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Neurology. 2014 Apr 29;82(17):1556-63. doi: 10.1212/WNL.0000000000000363.

Systematic review: efficacy and safety of medical marijuana in selected neurologic disorders: report of the Guideline Development Subcommittee of the American Academy of Neurology.

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From the Department of Neurology (B.S.K.), New York Medical College, New York; the Department of Neurology (J.C.M.B.), Columbia University College of Physicians & Surgeons, New York Neurological Institute, New York; University of Arizona College of Medicine (T.F.), Phoenix; the Department of Neurology (J.B.), David Geffen School of Medicine at University of California Los Angeles, The VA Greater Los Angeles Healthcare System; the Department of Neurology (S.Y.), University of New Mexico Health Sciences Center, Albuquerque; the Department of Neurology (G.G.), University of Kansas School of Medicine, Kansas City; and the Department of Neurology (D.G.), Geisinger Health System, Danville, PA.



To determine the efficacy of medical marijuana in several neurologic conditions.


We performed a systematic review of medical marijuana (1948-November 2013) to address treatment of symptoms of multiple sclerosis (MS), epilepsy, and movement disorders. We graded the studies according to the American Academy of Neurology classification scheme for therapeutic articles.


Thirty-four studies met inclusion criteria; 8 were rated as Class I.


The following were studied in patients with MS: (1) Spasticity: oral cannabis extract (OCE) is effective, and nabiximols and tetrahydrocannabinol (THC) are probably effective, for reducing patient-centered measures; it is possible both OCE and THC are effective for reducing both patient-centered and objective measures at 1 year. (2) Central pain or painful spasms (including spasticity-related pain, excluding neuropathic pain): OCE is effective; THC and nabiximols are probably effective. (3) Urinary dysfunction: nabiximols is probably effective for reducing bladder voids/day; THC and OCE are probably ineffective for reducing bladder complaints. (4) Tremor: THC and OCE are probably ineffective; nabiximols is possibly ineffective. (5) Other neurologic conditions: OCE is probably ineffective for treating levodopa-induced dyskinesias in patients with Parkinson disease. Oral cannabinoids are of unknown efficacy in non-chorea-related symptoms of Huntington disease, Tourette syndrome, cervical dystonia, and epilepsy. The risks and benefits of medical marijuana should be weighed carefully. Risk of serious adverse psychopathologic effects was nearly 1%. Comparative effectiveness of medical marijuana vs other therapies is unknown for these indications.

[Indexed for MEDLINE]
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