CHICAGO, Feb 3 (Reuters) - A new study suggests that use of cocaine causes blood vessels in the brain to became constricted, a condition associated with impaired thinking ability and memory loss.
In the study, published on Tuesday in the Journal of the American Medical Association, twenty-four past cocaine users were given varying doses of the drug.
Images of the subjects brains, called magnetic resonance angiography, taken before and 20 minutes after the cocaine was administered revealed vasoconstriction, or narrowing of the arteries that deliver blood to the brain, Marc Kaufman and colleagues at McLean Hospital in Belmont, Massachusetts, said.
The effect was cumulative, increasing with length and intensity of cocaine use, and could heighten the risk of suffering a drug-induced stroke and the loss of memory or learning deficits, they said.
Otherwise healthy subjects between the ages of 24 and 34 who had used cocaine a median of eight times before were either given one of two intravenous dosages of the drug or a placebo.
The higher the dosage and the greater the frequency of past usage correlated with more blood vessel constriction.
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