Parkinson’s disease is a progressive, neurodegenerative disorder of the central nervous system. It primarily affects motor function and intentional muscle movement. One out of every 500 Canadians is affected by Parkinson’s, with roughly 6,600 new cases diagnosed annually. And while the exact cause of Parkinson’s remains unknown, there is hope for better treatment.
Recently, the European Journal of Pain published a study on the effect of cannabis on motor and nonmotor symptoms of Parkinson’s. Conducted by the Rabin Medical Center and Tel Aviv University, the report found that pain symptoms and motor control improved in the 30 minutes following cannabis exposure. The March 2017 issue of Clinical Neuropharmacology reported similar findings, including “significant improvement” in tremors, rigidity, and slowness of movement (bradykinsea), plus quality and duration of sleep and improved pain scores following cannabis treatment.
The Parkinson’s-dopamine connection
Dopamine is a neurotransmitter, a chemical in the brain responsible for transmitting signals between neurons (nerve cells) and the brain. It also plays a vital role in smooth muscle movement. With Parkinson’s disease, dopamine-producing brain cells begin to deteriorate and eventually shut down. As dopamine levels drop, the body responds with symptoms that include:
- Hand tremors
- Uncontrollable shaking of limbs
- Muscle spasms
- Muscle rigidity
- Decreased ability to execute fine muscle movement
- Inability to sleep
- Decreased quality of sleep
- Loss of balance
- Diminished cognitive function
- Memory loss and forgetfulness
Minor symptoms, such as a fingers twitching uncontrollably, are often the first noticeable signs of the disease. But as Parkinson’s progresses, the tell-tale tremors become more prominent and disruptive to daily life. Without healthy, functioning neurotransmitters, such as dopamine, the brain can’t ‘tell’ the body how to move. Patients lose more and more control over their movements as muscles lock, tremor, or spasm violently.
Recent research has found that using cannabis increases dopamine levels in the body, which thereby eases muscle tremors. However, cannabis prescriptions for tremors is nothing new, with cases of cannabinoids being prescribed for parkinsonian symptoms reported as far back as the late 1800s.
Cannabis and the endocannabinoid system (ECS)
The human body naturally creates endocannabinoid compounds that trigger the same receptors as tetrahydrocannabinol, or THC, the cannabis compound that gives you a “high”.
When you use medical cannabis, the cannabinoids within the plant—including but not limited to THC—engage a large network of cell receptors known as the endocannabinoid system. And that’s good news for Parkinson’s patients: the ECS plays an active role in a wide range of bodily functions, including:
- Immune system functionality
Dopamine levels stimulate a large concentration of the ECS found in the basal ganglia, the part of the brain responsible for voluntary muscle movements. While healthy bodies manufacture adequate levels of dopamine deep in the brain (also near the basal ganglia), people with Parkinson’s have decreased dopamine levels, making it harder for the body to execute intentional muscle movements.
Studies suggest that cannabis supports the ECS by increasing the body’s own dopamine levels, making this neural network more responsive and better able to execute motor function while also alleviating other Parkinson’s symptoms.
Decreased brain cell degeneration
A buildup of neurotoxins that the body cannot eliminate is believed to contribute to Parkinson’s. Studies have found that cannabis can aid cells in the elimination of toxins and other waste products. Ingested cannabinoids support and improve mitochondrial function, which is responsible for cellular respiration, the metabolizing of carbohydrates into energy, and the excretion of waste products. Cannabinoids have also been found to slow neurodegeneration, the leading cause of cell decay and cognitive function impairment among those living with Parkinson’s.