Could cannabinoids be used as a future treatment for tremors?

Cannabinoids, which are already known to act on the endocannabinoid system, are also believed to act on certain cells in the spinal cord. According to a Danish study, cannabinoids could therefore relieve pathological tremors. A promising new field of application for medical cannabis.

What is the definition of a pathological tremor?

Pathological tremors are chronic involuntary and uncontrollable movements that often affect the arms, legs or head. People with this condition may find it difficult to perform day-to-day activities, or even simply to move around. Their quality of life, and often their self-confidence, are greatly affected.

These tremors can be cause by a wide variety of factors: trauma, neurological or neurodegenerative diseases (e.g. multiple sclerosis), etc. Spinal cord lesions are often to blame. All of our movements, whether voluntary or not, originate in the spinal cord. They are due to the activity of motor neurons which trigger muscle contractions. When there is abnormal neuron activity, they can send the body conflicting signals, resulting in uncontrolled and involuntary tremors. However, a study has just revealed that cannabinoids can act on the spinal cord and calm pathological tremors.

Cannabinoids and the spinal cord, a groundbreaking study

The Department of Neuroscience at the Faculty of Health and Medical Sciences at the University of Copenhagen has published a study which looked at mice with involuntary limb movements in the Nature Neuroscience journal.

While most research on CBD and other cannabinoids has focused on the impact of these molecules on the endocannabinoid system, on this occasion, the researchers studied the biological mechanisms at play in the spinal cord. The researchers injected the cannabinoid WIN55 212-2 into the spine. As a result, they observed astrocyte cell activation which released more neurotransmitters, such as adenosine. The mice’s tremors subsided. The study showed that cannabinoids, through their action on astrocytes in the spinal cord, alleviated the involuntary movements experienced by the mice being treated. 

How do cannabinoids act on the spinal cord?

Astrocytes are specialised star-shaped cells found in the spinal cord. Their role is to facilitate the transfer of information by promoting the circulation of neurotransmitters. According to the Danish researchers, introducing cannabinoids into the spinal column would activate astrocytes, which would then release more transmitters such as purines or adenosine. This release of metabolites is thought to promote better neurotransmitter circulation. This would help to calm nervous system activity and reduce any resulting uncontrollable tremors.

Cannabinoids and treating pathological tremors

Although the studies are still in their infancy, the Danish researchers’ work is generating a great deal of hope among both patients and those in the medical world. The discovery of cannabinoid receptors in the spinal cord opens up new opportunities for the use of medical cannabis. Cannabinoids could be used in a very targeted way to relieve disabling tremors in patients, with no side effects on cognitive abilities and memory in particular. In the USA alone, more than 200,000 people suffer from pathological tremors every year.