Stem Cells For Stroke Treatment

About Stroke

The brain needs oxygen for normal functioning, which is delivered by the intricate network of blood vessels carrying oxygen-rich blood. Therefore, any compromise in the blood flow reduces/blocks the oxygen supply. Oxygen-starved brain cells begin to die within minutes. This causes a stroke, resulting in irreversible damage to the brain with life-altering consequences.

What is “Time is Brain”?

In case of a stroke, urgent medical treatment is critical. The longer the brain is deprived of oxygen, the more tissue is lost and with it, essential abilities like speech, memory, or movement. Therefore, a medical slogan- time is brain – was introduced to highlight the need for swift intervention to protect as many brain cells as possible. Timely and rapid treatment can not only minimize the risk of disability but also save lives.

What is a Thunderclap Headache?

A thunderclap headache is a sudden, severe, and explosive headache that reaches its peak intensity within seconds to a minute. Often described as “the worst headache of your life”, it can strike without warning and is associated with a hemorrhagic stroke caused by the rupture of a blood vessel in the brain.

Can someone recover after a stroke?

Rehabilitative therapies are commonly recommended for functional recovery after stroke. It depends on several factors, including the type, location, and severity of the stroke, as well as the timeliness of treatment and the individual's overall health. Many stroke survivors experience lasting disabilities. Recovery can be partial or, in some cases, very limited. Some individuals may require long-term assistance for daily activities such as walking, eating, dressing, or speaking.

Effective stroke treatment demands a two-pronged approach - restoring blood flow to prevent further brain damage, and repairing the tissue that’s already been harmed. Current therapies primarily focus on the preventive aspect, that is, reestablishing circulation. They often fall short when it comes to healing damaged brain cells. However, ongoing scientific advancements have brought stem cell therapy to the forefront, offering a powerful new tool to stimulate tissue repair and support meaningful recovery.

Integrating the unique requirements of each individual and disease presentation in regenerative medicine develops more customized solutions. It maximizes the therapeutic benefits of the therapy, venturing into the new area of personalized regenerative medicine.

Diagnosis

Diagnosis of a brain stroke is urgent to prevent further tissue damage and enable timely treatment. It involves several steps to quickly distinguish between ischemic and hemorrhagic strokes, as treatment options greatly differ for each type. The process begins with a physical and neurological examination, assessing symptoms and taking a detailed medical history. Commonly used diagnostic tools include:

CT Scan: The first imaging test performed in the emergency room is a CT scan to rapidly determine if the stroke is due to bleeding (hemorrhagic) or a blocked vessel (ischemic). It is often combined with angiography and CT perfusion to visualize blood vessels and assess blood flow.

MRI: It provides detailed images with higher sensitivity than a CT scan for detecting tissue damage. It is particularly beneficial in small or deep strokes. Like CT angiography, MRI angiography can also highlight blood vessels in the brain.

Vascular Imaging: Techniques such as carotid ultrasound and cerebral angiography help visualize the arteries in the neck and brain to find clots, narrowing, or blockages. These are crucial for planning further treatment, including surgery or other interventions.

Lumbar Puncture: In case of high suspicion of stroke and absence of a conclusive imaging result, lumbar puncture is used to detect stroke markers such as blood in cerebrospinal fluid in subarachnoid hemorrhage.

Blood Tests: Routine tests assess blood glucose, clotting factors, infection markers, etc., to find the factors that contributed to the stroke. Managing these factors can reduce the risk of stroke in future.

Electrocardiogram (ECG): It analyzes issues in cardiac rhythm, which indicate the source of clots within the heart.

