Clinical perspectives on medical marijuana (cannabis) for neurologic disorders

Therapeutic use of medical Cannabis in neurological diseases: a clinical update

The use of medical Cannabis has increased in recent years due to changing legal circumstances in many countries. Approval exists only for a few neurological conditions such as rare forms of epilepsy or spasticity in multiple sclerosis. Beyond that, however, medical Cannabis is used for a wide range of neurological conditions and symptoms. In Germany, in parallel with new legislation that has simplified the prescription of medical Cannabis, an accompanying survey has been implemented for which initial data are now available. In this context, our review provides an overview of the evidence for the therapeutic use of medical Cannabis in neurology, the potential benefits, and side effects.

Marijuana use and post-transplant complications and non-compliance in liver transplant patients

BACKGROUND

Liver transplant (LT) is a lifesaving treatment for patients with end stage liver disease. Historically, institutions across the United States have deemed active marijuana use as an exclusion criterion for listing. This study aims to investigate LT outcomes in patients with history of marijuana use prior to LT.

METHODS

We performed a retrospective review of 111 patients who tested positive for marijuana on urine drug screen during initial LT evaluation between February 2016 and January 2021. 100 non-marijuana users who underwent LT were cross matched for control. Patient demographics, substance use history, and transplant decisions were recorded. Post-LT variables were also collected up to 1 year post surgery including postoperative infections, issues with non-compliance, and continued substance use. Chi-square analysis was used to assess the association between pre-transplant marijuana use and post-transplant complications. Logistics regression was implemented to measure associations amongst the entire cohort.

RESULTS

From 111 marijuana users, 32 (29%) received a transplant. There was no statistical difference in post-LT outcomes between marijuana and non-marijuana users, including incidence of cardiac, respiratory, renal, psychiatric, or neurological complications, as well as readmission rates post-surgery. There were no statistically significant associations between marijuana use with post-transplant bacterial or fungal infections, medication non-compliance, or continued substance use (all p>0.05). Marijuana use was associated with pre-LT tobacco use (p = 0.020).

CONCLUSIONS

Our data indicates that marijuana is not associated with increased risk of postoperative noncompliance, other organ complications, infections, or death. As a single factor, marijuana may not need to be a contraindication for LT.

Efficacy and safety of therapeutic use of cannabis derivatives and their synthetic analogs: Overview of systematic reviews

The debate on the use of cannabinoids for therapeutic purposes is constantly on the rise. This overview aimed to map the evidence on the therapeutic effects of cannabis derivatives and their synthetic analogs. Systematic reviews (SRs) of randomized trials were identified through a comprehensive search in several databases, and their methodological quality were evaluated with AMSTAR-2. The results for main outcomes are presented, prioritizing those from updated and better quality SRs. Finally, 68 SRs, addressing 37 different health conditions, were included. The methodological quality was high for eight SRs. The evidence certainty (GRADE) for the effects of cannabinoids is not high for any of the outcomes identified. Evidence certainty was moderate for the following: (a) cannabidiol appears to be beneficial for quality of life but increases the risk of adverse events in ulcerative colitis; (b) cannabinoids in general appear to have no clinically important benefit for chronic non-oncologic pain, spasticity-related pain in multiple sclerosis, or for acute post-operative pain; (c) cannabinoids in general appear to have a benefit in reducing chemotherapy-related nausea and vomiting. For all other outcomes from remaining comparisons, the evidence certainty was low, very low, or not evaluated, which prevents recommendations for or against their routine use.

Clinical Profiles of Concurrent Cannabis Use in Chronic Pain: A CHOIR Study

OBJECTIVE

Despite evidence of the analgesic benefits of cannabis, there remains a relative scarcity of research on the short- and long-term effects of cannabis use in individuals with chronic pain.

DESIGN

The current study is a secondary analysis of clinical data from the Collaborative Health Outcomes Information Registry (CHOIR).

SETTING

Data were drawn from a cohort of patients of a multidisciplinary tertiary care pain clinic.

SUBJECTS

The study sample consisted of data from 7,026 new patient visits from CHOIR; of these, 1,668 patients with a follow-up time point within 180 days were included in a longitudinal analysis.

