Cannabis and Lou Gehrig's DiseaseJun4
6/4/2010 9:56 AM
As we have seen, a number of states allowing the medical use of marijuana specify individual diseases for which marijuana may be used. Among them is amyotrophic lateral sclerosis (ALS), also called Lou Gehrig’s Disease after the extraordinary New York Yankees player who developed the condition in 1939 and was forced to stop playing baseball. He died of ALS in 1941. British physicist Stephen Hawking is perhaps the best-known ALS patient today, though other prominent figures have had the disease, including Senator Jacob Javits of New York, the actor David Niven, and jazz musician Charles Mingus. Some 30,000 people in the US have been diagnosed with ALS, and around 5,000 new cases are diagnosed each year.
ALS is one of several conditions called” motor neuron diseases” that are characterized by the degeneration and ultimate death of the nerves that control voluntary muscles. It is a rapidly progressive, invariably fatal disease. Motor neurons are located in the brain (upper motor neurons) and the spinal cord (lower motor neurons) and communicate with nerves supplying the voluntary muscles. As the nerves degenerate, the muscles they supply gradually lose strength, waste away, and ultimately stop working. When that happens to the nerves controlling the diaphragm and chest wall muscles, patients are no longer able to breathe and die of respiratory failure. On average, this process can take 3 to 5 years, though an estimated 10% of patients may live with the condition for up to 10 years.
The earliest symptoms of ALS may include muscle twitching, stiffness, spasms or weakness, or difficulty chewing and swallowing. These symptoms worsen over time and may involve other muscle groups such as the arms and legs before the diagnosis is made. The cause of ALS is not known, though the discovery of an abnormality in the gene that controls the production of a powerful antioxidant called “superoxide dismutase 1”, or SOD1, in some familial forms of the disease was an important step forward in understanding it. Since SOD1 scavenges free radicals that can damage cells, this suggests that ALS may be caused by damage to nerves from free radicals. A neurotransmitter called glutamate may also play a role in the development of ALS via a mechanism called “excitotoxicity”. Patients with ALS have been found to have high levels of glutamate in their spinal fluid, and in laboratory studies, neurons exposed to abnormally high levels of glutamate eventually die, suggesting that elevated glutamate levels may also be involved, as may as yet unknown autoimmune processes.
Conventional treatment of ALS is directed primarily at controlling the symptoms of ALS, including pain, loss of appetite, depression, and muscle spasms and spasticity. Only one prescription drug called riluzole has been approved by the FDA for the treatment of the disease itself and has been somewhat successful in delaying the final failure of the respiratory muscles by several months. In animal studies and in a number of individual cases of ALS in humans, however, cannabis has been shown to slow the progression of the disease, in some cases dramatically. Several patients have reported that using cannabis has enabled them to live from 5 to 15 years after the initial diagnosis was made and is much more successful in controlling the symptoms of ALS than prescription medications. A survey of ALS patients conducted in 2004 provided additional support for those anecdotal reports. Although no clinical trials have been conducted in humans on cannabis and ALS, animal studies indicate that the patient reports are likely to be based on real physiological effects. Researchers at California Pacific Medical Center reported in 2004 that administering THC to mice with a genetic defect predisposing them to ALS delayed the onset of the disease and prolonged survival. This same study showed that adding THC to cultures of spinal cord neurons significantly reduced damage from oxidative free radicals. A British research group reported in 2006 that cannabinoids significantly extended survival in SOD1 deficient mice, and commented that “…these results show that cannabinoids have significant neuroprotective effects in this model of ALS…” These studies built on earlier reports published in the Proceedings of the National Academy of Sciences in 1999 indicating that cannabidiol and THC are neuroprotectant antioxidants.
Along with the anecdotal reports of ALS patients, these and other studies are so strongly suggestive of significant benefit from the use of cannabis in ALS that researchers at the University of Washington School of Medicine suggested in a study published in the American Journal of Hospice and Palliative Care that “In areas where it is legal to do so, marijuana should be considered in the pharmacological management of ALS.” Taken together, these admittedly preliminary results are so promising that the authors also suggested, as have others, that additional research is warranted.