Dr Ashleigh Bhanjan

Sep 1, 20235 min read

Shining a Light on Stroke

Stroke is a clinically defined syndrome of acute, focal neurological deficit attributed to vascular injury of the central nervous system.

It is the 2nd leading cause of death and disability worldwide

In this blog, we will explore the causes, clinical presentation, current treatment modalities, complications, prevention, and the emerging use of photobiomodulation therapy (aka low level laser therapy, or LLLT) in stroke management.

Causes of Stroke

Stroke can be caused by a wide range of risk factors, disease processes, and mechanisms

The most important modifiable risk factor for stroke is hypertension.

Other risk factors include:

Atrial fibrillation
Diabetes
High cholesterol
Smoking
Obesity
Sedentary lifestyle
Family history of stroke

Clinical Presentation of Stroke

The clinical presentation of stroke can vary depending on the location and extent of the vascular injury.

Common symptoms and signs of stroke include :

Sudden weakness or numbness on one side of the body
Difficulty speaking or understanding speech
Sudden severe headache
Loss of balance or coordination
Vision changes
Confusion or altered mental status

MRI brain images demonstrating acute right middle cerebral artery infarct (white)

MRI brain images demonstrating acute left middle cerebral artery infarct (white)

Current Treatment Modalities for Stroke

The treatment of stroke aims to restore blood flow to the affected area of the brain and prevent further damage.

Time is BRAIN !

The phrase "time is brain" emphasizes that human nervous tissue is rapidly lost as stroke progresses and emergent evaluation and therapy are required.

Reperfusion strategies

1. Thrombolytic Therapy: Intravenous administration of tissue plasminogen activator (tPA) to dissolve blood clots and restore blood flow.

When administered quickly after stroke onset (within 3 hours, as approved by the FDA), tPA helps to restore blood flow to brain regions affected by a stroke, thereby limiting the risk of damage and functional impairment.

2. Mechanical Thrombectomy: Minimally invasive procedure to remove blood clots using a catheter-based device.

Mechanical thrombectomy (MT) is the standard of care for acute ischemic stroke (AIS) caused by large vessel occlusion of the anterior circulation within 6 hours of symptoms onset and can be performed with an extended window up to 24 hours in selected patients.

Secondary Prevention

Antiplatelet and Anticoagulant Medications : Medications to prevent blood clot formation and reduce the risk of recurrent stroke.

Rehabilitation

Physical, occupational, psychotherapy, and speech therapy to regain lost functions and improve quality of life, referral to a rehabilitation unit

Complications of Stroke

Stroke can lead to various complications, including :

Paralysis or weakness on one side of the body
Difficulty speaking or understanding speech
Cognitive impairment
Emotional and behavioral changes
Swallowing difficulties
Chronic pain
Depression and anxiety
Increased risk of recurrent stroke
Seizures

Prevention of Stroke

Prevention is always better than CURE !

Prevention plays a crucial role in reducing the incidence of stroke. Strategies for stroke prevention include :

Controlling hypertension, diabetes, and high cholesterol through lifestyle modifications and medications.
Quitting smoking and avoiding second hand smoke.
Maintaining a healthy weight through regular exercise and a balanced diet.
Limiting alcohol consumption.
Managing stress levels.
Taking medications as prescribed for underlying medical conditions.

Photobiomodulation Therapy in Stroke Management

Photobiomodulation therapy (PBM) is an emerging treatment modality that involves the use of low-level light therapy to stimulate cellular function and promote tissue healing.

Recent studies have explored the potential benefits of PBM in stroke management.

Research indicates that PBM therapy applied within 24 hours from stroke onset can reduce neurological damage, final infarct volume, and mortality rate

PBM therapy has shown promising results in animal models of ischemic stroke, indicating its potential as a neuroprotective intervention.

