ST. PAUL, MN "Chasing the dragon," a form of heroin use in which the drug is heated and the resulting vapor is inhaled, can produce a progressive and permanent brain disorder and even death, according to a study published in the November 10 issue of Neurology, the American Academy of Neurology's scientific journal.
"Chasing the dragon" has become a more common technique of using heroin as it avoids the risks, including HIV and hepatitis infection, associated with direct injection of the drug. However, users run the risk of developing spongiform leukoencephalopathy, in which the brain's white matter becomes covered with microscopic fluid-filled spaces, creating a sponge-like appearance. The disease targets specific cells, causing them to block nerve impulses in the brain. Because the cerebellum and motor pathways are the most severely affected brain regions, patients become uncoordinated and have difficulty moving and talking.
"The illness is extremely grave, with no known treatment and progression to inability to move or speak and death in approximately 20 percent of reported cases," said neurologist Arnold Kriegstein, MD, PhD, author of the study and professor of neurology at Columbia University in New York. "Most patients who survive have permanent deficits. The symptoms usually progress rapidly over days to weeks, even after the drug is no longer present in the body. They may improve gradually over months to years, but most patients do not return to normal."
Numerous cases related to "chasing the dragon" have been documented in Europe and other regions of the world. Kriegstein's study reports the first three known cases in the United States. "We suspect that there may be many more cases that are being misdiagnosed," he said.
The first patient in the report, a 21-year-old woman, had a severe and near fatal condition. After six months of daily inhalation of heated heroin, she lost the ability to stand, sit or perform any daily activities. However, two years later, she is nearly completely recovered with only mild movement problems remaining.
The woman's 40-year-old boyfriend agreed to be seen after his girlfriend was admitted. He had also begun "chasing the dragon" six months prior, although to a lesser extent than his girlfriend. Upon admission, he had severe speech, reflex and movement difficulty. He began treatment, but relapsed into his drug habit. Therapy was later restarted and he began to improve, although he developed a tremor that resulted in some ongoing impairment of his daily activities.
The third patient had inhaled heroin on a few occasions with the first two patients, and agreed to be seen after their admissions. The 28-year-old man had subtle movement dysfunction but no other neurological complaints. He did not complete any therapy or follow-up visits.
The first two patients were treated with antioxidants coenzyme Q, vitamin E and vitamin C. Other patients of similar age with less severe stages of illness have been reported to have much less positive recovery. "The use of antioxidants is an experimental treatment that has not been used in this condition before, although it has been proposed as a possible treatment for other similar disorders," said Kriegstein. "While the role of antioxidant therapy in this condition remains uncertain, it may be worthwhile to try this treatment with future patients since it was well tolerated and might have contributed to recovery in our patients."
What actually produces this condition is not known. "Because these cases occur when other people who inhale heated heroin vapor are unaffected, we suspect the most likely cause is an unidentified substance added to the heroin," Kriegstein said. "It seems clear that only the heated vapor is toxic, since this condition has never been reported in persons using heroin by other means, such as injection or snorting."
Because the heroin is placed on aluminum foil and heated, researchers also tested for organic tin poisoning, which can produce brain degeneration much like that in the reported cases. However, only trace amounts of tin were detected in the foil and the possibility of converting the metallic tin to the toxic form is very slight.
"Officials estimate that nationwide, there are between 500,000 and 1 million hard-core, chronic heroin users," said Kriegstein. "More overdoses and overdose deaths, greater demand for treatment, larger heroin seizures at all distribution levels and related arrests, and broader media coverage are evidence that supplemental users may be ushering in another heroin era. It is also interesting to note that one of our patients learned how to Œchase the dragon' from observing a scene in a movie."
The American Academy of Neurology, an association of more than 16,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research.
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Neurology