Stroke remains a leading cause of mortality and disability worldwide, claiming nearly six million lives annually and contributing to 10% of global deaths. While over 80 million people have survived strokes, two-thirds face long-term disabilities. Ischaemic strokes, which constitute 70% of cases, result from a lack of blood supply to the brain. Despite advances in imaging and thrombectomy technologies, thrombolysis is not widely utilized due to its limited therapeutic window and the risk of hemorrhagic complications. Stem cell therapy has emerged as a potential treatment for enhancing neurological recovery post-stroke, transitioning from theoretical exploration to practical application. Mesenchymal stem cells (MSCs), with their ability to proliferate, differentiate, and modulate immune responses, offer a promising approach for stroke rehabilitation. These cells can be sourced from bone marrow, adipose tissue, or placenta, all of which exhibit migratory and immunomodulatory properties.
Mechanisms of Action
- Anti-inflammatory Effects: Stem cells release anti-inflammatory cytokines and modulate immune cell activity, reducing inflammation in the brain.
- Neuroprotection: Growth factors secreted by stem cells, such as vascular endothelial growth factor (VEGF) and brain-derived neurotrophic factor (BDNF), aid in tissue repair and protect neurons from damage.
- Angiogenesis: MSCs promote the formation of new blood vessels, improving oxygen and blood supply to the ischaemic region.
- Neurogenesis: MSCs stimulate the growth of new neurons and support the survival of existing ones, facilitating brain function recovery.
Potential Benefits of MSC Therapy
- Reduced Brain Damage: Stem cells therapy may mitigate the extent of brain injury caused by oxygen deprivation during an ischaemic stroke.
- Improved Functional Recovery: Early studies suggest stem cells can enhance motor skills, cognitive function, and overall neurological recovery in stroke patients.
- Minimally Invasive Delivery: Stem cells can be administered via various methods, including intravenous injections and direct brain delivery, offering flexibility in treatment options.
Challenges and Recommendations
- Delivery Method: Research is ongoing to identify the most effective method for delivering stem cells, whether through intravenous, intra-arterial, or direct brain injection.
- Timing of Treatment: Determining the optimal timing for MSC therapy post-stroke is crucial. While early intervention may yield better results, treatment during the chronic phase could also be beneficial.
- Cell Source: Stem cells can be derived from different tissues, including bone marrow, umbilical cords, and adipose tissue, but the most effective source for stroke treatment remains unclear.
- Further Research: More studies are needed to fully understand the long-term effects of stem cells therapy, standardize treatment protocols, and determine optimal dosages.
Patient Assessment and Eligibility
- Stroke Identification: Accurate diagnosis using imaging techniques such as MRI or CT scans is essential to confirm the type of stroke, whether ischaemic or hemorrhagic.
- Eligibility Criteria: Not all stroke patients are suitable for stem cell therapy. Factors such as the extent of brain damage, time since the stroke, overall health, and coexisting medical conditions play a critical role in determining eligibility. Assessments are typically conducted during both the acute and chronic phases of stroke recovery.
Choosing a Stem Cell Source
- Bone Marrow-Derived MSCs (BM-MSCs): Sourced from the patient’s or donor’s bone marrow.
- Umbilical Cord-Derived MSCs Stem Cells (UC-MSCs): Collected from donated umbilical cords, avoiding the need for invasive procedures.
- Adipose-Derived MSCs (AD-MSCs): Extracted from fat tissue via liposuction.
- Induced Pluripotent Stem Cells (iPSCs): Experimental research is exploring the use of iPSCs, which can differentiate into various cell types, including neurons.
Preparation and Quality Control
- Cell Isolation: After obtaining the tissue (bone marrow, fat, or umbilical cord), stem cells are isolated in a laboratory and cultured to increase their quantity.
- Quality Assurance: The cells undergo rigorous testing to ensure they meet therapeutic standards for viability, sterility, and functionality.
Conclusion
Stem cell therapy offers significant potential for stroke rehabilitation, particularly in reducing brain damage, enhancing recovery, and providing minimally invasive treatment options. However, research in this field is still evolving. Patients considering this therapy are encouraged to consult specialists and participate in controlled clinical trials to explore its benefits under expert guidance.