Brain damage caused by cocaine partially heals after people stop using the drug, a researcher reports.
Because cocaine use reduces blood flow to the brain, cocaine users often suffer from impaired thinking, memory, learning and decisionmaking skills, said Dr. B. Leonard Holman of Brigham and Women's Hospital in Boston.Using sophisticated brain imaging techniques, Holman found that blood flow in the brains of 10 cocaine users began to return to normal during abstinence and impaired skills improved between 50 percent and 70 percent.
"This study shows that it is possible to at least partially restore blood flow to the brain and it makes treatment all that more important," said Holman, who presented his findings to the Society of Nuclear Medicine.
The results of the one-month study were surprising because a number of other studies suggested that brain-blood flow deficits caused by long-term cocaine use are permanent, he said.
Holman said cocaine users' brain cells apparently are not killed by the drug but simply do not function as they normally would.
"The cells aren't dead, and with new blood the neurons can start functioning near normal," he said.
Researchers were able to detect the return of blood flow to the impaired areas by using a medical imaging device to scan the brains of patients undergoing treatment for cocaine addiction.
The patients were injected with a small amount of a radioactive drug that was distributed in the brain in proportion to the amount of blood circulation, Holman said.
In the first set of scans, the brain appeared riddled with holes that indicated decreased blood flow.
After one week of abstention, a second series of scans showed that blood flow in the brain increased by 11 percent. Scans taken 17 to 29 days after abstention showed blood flow increase of about 23 percent, Holman said.
The researcher emphasized his results do not mean that brain function returns to "completely normal after abstinence, but it does prove that treatment can improve blood flow to the brain and return subjects to near normal levels of brain function."