Exploring the facts about cannabis and dyskinesia.
Dyskinesia is defined as an “abnormality or impairment of voluntary movement.” It is not a disease in its own right but can be a symptom of several other conditions or a side effect of certain medications.
Dyskinesia can be very distressing for the sufferer and may have a serious impact on their overall quality of life. Therefore, effective treatments are highly sought after but are currently somewhat lacking.
Is it possible that cannabis, a medicinal herb with a checkered history, could help? We take a closer look.
What is Dyskinesia?
Dyskinesia is a broad term used to describe a group of movement disorders which may arise as a result of another condition, or as a side effect of some medications. Dyskinesia should not be confused with dystonia, a similar symptom which may occur together with, or independently of, dyskinesia.
Whereas the word dystonia describes the prolonged contraction of a specific muscle, for example, the toes or the neck, dyskinesia describes the rhythmic contraction of an entire muscle group. Dystonia may cause painful spasms and stiffness, but dyskinesia is more likely to result in involuntary writhing or squirming movements.
Types of Dyskinesia
There are several different types of dyskinesia, some of which are a result of medical conditions and some of which are an unfortunate side effect of medication. Here are some of the most common types of dyskinesia and their causes:
Parkinson’s Disease Dyskinesia
Parkinson’s disease (PD) is a widespread, degenerative disease which is estimated to affect as many as 1–2% of people over the age of 65. Patients with PD have lower than average levels of the neurotransmitter dopamine in their brains. Dopamine is most often associated with the reward response, but it also plays a vital role in motor control.
When dopamine levels fall, symptoms such as tremors, stiffness, slow movement, and postural instability can occur. These symptoms are generally treated with a drug called levodopa which mimics the effects of dopamine in the brain.
Although levodopa does a good job of relieving the symptoms of PD in most patients, it does not work as well as natural dopamine. Rather than allowing smooth, voluntary movement to be restored, levodopa can cause movements which are jerky, unnatural, and uncontrolled. This is known as levodopa-induced dyskinesia and is one of the most common types of dyskinesia there is.
Tardive dyskinesia is also a side effect of medication, this time neuroleptic (antipsychotic) drugs which are used to treat disorders such as psychosis and schizophrenia. Tardive dyskinesia is a common side effect of neuroleptic drugs, estimated to affect around 23% of people treated with this type of medication.
This type of dyskinesia most often affects the facial muscles leading to symptoms such as lip smacking, grimacing, involuntary tongue or jaw movements, and excessive blinking. However, it can also affect the muscles of the trunk and limbs, causing symptoms such as writhing or finger tapping.
Cerebral Palsy Dyskinesia
Cerebral palsy (CP) is a disorder caused by abnormal development of the brain and is the most common cause of movement disorders in children. There are four different types of CP; spastic, ataxic, dyskinetic, and mixed.
People with dyskinetic CP suffer from uncontrolled movements and may have difficulty with everyday activities such as walking, eating, and talking. They may also suffer from jerky or writhing movements which can vary from fast to slow.
Other Types of Dyskinesia
There are several other medical conditions which can cause movement disorders which could be classed as types of dyskinesia. These include:
- Huntington’s disease
- Tourette syndrome
Let’s take a look at exactly what causes dyskinesia, and how cannabis could help.
Dyskinesia and the Endocannabinoid System
As previously mentioned, dopamine is one of the key neurotransmitters involved in motor function. However, normal movement also relies on two more neurotransmitters; glutamate and gamma-aminobutyric acid (GABA).
Glutamate is the primary excitatory neurotransmitter, meaning that it stimulates the central nervous system. GABA is the primary inhibitory neurotransmitter and has the opposite effect. Although the mechanism of dyskinesia is still not fully understood, it is thought that an imbalance between glutamate and GABA could be involved.
The cells that produce these two chemical messengers are influenced significantly by compounds known as endocannabinoids. Endocannabinoids are molecules which help to regulate a wide range of biological functions including mood, appetite, cognitive function, pain, and, of course, movement. They do this by binding with receptors known as cannabinoid receptors, which are located on cells throughout the entire body and brain.
