Showing posts with label stroke. Show all posts
Showing posts with label stroke. Show all posts

Thursday, October 2, 2014

Strokes in Young People


Drug use as a risk factor.

(First published 12-09-12)

When a stroke happens to anyone under the age of 55, a major suspect is drugs, specifically the stimulants—methamphetamine and cocaine. In the journal Stroke, researcher Brett Kissela and his associates provided additional evidence to support that unpleasant truth.

“We know that even with vascular risk factors that are prevalent—smoking, high blood pressure—most people still don’t have a stroke until they’re older,” Kissela said in a Reuters article. “When a young person has a stroke, it is probably much more likely that the cause of their stroke is something other than traditional risk factors.”

The modest study involved residents of Cincinnati and Northern Kentucky who had suffered a stroke before turning 55. The researchers found that the rate of substance abuse among the stroke group was higher than in control populations. This doesn’t prove that drug or alcohol addiction lead directly to strokes, since drug users often have additional risk factors for stroke and heart disease, particularly if they are also cigarette smokers.

But the suspected link between strokes and young drug abusers is by no means a new one. In 2007, scientists at the University of Texas Southwestern Medical Center in Dallas published a massive survey of more than 3 million records of Texas hospital patients from 2000 through 2003 in the Archives of General Psychiatry. This gigantic database gave the researchers access to the records of virtually every stroke patient in the state of Texas. The researchers found that strokes associated with amphetamine use among young people 18 to 44 years of age represented a rapidly growing category. In fact, the Texas group found that “the rate of strokes among amphetamine abusers was increasing faster than the rate of strokes among abusers of any other drug.”

Curiously, amphetamine and cocaine are responsible for different kinds of strokes. An ischemic stroke, the classic blood clot, is caused by a blockage of blood vessels to the brain. Hemorrhagic strokes result from bleeding caused by the rupture of a weakened blood vessel. In general, hemorrhagic strokes are more severe and more likely to cause death. And what the researchers found was more bad news for speed freaks: “Amphetamine abuse was strongly associated with hemorrhagic stroke, but not with ischemic stroke.” Cocaine abuse was more robustly linked to ischemic strokes. So, it’s not surprising that when it comes to drug and fatal strokes, the clear winner was amphetamine. It’s not entirely clear what causes the difference, but the investigators pointed out that meth injections in lab animals can cause microhemorrhaging, heart attacks, fragmentation of capillary beds, and something called “poor vascular filling.” For cocaine, the culprits are vasoconstriction and disrupted regulation of blood pressure.

More than 14 percent of strokes in hospitals “were accounted for by abuse of drugs,” the researchers wrote. The data showed that for patients with hemorrhagic strokes, “only amphetamine abuse, coagulation defects, and hypertension were strong independent predictors of in-hospital death.”

So what can we conclude? Either the number of speed users in these communities is increasing, or the existing speed communities are using the drug more intensely. Since the rate of increase of speed use was relatively modest during the study years, the researchers concluded that “increased rate in our hospital population is because of the increased intensity of methamphetamine use.” Meaning higher dosages, stronger meth, and more needles.

Sadly, much of this has been known since it least 1990. In that year, research published in the Annals of Internal Medicine, based on a study of stroke victims at San Francisco General Hospital, concluded that “the possibility of serious and sometimes fatal cerebrovascular accidents in people taking potent stimulants and using the intravenous route of administration is not as widely known as it needs to be.”

About 800,000 people in the U.S. suffer a stroke each year, according to figures from the U.S. Centers for Disease Control and Prevention. Strokes are considered America’s leading cause of serious long-term disability.

de los Rios F., Kleindorfer D.O., Khoury J., Broderick J.P., Moomaw C.J., Adeoye O., Flaherty M.L., Khatri P., Woo D. & Alwell K.;  (2012). Trends in Substance Abuse Preceding Stroke Among Young Adults: A Population-Based Study, Stroke, 43 (12) 3179-3183. DOI: 10.1161/STROKEAHA.112.667808

Sunday, April 7, 2013

Marijuana and Strokes: Medical Reality or Scare Story?


Heavy tokers may be at higher risk, but alcohol is the hidden confounder.

Young people don’t suffer from strokes, as a rule. And when they do, at least half the time there is no obvious cardiovascular explanation. So it’s not surprising that drugs are often invoked as the culprit.

A New Zealand study earlier this year once again raised the specter of a possible link between stroke and marijuana smoking. As reported by Maia Szalavitz at Time Healthland, the confounding issue, as is typical of such studies, is the coexisting use of other drugs, like alcohol and cigarettes. As Szalavitz writes:

The stroke study, which incorporated preliminary data, is the first trial of its kind to study a possible connection between marijuana use and stroke. It included 160 patients aged 18 to 55 who had suffered a stroke connected to a blood clot in the brain, and who agreed to have their urine tested for marijuana within 72 hours of the stroke.  These results were compared to those from 160 controls who had not had a stroke but came to the hospital for other reasons. They were matched on age, gender and ethnic background, all of which can also affect the risk for this type of stroke. About 16% of the stroke patients showed traces of marijuana in their urine, compared to 8% of those in the control group, suggesting a doubling of the risk of stroke.

