A muscle spasm is a sudden, involuntary contraction of a muscle. Anyone who has suffered through a "Charlie horse", a sudden tight cramping of the thigh muscle, has experienced a muscle spasm. Most people will suffer a transitory muscle spasm or "cramp" on occasion throughout their lives, but others will have ongoing occurrences. Muscle spasms and spasticity are symptoms of various chronic debilitating diseases, most notably multiple sclerosis (MS), cerebral palsy, ALS (Amyotrophic Lateral Sclerosis, commonly known as Lou Gehrig's Disease), and Tourette's Syndrome. Muscle spasms also occur due to spinal nerve injuries and stroke, and they are associated with paraplegia. While conventional treatment offers small benefit with a risk of serious side effects, medical marijuana shows promise as a safe and effective treatment for muscle spasms associated with these debilitating conditions.
Conventional treatment for muscle spasms generally consists of muscle relaxants or barbiturates, both of which have high potential for abuse and a long list of serious side effects. Common side effects include nausea, dizziness, fatigue, gastrointestinal disturbance, memory problems, and muscle weakness. More dangerous side effects can include slowed heartbeat and shallow breathing, seizures, hallucinations, and sudden muscle weakness. Serious allergic reactions are a possibility, and coma and death have been reported.
MS patients, including high-profile personalities such as talk show host Montel Williams, have long regarded medical marijuana as an effective treatment for symptoms. Although the mechanism of action isn't well-understood due to the historical limitations on cannabis research, it is well-established that marijuana is effective for relieving muscle spasms and accompanying pain without the serious side effects associated with conventional drugs. Theory states that cannabidiol, one of the active chemical compounds in marijuana, "turns on" nerve receptors that affect motor functioning. This makes it a plausible treatment for many conditions involving muscular spasms.
British pharmaceutical company, GW Pharmaceuticals, has developed a cannabis-derived MS drug which has so far been approved in 15 countries, including Canada and Great Britain. The drug, called Sativex, is a sublingual spray that contains both THC and cannabidiol in a 1:1 ratio. Although it isn't currently available in the United States, it has been fast-tracked by the FDA and is awaiting approval, hopefully by 2016.