Cannabidiol in low back pain: scientific rationale for clinical trials in low back pain

An update on animal models of intervertebral disc degeneration and low back pain: Exploring the potential of artificial intelligence to improve research analysis and development of prospective therapeutics

Animal models have been invaluable in the identification of molecular events occurring in and contributing to intervertebral disc (IVD) degeneration and important therapeutic targets have been identified. Some outstanding animal models (murine, ovine, chondrodystrophoid canine) have been identified with their own strengths and weaknesses. The llama/alpaca, horse and kangaroo have emerged as new large species for IVD studies, and only time will tell if they will surpass the utility of existing models. The complexity of IVD degeneration poses difficulties in the selection of the most appropriate molecular target of many potential candidates, to focus on in the formulation of strategies to effect disc repair and regeneration. It may well be that many therapeutic objectives should be targeted simultaneously to effect a favorable outcome in human IVD degeneration. Use of animal models in isolation will not allow resolution of this complex issue and a paradigm shift and adoption of new methodologies is required to provide the next step forward in the determination of an effective repairative strategy for the IVD. AI has improved the accuracy and assessment of spinal imaging supporting clinical diagnostics and research efforts to better understand IVD degeneration and its treatment. Implementation of AI in the evaluation of histology data has improved the usefulness of a popular murine IVD model and could also be used in an ovine histopathological grading scheme that has been used to quantify degenerative IVD changes and stem cell mediated regeneration. These models are also attractive candidates for the evaluation of novel anti-oxidant compounds that counter inflammatory conditions in degenerate IVDs and promote IVD regeneration. Some of these compounds also have pain-relieving properties. AI has facilitated development of facial recognition pain assessment in animal IVD models offering the possibility of correlating the potential pain alleviating properties of some of these compounds with IVD regeneration.

Intervertebral disc degeneration and how it leads to low back pain

The purpose of this review was to evaluate data generated by animal models of intervertebral disc (IVD) degeneration published in the last decade and show how this has made invaluable contributions to the identification of molecular events occurring in and contributing to pain generation. IVD degeneration and associated spinal pain is a complex multifactorial process, its complexity poses difficulties in the selection of the most appropriate therapeutic target to focus on of many potential candidates in the formulation of strategies to alleviate pain perception and to effect disc repair and regeneration and the prevention of associated neuropathic and nociceptive pain. Nerve ingrowth and increased numbers of nociceptors and mechanoreceptors in the degenerate IVD are mechanically stimulated in the biomechanically incompetent abnormally loaded degenerate IVD leading to increased generation of low back pain. Maintenance of a healthy IVD is, thus, an important preventative measure that warrants further investigation to preclude the generation of low back pain. Recent studies with growth and differentiation factor 6 in IVD puncture and multi-level IVD degeneration models and a rat xenograft radiculopathy pain model have shown it has considerable potential in the prevention of further deterioration in degenerate IVDs, has regenerative properties that promote recovery of normal IVD architectural functional organization and inhibits the generation of inflammatory mediators that lead to disc degeneration and the generation of low back pain. Human clinical trials are warranted and eagerly anticipated with this compound to assess its efficacy in the treatment of IVD degeneration and the prevention of the generation of low back pain.

Comparing Sublingual and Inhaled Cannabis Therapies for Low Back Pain: An Observational Open-Label Study

BACKGROUND AND OBJECTIVE

Medical cannabis is becoming an acceptable treatment modality in medicine, especially for pain relief. Concurrently, cannabis use is becoming more prevalent worldwide, a public demand-driven trend despite the lack of established scientific basis. This observational open-label study sought to investigate the effectiveness of cannabis therapy for alleviating low back pain symptoms.

METHODS

Two types of cannabis treatment modalities were sequentially administered to chronic low back pain patients. After an initial 1-month washout period (WO1), the first modality was cannabidiol (CBD)-rich sublingual extract treatment administered for 10 months. Following another washout period, the second modality, Δ⁹-tetrahydrocannabinol (THC)-rich smoked inflorescence (whole dried cannabis flowers) was administered for 12 months.

RESULTS

Enrolled in the study were 24 patients whose advanced imaging studies (i.e. computerized tomography or magnetic resonance imaging of the lumbar spine) revealed disc herniation or spinal stenosis. Three patients dropped out of extract therapy treatment but resumed study participation to receive THC-rich smoking therapy. After a minimum of 2 years, cannabis therapy had reduced lower back pain symptoms, as assessed by Oswestry Disability Index, the SF-12 patient-reported outcome questionnaire, and the visual analogue scale. Pain reduction was not significant during the extract treatment part of the study; however, pain reduction was significant during the inhaled therapy part of the study.

CONCLUSIONS

Our findings indicate that inhaled THC-rich therapy is more effective than CBD-rich sublingual extract therapy for treating low back pain and that cannabis therapy is safe and effective for chronic low back pain.

Observation of curative effect on meridian theory-based extracorporeal shock wave therapy for non-specific low back pain: study protocol for a randomized controlled trial

Background

Non-specific low back pain (NLBP) is a major global socioeconomic burden, and the prevalence of NLBP is still on the rise. At present, there is no ideal drug to cure this disease. This may be the reason why patients often use complementary therapies. Among them, extracorporeal shock wave therapy (ESWT) has gradually received more attention and has become the main treatment method for NLBP. The purpose of this study is to provide scientific evidence for the effect and safety of meridian theory-based ESWT on NLBP.

