Medical Cannabis and Stroke or Traumatic Brain Injury (TBI)
Traumatic brain injuries (TBIs) and strokes are two different conditions, but both involve brain neurotoxicity and cell death, so treatment has similarities. Medical cannabis contains several phytocannabinoids (plant cannabinoids) with antioxidant, neuroprotective, and possible neurogenic properties.
What is Stroke/Traumatic Brain Injury?
A stroke is caused by a blockage of blood flow or rupture of an artery, leading to a lack of oxygen to brain cells and cell death. Common symptoms include sudden loss of speech, weakness, or paralysis of one side of the body. Every year, more than 795,000 people in the United States have a stroke. Smoking, cardiovascular diseases (CVDs), high cholesterol, high blood pressure, obesity, and diabetes are leading causes of stroke.
Traumatic brain injury (TBI) is a nondegenerative, non-congenital condition caused by external mechanical force to the head. This can lead to temporary or permanent impairment of physical, mental, and psychosocial functions. The CDC estimates that about 1.5 million Americans survive a TBI every year, with approximately 230,000 hospitalized and a mortality of 3% across all TBI severities. Those involved in professions and activities like athletics, construction, or working in the military or emergency services are at greater risk of suffering a TBI.
Those managing a TBI share nerve pain (neuropathy) and headaches. Post-traumatic stress disorder (PTSD) is a high-risk factor in those with a TBI. TBIs can cause long-term physical, emotional, and cognitive problems.
Strokes and TBIs may increase glutamate neurotoxicity in the brain. Glutamate (glutamic acid) is an excitatory neurotransmitter abundant throughout the brain and nervous system, and it is necessary for various functions, including metabolism, learning, and memory. However, when glutamate builds up in the brain, it can lead to stroke.
Brief Summary of Current Treatments
Although most cases of TBI are mild and can be overcome with rest, ice packs, and over-the-counter drugs like acetaminophen (Tylenol, paracetamol) or ibuprofen (Advil, Nurofen), it is still essential to keep an eye on symptoms like worsening headaches, blurred vision, an increase in fatigue and extreme sleepiness.
More long-term and severe instances of TBI (as well as stroke, which could be seen as a subset of TBI to some extent) may require treatments such as:
- Surgery, such as carotid endarterectomy or craniotomy
- Rehabilitation, including physical, occupational, and speech therapy
Medications for TBI include:
- Sedative agents like benzodiazepines and barbiturates reduce pressure in the brain (intracranial pressure)
- Anticonvulsants like gabapentin for nerve pain
- Diuretics to drain excess cerebrospinal fluid and reduce intracranial pressure
- Magnesium improves blood flow in the brain and maintains a stable state (homeostasis) in the brain
Medications for strokes can include:
- Alteplase, which is a clot-busting medication
- Blood-thinners like aspirin and clopidogrel
- Anticoagulants like warfarin and apixaban
- Blood pressure medications like beta-blockers and angiotensin-converting enzyme (ACE) inhibitors
- Statins like atorvastatin (Lipitor), pravastatin (Lipostat) and simvastatin (Zocor) to reduce cholesterol
Lifestyle changes like exercise and following a flavonoid-rich diet may also be recommended.
How Might Medical Cannabis Help?
There is mixed evidence on cannabis and whether or not it can cause strokes or help manage the aftereffects of suffering one. Several studies show a correlation between the use of cannabis (in particular smoking it) and the likelihood of suffering a stroke, but, as they say, correlation does not necessarily mean causation. There are many factors to account for, including diet, tobacco smoking, and previous TBIs. Similarly, several studies show that cannabinoids like cannabidiol (CBD) and cannabigerol (CBG) have neuroprotective effects that could help treat acute brain damage. The roots of the cannabis plant also contain a type of phytosterol that may help lower cholesterol, called beta-sitosterol.
There is also a not-insignificant amount of scientific research into the use of cannabinoids to treat TBIs and chronic traumatic encephalopathy (CTE, previously known as dementia pugilistica or “punch-drunk syndrome”), as cannabinoids such as CBD may help protect the brain from neuroinflammation. Several cannabinoids, including tetrahydrocannabinol (THC) and CBD, may help prevent dangerous amounts of glutamate from forming, potentially preventing further brain damage. THC may do this by depressing glutamate transmission.
- CBD, CBG, and CBC may help protect the brain.
