"Medicine and diagnosis is about the probability of things," says Dr. John England, head of the neurology department at LSU Health Sciences Center.
Take the story of Karen Doerries.
When she arrived at East Jefferson General Hospital (EJGH), Doerries was screaming from pain and was immediately given a CAT scan. The test revealed nothing abnormal, and Doerries was sent home. Later that day, she went to her primary physician, Dr. Miguel Rivera, who gave her a shot of the migraine headache medication Imitrex and referred her to a neurologist.
By the next day, Doerries was popping Vicodin and was so incapacitated by pain that she was relegated to a wheelchair. Her partner, Ann Campbell, wheeled her in to see neurologist Dr. Mossadiq Jaffri, who ordered an MRI examination. Doerries had the MRI and returned home, expecting a call to tell her the results of the test.
But before that could happen, Doerries, a physical therapist who worked with brain-injury patients and stroke victims, woke up at 4 a.m. the following morning and discovered she no longer could feel the left side of her body. Terrified that she might be having a stroke, she called 911 and an ambulance transported her back to EJGH. Once there, Doerries underwent a lumbar puncture a procedure in which spinal fluid is drawn from the spinal canal and tested but doctors found no blood in the fluid, which would have indicated a possible stroke.
Doerries says that after the negative result, the staff at EJGH wanted to release her, but she convinced them to keep her there for observation. According to Campbell, on Doerries medical chart was written, "Patient in no apparent distress." Moments later, in an elevator, going up to her room, Doerries noticed her fingers clench, her face sag and her left wrist and elbow uncontrollably draw up toward her face. She knew she was having a stroke.
In her room, Doerries managed to whisper to Campbell, "I've had a stroke." Hearing her slurred voice and seeing tears dripping down her drooped face, Campbell realized her partner was in trouble. Campbell says that because of the statement on the chart, she had a hard time convincing nurses to call a doctor to examine Doerries. When a doctor did arrive, however, he confirmed what the two women already knew: Doerries had suffered a stroke and something needed to be done to prevent her from having another.
No one knew what caused Doerries' stroke none of the imaging tests revealed anything abnormal and without a cause there could be no treatment. Because the imaging scans showed no evidence of a burst or blocked artery, doctors ruled out an arterial stroke, which accounts for 95 percent of all strokes. Jaffri and Rivera, who had by now arrived at EJGH, decided to perform an angiogram, which is an X-ray of the blood vessels. Although rare, strokes can be caused by a burst or blocked vein (referred to as venous strokes). All cerebral strokes are literally brain cells dying when blood flow to the brain is impeded.
Before starting the angiogram, Campbell says the doctors allowed family and friends to visit Doerries in the intensive care unit.
"They had us come in and say goodbye," Campbell says.
The angiogram revealed that Doerries was suffering from a cerebral venous thrombosis (CVT), a blood clot in the brain. The clot had blocked one of the veins in her brain, causing the stroke. But the team of doctors now assembled to treat Doerries still did not know why the clot had developed. Even if they had known the cause, the doctors couldn't administer blood thinner to stop the clotting because Doerries was experiencing arterial bleeding in her brain. If they gave her blood thinners, she could die. Plus, intracranial pressure was building up inside Doerries' head, increasing the chances of more bleeding, more burst blood vessels and more strokes.
Faced with these circumstances, the only course of action was to try to relieve some of the pressure through steroids and oxygen. After that, it would be up to Doerries' body to heal itself. In order to best facilitate this healing, Doerries would be put in a monthlong, drug-induced coma. Doctors presented Doerries' friends and family with what the physicians considered to be a realistic assessment of the situation: "We can offer you no hope."
While Doerries was in the coma, her intracranial pressure increased, her body temperature shot up to 106 degrees ICU nurses packed Doerries' body in ice to try to bring it down and her heart rate increased to 158. Yet Doerries hung on, surprising her doctors.
"They didn't know how she was alive," Campbell recalls.
Today, eight years later, Karen Doerries leads a normal life and displays few signs of her stroke. Although CVTs are extremely dangerous England says that they have a 10-20 percent mortality rate patients often recover and function fully. After Doerries was brought out of the coma, she went through weeks of rehab at EJGH, but four weeks later she walked out of the hospital on her own power. Her one setback from the stroke has been a loss of physical strength; consequently, she no longer can work as a physical therapist, which can be demanding on the body.
Something else she doesn't have is any resentment toward EJGH or any of the doctors who helped treat her.
"I didn't sue anyone at East Jefferson because at the end of the day, they saved my life," Doerries says.
England doesn't find fault with the doctors involved in Doerries' case. "This is not a problem of the individual doctors," he says. "This is the evolution of disease and one that's very rare and hard to recognize."
Strangely enough, though, Doerries' diagnosis and continuing treatment are still based on probability. When she was in the coma, Dr. Cindy Leissinger, a hematologist and medical director for Tulane Medical Center's Louisiana Center for Bleeding & Clotting Disorders, consulted on the case and discovered that Doerries' had acquired thrombophilia, a syndrome in which the blood clots. To complicate matters, to alleviate pre-menopause symptoms, Doerries had begun taking birth-control pills, which increase the risk of clotting as well. Based on these factors, after the arterial bleeding ceased, Doerries was put on a regimen of anti-coagulating medication, which she continues to take regularly.
It would seem to be a slam dunk: The birth control pills combined with Doerries' thrombophilia ultimately caused her stroke, right? Not necessarily, Leissinger says.
"Birth-control pills add to the risk of developing a clot in someone who has an underlying clotting tendency," Leissinger explains. "To say that there is a direct cause and effect, we can't say that."
On the other hand, as the patient Doerries can make that connection. She's convinced that her clotting condition, which she was never aware of, and the birth control medication led to her CVT. In her opinion, doctors over-prescribe oral contraceptives and drug companies don't give the women who take them strong enough warnings about the possibility of strokes.
"Why don't physicians evaluate and test women before they give them the pill?" Doerries asks.
LSU's Dr. England agrees that before someone is prescribed a contraceptive, doctors (and their patients) should consider a number of circumstances including a woman's age, family medical history and health. But he points out that in addition to limited certainty in medical science, there also are imited dollars.
"It wouldn't be cost effective for people to be screened," England says of screeing for potential blood-clotting problems. "You would spend an inordinate amount of time looking and you'd find only a few people with them."
That's because Doerries' thrombophilia is rare and so was her CVT. England says it would be very difficult for a physician to identify venous thrombosis and that Doerries' experience is typical in patients who develop the condition.
"Unfortunately, this is a common phenomenon in that venous thrombosis in the brain isn't diagnosed until very late or until a real clear stroke happens," England says. However, he adds that because Doerries did get an X-ray and that imaging systems have dramatically improved since her experience eight years ago, "It is much less likely that this (Doerries' thrombosis) would have been missed in the beginning" if she had had the experience today.
Nevertheless, it all started out as a headache. Almost everyone gets headaches and England says most of the time they are not caused by something as serious as a potential stroke. But Karen Doerries realized as the pain continued and increased that something was very wrong. Her insistence that doctors look more deeply into the cause ultimately helped save her life.