Photobiomodulation therapy (PBM) : Biological effects, in Stroke

Neuroprotection: PBM therapy may help protect brain cells from further damage after a stroke. Animal models of ischemic stroke have shown that PBM therapy applied within 24 hours from stroke onset reduces neurological damage, final infarct volume, and mortality rate. PBM therapy may also promote the survival of neurons and glial cells by increasing the production of neurotrophic factors

Anti-inflammatory effects : PBM therapy may have anti-inflammatory effects that can reduce the inflammatory response associated with stroke. Inflammation plays a crucial role in the pathogenesis of stroke, and reducing inflammation can help prevent further damage to brain tissue. PBM therapy has been shown to reduce the expression of pro-inflammatory cytokines and increase the expression of anti-inflammatory cytokines.

Improved blood flow: PBM therapy may improve blood flow to the affected area of the brain, which can help promote tissue healing and recovery. PBM therapy has been shown to increase the production of nitric oxide, which can dilate blood vessels and improve blood flow.

Enhanced cellular metabolism: PBM therapy may enhance cellular metabolism, which can promote tissue healing and recovery. PBM therapy has been shown to increase the production of ATP, which is the primary energy source for cellular metabolism.

Promotion of neurogenesis : PBM therapy may promote neurogenesis in stroke patients. Studies have shown that PBM therapy promotes neurogenesis by improving the post-stroke local microenvironment and stimulating neuroprogenitor cells

Why Consider Photobiomodulation Therapy?

Supported by Research : Multiple studies have demonstrated the positive effects of PBMT on stroke-related outcomes, including motor function improvement, reduced neurological deficits, and enhanced recovery rates.

Non-Invasive and Safe : PBMT is non-invasive and well-tolerated, making it a favorable option for patients who may have contraindications to other treatments.

Complementary Approach : PBMT can be used alongside conventional stroke treatments to potentially enhance their efficacy and accelerate recovery.

Minimal Side Effects : Unlike some medications or interventions, PBMT is associated with minimal side effects, further increasing its appeal as an adjunctive therapy.

Neuroprotection : PBM therapy may help protect brain cells from further damage after a stroke.

Neuroplasticity : It is well established that rehabilitation after a stroke depends strongly on the stimulation of neuroplasticity within the injured brain.

The brain has the capacity to rearrange or “rewire” itself to develop new neural pathways that can take over the function of lost pathways caused by brain damage after a stroke

Once a stroke has occured, there are minimal neuroprotective therapies available, hence one should consider PBMT early in stroke management.

It is important to note that PBM therapy should be used as an adjunct to standard stroke treatments and under the guidance of healthcare professionals.

Further research and clinical trials are necessary to fully understand the potential of PBM therapy in stroke management.

How many photobiomodulation treatments are required for stroke ?

The number of photobiomodulation treatments required for stroke varies depending on the protocol implemented, individual patient neuroplasticity, extent of stroke etc.

Animal models of ischemic stroke have shown that PBM therapy applied within 24 hours from stroke onset reduces neurological damage, final infarct volume, and mortality rate.

In a case series study, chronic stroke patients were treated with a high power, FDA-approved superpulsed laser system applied to the head for 12 weeks.

However, further research and clinical trials are necessary to establish the optimal protocols and number of treatments required for PBM therapy in stroke management

Are there any risks or side effects associated with photobiomodulation therapy for stroke ?

Based on the available research, PBM therapy appears to be a safe and well-tolerated treatment modality for stroke.

In fact, the almost complete lack of any adverse side-effects of PBM is one of its advantages, coupled with growing disillusion with pharmaceutical drugs that affect brain function.

Conclusion : Embracing Innovation in Stroke Care

Stroke remains a significant global health concern, but advancements in stroke care continue to improve outcomes for patients.

Beyond conventional therapies, the emerging role of photobiomodulation therapy offers new hope by harnessing the power of light to facilitate brain healing and recovery.

While further research is needed, the evidence thus far underscores the potential of PBMT as an adjunctive therapy in stroke management.