METHODS

Clinical data were analyzed to characterize cross-sectional differences in pain and indicators of psychological and physical function according to self-reported, concurrent cannabis use. Additionally, a propensity score-weighted longitudinal analysis was conducted, examining cannabis use as a predictor of changes in clinical variables across time.

RESULTS

Cross-sectional analyses suggested significantly poorer sleep and significantly higher intensities of pain, emotional distress, and physical and social dysfunction in patients reporting ongoing cannabis use; however, these differences were relatively small in magnitude. However, no differences between cannabis users and nonusers in terms of longitudinal changes in clinical variables were noted.

DISCUSSION

Our results are among the first to examine concurrent cannabis use as a prognostic variable regarding trajectories of pain-related variables in tertiary care. Future studies may benefit from examining the effect of cannabis initiation, concurrent medication use, and specific aspects of cannabis use (dose, duration of use, or cannabis type) on clinical outcomes.

Use of cannabis in patients with multiple sclerosis from Argentina

BACKGROUND

The use of cannabis to treat some symptoms of neurological diseases, including multiple sclerosis (MS), has increased worldwide. We aimed to assess the use of cannabis in patients with MS (PwMS) from Argentina, its reasons and patients' perceptions on the management of MS symptoms. Additionally, we assessed their association with socio-demographic and clinical aspects.

METHODS

A cross-sectional online survey that included 281 PwMS from Argentina was conducted. Screening instruments: Demographics and clinical data, health-related QoL (MS Impact Scale-29), Fatigue Severity Scale, The Hospital Anxiety and Depression Scale, sleep disorders, physical disability (self-administrated Expanded Disability Status Scale) and medical or recreational cannabis use were evaluated. A logistic regression model was carried out.

RESULTS

Current users (cannabis was used within the past year) was reported in 34.2% and former users (had tried cannabis but not used it within the past year) in 22.7%. Daily cannabis use was reported in 31.3% (current + former users) of the studied cohort, 41.9% started their use after MS diagnosis and 54.3% of them had never discussed about cannabis use with their neurologist. Recreational use was reported in 47.5%. Younger (age below 30 years) PwMS (OR = 2.39, p = 0.03), presence of chronic pain (OR = 2.42, p = 0.002) and current alcohol intake (OR = 3.33, p = 0.001) were predictors of current cannabis use in our multivariate model.

CONCLUSION

A high prevalence of use of cannabis in PwMS from Argentina was observed. Demographic, symptoms and lifestyle factors predict cannabis use. Identifying the presence and severity of these conditions would contribute to a better MS management and treatment.

Cannabinoid-Based Medicines and Multiple Sclerosis

The emerging role of the endocannabinoid system (ECS) in the control of symptoms and disease progression in multiple sclerosis (MS) has been highlighted by recent studies. MS is a chronic, immune-mediated, and demyelinating disorder of the central nervous system with no cure so far. It is widely reported that cannabinoids might be used to control MS symptoms and that they also might exert neuroprotective effects and slow down disease progression. The aim of this chapter is to give an overview of the main endogenous and synthetic cannabinoids used for the symptomatic amelioration of MS and their beneficial outcomes, providing new possible perspectives for the treatment of this disease.

Deleterious Effects of Ethanol, Δ(9)-Tetrahydrocannabinol (THC), and Their Combination on the Spatial Memory and Cognitive Flexibility in Adolescent and Adult Male Rats in the Barnes Maze Task

Research demonstrates that adolescents differ from adults in their response to drugs of abuse. The aim of the present study was to examine the influence of ethanol, Δ9-tetrahydrocannabinol hydrochloride (THC), and a combination of these drugs given during adolescence on spatial memory in adolescent and adult rats. Thus, adolescent rats (postnatal day (PND) 30) were subjected to the following groups: 0.9% NaCl; 1.5 g/kg ethanol; 1.0 mg/kg THC; 1.5 g/kg ethanol + 1.0 mg/kg THC. Rats received drug injection four times at three-day intervals. One day after the last injection, half of the treated animals were tested in the Barnes maze task, whereas the remaining animals were tested on PND 70. Results show that there was a significant age effect on spatial memory in the Barnes maze task after these drug administrations. Adolescent animals demonstrated more potent deficits in the spatial learning and memory (probe trial) and in cognitive flexibility (reversal learning) than did adults. However, in adult rats that received these drugs in adolescence, memory decline was observed only after ethanol and ethanol + THC administration. Thus, our results are important in understanding the deleterious impact of THC and/or ethanol abuse during adolescence on memory function across the lifespan (adolescent versus adult).

