Complex Regional Pain Syndrome (CRPS) is a severe, chronic pain condition that can be difficult to treat. The pain associated with CRPS is caused by physical trauma, but the pain experienced is often disproportionate to the initial injury and can persist long after the expected healing time. There are often limited therapeutic options for individuals with CRPS. This leaves many patients with few options and a significant need for new therapeutic approaches.
The cause of CRPS is not fully understood; however, it is believed to be the result of the body responding abnormally to trauma. Current figures suggest that 5 in 10,000 people in the UK are affected by the condition; however, as the condition is commonly underdiagnosed or misdiagnosed, the true figure may be significantly higher.
Current Treatments for Complex Regional Pain Syndrome
Current pharmacological therapies for CRPS include non-steroidal anti-inflammatory drugs (NSAIDs), gabapentinoids, antidepressants, and opioids. Despite their wide use, there is a paucity of high-quality evidence supporting the long-term safety and efficacy of these for CRPS.
Current estimates suggest that 20-40% of patients with CRPS experience pain refractory to first-line pharmacological therapies. This highlights the urgent need for novel treatments for chronic pain secondary to CRPS.
Medical Cannabis and Complex Regional Pain Syndrome
Interest in the endocannabinoid system (ECS) as a target for CRPS has been growing in recent years. In particular, THC and CBD – the most common cannabinoids produced by the cannabis plant – have been increasingly researched in the setting of chronic pain. However, while preclinical data are promising, there is a lack of high-quality evidence evaluating the safety and efficacy of medical cannabis for chronic pain, and specifically CRPS.
The UK Medical Cannabis Registry
Since it was established by Curaleaf Clinic in 2019, over 40,000 patients have contributed to the UK Medical Cannabis Registry. The registry was designed to gather real-world data from patients prescribed CBMPs for a wide range of conditions by recording patient-reported outcome measures and adverse events.
A recent study, published in Brain and Behaviour, has analysed clinical outcomes for 64 patients with CRPS who were prescribed medical cannabis, captured through the UK Medical Cannabis Registry. This research marks the first time a clinical study has focused specifically on the effects of medical cannabis in individuals with CRPS.
What Did the Study Investigate?
This was a case series study, which means it followed a group of patients to observe how they reported changes in their outcomes over time. The study included 64 patients with a primary diagnosis of CRPS and analysed data collected over a six-month period.
The researchers looked at changes in patient-reported outcome measures, which are surveys used to measure a patient’s own perspective on their health. These measures focused on:
- Pain severity and how much pain interfered with daily life.
- Anxiety symptoms and sleep quality.
- General health-related quality of life.
The study also tracked and graded any reported adverse events.
Key Findings from the Analysis
The results from the UK Medical Cannabis Registry data showed several interesting outcomes:
- Pain: Patients reported changes in pain severity and interference with daily activities, which were sustained over the six-month follow-up period.
- Quality of Life: In addition to pain, participants also reported changes in other important areas, including anxiety, sleep, and general health-related quality of life. This is a notable finding, as CRPS is known to have a significant negative impact on quality of life.
- Adverse Events: Adverse events were reported by five out of 64 participants. The most common adverse events were nausea and headache.
It is important to note that this was an observational study and cannot prove that medical cannabis was the direct cause of these changes. However, the findings do suggest a potential association between starting medical cannabis treatment and these outcomes for patients with CRPS.
The Importance of Real-World Evidence
This study highlights the importance of real-world evidence in medical research. While traditional randomised controlled trials are considered the gold standard, they can be difficult to conduct for rare conditions like CRPS. Real-world data from registries like the UK Medical Cannabis Registry can provide valuable insights in a diverse, real-life patient population.
By collecting and analysing this data, we can start to build a clearer picture of medical cannabis’s potential. This information is crucial for guiding clinical practice and helping to inform the larger, high-quality randomised controlled trials that are needed to confirm these findings and advance patient access.
Thank You to Our Patients
We would like to extend our sincerest gratitude to the patients who have signed up for the Curaleaf Access Scheme and contributed their data to the UK Medical Cannabis Registry. Your participation is invaluable. By sharing your experiences, you are directly helping to build the evidence base that drives forward research and improves our understanding of medical cannabis for everyone.
Disclaimer: This blog post is for informational purposes only and is based on a specific clinical study. It is not medical advice. The efficacy and safety of medical cannabis have not been established. Patients should always consult a qualified healthcare professional before making any decisions about their treatment.
