Cannabidiol (or CBD) oil is made by diluting the phytocannabinoid, CBD, extracted from Cannabis sativa with a carrier oil like hemp seed oil.
CBD belongs to a class of compounds called cannabinoids which bind to specific receptors of the endocannabinoid system (ECS) to produce a variety of physiological responses.
CBD is not psychoactive and has been proven to have health benefits by relieving stress, inflammation, and pain.
Overview of Cerebrovascular Disorders
Cerebrovascular disorders are inclusive of a wide spectrum of conditions that damage blood vessels, particularly arteries, of the brain and affect cerebral circulation.
The most common manifestations include ischaemic stroke and, at times, a haemorrhagic stroke.
High blood pressure is a potential risk factor as it affects the blood flow and can lead to atherosclerosis which narrows arteries in the brain causing ischaemia or hypoxia (lack of oxygen supply).
CBD Oil Benefits in Cerebrovascular Disorders
The major benefits of CBD for cerebrovascular disorders are linked to its neuroprotective activity. It exerts this action by promoting the normal flow of blood in the cerebral arteries and preventing the occurrence of cerebral infarctions. It helps in combating inflammation and therefore, lowers atherosclerotic plaques and thrombi from the blood vessels.
CBD treats the damage caused by ischaemic stroke by restoring blood supply and also prevents the development of ischaemic-reperfusion injury by stabilizing the blood flow into the tissues and combating the action free radicals. It also prevents secondary damage after stroke and hypoxic-ischaemic brain injury by lowering risk factors like ionic and neurotransmitter imbalances.
1. CBD Oil Prevents Cerebral Infarction
A cerebral infarction is an outcome of the presence of necrotic (dying) tissue in the brain.
This usually happens as a consequence of a blockage in the arteries supplying oxygenated blood to the brain.
Due to the restriction of oxygen supply to the nervous tissue, the patient can experience can an ischaemic stroke which ultimately causes the infarction if the oxygen supply is not restored immediately.
The narrowing of the arterial walls is further aggravated by blockages caused by embolisms, particularly blood clots (thrombus).
The type of arteries being affected by blockages will determine the area of the brain that will suffer from ischaemia (inadequate oxygen supply).
Depending on the area infarcted, the patient will exhibit different symptoms with minor to severely fatal consequences.
The major indicators of a cerebral infarction are extreme weakness and rapid loss of sensation on the other side of the body.
Detailed examination of the head might reveal unusual pupil dilation and complete lack of eye movement on the other side. Slurred speech is an outcome of infarction on the left side of the brain.
Most of the cases of cerebral infarctions are brought about by thrombotic ischaemia wherein a thrombus restricts the blood flow.
Platelet aggregation in the artery which grows into a platelet plug is the chief reason behind the development of a thrombus.
Thrombi contribute to stenosis (abnormal narrowing) of large and small blood vessels. The large vessels are affected by atherosclerosis while the smaller ones by lipohyalinosis (build-up of fatty hyaline matter).
Most drugs that are used to treat such conditions of ischaemia exert thrombolytic effects and act as blood thinners.
Research has shown that phytocannabinoids like CBD have shown great potential in resolving such conditions and provide relief.
A 2005 experimental study at the Fukuoka University investigated the neuroprotective activity of CBD by blocking the middle cerebral artery in male mice.
The mice treated with CBD showed experienced lesser infarction and recorded better cerebral blood flow as opposed to the placebo group. It was inferred that CBD mediates its effects via the serotonergic 5-H1TA receptor.
What does it mean?
CBD prevents cerebral infarction even in the presence of blocked arteries as it promotes cerebral blood flow via the serotonergic receptors.
2. CBD oil Treats Ischaemic Stroke
Stroke is a medical condition wherein the cerebral blood flow is impaired as a result of which cell death occurs.
Ischemic stroke is a type wherein there is inadequate blood supply to a part of the brain. If deprived of oxygen for over a minute, the brain cells cease to function and after 3 hours of inadequate oxygen supply, tissue necrosis occurs.
This is referred to as an infarction.
One of the major reasons behind stunted blood flow is the development of arterial stenosis. Atherosclerosis or plaque formation is one of the main reasons behind the narrowing of the lumen of blood vessels which disrupts normal blood flow.
It also promotes the development of embolisms when the atherosclerotic plaques disintegrate and form clumps.
Another reason behind ischaemic stroke is the presence of an embolic infarction which occurs when an embolus formed elsewhere in the vascular system, particularly in the heart or the carotid artery, enters into the cerebral circulation to block the arteries and cut off the oxygen supply to brain tissues.
During a stroke, the brain becomes low in energy and resorts to anaerobic metabolism to meet the energy requirements.
