Summary of a symposium on a review of the subject for patients and their families

A publication of the American Academy of Neurology

These information sheets present the updated studies on medical marijuana (cannabis) for the treatment of certain diseases of the nervous system.

The American Academy of Neurology (AAN) is one of the largest associations in the world that brings together neurologists and professionals in the field of neurobiology. The AAN is dedicated to promoting the highest quality care for patients with brain and nervous system diseases. Experts from the AAN scrutinized the existing trials on the safety and activity of cannabis use in certain neurological diseases. The information below is based on the evidence from these studies.

To read the review in full, go to the following link: AAN.com/guidelines

What is medical marijuana?
Marijuana is a wild plant that grows naturally in the USA. It is also known as cannabis. Medical marijuana is cannabis that is used as a medicine. Its use as a medicine creates mental and physical effects. These are due to two main groups of substances in the plant: cannabidiol (CBD) and tetrahydrocannabinol (THC). THC and CBD are taken from the cannabis plant for medicinal use. They can also be created in a laboratory. THC has a stronger toxic activity than CBD.

Is the use of medical marijuana legal? Are there regulations?
Cannabis is a substance subject to the supervision of the federal authorities in the USA. Until recently, it was prohibited to sell, possess and carry or use. Today, doctors in 21 states in the USA and in the Washington District are allowed to write legal prescriptions for medical marijuana. The US Food and Drug Administration (FDA) has approved only two forms of marijuana for medical use DRONABINOL (trade name MARINOL) and NABINOLE (trade name CESAMET). Both are in tablet form. Both drugs are manufactured in a laboratory and contain the key ingredients in the marijuana plant. The FDA approved the two drugs for the treatment of nausea and vomiting associated with cancer chemotherapy, which do not respond to standard treatment. Dronabinol is also approved for use in anorexia accompanied by weight loss in AIDS patients. Use for other purposes is not approved. In general it will be given when no standard topol is active.

The studies reviewed here deal with four forms of medical marijuana:

Oral cannabis extract, a pill made from pure CBD or a combination of THC and CBD.

Synthetic THC in pill form

NABIXIMOLS (trade name SATIVEX) – a mixture of THC and CBD in the form of an oral spray

Marijuana cigarettes for smoking with standard drug strength.

What diseases have been studied? What do the studies show about medical marijuana treatment as a treatment for these diseases?

The review includes only studies that met the standards of the AAN. Well-designed studies have shown the most compelling evidence. The diseases in which the efficacy and safety of medical marijuana were tested included:

Various symptoms of multiple sclerosis

Involuntary and temporary movements as a Lewy phenomenon for drug treatment in Parkinson's disease

Motor symptoms in Huntington's disease

Tics in Tourette's disease

Cervical dystonia (abnormal neck movements)

Convulsions in epilepsy

Only two of the studies here looked at the effect of smoking marijuana. One of the two tested the effect of smoking marijuana as a treatment for pain in multiple sclerosis caused by muscle tension. The second tested safety in multiple sclerosis patients. Both studies did not show enough findings to prove the effectiveness or safety of smoking marijuana*.

The results of the studies are described below in the table.
Multiple sclerosis symptoms
Studies have shown that medical marijuana given by pill or oral spray can help mask the following symptoms of the disease.

Muscle spasms (spasticity) and related symptoms
Spasticity is chronic muscle tension. It makes the muscles hard and hard to the touch. It can cause pain and painful muscle spasms. This happens due to uncontrolled muscle contractions.

Supporting evidence
There is strong evidence* that OCE pills made from pure CBD:
can relieve symptoms caused by muscle spasms in the short term.

There is moderate* evidence that THC is administered in an oral pill or spray
can relieve symptoms caused by muscle tension in the short term

Can relieve muscle spasm pain.

There is weak evidence* that OCE and THC pills
can relieve symptoms caused by muscle strains if the treatment lasts for at least a year.

Contradictory testimony
There was moderate evidence that OCE and THC pills and oral spray
Probably do not lead to short-term improvement in spasticity tests performed by a doctor.

Other symptoms of multiple sclerosis

Supporting evidence
Strong evidence* shows that OCE pills:
can reduce central pain (burning sensation, stabbing and circumcision)

Moderate* evidence shows that the oral spray:
Reduces the frequency of urination.

Contradictory testimony
Moderate evidence* shows that OCE and THC pills
Probably do not affect the frequency of urination and bladder control problems.