- Cannabidiolic acid (CBDA), tetrahydrocannabinolic acid (THCA), and cannabidivarin (CBDV) may also be helpful for their anti-inflammatory and antioxidant properties.
- THC may be helpful for its analgesic and sedative properties.
- THC:CBD 1:20
- THC:CBD 1:3
- THC:CBD 1:2
- THC:CBD 1:1
- THC:CBD 2:1
Terpenes and Terpenoids
Effective Ways of Taking Medical Cannabis for Stroke/Traumatic Brain Injury
Routes of Administration
- Inhalation (especially for TBI patients)
A product rich in terpenes may be ideal. Some may prefer CBD-rich formulations, others THC-rich ones. Cannabinoids like CBD, CBG, and CBC may be useful for their ability to promote neurogenesis.
What are the Pros and Cons of Taking Medical Cannabis for Stroke/Traumatic Brain Injury?
- CBD could prevent infarction and cerebral infarction via the non-CB1 cannabinoid receptor mechanism.
- Phytocannabinoids may be neuroprotective and help prevent an overabundance of glutamate from forming.
- Some studies show an increase in the likelihood of stroke among cannabis users. Many of these dangers may be related to smoking cannabis, but this could hold regardless of the administration route, as THC can increase heart rate.
- High doses of THC may have adverse effects on short-term memory and balance.
Useful Anecdotal Information
- “Using Marijuana to Treat Traumatic Brain Injuries.” CBS Denver, Dec. 6, 2018
- “Former NFL player promotes CBD use for CTE, brain injuries in athletes.” First Coast News, Sep. 27 2019
Scientific Data Overview and Studies
- Total Studies = 56
- Positive Studies = 47
- Inconclusive Studies = 4
- Negative Studies = 5
- 22 Meta-Analyses (14 positive, 3 inconclusive, 5 negative); 30 Animal Studies (29 positive, 1 inconclusive); 2 Double-Blind Human Trials (both positive); 2 Lab Studies (both positive)
- 17 studies include CBD (all positive); 7 studies include THC (all positive)
- Possible Overall Efficacy: Moderate
TBI and CTE
- Total Studies = 24
- Positive Studies = 23
- Inconclusive Studies = 1
- Negative Studies = 0
- 12 Meta-Analyses (all positive); 10 Animal Studies (all positive); 1 Double-Blind Human Trials (inconclusive); 1 Lab Study (positive)
- 5 studies include CBD (all positive); 2 studies include THC (both positive)
- Possible Overall Efficacy: Moderate
Quotes from Studies
“Pre-clinical TBI research suggests that cannabinoids have neuroprotective and psychotherapeutic properties. In contrast, recreational cannabis use has consistently shown to have detrimental effects. Our review identified a paucity of high-quality studies examining the beneficial and adverse effects of medical cannabis on TBI, with only a single phase III randomized control trial. However, observational studies demonstrate that TBI patients are using medical and recreational cannabis to treat their symptoms, highlighting inconsistencies between public policy, perception of potential efficacy, and the dearth of empirical evidence.”
Source: Hergert DC, Robertson-Benta C, Sicard V, Schwotzer D, Hutchison K, Covey DP, Quinn DK, Sadek JR, McDonald J, Mayer AR. “Use of Medical Cannabis to Treat Traumatic Brain Injury“. J Neurotrauma. 2021 Jul 15;38(14):1904-1917. doi: 10.1089/neu.2020.7148. Epub 2021 Jan 25. PMID: 33256496; PMCID: PMC8260892.
“…[T]he endocannabinoid system possesses potential drugable receptor and enzyme targets for the treatment of diverse TBI pathology. Yet, full characterization of TBI-induced changes in endocannabinoid ligands, enzymes, and receptor populations will be important to understand that role this system plays in TBI pathology. Promising classes of compounds, such as the plant-derived phytocannabinoids, synthetic cannabinoids, and endocannabinoids, as well as their non-cannabinoid receptor targets, such as TRPV1 receptors, represent important areas of basic research and potential therapeutic interest to treat TBI.”
Source: Schurman LD, Lichtman AH. “Endocannabinoids: A Promising Impact for Traumatic Brain Injury“. Front Pharmacol. 2017;8:69. Published 2017 Feb 17. doi:10.3389/fphar.2017.00069
There is good preclinical and anecdotal evidence that medical cannabis could be helpful in the management of symptoms associated with both strokes and traumatic brain injuries. However, more clinical trials are needed.
Please note: the information in this article does not constitute medical advice.
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