To speed up the diagnostic process, many novel state-of-the-art techniques have emerged, such as Doppler ultrasound, transcranial ultrasound, microwave-based diagnostics, volumetric impedance phase shift spectroscopy, etc. Further research is also exploring biomarkers for stroke for easy and rapid detection of stroke

Early Signs & Symptoms of Stroke

When it comes to strokes, time is critical. Immediate medical attention can make the difference between full recovery and long-term disability, or even save a life. Recognizing the early signs is essential to ensure fast and effective treatment. Common ischemic stroke symptoms may include:

• Sudden weakness or numbness on one side of the face, arm, or leg
• Difficulty in speaking
• Trouble finding words or forming coherent sentences
• Loss of balance or difficulty walking
• Visual disturbances in one or both eyes
• Loss of control of eye movement or abnormal eye alignment
• Sudden confusion and dizziness

Hemorrhagic stroke symptoms include the symptoms of ischemic stroke in addition to the following signs:

• Sudden, severe headache without a known cause
• Vomiting
• Seizures
• Decreased level of consciousness or coma

To help people quickly identify a stroke, a simple acronym has been developed: FAST.

F - Face Drooping: One side of the face feels numb. Ask the person to smile, does it look uneven?

A - Arm Weakness: One arm is weak or numb. Ask them to raise both arms, does one drift downward?

S - Speech Difficulty: Slurred speech. Can they repeat a simple sentence correctly?

T - Time to Call Emergency Services: If any of these signs are present, call emergency help immediately. Don’t wait.

BE FAST is another acronym introduced, where

B refers to loss of balance

E refers to blurred eyesight.

Remember, the sooner a stroke is recognized and treated, the better the chances of minimizing brain damage and improving recovery.

Available Types of Stroke

Strokes are broadly classified into two types based on the reason for reduced blood flow, each with distinct mechanisms and clinical implications:

Ischemic Stroke: Cerebral Ischemic stroke definition includes narrowing or blockage of blood vessels due to a blood clot or cholesterol deposition, commonly referred to as plaque. Depending on the origin of the blockage, types of ischemic stroke are as follows:

Thrombotic Stroke: It is the most common form of ischemic stroke, characterized by the clot formation within the brain’s blood vessels

Embolic Stroke: It occurs when a clot or plaque forms in the heart and travels to the brain, lodging in the cerebral arteries.

Additionally, vessel hardening due to specific risk factors can also lead to narrowing of blood vessels, adding to the ischemic stroke causes. The resulting insufficient blood supply to brain tissue diminishes cellular energy levels. This lack of oxygen and nutrients triggers inflammation, ultimately leading to neuron loss in affected brain regions.

Hemorrhagic Stroke: Hemorrhagic stroke accounts for 10-20% of all incidences of stroke. In contrast to ischemic stroke, hemorrhagic stroke occurs due to the rupture of a blood vessel, causing leakage of blood into the brain. This leaking blood collects and forms a hematoma, which increases pressure on surrounding brain tissue. Hemorrhagic stroke is further divided into two main types:

Intracerebral Hemorrhage: Bleeding occurs directly within brain tissue due to the rupture of small arteries. The resulting increase in intracranial pressure impairs blood flow and may lead to ischemic injury.

Subarachnoid Hemorrhage: Bleeding occurs in the space between the brain and the thin tissues covering it- the subarachnoid space. It typically occurs due to the rupture of an aneurysm—a balloon-like bulge in a weakened artery wall.

The difference between ischemic stroke and hemorrhagic stroke is that ischemic cerebrovascular stroke occurs due to vessel obstruction, and hemorrhagic stroke results from vessel rupture and leakage. Thus, the CT scan of ischemic vs hemorrhagic stroke demonstrates darker regions in the brain (hypodense) due to low blood flow in ischemic stroke, whereas the scan shows brighter white areas in the brain (hyperdense) corresponding to bleeding in hemorrhagic stroke.

Transient Ischemic Attack (TIA): It is another type of stroke, involving a temporary interruption of the blood flow to the brain, causing stroke-like symptoms that resolve within 24 hours. Therefore, it is often referred to as a mini stroke. However, TIAs serve as critical warning signs of a potential major stroke and should never be ignored.

Understanding the cause and type of stroke is crucial for selecting the safest and most effective treatment strategy.

What Causes Stroke?

The causes of brain stroke are complex and multifactorial, involving both medical conditions and lifestyle factors. The stroke arises from the obstruction of blood flow to the brain, including clot formation, plaque deposition in vessels, or vessel rupture. Major medical causes and risk factors include:

High blood pressure: It is the leading cause, as it damages blood vessels and increases the risk for both clotting and bleeding events.