This leads to an inadequate production of energy as well as the accumulation of the by-product, lactic acid. This acts as an irritant as it negatively affects the normal acid-base balance of the brain.
Ischaemia also leads to the production of free radicals which further damages the lining of the blood vessels.
Lack of oxygen also stimulates the release of the excitatory neurotransmitter, glutamate, which causes calcium influx and aggravates the neuronal injury.
The major symptoms of ischaemic stroke are disorientation, loss of sensation in the opposite side of the body, and loss of vision.
Thrombolytic drugs which can cross the blood-brain barrier are usually chosen to treat such a condition.
Cannabidiol has also emerged as a potential therapy for resolving embolisms in the brain.
A 2010 review published in the journal, Pharmaceuticals, revealed that CBD is neuroprotective and protects the brain from ischaemic injury by stimulating cerebral blood flow.
It also protects the brain from the activity of free radicals.
What does it mean?
As CBD stimulates the flow of blood in the brain and protects the tissues from free radical damage, it acts as a neuroprotectant and prevents ischaemic stroke.
3. CBD oil Protects from Ischaemia Reperfusion Injury
Ischaemia-reperfusion injury (IRI) or reoxygenation injury is, as the name suggests, tissue damage caused when blood supply is restored to the brain tissue after a period of ischaemia.
After the period of limited or no oxygen, restoration of blood supply often results in an inflammatory response and the situation is aggravated by the activity of free radicals.
Reperfusion insult is often accompanied by vascular injury, particularly in the smaller arteries and capillaries.
This occurs due to the increased permeability of the blood vessels to compensate for the earlier restriction which abnormally amplifies the rate of diffusion of blood across the tissues and causes damage.
Reperfusion is also associated with a dip in nitric oxide levels which causes inflammation.
As mentioned earlier, inflammation exacerbates the reoxygenation injury. Circulating white blood cells (WBCs) release a host of inflammatory factors like interleukins and free radicals that damage the cellular framework.
The restored blood brings about the oxidative damage which ruptures the cell membranes and releases cell contents into the extracellular matrix.
IRI constitutes the brain’s ischaemic cascade which brings about stroke or even brain trauma.
These processes are often involved in cerebrovascular disorders following a cardiac arrest and hence, controlling and reversing them are active areas of interest in medical research.
Repeated instances of stroke and IRI could lead to permanent inflammation and brain damage.
While many studies have been conducted to find therapeutic solutions to treat reperfusion injury, a 2017 study by the Fudan University investigated the role of CBD in promoting cerebrovascular health by protecting against IRI.
The results showed that CBD attenuates such injury by counteracting the oxidative stress caused by free radicals, enhances the mitochondrial functioning, and improves glucose metabolism.
What does it mean?
CBD helps in protecting the brain from reperfusion energy by amplifying the activity of the mitochondria and combating the toxic effects of the free radicals.
4. CBD oil Prevents Secondary Damage After Stroke
Secondary brain injury occurs as an indirect outcome of the primary damage. It is usually a consequence of some form of trauma experienced by the brain.
It generally happens in the hours and days following the primary trauma and often plays a major role in causing permanent brain tissue damage and even cell death.
It also increases disease morbidity and a majority of people dying from cerebrovascular disorders succumb to them weeks after the initial stroke.
Furthermore, unlike other diseases, patients suffering from cerebral ischaemic trauma mostly do not improve after being hospitalized and around 40% of these patients worsen over time. This is mostly because of secondary damage following the stroke.
Secondary complications not only involve the usual problems like ischaemia (inadequate blood flow) and hypoxia (insufficient oxygen supply) but also include a variety of conditions like cerebral hypotension, swelling or oedema, unusual and abnormally high blood flow rates during reperfusion, and amplified intracranial pressure which, if too high, can lead to brain herniation (squeezing out parts of the brain from the skull).
Excessive carbon dioxide accumulation, acidosis, and meningitis are other examples of secondary brain injury.
Furthermore, a primary injury like a stroke can be succeeded by an imbalance in the levels and activities of neurotransmitters which can trigger a cascade of events and stimulate oxidative stress by the release of free radicals.
While little can be done to prevent primary brain injuries, extensive research has been done to treat secondary damage to lower the morbidity rates.
As these injuries take time to progress, preventive measures can be taken to prevent hypoxia or hypotension within the brain.
A variety of mechanisms come into play to bring about secondary damage, hence therapeutic solutions should address these complications to mitigate their effects.
A 2015 meta-analysis by the Universidad Complutense evaluated the role of cannabinoids in protecting the brain following trauma and stroke.
The results of several experimental models and clinical trials revealed that cannabinoids like CBD have a holistic neuroprotective function mediated by activating its receptors in the nerve cells and their precursors.
