Spinal cord injury and cannabis: pain, spasticity and evidence limitations

A spinal cord injury can change pain signals long after the injury

The spinal cord carries movement commands from the brain and sensory information back to it. An injury can disrupt these pathways, with consequences that vary according to the level and severity of the damage. Two particularly difficult long-term problems are neuropathic pain and spasticity. A person may describe burning, electric shocks or stabbing pain below a level where ordinary touch sensation has diminished. This is not contradictory: pain can be generated or amplified by altered activity in damaged neural circuits, even without new tissue damage.

What spasticity means in everyday life

Spasticity involves an abnormal increase in resistance when a muscle is stretched, typically more pronounced with faster stretching, following damage to pathways controlling movement. Involuntary muscle spasms may occur alongside it. It may interfere with sleep, dressing, positioning or transfers between a wheelchair and bed. Yet a certain amount of muscle tone can sometimes assist an individual's function. The goal of treatment is therefore not necessarily to eliminate every contraction but to reduce troublesome symptoms while protecting independence and safety.

Why the endocannabinoid system is of interest

CB1 receptors participate in the regulation of neurotransmitter release and are found along pain pathways, including in the spinal cord. CB2 signaling and immune cells are studied in relation to neuroinflammation. These mechanisms make cannabinoids scientifically plausible candidates for symptom research, but a plausible mechanism cannot establish whether a particular product works for a person with spinal cord injury. THC, CBD, their combinations and different routes of administration are not interchangeable.

What a short vaporized-cannabis experiment showed

An exploratory crossover laboratory study compared placebo with vaporized cannabis containing 2.9% or 6.7% THC in people with neuropathic pain related to spinal cord injury or disease. Both active strengths showed short-term pain reductions compared with placebo; the higher strength did not clearly outperform the lower one for pain relief. Researchers also observed some signals involving spasticity. The observation period was measured in hours, however, and cannot answer questions about sustained benefit, long-term safety or optimal dosing over years.

Why clinical studies do not all agree

A multicenter randomized trial published in 2023 compared THC, CBD, their combination and placebo for neuropathic pain or spasticity in participants with multiple sclerosis or spinal cord injury. It did not demonstrate a significant advantage of the active treatments on the principal clinical outcomes; only a small subset of participants had spinal cord injury. In 2026, another randomized crossover trial of oral CBD in spinal-cord-injury-related neuropathic pain found a statistically significant but modest average improvement of approximately 0.54 points on a pain scale from 0 to 10 during six-week treatment periods. Its small sample and medically supervised high-dose formulation limit what can be concluded about everyday products. These differing results justify further controlled research, not a blanket claim of success or failure.

How guidance and treatment decisions fit together

The 2021 CanPainSCI guideline gives a weak recommendation to consider cannabinoids for neuropathic pain after spinal cord injury, based on moderate-quality evidence. Established options and rehabilitation strategies remain important. A careful clinical discussion should distinguish neuropathic pain from other causes, examine current medication and personal goals, and record pain together with sleep, mobility, transfers, concentration, mood and quality of life. A small change in a pain score may matter differently to different people.

Side effects can have disproportionate consequences

THC-containing products may cause dizziness, sedation, impaired attention, anxiety or altered coordination. CBD also can cause adverse effects and interact with prescribed medicines. In someone who relies on precise arm movements for transfers or mobility, even mild dizziness may raise the risk of falls or loss of independence. Any potential symptomatic benefit has to be assessed alongside these functional risks; cannabinoids should not be combined with or substituted for prescribed treatment without clinician supervision.

Do cannabinoids repair the spinal cord?

There is no established clinical evidence that consuming cannabis regenerates destroyed spinal pathways or reverses a spinal cord injury. Laboratory work on inflammation and neuronal survival does not prove tissue repair in humans. The clinical question remains narrower: can certain cannabinoids relieve particular symptoms in certain patients, and for how long?

Key conclusion

Cannabinoids have a credible biological rationale and some encouraging controlled findings for symptoms after spinal cord injury, but the clinical evidence is mixed and products differ greatly. Neither guaranteed relief nor neurological regeneration has been demonstrated. Treatment decisions should be individualized, function-focused and guided by a qualified clinical team.

Original references and Hebrew article

This article is an editorial adaptation of the Hebrew original.

1. The CanPain SCI clinical practice guidelines for rehabilitation management of neuropathic pain after spinal cord injury: 2021 update. Read source ↗
2. Nabata KJ, et al. The Therapeutic Potential and Usage Patterns of Cannabinoids in People with Spinal Cord Injuries: Systematic Review. Read source ↗
3. Cannabis-Based Medicine for Neuropathic Pain and Spasticity: Randomized Double-Blind Placebo-Controlled Trial. Read source ↗
4. An Exploratory Human Laboratory Experiment Evaluating Vaporized Cannabis in the Treatment of Neuropathic Pain From Spinal Cord Injury and Disease. 2016. Read source ↗
5. High-dose cannabidiol for chronic neuropathic pain associated with spinal cord injury: a randomised clinical trial. 2026. Read source ↗

Read original Hebrew article ↗

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