Cannabis Reduces Blood Pressure Instability Following Spinal Cord Injury: Case Report

By Will Boggs MD

June 17, 2020

NEW YORK (Reuters Health) - Regular cannabis use reduces the frequency of autonomic dysreflexia manifested as blood pressure instability following spinal cord injury (SCI), according to a new case report.

"Importantly, not only was the severity and frequency of transient episodes of hypertension (autonomic dysreflexia) drastically reduced over 24-hours, but smoking cannabis was able to treat a refractory episode of autonomic dysreflexia," Dr. Tom E. Nightingale of the University of Birmingham, in the U.K., told Reuters Health by email.

In patients with SCI that disrupts autonomic pathways, routine peripheral stimuli can trigger episodes of transient hypertension in a process called autonomic dysreflexia.

Dr. Nightingale and colleagues describe the case of a 41-year-old man with a C5 spinal cord injury 21 years earlier that produced a complete loss of sensory and motor function below the injury.

He had been smoking cannabis daily for 13 years (about 1 g of cannabis concentrate via a vaporizer) and also consumed several edibles containing tetrahydrocannabinol (THC), the authors report in Annals of Internal Medicine.

The man's blood pressure stability - evaluated using a 24-hour ambulatory blood pressure monitor on four separate occasions, twice while following his standard cannabis routine and twice after abstinence from cannabis for three days and four seven days - was worse on days when he did not use cannabis and better on days when he did.

Dr. Nightingale said that the patient experienced 56 and 57 episodes of autonomic dysreflexia on the days without cannabis versus five and 17 episodes on the days when he used cannabis.

On another occasion, after eight days of cannabis abstinence, cannabis smoking successfully treated a refractory episode of autonomic dysreflexia, but also produced prolonged hypotension.

Cannabis also reportedly reduced global pain intensity, spasm frequency, and spasm severity; improved sleep; and improved overall well-being by reducing anxiety, impairment, confusion, and sensation and enhancing motivation and attention, according to the authors.

"We believe that our findings document that cannabis use improved blood pressure stability in this patient by reducing the intensity and frequency of the visceral stimuli, such as pain and spasms, that are known to trigger autonomic dysreflexia," the authors note.

"While these findings are promising, information is lacking on optimal dosage, method of delivery, composition, and concentration of cannabinoid compounds to manage secondary conditions associated with SCI," Dr. Nightingale said. "To answer these questions, long-term, double-blind, randomized clinical trials assessing a wider range of outcomes should be conducted to further understanding of the effects of cannabinoid use in people with SCI."

Dr. Alexander Rabchevsky of the University of Kentucky, in Lexington, said that although the findings were based on just one person, "this report has been done by the best SCI physiatrists and urologists that I know personally, having been a paraplegic neuroscientist for 35 years studying autonomic dysreflexia (AD). The results are compelling and warrant further investigations into alternative medicines to treat/alleviate and perhaps even curtail AD episodes from occurring, especially since the medications available are highly variable in efficacy, at best, and can be very costly."

He suggested that physicians "encourage SCI folks to be open with their reports of marijuana use (or other drugs) so that countless others may either support or rebuke myths about marijuana or other potential remedies that are not recognized or regulated by the" U.S. Food and Drug Administration.

"Future studies require equal diligence and compliance, but it is far overdue that such studies be funded as nations worldwide are moving to decriminalize and legalize marijuana usage," Dr. Rabchevsky told Reuters Health by email.

SOURCE: Annals of Internal Medicine, online June 16, 2020.