Saving the nerves: Cannabis & CBD for neurological health in the UK
"It’s me suspended in a defenseless test, being tested by a ruthless examinant." This line from Twenty One Pilots’ song perfectly describes one of the most ruthless neurological disorders - a migraine. Imagine feeling the pain that throbs or pulses on both sides of your head, sensitivity to everything that surrounds you, nausea and vomiting. It seems like your body betrays you, making you experience such torture.
Hundreds of millions of people all over the world are affected by neurological disorders. Half of survey respondents admit that their condition impacts their quality of life to a great extent. These conditions may be alleviated and treated with many methods, such as neuroleptics or simple analgesics, neurological rehabilitation, physiotherapy, or surgeries. Some conditions, such as Dravet syndrome, a severe type of epilepsy characterised by multiple seizures, may be especially challenging. There is no treatment for Dravet syndrome, and most treatments aim to diminish seizures. This condition can be safely treated with medicinal cannabis oil, which provides a treatment option for children who do not respond to traditional medications. The good thing is that cannabis and cannabidiol (CBD) may also be helpful in other neurological disorders, helping people to improve their quality of life. Let's consider if cannabis may help with other disorders of the nervous system.
What is a neurological disorder?
The nervous system coordinates the movements and functions of the body. Without the nervous system, we couldn't walk, move, eat, talk, or function at all. This sophisticated system consists of two parts:
The central nervous system that includes the brain and spinal cord.
The peripheral nervous system, including peripheral nerves and the autonomic nerves, running throughout your body.
In addition to the main systems, the nervous system includes the eyes, ears, sensory organs of taste and smell, and sensory receptors in the skin, muscles, joints, and other parts of the body.
A neurological disorder is an impairment in any of the main parts of the nervous system. These conditions may be caused by different reasons, such as mutated genes, malnutrition, or brain and spinal cord injuries. There are more than 600 known types of neurological conditions. The most common neurological disorders can be divided into categories, though there is also overlap in the types:
Vascular disorders. These disorders may be caused by blockages in the vessels that carry blood to and from the heart. These disorders include stroke, transient ischemic attack, or subarachnoid haemorrhage, subdural haemorrhage, and extradural haemorrhage.
Degeneration. The death or damage of nerve cells may cause Parkinson's disease, multiple sclerosis, dementia, Huntington chorea, and Alzheimer's disease.
Headache disorders. The most common neurological condition is characterised by pain in the head. Stress, physical or mental disorders may cause migraines and tension-type headache.
Seizures. Disorders, such as epilepsy, occur when electrical signals between nerve cells are disrupted, and this affects how you feel. There are also severe disorders, such as Lennox-Gastout and Dravet syndromes.
Genetic neurological disorders. Abnormalities, such as Huntington's disease, occur when a mutated gene or group of genes is inherited from parents through genes and chromosomes.
Infectious diseases. These disorders are caused by viral or bacterial infections, such as meningitis, encephalitis, polio, and epidural abscess, in the nervous system.
Movement disorders. These are neurological conditions that cause abnormal voluntary or involuntary movements.
Neuromuscular disease. The impairment in the nerves that control the muscles causes spinal muscular atrophy and amyotrophic lateral sclerosis.
Functional neurological disorder (FND). This disability restricts normal functioning of individuals and causes loss of vision or double vision, tremors, dystonia (spasms), and blackouts.
Neuro-oncology. Cancers in the nervous system include brain stem glioma and tumours of the medulla.
The signs and symptoms of a neurological disorder can vary depending on the condition, though the most common ones include:
Loss or weakness of muscle strength
Lack of coordination
Trouble speaking, breathing or swallowing
Loss of sight, double vision or excessive blinking
Memory loss or difficulty learning
Numbness or tingling in a single extremity or on one side of the body
Headache that changes or occurs suddenly
Tremors and seizures
Changes in mood or behaviour
Loss of feeling or tingling
Impaired mental ability
Back pain that spreads to other parts of the body
Expression or comprehension problems
The symptoms of a nervous system disorder may look similar to other medical conditions. Therefore, a consultation with a physician for diagnosis is required.
Neurological conditions in the UK
Report on Deaths Associated with Neurological Conditions states that the number of deaths in England associated with neurological disorders increased by 39% over 13 years, while the rate of deaths in the general population decreased by 6% over the same period. In 2016/17, there was also an increase in hospital and emergency admissions related to neurological conditions by 24% and 21% accordingly. The expenditure on neurological conditions by The National Health Service (NHS) reached £4.4 billion in 2012/13, which is the latest data available.
