Spasticity from neurological conditions

Spasticity is a common symptom of many neurological conditions, including multiple sclerosis (MS), spinal cord injury, cerebral palsy, and other conditions that affect the central nervous system. Spasticity is characterized by increased muscle tone, muscle stiffness, and involuntary muscle contractions, which can result in pain, discomfort, and reduced mobility. Conventional treatment options for spasticity include physical therapy, muscle relaxants, and other medications, but these may not always provide adequate relief for all patients. As a result, there has been growing interest in exploring the potential use of medical cannabis as an alternative or adjunctive treatment for spasticity associated with neurological conditions. In this review, we will discuss the available evidence on how research indicates medical cannabis may work in treating spasticity from neurological conditions.

The endocannabinoid system (ECS) is a complex cell-signaling system that plays a crucial role in regulating various physiological processes, including pain, inflammation, immune response, and muscle tone. The ECS consists of three main components: endocannabinoids (endogenous cannabinoids), receptors, and enzymes. Endocannabinoids are naturally occurring compounds that are similar in structure to cannabinoids found in cannabis, and they bind to cannabinoid receptors to modulate various physiological functions. There are two main types of cannabinoid receptors: CB1 receptors, which are primarily found in the central nervous system (CNS), and CB2 receptors, which are mainly found in the immune system and peripheral tissues.

Cannabis contains more than 100 different cannabinoids, including delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), which are the most well-known and studied cannabinoids. THC is the psychoactive compound in cannabis responsible for its euphoric effects, while CBD is non-psychoactive and has been shown to have various potential therapeutic properties. Both THC and CBD have been studied for their effects on spasticity associated with neurological conditions.

Research indicates that cannabinoids may work in treating spasticity through their interactions with the ECS. Activation of CB1 receptors in the CNS by cannabinoids, particularly THC, has been shown to modulate the release of neurotransmitters involved in muscle tone regulation, such as gamma-aminobutyric acid (GABA) and glutamate. GABA is an inhibitory neurotransmitter that helps to reduce neuronal activity and muscle tone, while glutamate is an excitatory neurotransmitter that increases neuronal activity and muscle tone. By modulating the release of GABA and glutamate, cannabinoids may help to reduce muscle stiffness and spasticity.

In addition to their effects on neurotransmitters, cannabinoids also have anti-inflammatory properties, which may contribute to their effects on spasticity. Inflammation is a common feature of many neurological conditions, and it can contribute to increased muscle tone and spasticity. Cannabinoids, particularly CBD, have been shown to reduce inflammation by inhibiting the production of pro-inflammatory cytokines and other inflammatory mediators. This anti-inflammatory effect of cannabinoids may help to reduce muscle inflammation, thereby alleviating spasticity.

Moreover, cannabinoids have been shown to have analgesic properties, which may further contribute to their potential effects on spasticity. Pain is often associated with spasticity, and it can exacerbate the discomfort and reduced mobility caused by spasticity. THC has been shown to have analgesic effects by binding to cannabinoid receptors in the spinal cord and brain, reducing the transmission of pain signals. CBD has also been shown to have analgesic properties by interacting with receptors involved in pain modulation, such as transient receptor potential (TRP) channels.

Furthermore, cannabinoids may also have anxiolytic properties, which may help to alleviate anxiety and stress associated with spasticity. Spasticity can cause discomfort, anxiety, and stress, which can further worsen the symptoms and impact the quality of life of individuals with neurological conditions. Research suggests that cannabinoids, particularly CBD, may have anxiolytic properties by interacting with serotonin receptors in the brain and regulating the release of serotonin, a neurotransmitter that plays a role in mood regulation. This may help to reduce anxiety and stress, potentially improving the overall well-being of individuals with spasticity.

Additionally, cannabinoids may also have neuroprotective properties, which may be beneficial in neurological conditions associated with spasticity. Neurodegenerative conditions such as multiple sclerosis and spinal cord injury can result in nerve damage and inflammation, leading to increased muscle tone and spasticity. Research indicates that cannabinoids, particularly CBD, may have neuroprotective effects by reducing oxidative stress, inflammation, and excitotoxicity, which can contribute to nerve damage. These neuroprotective properties of cannabinoids may help to preserve nerve function and reduce the severity of spasticity in individuals with neurological conditions.