Diabetes: Chronic high blood sugar damages blood vessels and increases the likelihood of clot formation.

High cholesterol: Increases plaque buildup in arteries (atherosclerosis), promoting vessel blockage.

Age: Increasing age also weakens blood vessels, elevating the risk for stroke.

Drinking or Smoking: Damages blood vessels, raises blood pressure, and increases the tendency of clotting.

Obesity: Increases the risk of disorders, such as diabetes and cardiovascular complications, which results in a higher chance of stroke.

Family History: Incidence of stroke in a family member also alludes to higher stroke risk.

Sickle Cell Disease: The abnormally shaped red blood cells get stuck in blood vessels and the clot can travel to the brain.

Gender: Women are more at risk of stroke than men, believed to occur due to pregnancy and the use of birth control pills.

Other risk factors include medications such as anti-platelets and anticoagulants, or drugs like cocaine.

Stem Cell Treatments

The current treatment of stroke primarily focuses on reducing blood clots or managing bleeding through medications and surgical interventions. However, the timing of treatment plays a crucial role in determining its effectiveness and outcome. Statistics reveal that only 10% of stroke patients achieve complete recovery. Most individuals are left with varying degrees of impairment and often require long-term care and rehabilitation.

In response to these limitations, scientists have developed a promising alternative—stem cell therapy. This innovative approach holds the potential to repair damaged brain tissue, offering a significantly higher chance of functional recovery. Research has identified several mechanisms through which stem cell therapy exerts its beneficial effects in stroke patients.

• Stem cells can convert into neural cells and promote their growth. MSCs boost the expression of GAP-43, a protein that supports neurogenesis and helps reorganize brain circuits.
• After a stroke, enzymes break down the blood-brain barrier, leading to swelling and pressure. Stem cells restore barrier integrity by reducing damaging enzymes and increasing protective proteins.
• Post-stroke inflammation worsens tissue damage. Stem cells reduce harmful cytokines, increase anti-inflammatory ones, and express TSG-6 to limit immune cell infiltration.
• Stem cells prevent neuronal loss by activating survival pathways, notably increasing Akt and Bcl-2 protein levels.
• Stem cells repair damaged blood vessels by promoting new vessel growth through the Wnt signaling pathway, aiding vascular stability and reducing leakage.

Therefore, hemorrhagic and ischemic stroke stem cell therapy is effective in accelerating recovery and improving outcomes.

Frequently Asked Questions

Q1. How can I prevent a stroke?

Stroke prevention focuses on healthy lifestyle choices and managing medical conditions. A balanced diet, regular exercise, avoiding smoking, and limiting alcohol consumption help to control weight and improve circulation. Controlling blood pressure, diabetes, and cholesterol through medication and regular checkups is essential to support cardiovascular health. Managing heart issues like atrial fibrillation also significantly reduces stroke risk.

Q2. How does stem cell therapy help in stroke?

Stem cell therapy assists in stroke recovery by facilitating brain tissue repair and regeneration. Stem cells migrate to the damaged brain areas, where they release growth factors that promote the growth of new blood vessels and help replace damaged neurons. By regulating cytokine levels, they also reduce inflammation, creating a healing microenvironment. Clinical research indicates that stem cell therapy can lead to improvements in motor function and cognitive abilities after stroke.

Q3. How long will it take to recover from a stroke after stem cell therapy?

The recovery time after receiving stem cell therapy for stroke varies widely depending on the severity of the stroke, the patient’s overall health, and the timing of therapy administration. Some patients may begin to observe functional improvements within a few months after treatment, while for others, recovery can be a longer and more gradual process.

Q4. Is stem cell treatment effective for both hemorrhagic and ischemic stroke?

Both hemorrhagic and ischemic stroke treatment with stem cells has shown promising potential. Neurological improvements have been seen in studies for each type. Stem cell therapy is generally safe and feasible in clinical trials for both stroke types. More large-scale studies will make it a standard treatment for either condition.