Objective

This study aims to evaluate the effect and safety of meridian theory-based ESWT on NLBP. This study will also provide more high-quality experimental evidence for the clinical application of meridian theory-based ESWT for the treatment of NLBP in future.

Methods

The study design is a single-blind, multi-center, randomized controlled trial. 66 patients with NLBP, aged 18 to 60 years, will be randomly divided into two groups: the experimental group (N = 33), which will receive meridian theory-based ESWT application, and the control group (N = 33) which will receive conventional ESWT treatment. These two applications will be carried out twice a week for two weeks. The primary outcome will be the Visual Analog Scale (VAS), and the secondary outcomes will be Oswestry Disability Index (ODI), Surface Electromyography (sEMG), and Patient Health Questionnaire-15 (PHQ-15). All outcomes will be evaluated at baseline and after the intervention (7 days, 14 days).

Discussion

Results of this trial will contribute to providing rigorous clinical evidence for the efficacy and security of meridian theory-based ESWT for NLBP.

Trial registration: Chinese Clinical Trial Registry, ChiCTR2100051049. Registered on 10 September 2021, http://www.chictr.org.cn/showproj.aspx?proj=46316.

Analyzing the Impact of Cannabinoids on the Treatment of Spinal Disorders

PURPOSE OF REVIEW

Cannabis is among the most used illicit substances globally, with medical applications, increased legalization, and shifting social attitudes leading to increased use in recent years. Cannabinoids are a group of psychoactive substances found within the cannabis plant, with the most common being Δ9-tetrahydrocannabinol and cannabidiol. Due to the high prevalence of use, it is increasingly important to evaluate the effects of cannabis and cannabinoids on spine patients, in both operative and nonoperative settings.

RECENT FINDINGS

Cannabis and cannabinoids may be effective in treating patients with chronic conditions such as back pain and spinal cord injuries. Longitudinal effects and implications on surgical outcomes and complications are poorly understood. High-quality, outcomes-focused research can inform approaches for clinicians to approach cannabis and cannabinoid use. Studies to elucidate the standardization of cannabis regimens can help develop guidelines for potential therapeutic applications. Cannabis and cannabinoids may be useful alternatives or additions for many spine patients, but future research is needed for recommendations to be determined. Our manuscript reviews the available literature regarding cannabis use and various spinal conditions, organizing our findings into the following narrative themes: (1) the management of chronic lower back pain, (2) perioperative outcomes, (3) cannabis use in general orthopaedic procedures, and (4) spinal cord injuries.

The Efficacy of Cannabis in Reducing Back Pain: A Systematic Review

OBJECTIVE

To critically analyze the evidence and efficacy of cannabis to treat surgical and nonsurgical back pain via a Systematic Review.

METHODS

We conducted a systematic review to investigate the efficacy of cannabis to treat non-surgical and surgical back pain. A literature search was performed with MEDLINE and Embase databases. Only RCTs and prospective cohort studies with concurrent control were included in this study. Risk of bias and quality grading was assessed for each included study.

RESULTS

Database searches returned 1738 non-duplicated results. An initial screening excluded 1716 results. Twenty-two full text articles were assessed for eligibility. Four articles ultimately met pre-determined eligibility and were included in the study. Two studies addressed post-SCI pain while other two studies addressed low back pain. No studies specifically examined the use of cannabis for surgical back pain. The type of cannabis varied between study and included THC, dronabinol, and Nabilone. A total of 110 patients were included in the four studies reviewed. In each study, there was a quantifiable advantage of cannabis therapy for alleviating back pain. There were no serious adverse effects reported.

CONCLUSIONS

In all articles, cannabis was shown to be effective to treat back pain with an acceptable side effect profile. However, long-term follow up is lacking. As medicinal cannabis is being used more commonly for analgesic effect and patients are "self-prescribing" cannabis for back pain, additional studies are needed for healthcare providers to confidently recommend cannabis therapy for back pain.

STUDY DESIGN

Systematic review.

Cannabis-Based Medicines and Medical Cannabis in the Treatment of Nociplastic Pain

Nociplastic pain is defined as pain due to sensitization of the nervous system, without a sufficient underlying anatomical abnormality to explain the severity of pain. Nociplastic pain may be manifest in various organ systems, is often perceived as being more widespread rather than localized and is commonly associated with central nervous system symptoms of fatigue, difficulties with cognition and sleep, and other somatic symptoms; all features that contribute to considerable suffering. Exemplified by fibromyalgia, nociplastic conditions also include chronic visceral pain, chronic headaches and facial pain, and chronic musculoskeletal pain. It has been theorized that dysfunction of the endocannabinoid system may contribute to persistent pain in these conditions. As traditional treatments for chronic pain in general and nociplastic pain in particular are imperfect, there is a need to identify other treatment options. Cannabis-based medicines and medical cannabis (MC) may hold promise and have been actively promoted by the media and advocacy. The medical community must be knowledgeable of the current evidence in this regard to be able to competently advise patients. This review will briefly explain the understanding of nociplastic pain, examine the evidence for the effect of cannabinoids in these conditions, and provide simplified guidance for healthcare providers who may consider prescribing cannabinoids for these conditions.