The concentration of cannabinoid receptors (specifically CB1 receptors) is exceptionally high in the basal ganglia region of the brain. This is the area associated with motor function, and this is where cannabis may offer some relief from dyskinetic symptoms.
Cannabis produces compounds known as phytocannabinoids, which have a very similar molecular structure to the endocannabinoids produced by our bodies. This means that they can bind with cannabinoid receptors and have a significant impact on any of the functions which are regulated by endocannabinoids.
Cannabis for Dyskinesia
The cannabinoids found in marijuana could help to relieve dyskinesia in several different ways. There have been over 100 phytocannabinoids identified to date, but by far the most thoroughly studied of these are delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD).
THC is the most abundant phytocannabinoid in the cannabis plant and is responsible for its characteristic ‘high.’ THC is also known to provide effective relief from pain and spasticity, as well as improving mood and aiding sleep.
Pain, anxiety, depression, and insomnia are all symptoms which may accompany dyskinesia, and therefore, it stands to reason that cannabis could help. THC is also a dopamine agonist, meaning that it stimulates dopamine receptors in the brain. This fact has led many scientists to believe that it could specifically help conditions such as Parkinson’s disease.
However, research into cannabis for dyskinesia is somewhat inconclusive. Although there have been individual reports of dyskinetic symptoms being relieved by marijuana, clinical trials have failed to provide any substantial evidence one way or the other. However, what studies do agree on is that cannabis is well-tolerated in patients with dyskinesia, and does not cause any worsening of symptoms.
Although cannabis can cause some side effects, these are usually mild and short-lived. It should, therefore, be safe to try marijuana for dyskinesia, but you should always check with your physician first.
CBD for Dyskinesia
Although the current research on THC and cannabis for dyskinesia is inconclusive, the cannabinoid CBD is showing great promise for conditions such as Parkinson’s disease.
PD is a progressive disease in which neurons in the brain are damaged over time by what is known as ‘oxidative stress.’ This is what causes dopaminergic cells and, therefore, dopamine levels to fall. CBD is known to have anti-inflammatory, antioxidative, and neuroprotective effects, meaning that it could slow down this process and the overall course of the disease.
Although this may not relieve the symptoms of dyskinesia directly, it could reduce the need for medications such as levodopa, which, as we know, is where many of the problems start. Likewise, CBD has been found to have antipsychotic effects and could reduce the need for neuroleptic medications which can lead to tardive dyskinesia.
Unlike THC, CBD does not cause intoxicating effects and is generally considered safe and well-tolerated. It is also legal in all 50 U.S. states providing that it is extracted from industrial hemp containing less than 0.3% THC.
Therefore, CBD has excellent potential as a treatment for conditions such as PD, along with its many other benefits for physical and mental health. However, one potential risk of CBD therapy is that it can affect the way that the body metabolizes other drugs. Therefore, if you take any prescribed or over-the-counter medication, or have a pre-existing medical condition, you should consult your physician before taking CBD for the first time.
Can Cannabis Help Dyskinesia? Final Thoughts
Dyskinesia is a distressing condition for which there is a real lack of effective treatment options. Cannabis could offer some relief through its interaction with the endocannabinoid system in the brain, although scientific studies are yet to find hard evidence of this.
That said, medical marijuana does offer many benefits to patients suffering from the pain, tiredness, and mood disorders which can often accompany dyskinesia. And one thing that studies do agree on is that cannabis should not make movement disorders any worse, so it could well be worth a try.
Another great option, especially for neurodegenerative diseases such as Parkinson’s, is CBD. With its antioxidant and neuroprotective effects, it could slow the progression of these conditions and thus reduce the need for dyskinesia-inducing drugs such as levodopa.
If you suffer from dyskinesia or any other movement disorder, talk to your physician to determine whether medical marijuana or CBD therapy could be an appropriate treatment for you. They will be able to offer guidance on where to begin and inform you of any potential risks.