According to the 2019 patient experience survey by the UK Neurological Alliance, having a neurological disorder has a huge impact on life quality and daily activities. 46% of respondents said that their condition affected them greatly, and 35% of them were impacted to a moderate extent. Respondents with neurological conditions, such as epilepsy or migraine, stated that the unpredictability of their condition has also affected their daily life. The 2013-14 survey conducted by NHS England on patients of GP practices has shown that people with long-term neurological conditions had the lowest quality of life among other long-term conditions.
Cannabis and CBD for neurological disorders
Medicinal cannabis, sometimes referred to as medical cannabis or medical marijuana, is made of the Cannabis sativa or Cannabis indica varieties. Medicinal cannabis may come in the form of a pill, oil, nasal spray or other forms of cannabis plant extract. It helps to relieve the symptoms of some medical conditions, though its use is highly regulated. An average cannabis plant contains more than 400 chemicals; 120 of them are cannabinoids, such as cannabidiol (CBD) and tetrahydrocannabinol (THC). Common approved medications contain just one or two cannabis compounds. Treatment with cannabis is difficult to classify and study due to the high amount of active chemicals.
Medicinal cannabis for neurological disorders in the UK
As cannabis is regulated in different ways all over the world, each country has its own rules regarding cannabis-based medications. In the UK, cannabis for medical purposes was legalised on November 1, 2018. The legalisation followed the cases of Billy Caldwell, aged 12, and Alfie Dingley, aged 6, who had severe epilepsy. Cannabis significantly improved their health condition, but they couldn't get the treatment under UK law, getting public attention to the case. In the UK, only three cannabis-based drugs are legal and available for prescription, of which two are designed for neurological disorders:
The drug by GW Pharmaceuticals is plant-derived cannabidiol, used to treat seizures associated with Lennox-Gastaut syndrome and Dravet syndrome in children. As of 2019, 3,000 people had Dravet syndrome, 5,000 people suffered from Lennox Gastaut syndrome, and over 2,000 people could qualify for Epidiolex in England. The medication does not contain THC, a psychoactive compound from the cannabis plant. NICE followed the recommendations of the European Commission, suggesting the combination of Epidiolex and anti-epileptic generic drug clobazam (brand names Onfi and Sympazan) for the patients, aged two and older.
Data from numerous trials and studies have shown that Epidiolex could reduce seizure frequency by half, and improve health in most people. Side effects of Epidiolex during trials included sleepiness, fever, appetite loss, diarrhoea, and vomiting.
The medication is a mouth spray containing two chemical extracts delta-9 tetrahydrocannabinol (THC) and cannabidiol (CBD). In the UK, the medication is approved for the treatment of spasticity in multiple sclerosis, though it is not allowed to treat pain in the same condition. Sativex is a Class B controlled drug under the Misuse of Drugs Act 1971 and is placed in less-restrictive Schedule 4 according to the Misuse of Drug Regulations 2001. Sativex can be prescribed by a specialist doctor experienced in the treatment of multiple sclerosis spasticity, such as consultant neurologists, consultant rehabilitation specialists, and consultant pain specialists. The drug can be prescribed legally in the UK with no restrictions on storage, supply and destruction.
There is a particular limitation of Sativex use: if patients respond positively during the first four weeks of treatment, they may continue with the drug. Common Side effects of Sativex include dizziness, drowsiness, diarrhoea, fatigue, constipation, concentration or memory loss, dry mouth, and altered sense of taste. Usually, side effects occur during the first days of the treatment.
Cannabis-based medications can be prescribed by a specialist medical practitioner, included in the register of specialist medical practitioners, or a tertiary paediatric specialist for children and young people. The patients can get prescriptions for licensed medical cannabis covered by the NHS or obtain private prescriptions with no NHC coverage.
A short list of approved cannabis-based medications and strict requirements to potential patients challenges the way to get a prescription for medical cannabis. The NHS coverage remains difficult and rare in the United Kingdom. Private clinics can provide an easier option to access medical cannabis, covering a broader range of conditions, such as pain and neurological conditions. Unfortunately, an easier way is more expensive, reaching up to £200-250 for private appointments and £600-800 for prescriptions per month.
Europe's first medical cannabis patient registry plans to enrol 20,000 patients with various conditions by the end of 2021. Project Twenty21 will also target patients with the following disorders, such as:
Post Traumatic Stress Disorder (PTSD);
Substance use disorder (as harm reduction strategy);
The project aims to create the largest single body of evidence in Europe to support the efficacy of medical cannabis. Drug Science, the UK's independent scientific body on drugs, expects the trial's findings will provide sufficient evidence of cannabis benefits for policymakers and healthcare specialists. It will facilitate wider adoption of medical cannabis, and help physicians become more confident in prescribing medical cannabis to patients.
