03 Oct Marijuana May Be Protective Against Traumatic Brain Injury
Medical Research: What are the main findings of the study?
Based on a survey of patients with traumatic brain injuries, a group of Los
Angeles Biomedical Research Institute researchers found those who tested
positive for tetrahydrocannabinol (THC), the active ingredient in marijuana, were more likely to survive than those who tested negative for the illicit substance.
We surveyed 446 patients who were admitted to a major urban hospital with
traumatic brain injuries between Jan. 1, 2010, and Dec. 31, 2012, who were
also tested for the presence of THC in their urine. We found 82 of the
patients had THC in their system. Of those, 2.4% died. Of the remaining
patients who didn’t have THC in their system, 11.5% died.
While most – but not all – the deaths in the study can be attributed to the
traumatic brain injury itself, it appears that both groups were similarly
injured. The similarities in the injuries between the two groups led to the
conclusion that testing positive for THC in the system is associated with a
decreased mortality in adult patients who have sustained traumatic brain
Medical Research: What caused you to pursue this study?
Dr. Plurad: Previous studies conducted by other researchers had found certain compounds in marijuana helped protect the brain in animals after a trauma.
This study was one of the first in a clinical setting to specifically associate THC use
as an independent predictor of survival after traumatic brain injury.
This timing of this study is also pertinent because of current efforts to
decriminalize marijuana and other research that has shown THC can increase
appetite, reduce ocular pressure, decrease muscle spasms, relieve pain and
alleviate symptoms associated with irritable bowel disease. But they noted
that their study has some significant limitations.
Medical Research: What was most surprising about the results?
Dr. Plurad: In previous studies, the presence of alcohol appeared to have a protective effect in traumatic brain injuries. However, in these previous studies, the effect of THC was not evaluated, despite the fact that patients tests may have been screened positive for both. In this study, we did evaluate for the presence of alcohol, and it appears that THC was more closely associated with survival.
Medical Research: What should clinicians and patients take away from your report?
Dr. Plurad: Marijuana appears to have a protective effect on the brain, which could have implications for illnesses that affect the brain. The neuro-protective
effects of cannabinoids have been documented in studies of neurodegenerative
diseases, such as Alzheimer’s disease, Huntington’s disease and multiple
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Plurad: The next step would be to study neurologic functional outcomes in survivors of traumatic brain injuries and comparing the results of those who tested positive for THC and those who tested negative for THC.
Effect of Marijuana Use on Outcomes in Traumatic Brain Injury
Authors: Nguyen, Brian M.; Kim, Dennis; Bricker, Scott; Bongard, Fred; Neville, Angela; Putnam, Brant; Smith, Jennifer; Plurad, David
Source: The American Surgeon, Volume 80, Number 10, October 2014, pp. 979-983(5)
Publisher: Southeastern Surgical Congress