Cannabis Medicinal Extracts
Among numerous cannabinoid compounds from plants belonging to the genus Cannabis, delta-9-tetrahydrocannabinol (THC) is known to have psychoactive effects while cannabidiol (CBD) is a non-psychoactive component that may have antioxidant and anti-inflammatory properties, as well as the ability to modulate the psychoactive effects of THC (Atakan 2012; Wade et al. 2003; Nabata et al. 2020).
More information about cannabis and SCI can be found in the SCIRE Cannabinoids chapter.
The use of cannabis medicinal extracts (CME) with SCI-related fatigue has not been widely researched yet. Only one RCT has investigated the use of CME through sublingual delivery and self-titration, its effect on neurological symptoms such as fatigue, and its potential side effects (Wade et al. 2003).
Discussion
In an RCT crossover, researchers explored the use of CME and their effect on neurological symptoms including fatigue, spasticity, pain, and bladder incontinence in participants with MS (N=18), SCI (N=4), brachial plexus damage (N=1), and limb amputation due to neurofibromatosis (N=1) (Wade et al. 2003). After two weeks of treatment, no significant differences in fatigue between the CME and placebo groups were observed (Wade et al. 2003). Conversely, all three groups of CME (THC, CBD, and 1:1 THC:CBD) showed significant improvements in spasticity, and both the THC and THC:CBD groups demonstrated significant improvements in muscle spasm frequency (Wade et al. 2003). A systematic review by Nabata et al. (2020) reported two other RCTs using cannabinoids in people with SCI and found improvements in spasticity, unfortunately neither study reported outcomes on fatigue (Hagenbach et al. 2007; Wilsey et al. 2016).
In other clinical populations, such as fibromyalgia, the use of cannabis for fatigue improvement has been understudied as well. Only one RCT showed that THC-rich cannabis oil provides better effects on fatigue scores than a placebo (olive oil) after eight weeks of intervention in 17 women with fibromyalgia (Chaves et al. 2020). In cancer, one follow-up study showed that the self-titration of THC/CBD or THC spray provided a decrease in fatigue, insomnia, or pain (Johnson et al. 2013). Overall, more research is needed to recommend the use of medical cannabis for fatigue in people with SCI.
Conclusions
There is level 1b evidence (from one RCT: Wade et al. 2003) that cannabis medicinal extracts (CME) had no significant effect on fatigue through sublingual delivery in people with neurological conditions, such as multiple sclerosis and SCI.