They probably don't reduce the tremors in multiple sclerosis.

Weak evidence* shows that the oral spray
Does not reduce tremors in multiple sclerosis.

There is not enough evidence that the oral spray reduces bladder problems in general.

other neurological diseases

Temporal involuntary movements in Parkinson's disease

The prominent signs in Parkinson's patients are tremors, muscle stiffness and movement problems. The common treatment is the administration of levodopa. But in late stages of treatment, the drug itself can cause movement problems.

Moderate* evidence shows that OCE pills likely reduce levodopa-induced involuntary movements,

Huntington's disease, Tourette's syndrome, cervical dystonia, epilepsy

There is not enough evidence to determine* whether medical marijuana in pill or oral spray form:

There is an ability to reduce symptoms in Huntington's disease.

Reduces the intensity of tics in Tourette's disease.

Reduces the abnormal movements of the neck in cervical dystonia.

Reduces the frequency of seizures in epilepsy.

Reasons for concern in cannabis

There are reasons for concern when using cannabis. All cannabis products have side effects, some of which can be serious. These include

Difficulties in interpersonal communication

Fatigue and sleepiness and fainting

Dizziness and fatigue

dry mouth

Feeling of toxicity

Hallucinations

Impaired judgment and coordination

Increased spasticity

weakness

Loss of balance and falls

nausea vomiting and constipation

Psychological problems such as depression and psychosis

Thinking and learning memory problems

The long-term safety of cannabis is unknown. Most of the studies were short-term and a long-term study is needed. These should include severe psychological problems such as depression, suicidal thoughts and psychosis. One in 100 people (or XNUMX percent of the population) will be affected. More research is also needed into the risks of lung cancer due to long-term smoking.

Table: Evidence for the activity and safety of medical marijuana

Findings by disease and form of administration
The strength of the evidence
Spasticity in multiple sclerosis and related symptoms

Father

can reduce patients' complaints of muscle spasm symptoms
strong
Father

· Probably does not improve in the short term (12-15 weeks) muscle spasm syndrome that is examined by a doctor

Synthetic THC

· Can apparently reduce patients' complaints of muscle spasm symptoms

· Can apparently reduce muscle spasms

· Probably does not improve in the short term (15 weeks) muscle spasm syndrome that is examined by a doctor

Oral spray (NABIXIMOLS)

· Can reduce patients' complaints about muscle spasm symptoms in the short term (6 weeks)

· Apparently does not improve in the short term (6 weeks) muscle tension syndrome that is examined by a doctor

· Can apparently reduce muscle spasms 

Medium
OCE and synthetic THC

· Can probably reduce patients' complaints of muscle spasm symptoms if the treatment lasts for at least a year

· Can probably improve muscle spasm syndrome that is checked by a doctor if the treatment lasts for at least a year
Weak
Smoking cannabis

· There is not enough information for safety or effectiveness in the treatment of pain from muscle spasm symptoms

Multiple sclerosis central pain

Father

· May help reduce central pain (burning sensation, stabbing and circumcision)

Multiple sclerosis and bladder problems

OCE and synthetic THC

· They probably do not reduce the frequency of urination and do not treat bladder problems

Oral spray (NABIXIMOLS)

· Probably reduces the frequency of urination (after 10 weeks)
unknown

strong

Medium
Oral spray (NABIXIMOLS)

· There is not enough information to determine whether it helps with bladder problems

Multiple sclerosis and tremors

OCE and synthetic THC

· They probably do not reduce tremors in multiple sclerosis
unknown

Medium
Oral spray (NABIXIMOLS)

· Probably does not reduce tremors in multiple sclerosis

Parkinson's disease temporary involuntary movements

Father

· Probably does not reduce the involuntary movements originating from levodopa

Weak

Medium
Huntington's motor symptoms

Synthetic THC

· There is not enough information to state that it reduces motor symptoms

Tourette's disease Severity of tics

Synthetic THC

· There is not enough information to say that it reduces the severity of tics

Cervical dystonia (abnormal neck movements)

Synthetic THC

· There is not enough information to state that it reduces abnormal neck movements

Epilepsy convulsions frequency

All forms of cannabis

· There is not enough information to say that it reduces the frequency of attacks

 This systematic review was published by the American Autonomic Society, the American Epilepsy Society, the Consortium of Multiple Sclerosis Centers, the International Organization of Multiple Sclerosis Nurses, and the International Rett Syndrome Association.