Neuropathic pain (also called nerve pain), is a common type of persistent chronic pain which is caused by issues with the nervous system such as nerve disease or nerve damage. The nervous system is a complex collection of nerves that allows our bodies to communicate with the outside world. It does this by taking in information through our senses, processing it and triggering reactions, such as making your muscles move or causing you to feel pain. For example, if we touch something hot with our hand, our automatic reflex will be to move away and let go; our nerves having sent pain signals to the brain. It is through the nervous system that we feel texture, pressure, pain, temperature and movement; nerves providing the electrical wiring that transmits these signals to the brain.
The nervous system is made up of two parts, the central nervous system and the peripheral nervous system. The central nervous system (CNS) includes the nerves in the brain and spinal cord whereas all other nerves in the body are part of the peripheral nervous system (PNS).
When this system is damaged in some way, it can cause nerve pain. The pain experienced is often described as a burning, shooting or stabbing sensation. There are copious conditions and causes that can bring on neuropathic pain that ranges from injury to the brain, spine or nerves, to cancer, diabetes and infections like shingles.
Nerve pain is notoriously hard to treat, and nerve pain patients are often prescribed strong steroid anti-inflammatories, antiepileptic drugs, or opioid-based medications, which we know can be dangerous. Could therapeutic compounds of cannabis prove to be a superior alternative to strong and potentially addictive pain relief?
Can cannabis help with nerve pain?
Back in 2013, a study undertaken in California evaluated the analgesic efficacy of vaporized cannabis in subjects who were experiencing neuropathic pain despite traditional treatment. Results showed that cannabis did offer significant pain relief, but it appeared likely that this relief was short term and wouldn’t have a consequential impact on the daily management of nerve pain.
The reason that experts are optimistic about cannabis’s potential to help with nerve pain is because it has been established that the endocannabinoid system plays an essential role in regulating neuroplasticity (the brain’s ability to adapt) and homeostasis (the process that allows the body to reach and maintain a state of equilibrium) of the central nervous system. The endocannabinoid system also helps to regulate pain transmission in the nerve pathways.
Endocannabinoids are molecules made by our bodies and they benefit us by helping to keep internal functions running smoothly. Our bodies also are made up of endocannabinoid receptors. The endocannabinoids that we naturally produce bind to receptors in order to signal that the endocannabinoid system needs to take action. There are two main endocannabinoid receptors: CB1 receptors, mainly in the central nervous system and CB2 receptors, found in your peripheral nervous system. Our endocannabinoids will bind to different receptors to assist with reducing pain. As cannabis compounds such as CBD bind to both CB1 and CB2 receptors, they can help activate receptors and provide therapeutic benefits, one of which may be pain management.
A 2014 study published in the Journal of Neurology assessed the long-term maintenance of effect, tolerance and safety of THC/CBD oromucosal spray in the management of neuropathic pain in 380 patients and deduced that ‘THC/CBD spray was beneficial for the majority of patients with PNP associated with diabetes or allodynia.’
Whilst thorough and incontestable evidence is yet to be presented, the research undertaken so far is looking promising.
Some exciting recent news which should lead to more concrete answers regarding cannabis as a treatment for nerve pain was recently announced: the Dutch government is supporting research into the use of medicinal cannabis in the treatment of neuropathic pain with a €1.9 million grant. The grant has been awarded to a joint project of the Centre for Human Drug Research (CHDR), a Dutch independent institute that specializes in clinical drug research, and the Leiden University Medical Center (LUMC). Neurologist Geert Jan Groeneveld will be conducting the research and commented on the study which will begin in spring this year: ‘We are going to isolate the THC and CBD from Bedrocan cannabis and administer them in tablet form in different proportions. We will then look at the influence of CBD on the effects of THC, and investigate which THC-CBD combination is best for the treatment of neuropathic pain.’
Like most of the conditions that CBD and THC have been touted as likely to benefit, we are still waiting for further research before knowing if cannabis can aid with neuropathic pain. Upcoming trials are expected to deliver evidence over the next few years which will give us a much stronger understanding of whether cannabis is a viable option to seriously manage pain caused by damage or injury to the nerves.
Each day scientists are expanding their understanding of how cannabis compounds interact with the body’s endocannabinoid system to produce a variety of therapeutic benefits. As it stands, there is still a lack of solid evidence to show that cannabis-derived products work for any chronic nerve pain and further long-term studies in humans are needed.