However, because of nicotine and other confounding variables, that study was considered inconclusive. In an earlier study published in Stroke, the journal of the American Heart Association, Valerie Wolff and colleagues from the University of Strasbourg in France searched the medical literature and found 59 cases of stroke in which cannabis could be considered a cardiovascular risk factor. The investigators used only cases that had been confirmed by neuroimaging. The researchers focused on cases where a stroke had occurred while smoking marijuana, or within a half hour after the last joint or bong hit.

But proving a cause and effect relationship is tricky. Assuming, for now, that all of the strokes in question were not caused or compounded by alcohol or drugs other than marijuana, the French scientists postulated several mechanisms that could conceivably account for a cannabis-related ischemic stroke (a stroke caused by obstruction of a blood vessel). These include orthostatic hypotension, altered cerebral vasomotor function, major swings in blood pressure, and cardiac arrhythmias. However, the only solid commonality in cannabis-related strokes was that the users were more likely to be heavy smokers.

In the 50 strokes the researchers were able to confirm by cerebral imaging, the patterns in some patients were similar to those observed in a syndrome called reversible cerebral vasoconstriction syndrome (RCVS). RCVS  is marked by severe headaches, strokes, and brain edema, but symptoms typically resolve in a few months.  “Reversibility of the vasoconstriction within 12 weeks is a key point of this syndrome,” the authors write. “The long duration of stenosis [blockage] argues in favor of a drug-induced immunoallergic vasculitis rather than vasospasm. Our point of view is that this disorder may be considered as a variant of RCVS,” rather than as a garden-variety ischemic stroke triggered by excessive use of cannabis.

According to the French study, “The most frequently presented characteristics of cannabis users who experienced a stroke are young male chronic tobacco and cannabis abusers who have had an unusual high consumption of cannabis and alcohol before stroke.” The most convincing mechanism to explain ischemic strokes in young people, the researchers say, is “reversible cerebral angiopathy involving several arteries, associated with cannabis consumption in association with tobacco and alcohol use.”

And there you have it. Smoke weed, and you appear to have a slight risk of suffering stroke, which, under age 50, is an extremely uncommon medical event.  Add tobacco, and the stroke risk goes up. Add alcohol, and the stroke risk ratchets even higher. By itself, marijuana appears to be a minor factor in strokes—but it appears likely that pot is indeed the culprit at least some of the time.

“Cannabis-related stroke is not a myth,” the scientists conclude, “and a likely mechanism of stroke in most cannabis users is the presence of reversible multifocal intracranial stenosis (MIS) induced by this drug. The reality of the relationship between cannabis and stroke is, however, complex, because other confounding factors have to be considered (ie, lifestyle and genetic factors).”

Wolff V., Armspach J.P., Lauer V., Rouyer O., Bataillard M., Marescaux C. & Geny B. (2013). Cannabis-related Stroke: Myth or Reality?, Stroke, 44 (2) 558-563. DOI:

Graphics Credit: http://www.strokegenomics.org/


Wednesday, January 2, 2013

Twelve Months of Addiction Box


(Inspired by Twelve Months of Drug Monkey)

Drug Monkey writes:

The rules for this blog meme are quite simple.
-Post the link and first sentence from the first blog entry for each month of the past year.
I originally did this meme, after seeing similar posted by Janet Stemwedel and John Lynch.

Okay, here we go:

January:

Say what you will about glutamate-gated chloride channels in the parasitic nematode Haemonchus contortus—but the one thing you probably wouldn’t say about the cellular channels in parasitic worms is that a drug capable of activating them may prove useful in the treatment of alcoholism and other addictions.

February:

Here’s a book I’m delighted to promote unabashedly.

March:

Mo Costandi at the UK Guardian expanded on his Nature article about the mechanisms that result in memory impairment when people smoke marijuana.

April:

Our latest participant in the “Five Question Interview” series is Dr. Keith Laws, professor of cognitive neuropsychology and head of research in the School of Psychology at the University of Hertfordshire, UK.

May:

I'm not a huge fan of infographics, mostly because they tend to overpromise and are often marred by factual errors.

June:

Reporting the results of published studies concerned with genetic risk factors has always been a tricky proposition.

July:

Dr. Tom McLellan, chief executive officer of the Treatment Research Institute, who served on President Obama’s healthcare reform task force, called the recent U. S. Supreme Court Decision on the Affordable Care Act “the beginning of a new era in prevention, early intervention, and office based care for patients who are not addicted—but whose drinking, smoking, and use of other substances is harming their health and compromising the effectiveness of the care they are receiving for other illnesses and conditions.

August:

Medical marijuana advocates will finally have their day in federal court, after the United States Court of Appeals for D.C. ended ten years of rebuffs by agreeing to hear oral arguments on the government’s classification of marijuana as a dangerous drug.

September:

Voters in The Netherlands may have lost their final chance to block the nationwide imposition of the wietpas, or so-called "weed pass," as the law of the land in The Netherlands next year.

October:

People who say they are addicted to marijuana tend to exhibit a characteristic withdrawal profile.

November:

Children with heavy alcohol exposure show decreased brain plasticity, according to recent research on fetal alcohol spectrum disorders (FAS) using magnetic resonance imaging (MRI) scans.

December:

When a stroke happens to anyone under the age of 55, a major suspect is drugs, specifically the stimulants—methamphetamine and cocaine.


Photo Credit: lotteryuniverse.com
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