Moreover, cannabinoids may also modulate the immune response, which may be relevant in autoimmune conditions associated with spasticity, such as multiple sclerosis. Multiple sclerosis is an autoimmune disease in which the immune system mistakenly attacks the myelin sheath, the protective covering of nerve fibers, leading to nerve damage and inflammation. Research suggests that cannabinoids, particularly CBD, may have immunomodulatory effects by reducing the production of pro-inflammatory cytokines and other immune mediators. This may help to attenuate the autoimmune response, reduce inflammation, and subsequently alleviate spasticity in individuals with multiple sclerosis.

Clinical evidence on the use of medical cannabis for treating spasticity associated with neurological conditions is still limited, and more research is needed to fully understand its safety and efficacy. However, some studies have shown promising results. For example, a randomized controlled trial published in the journal Annals of Neurology in 2012 evaluated the effects of oral cannabis extract containing THC and CBD on spasticity in individuals with multiple sclerosis. The study found that the cannabis extract significantly reduced spasticity compared to placebo, with a favorable side effect profile. Another randomized controlled trial published in the journal JAMA Network Open in 2018 investigated the effects of nabiximols, a cannabinoid-based oromucosal spray containing THC and CBD, on spasticity in individuals with multiple sclerosis. The study found that nabiximols significantly reduced spasticity compared to placebo, with mild to moderate adverse events.

In addition to clinical trials, there are also several observational studies, case reports, and patient surveys that suggest potential benefits of medical cannabis in treating spasticity associated with neurological conditions. For example, a survey-based study published in the journal European Neurology in 2013 evaluated the use of cannabis in individuals with multiple sclerosis and reported that the majority of participants perceived improvement in spasticity and other symptoms. Similarly, a study published in the journal Clinical Rehabilitation in 2017 assessed the effects of medical cannabis on spasticity and quality of life in individuals with multiple sclerosis and found that medical cannabis was associated with significant improvements in spasticity and quality of life.

It's important to note that the optimal dosage, formulation, and administration of medical cannabis for spasticity may vary depending on the individual, the specific neurological condition, and other factors. Different strains of cannabis with varying THC and CBD content, as well as different routes of administration (such as oral, inhalation, or topical), may have different effects on spasticity and may require individualized dosing. Moreover, potential side effects of medical cannabis, such as drowsiness, dizziness, dry mouth, and cognitive impairment, should also be considered and monitored closely, particularly in elderly individuals or those with other health conditions.

In conclusion, research indicates that medical cannabis may hold promise in the treatment of spasticity associated with neurological conditions. The complex interactions between cannabinoids and the endocannabinoid system, as well as their effects on inflammation, oxidative stress, immune modulation, and neuroprotection, suggest that cannabinoids, particularly CBD, may have potential therapeutic benefits in reducing spasticity and improving the quality of life for individuals with neurological conditions.

However, it is important to note that the evidence on the use of medical cannabis for spasticity is still limited and further research is needed to fully understand its safety and efficacy. Clinical trials with larger sample sizes, standardized dosing regimens, and longer-term follow-up are warranted to establish the optimal use of medical cannabis for spasticity. Additionally, more research is needed to determine the long-term safety profile of medical cannabis, particularly in vulnerable populations such as pregnant women, elderly individuals, and those with comorbidities.

Moreover, medical cannabis should be used as part of a comprehensive treatment plan that includes regular monitoring and assessment by qualified healthcare professionals. The use of medical cannabis should be based on an individualized approach, taking into consideration the specific needs and characteristics of each patient, and should be accompanied by appropriate patient education and counseling on potential risks, benefits, and limitations of medical cannabis.

Furthermore, the legal and regulatory landscape surrounding medical cannabis varies across different jurisdictions, and healthcare professionals and patients should be aware of the local laws and regulations regarding the use of medical cannabis for spasticity. It is important to ensure that medical cannabis is obtained from reputable sources, with proper quality control measures in place, and that patients are aware of the potential risks of using unregulated cannabis products.

In summary, while research suggests that medical cannabis may have potential therapeutic benefits in treating spasticity associated with neurological conditions, more research is needed to establish its safety and efficacy. Medical cannabis should be used as part of a comprehensive treatment plan under the guidance of qualified healthcare professionals, and in compliance with local laws and regulations. Further research and clinical trials are warranted to better understand the optimal use of medical cannabis for spasticity and its potential benefits in improving the quality of life for individuals with neurological conditions.