagnosed using a brain CT scan, which can show bleeding in the brain or damage to the brain cells. Doctors can also use an MRI or ultrasound scan to check in and around the brain.

During a lumbar puncture, a patient is usually given a local anaesthetic and asked to lie down on their side with their knees pulled up to their chest or sit down with their head and shoulders bent forward. The doctor then slowly inserts the needle between the bones in the spine (vertebrae). The patient may feel some pressure and discomfort on their back and a pins-and-needles sensation for a few seconds.

Once the needle is in place, a small amount of CSF (about one tablespoon) is collected into test tubes and sent to a lab for testing. The fluid is typically tested for red and white blood cells, protein, and glucose (sugar). The clarity and colour of the fluid are also checked, and it is tested for the presence of bacteria, viruses, or abnormal cells.

A lumbar puncture procedure can help diagnose various diseases and disorders, including meningitis, encephalitis, certain cancers, bleeding in the subarachnoid space, Reye syndrome, myelitis, neurosyphilis, Guillain-Barré syndrome, demyelinating diseases, pseudotumor cerebri, and normal pressure hydrocephalus.

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