Cannabis for Neurological disorders
Cannabis can be helpful when treating spasms and seizures, pain, anxiety, muscle weakness and other symptoms caused by neurological disorders.
The studies on medical cannabis for neurological impairments have shown promising results.
The disease attacks the brain, spinal cord, and nerves. Some evidence suggests that cannabis can help relieve stiffness and muscle spasms and sleep disorders that are common with multiple sclerosis.
The use of Sativex, a cannabinoid-based oromucosal spray, has been proven to be a safe and effective way to reduce muscle spasticity in patients with moderate to severe multiple sclerosis resistant to other medications. One study found that Sativex provided relief in resistant multiple sclerosis spasticity in 75% of 276 people, proving the drug is an effective and well-tolerated treatment. Studies also indicate that cannabis use may diminish some symptoms associated with multiple sclerosis, such as decreased pain and spasticity.
Trials on Epidiolex, an oral solution of cannabidiol, have shown a decrease in seizure frequency in epilepsy. In contrast, other clinical trials on cannabis-based medications show benefit in severe epilepsy syndromes in children and adolescents, such as the reduction in seizure frequency or even seizure-freedom. Another study on 214 people with severe epilepsy, receiving 0.9–2.3 grams of CBD oil per pound of body weight, has shown 36.5% median reduction of seizures.
There is also promising evidence on Epidiolex efficacy and adequate safety profiles for children with Dravet Syndrome and Lennox-Gastaut Syndrome.
Another study has found that CBD oil significantly reduced the median frequency of convulsive seizures in children and young people with Dravet syndrome, a complex childhood epilepsy disorder, in comparison to a placebo.
Parkinson's is a chronic progressive neurological disease, mainly affecting middle-aged and older people. The disease is associated with decreased dopamine production and symptoms, such as rigidity of the muscles, tremor and slow movement. Cannabidiol has been shown to cause brain-protective, antioxidant and anti-inflammatory properties which may be useful for managing Parkinson's disease. Cannabis may also produce positive impacts on memory, mood, fatigue, and obesity in people with Parkinson's disease and multiple sclerosis. Several studies have found that treatment with CBD could improve sleep quality and quality of life for people with Parkinson's disease.
CBD has been shown to alleviate or remove the impact of oxygen buildup, inflammation, and brain cell decline in people with Alzheimer's disease. Inflammation occurs when the brain's immune cells can not clear disorienting blockages. The inflammation, a core and challenging Alzheimer's symptom can be reduced by CBD oil. Additionally, the brain's inflammation leads to oxygen release, decreasing important brain functions, such as memory. CBD acts as an antioxidant, reducing the problems related to oxygen stress. CBD may improve brain functions negatively impacted by oxygen stress and stimulate brain tissue. Some clinical trials have shown CBD's ability to reverse and prevent the development of Alzheimer's negative impact. Animal and test-tube studies have suggested that CBD may alleviate inflammation and help prevent neurodegeneration processes linked to Alzheimer's disease. Long-term studies on mice that were given CBD and genetically predisposed to Alzheimer's disease have found that it might prevent cognitive decline and slow down the progression of the disease.
Huntington's disease, known as Huntington's chorea, is an inherited disease that leads to the death of brain cells. The earliest symptoms include slight problems with mood or mental functions, that develop into a lack of coordination and an unsteady walk. The studies on the role of CBD on the treatment of Huntington's disease and movement disorders are few. Animal studies have shown beneficial neuroprotective properties of CBD and its preventive role in disease rather than a therapeutic one.
Tourette's syndrome that appears during childhood may cause involuntary, rapid, repetitive movements and vocalisations, called tics. Some clinical cases indicate that cannabis use can reduce tics in patients with Tourette's syndrome. In most cases, the researchers suggest that cannabis may improve patients' symptoms due to its anxiety-reducing properties.
Chronic pain is a common symptom of many neurological disorders, affecting up to 40% of patients with primary neurological diseases, coming from traumatic injury to the central nervous system, neurodegeneration and neuroinflammation, and exploring the aetiology of pain in these disorders is an opportunity to achieve new insight into pain processing.
CBD may be helpful in pain alleviation. The cannabis-based Sativex is approved in multiple countries, besides the UK, for the treatment of neuropathic pain and multiple sclerosis-related muscle spasms. In 2005 Sativex was approved in Canada for treatment of central neuropathic pain in patients with multiple sclerosis. The Canadian Pain Society created recommendations on cannabis‐based medications as third‐line therapy for chronic neuropathic pain syndromes in the case established therapies, such as anticonvulsants or antidepressants had failed. Numerous clinical trials have shown the efficacy and safety of Sativex in central and peripheral neuropathic pain. CBD oil has also shown potential for chronic pain relief with low potential side effects than many other pain medications. However, it is not commonly applied for severe pain.
