Marijuana for Epilepsy?

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There has been a great deal of press regarding medical marijuana recently, including programs on Anderson Cooper 360 and Crossfire.  A large part of the excitement is due to a much publicized “apology” by Sanjay Gupta, MD, CNN’s chief medical correspondent, regarding his prior stance against medical marijuana. He wrote, “We have been terribly and systematically misled for nearly 70 years in the United States, and I apologize for my own role in that” (Gupta, August 9, 2013). This article was followed by his documentary, “Weed,” which featured the case of Charlotte Figi, a child with intractable epilepsy due to Dravet syndrome. Charlotte’s daily seizures miraculously improved after treatment with a marijuana formulation high in cannabidiol (CBD) and low in tetrahydrocannabinol (THC), which has come to be known as “Charlotte’s Web.”

Some Background

To date, medical marijuana is legalized in 20 states and the District of Columbia. Recreational marijuana is legal in Colorado and Washington states. The federal government still considers marijuana a Schedule I drug, a classification with high potential for abuse and no accepted medical use. A standardized, plant-derived cannabinoid preparation, Sativex, has been approved outside the US for spasticity and neuropathic pain related to multiple sclerosis as well as cancer-related pain (GW Pharma). Otherwise, there are no clinically proven indications for marijuana in neurologic disorders (Robson 2013).

The Documentary

Dr. Gupta picks up where Dr. Oz left off in highlighting anecdotal successes of medical marijuana (Wilner 2011). The documentary also featured a second case of a young man who had “convulsing of the diaphragm” and a symptomatic response to smoking marijuana. The use of the word “convulsing” would lead most viewers to conclude that this is also a case of epilepsy. If it is, it is epilepsy of the rarest kind (Hahn and Neubauer 2012).

The documentary is terribly unbalanced in favor of medical marijuana, although it does mention that marijuana can adversely affect the brain. Specifically, it states that prefrontal functions such as planning, thinking, and coordinating behaviors can be affected, and “could be dangerous.” Further, young people could be particularly vulnerable to adverse effects. One expert interviewed for the program, Staci Gruber, PhD, Director of the Cognitive and Clinical Neuroimaging Core, McLean Hospital’s Brain Imaging Center, Belmont, MA, observed that “white matter is impaired in those who start smoking early.”

Other important information included, “early onset smokers are slower at tasks,” may have “lower IQs later in life,” “higher risks of strokes,” and “increased incidence of psychotic disorders.” But the documentary dismisses these concerns as “not conclusive.”

Dr. Gupta’s Views

With respect to young users, Dr. Gupta admits in his article, “Some recent studies suggest that regular use in teenage years leads to a permanent decrease in IQ. Other research hints at a possible heightened risk of developing psychosis.” He adds, “I wouldn’t permit marijuana until they are adults.”

Dr. Gupta acknowledges that marijuana may cause addiction in 9% of users. But he downplays the significance of this by contrasting it with the higher addiction rates of cocaine, heroine and smoking.

Dr. Gupta’s assertion that the Food and Drug Administration’s (FDA) classification of marijuana as a Schedule I drug was based on lack of evidence rather than evidence of harm may be accurate. However, it is a long way from reclassification of marijuana from Schedule I to the popular opinion that marijuana is safe.

Evidence for Epilepsy?

The scientific evidence that marijuana helps control seizures can be summarized in one sentence: Apart from anecdotal cases like Charlotte Figi’s, the evidence that marijuana is helpful for people with epilepsy is nil.

Conclusions

Although not inaccurate, this documentary is deliberately misleading regarding the safety and efficacy of medical marijuana for epilepsy and not worthy of Dr. Gupta or CNN. No one would deny the use of marijuana to a patient who has tried all conventional options and is in extremis. But the case of Charlotte Figi is an “N of 1″ and hardly representative of most people with epilepsy. At best, it suggests that more research on marijuana is warranted; catastrophic Dravet syndrome might be a good place to start clinical trials.

For now, medical marijuana should be considered as a last resort for people with seizures. Given that there are more than 15 FDA approved oral antiepileptic drugs, proven devices such as the vagus nerve stimulator and the new NeuroPace responsive neurostimulator, as well as the ketogenic diet, the use of marijuana for epilepsy should be infrequent indeed.

References

• Cooper, A. Anderson Cooper 360, http://www.youtube.com/watch?v=gQ772O70wRE
• Jones, V. Crossfire: Legalize marijuana? http://crossfire.blogs.cnn.com/category/marijuana/
• Gupta, S. CNN, http://edition.cnn.com/2013/08/08/health/gupta-changed-mind-marijuana/index.html, August 9, 2013
• Gupta, S. “Weed.” CNN Report: http://www.youtube.com/watch?v=vyf-ffoatHg
• http://www.gwpharm.com/prescriberinformation.aspx
• Hahn A, Neubauer BA. Epileptic diaphragm myoclonus. Epileptic Disorders 2012;14(4):418-421.
• Robson PJ. Therapeutic potential of cannabinoid medicines. Drug Testing and Analysis 2014;6:24-30.
• Wilner, A. Marijuana: A viable epilepsy therapy? http://www.medscape.com/viewarticle/744011_1, June 9, 2011