CBD protects patients from secondary damage by improving cerebral blood flow as well as curbing oxidative stress.
What does it mean?
CBD holds great potential in protecting against secondary damage after stroke because it stimulates cerebral blood flow and thereby prevents complications like hypoxia, ischaemia, and cerebral hypotension.
5. CBD oil Treats Hypoxic-Ischaemia
Hypoxic-ischaemic (HI) brain injury refers to a class of cerebrovascular disorders characterized by certain injuries to the brain such as hypoxia, ischaemia, cytotoxicity, as well as tissue necrosis.
The typical causes can range from cardiac arrest to respiratory failure and include any factor that leads to the formation of embolisms.
These factors make the brain susceptible to marked reductions in oxygen supply (hypoxia) and blood and energy supply (ischaemia).
Diminished oxygen levels in the brain may occur due to improper gaseous exchange in the lungs, reduction in the blood-oxygen saturation limit due to pulmonary dysfunction, decreased haemoglobin levels, a lowered rate of blood flow in the brain due to arterial stenosis, or even cardiac arrest.
It is important to note that these conditions not only lower the oxygen levels of the brain but also affect glucose which is needed to produce metabolic energy.
Due to restricted blood flow, metabolic wastes are also not removed from the brain tissues and can contribute to toxicity and cellular damage.
All these factors contribute to the hypoxic-ischaemic state that is characterized by low cellular energy, excess release of excitatory neurotransmitters, ionic imbalances, cerebral swelling and oedema, disruption in the autoregulation of cerebral blood flow and increase in oxygen-free radicals.
This condition, if not treated, can lead to irreversible brain injury. The major symptoms include seizures and motor disorders.
Several studies have been undertaken to suitably treat such injuries and reduce their impact on the brain tissue. Recently, phytocannabinoids such as CBD have shown marked potential in altering the HI state.
A 2014 collaborative study between the New York University and the University of California, San Francisco reviewed the impact of CBD on neurological and cerebrovascular disorders.
It was established that CBD usage remarkably counteracted the HI state by stimulating cerebral blood flood and stunting the excess release of excitatory neurotransmitters via the endocannabinoid system (ECS).
What does it mean?
CBD helps in treating HI brain injury by promoting the normal flow of blood in the cerebral arteries and preventing the excess release of certain neurotransmitters.
As CBD oil might contain trace amounts of the psychoactive tetrahydrocannabinol (THC), it is advisable to consult a medical practitioner before taking CBD medication.
The dosage and efficacy are dependent on the mode of delivery.
There is no prescribed dosage for using CBD to treat cerebrovascular disorders like stroke and HI brain injury. However, patients should begin with mild doses of 90-100mg daily and increase it steadily, as per their tolerance levels.
In case of severe headaches, vaporizers can be used and 6-8mg (2 puffs) should be inhaled to have a good effect.
CBD generally has very few known side-effects. In fact, daily doses of up to 500mg can be tolerated for as long as 6 months without producing any untoward complications.
As per a 2011 review, the cannabinoid can also be consumed in high doses (1500mg) daily for a period of 3 months.
It is to be noted that most of the CBD products have some amounts of THC in them and this component, being psychoactive, might produce some side-effects.
While most individuals are not affected by such meagre amounts, some sensitive patients may be susceptible and experience hallucinations.
Hence, it is recommended to begin with small doses to build a tolerance.
The liver enzyme, cytochrome p450, gets inhibited by CBD and as this enzyme is involved in the metabolism and uptake of certain medications, cannabidiol usage might lower the efficacies of certain prescription drugs.
Products containing high amounts of THC might also cause dizziness, disorientation, nausea, fatigue, impaired balance, hallucinations, and paranoia.
Adverse effects also include tachycardia, a condition wherein the heart rate gets extremely amplified for a short duration.
Cannabis products containing high amounts of THC should also not be accompanied by alcohol.
Pregnant and lactating women should consult a gynaecologist before consuming CBD products. Caution should also be maintained while administering THC-containing products to children and adolescents as it might affect their CNS differently.
To summarize, it can be said that CBD offers several neuroprotective benefits and helps in treating cerebrovascular disorders.
It prevents cerebral infarctions by restoring the blood supply in the cerebral arteries.
It prevents the inflammatory response and lowers atherosclerosis from developing in the blood vessels of the brain.
CBD not only treats ischaemic stroke but also prevents the development of secondary damage like hypoxia, hypotension, acidosis, and ischaemia.
It does so by combating oxidative stress brought about by free radicals and restoring the normal rate of blood flow to protect the brain tissue from reperfusion injury.
Finally, it prevents HI brain injury by re-establishing the normal supply of oxygen and nutrients across the brain.