A fifth of young adults whose blood vessels ruptured inside their brain abused drugs and more than 40 percent had malformed blood vessels, according to a study reported Feb. 17 at the American Stroke Association's International Stroke Conference 2006 in Kissimmee, FL.
The study included 307 patients with intracerebral hemorrhage (ICH) -- a stroke caused by a blood vessel bursting inside the brain. Of the 75 patients 49-years-old or younger, 20 percent had drugs in their system.
"The dominant drug of abuse was cocaine, long recognized as a risk factor for ICH," said Michael Hoffmann, MD, lead author of the study and director of the stroke program at the University of South Florida-Tampa General Hospital. "Marijuana was another frequently abused drug and is beginning to emerge as a risk factor for stroke. Amphetamines also were commonly abused."
How these drugs make brain blood vessels prone to rupture is not clear, but is being studied, Dr. Hoffmann said.
The study analyzed the causes and outcomes of ICH patients. Twenty-four percent of ICH patients in a registry at Tampa General Hospital were ages 18 to 49. Half were women, about two thirds were Caucasian, 15 percent were black and 12 percent were Hispanic.
ICH is often linked with high blood pressure in people over age 50, and in this study, 57 percent of those age 50 and older had it. Only 33 percent of ICH patients ages 18 to 49 had high blood pressure.
Of the younger patients in the study, 41 percent had malformed blood vessels, known as arteriovenous malformations, aneurysms or other vascular disorders. Cerebral arteriovenous malformation occurs when blood vessels in the brain develop in an abnormal tangle in which the arteries connect directly to the veins without the normal capillaries between them. A cerebral aneurysm is the bulging of the wall of an artery in the brain. Both these conditions weaken blood vessels and increase the risk of a hemorrhagic (bleeding) stroke.
The good news is that patients under age 50 who experience this vessel rupture inside the brain have better outcomes than older patients.
"Surprisingly, our study showed a low mortality rate compared to population studies," said Dr. Hoffmann, professor of neurology at USF.
The 30-day mortality was 14.6 percent for the younger group, significantly lower than for older patients, whose mortality rate was 21 percent, he said. Previously, national population studies have found a high 30-day mortality rate for stroke patients with ICH. Some epidemiological data have suggested a 45 percent to 50 percent mortality rate, Dr. Hoffmann said.
ICH has traditionally been associated with older age groups and higher mortality rates.
Dr. Hoffmann attributes the low mortality rate in younger ICH patients to intensive neurocritical care management at Tampa General. The protocol includes decreasing intracranial pressure and using drains to prevent hydrocephalus, mechanical ventilation, sepsis control, blood pressure control and cooling.
The younger patients came into the emergency room, then were rapidly transferred to a neurocritical care unit within six hours. Typically, patients are hospitalized in the neurocritical care unit for one to eight weeks. Patients were evaluated by MRI, CT and angiography.
"This new way of thinking about how to manage patients with ICH is an important approach, and patients are reaping benefits," Dr. Hoffmann said.
Most of the younger patients were able to live independently three to six months after their ICH, with only mild to moderate cognitive impairment that tends to improve over time, he said.
Dr. Hoffmann said the degree and nature of disability at six months is now the focus of the extension of this study.
"Intensive neurocritical care is the key to successful outcome," Dr. Hoffmann said. "Good medical care can salvage a high quality of life after a stroke."
The study was funded by USF Health and the Tampa General Hospital Stroke Registry. Co-author is Ali Malek, MD, USF assistant professor of neurology.