Cannabis May Ease Neuropathic Pain After Spinal Cord Injury
Myelopathy and myelomalacia are related spinal cord conditions, but they are not interchangeable terms. Myelopathy describes spinal cord dysfunction caused by problems such as compression, trauma, inflammation, tumors, or degenerative changes. Myelomalacia refers more specifically to softening and tissue damage within the spinal cord, often occurring after severe injury, reduced blood flow, or prolonged compression.
Because myelomalacia reflects damage to spinal cord tissue, its effects depend on the location and extent of the injury. Possible symptoms include numbness or altered sensation, limb weakness, muscle spasms, impaired coordination, difficulty walking, and problems with bladder or bowel control. Neuropathic pain—often described as burning, shooting, electric, or unusually painful responses to touch—can also develop after spinal cord injury.
How myelomalacia is evaluated
Evaluation generally includes a neurological examination and magnetic resonance imaging (MRI). MRI can show spinal cord compression and signal changes associated with edema, scarring, tissue loss, or myelomalacia. Additional testing, such as CT imaging or nerve and muscle studies, may be used when clinicians need more information about the spine or the function of peripheral nerves.
Treatment depends on the cause and whether the spinal cord remains under pressure. Urgent management may be needed when compression is caused by a disc problem, fracture, tumor, abscess, or another structural condition. Depending on the circumstances, care may include surgery, rehabilitation, medicines for pain or spasticity, and strategies to prevent complications. Existing spinal cord damage cannot necessarily be reversed, so treatment should be guided by a neurologist, neurosurgeon, or specialist in physical medicine and rehabilitation.
What research says about cannabis for spinal cord–related pain
The evidence for cannabis is focused mainly on neuropathic pain after spinal cord injury—not on reversing myelomalacia itself.
In a 2016 randomized, placebo-controlled crossover study, researchers tested vaporized cannabis containing either 2.9% or 6.7% delta-9-tetrahydrocannabinol (THC) in 42 people with neuropathic pain related to spinal cord injury or disease. Participants received the study treatment during short, approximately eight-hour laboratory sessions.
Both active THC doses reduced reported pain more than placebo, and the lower dose appeared to offer a more favorable balance between pain relief and psychoactive effects. However, the study examined short-term effects, not long-term treatment. Participants also reported dose-related psychoactive effects, and the design made it difficult to maintain full blinding because people could often tell when they had received THC.
That distinction matters. The study did not show that cannabis repairs spinal cord tissue, stops the progression of myelomalacia, or improves paralysis. It provided preliminary evidence that inhaled THC may reduce central neuropathic pain in some people with spinal cord injury or disease.
Evidence is mixed
Clinical guidance has become somewhat more permissive while still emphasizing uncertainty. The 2021 CanPain SCI clinical practice guideline states that cannabinoids may be considered for neuropathic pain after spinal cord injury, but gives the recommendation a weak strength because studies are small, short, and limited in number.
More recent evidence has not produced a clear answer. A 2023 randomized trial evaluated THC, CBD, and a THC-CBD combination in people with multiple sclerosis or spinal cord injury. It found no significant improvement in neuropathic pain or spasticity compared with placebo. Only 15 of the 134 participants had spinal cord injury, however, and recruitment ended below the study’s planned sample size, limiting how confidently the findings can be applied specifically to myelomalacia.
Potential adverse effects include dizziness, drowsiness, impaired attention, dry mouth, nausea, balance problems, and anxiety or other psychological effects. THC can also impair activities such as driving. Cannabis products may interact with prescription medicines, and their legal status and formulation vary by jurisdiction. CBD is not interchangeable with THC, and evidence from studies of one cannabinoid or delivery method cannot automatically be applied to another.
The practical takeaway
Medical cannabis may be an option to discuss for persistent neuropathic pain after spinal cord injury when established treatments have not provided adequate relief. It should be considered an adjunct for symptom management—not a treatment for the underlying myelomalacia—and should not delay evaluation of potentially treatable spinal cord compression.
Anyone with new or worsening weakness, loss of sensation, difficulty walking, or changes in bladder or bowel control should seek prompt medical attention. A clinician can assess the cause of the symptoms, review safer and better-established treatments, and determine whether a cannabinoid product is appropriate for the individual’s medical history and current medications.