Headaches and migraines
The migraine is more than just an intense headache, as it includes a number of neurological symptoms, such as a throbbing recurring pain on one side of the head and muscle stiffness. A 2019 review suggested that cannabinoids may modulate activity and functions of signalling pathways, helping to alleviate the pain associated with migraines. Initial clinical findings show that modulation of the endocannabinoid system with cannabinoids may be helpful for migraine. CBD may also reduce the release of proteins, associated with inflammatory pain, and modulate the immune cell system. A 2007 study suggested that people with migraine might have low anandamide levels in the cerebrospinal fluid, which is a potential indication of a compromised ECS. Therefore, modulation of the ECS with cannabinoids could become a promising treatment for migraines. Nevertheless, further studies will show the mechanisms by which it happens. CBD has also shown efficacy for headache-related conditions, such as anxiety. Animal studies suggested THC's anti-migraine effect by CB1 receptors mediation if administered at the right dose and time. The study is based on big data from migraine sufferers using cannabis in real time. The study indicated that inhaled cannabis might reduce the severity of headache and migraine by half. Cannabis concentrates also reduced a headache better than flowers. Cannabis didn't seem to result in the medication overuse headache, linked to conventional medications.
Anxiety and sleep loss
Anxiety and panic are common after-effects in epilepsy, while insomnia may stem from neurological conditions, such as Parkinson's disease. Evidence suggests a calming effect of CBD in the central nervous system. The exact way CBD affects sleep and anxiety isn't entirely clear, though it may alter serotonin signals. Serotonin is a neurotransmitter, important for mental health.
A 2019 large retrospective case series at a psychiatric clinic evaluated the clinical application of cannabidiol for anxiety and sleep disorders in addition to common treatment. The study included 103 adult patients. The findings have shown that anxiety scores diminished within the first month in up to 80% of the patients and remained lowered during the study. Sleep quality improved within the first month in 66.7% of the patients, though reduced over time. Indeed, the cannabidiol may benefit patients with anxiety-related disorders, but further clinical studies are needed.
Cannabis and CBD side effects
Just as any other medication, cannabis may cause side effects and paradoxical effects; therefore, further research on cannabis effectiveness in neurological disorders is required. The most commonly reported side effects of medicinal cannabis included red eyes, dizziness, low blood pressure, increased heartbeat, affected judgment and coordination. CBD is commonly well-tolerated, though it may cause dry mouth, diarrhoea, appetite loss, fatigue and drowsiness. CBD can also interact with other or dietary supplements and medications, such as blood thinners. In any case, prior consultation with a physician is highly required.
Most studies have proven low risk of addiction and low toxicity of medical cannabis if taken according to medical recommendations in small therapeutic doses and under medical control.
Neurological disorders and COVID-19
The recent findings show that in addition to respiratory symptoms, patients with COVID-19 can develop neurological complications. The novel coronavirus disease can affect the central and peripheral nervous system. In the peripheral nervous system, COVID-19 might cause headache, smell and taste disturbance, muscle injury, and Guillain-Barre syndrome. Example of COVID-19 central nervous system injury includes encephalitis, encephalopathy, acute disseminated encephalomyelitis, ischemic and hemorrhagic stroke, meningitis, venous sinus thrombosis, and endothelialitis. Headache affected more than 10% of patients, while the loss of smell and taste were reported in a smaller percentage of cases. Acute cerebrovascular events were diagnosed in less than 3% of patients with COVID-19, but patients with more severe conditions suffered from cerebrovascular events in more than 6% of the cases. These complications can challenge the course of COVID-19 in low-risk patients. Guillain-Barre syndrome can become a life-threatening event. The understanding of SARS-CoV-2 neuropathogenesis is incomplete and requires further research.
The bottom line
As the report by Global Market Insights, Inc. states, the global cannabidiol market may exceed $89bn by 2026. The global medical cannabis market is forecasted to reach a value of $44.4 billion by 2024. A growing number of neurological disorders partly justifies such a demand in recent years. According to the European Brain Council, a total of 220.7 million Europeans suffer from at least one neurological condition. Headaches lead with over 152 million sufferers, followed by sleep disorders with 44.9 million people, strokes - 8.2 million and dementia - 6.3 million.
Ongoing research and development into potential health benefits, a rise in the availability of cannabis products, and more favourable public opinion contribute to CBD popularity. Many people add CBD to their daily routine to reduce stress and anxiety, sleep better, and relieve chronic pain. Increasing awareness of CBD's health benefits along with its safety and efficacy, will push CBD popularity even further. The market will continue to grow, though the industry needs to overcome the complex regulations and quality challenges in the short run.