DOI: 10.1177/17562864261468464 ISSN: 1756-2864

Medical cannabis improved self-reported spasticity rating in patients with chronic spinal cord injury: a placebo-controlled, double-blind, crossover pilot clinical trial

Nattha Boonthanakorn, Sintip Pattanakuhar, Pratchayapon Kammuang-lue, Siam Tongprasert, Apichana Kovindha

Background:

Previous studies demonstrated that cannabinoids may reduce spasticity in patients with spinal cord injury (SCI); however, the effect of naturally extracted THC:CBD oil, the most commonly used naturally extracted cannabinoids, has yet to be elucidated.

Objectives:

To assess the effect of a 1:1 THC:CBD oil on reducing spasticity in chronic SCI patients

Design:

A single-center, placebo-controlled, double-blind crossover clinical trial.

Methods:

Sixteen chronic SCI patients with intractable spasticity were randomly assigned to either the intervention (1:1 THC:CBD oil) or control (placebo) phase for 1 month, then crossed over. The primary outcome (combined Ashworth Scale [AS] of all involved muscle groups) and the secondary outcomes, including patient-rated visual analog scale (VAS) of spasticity, were assessed before and after both phases and analyzed using a multilevel mixed-effects model.

Results:

All participants completed the study. The average (SD) dose of THC:CBD oil was 11.6 (1.3) mg. No significant difference in the total AS score for all involved muscle groups was found between the pre- and post-treatment phases, or between the experimental and control phases (all p  > 0.05). A significant reduction was observed in the patient rating VAS (effect size = −13.9 [95% CI: −25.5 to −2.3; p  = 0.010).

Conclusion:

In people with chronic SCI who had intractable spasticity, there was no statistically significant effect of 1:1 THC:CBD oil on spasticity-related outcomes, except for patient rating VAS reduction. Further studies are needed to evaluate the efficacy of higher doses of THC (>12 mg/day) and to use patient-reported spasticity scores as the primary outcome measure.

Trial registration:

The study was registered with the Thai Clinical Trials Registry (TCTR identification number: TCTR20220329001).

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