DNA Damaging Effects, Oxidative Stress Responses and Cholinesterase Activity in Blood and Brain of Wistar Rats Exposed to Δ9-Tetrahydrocannabinol

Currently we are faced with an ever-growing use of Δ9-tetrahydrocannabinol (THC) preparations, often used as supportive therapies for various malignancies and neurological disorders. As some of illegally distributed forms of such preparations, like cannabis oils and butane hash oil, might contain over 80% of THC, their consumers can become intoxicated or experience various detrimental effects. This fact motivated us for the assessments of THC toxicity in vivo on a Wistar rat model, at a daily oral dose of 7 mg/kg which is comparable to those found in illicit preparations. The main objective of the present study was to establish the magnitude and dynamics of DNA breakage associated with THC exposure in white blood and brain cells of treated rats using the alkaline comet assay. The extent of oxidative stress after acute 24 h exposure to THC was also determined as well as changes in activities of plasma and brain cholinesterases (ChE) in THC-treated and control rats. The DNA of brain cells was more prone to breakage after THC treatment compared to DNA in white blood cells. Even though DNA damage quantified by the alkaline comet assay is subject to repair, its elevated level detected in the brain cells of THC-treated rats was reason for concern. Since neurons do not proliferate, increased levels of DNA damage present threats to these cells in terms of both viability and genome stability, while inefficient DNA repair might lead to their progressive loss. The present study contributes to existing knowledge with evidence that acute exposure to a high THC dose led to low-level DNA damage in white blood cells and brain cells of rats and induced oxidative stress in brain, but did not disturb ChE activities.

Cannabis Therapeutics and the Future of Neurology

Neurological therapeutics have been hampered by its inability to advance beyond symptomatic treatment of neurodegenerative disorders into the realm of actual palliation, arrest or reversal of the attendant pathological processes. While cannabis-based medicines have demonstrated safety, efficacy and consistency sufficient for regulatory approval in spasticity in multiple sclerosis (MS), and in Dravet and Lennox-Gastaut Syndromes (LGS), many therapeutic challenges remain. This review will examine the intriguing promise that recent discoveries regarding cannabis-based medicines offer to neurological therapeutics by incorporating the neutral phytocannabinoids tetrahydrocannabinol (THC), cannabidiol (CBD), their acidic precursors, tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA), and cannabis terpenoids in the putative treatment of five syndromes, currently labeled recalcitrant to therapeutic success, and wherein improved pharmacological intervention is required: intractable epilepsy, brain tumors, Parkinson disease (PD), Alzheimer disease (AD) and traumatic brain injury (TBI)/chronic traumatic encephalopathy (CTE). Current basic science and clinical investigations support the safety and efficacy of such interventions in treatment of these currently intractable conditions, that in some cases share pathological processes, and the plausibility of interventions that harness endocannabinoid mechanisms, whether mediated via direct activity on CB₁ and CB₂ (tetrahydrocannabinol, THC, caryophyllene), peroxisome proliferator-activated receptor-gamma (PPARγ; THCA), 5-HT_1A (CBD, CBDA) or even nutritional approaches utilizing prebiotics and probiotics. The inherent polypharmaceutical properties of cannabis botanicals offer distinct advantages over the current single-target pharmaceutical model and portend to revolutionize neurological treatment into a new reality of effective interventional and even preventative treatment.

Traditional Uses of Cannabinoids and New Perspectives in the Treatment of Multiple Sclerosis

Recent findings highlight the emerging role of the endocannabinoid system in the control of symptoms and disease progression in multiple sclerosis (MS). MS is a chronic, immune-mediated, demyelinating disorder of the central nervous system with no cure so far. It is widely reported in the literature that cannabinoids might be used to control MS symptoms and that they also might exert neuroprotective effects and slow down disease progression. This review aims to give an overview of the principal cannabinoids (synthetic and endogenous) used for the symptomatic amelioration of MS and their beneficial outcomes, providing new potentially possible perspectives for the treatment of this disease.