Diagnosis: When a strokelike spell isn't a stroke

Diagnosis: When a strokelike spell isn't a stroke
By Lisa Sanders, M.d.
Monday, June 16, 2008
1. Symptoms
The boy was sitting in his 10th-grade math class at a high school in Atlanta when he had his first attack. He does not remember what happened, but his classmates noticed that he seemed to be in some sort of trance. He stared straight ahead, eyes unfocused. His lips moved, but no words came out — just a few jumbled syllables. His face looked strangely lopsided.
As the school nurse hurried into the classroom, her first thought was that — as unlikely as it seemed — this 15-year-old boy was having a stroke. But as she examined the boy, he began to improve. The color seeped back into his face, and the asymmetry disappeared. His pulse and blood pressure were normal. By the time the boy's mother got to the school, he was back to his usual self.
His mother took him home, but she was worried. Her son had always been healthy. Certainly he'd never had anything like this happen before. At an event that night she described the strange symptoms to some friends. A man she didn't know, sitting nearby, leaned forward. "Your son could have had a stroke," he announced to the group of women. He apologized for eavesdropping but said something similar had happened to the teenage son of a friend. That boy had ended up completely paralyzed on one side of his body before they figured out what was going on.
When she got home that night, the now-terrified mother called Dr. Norman Harbaugh, her son's doctor. "Did my son have a stroke?" she asked after describing the incident. Maybe, he said. If he was all right now, they should come to his office first thing in the morning. If anything else happened, they should go directly to the emergency room.
Harbaugh had been their pediatrician since the boy was 3. The mother was confident that he would know what this was. But the next day the doctor had no answers, only worries. Although the boy's exam was completely normal, Harbaugh was concerned that this might not have been a stroke but a T.I.A. — a transient ischemic attack — the start of a stroke that somehow repairs itself. If it happened again, the boy might not be so lucky. He sent the boy to a neurologist and a cardiologist that morning. They found no risks for a stroke or evidence that he'd had one.
2. Investigation
Let's watch and wait, Harbaugh advised. Maybe this was just a fluke. And for six months nothing happened. Then in July, the boy had a second attack, and in September, a third. With each attack, the boy was lightheaded and dazed, and there was a new symptom — in addition to the facial droop, his right hand and sometimes his right leg would shake. He was taken to the emergency room each time, but when he arrived, the symptoms were gone. Harbaugh sent him to another neurologist, another cardiologist, a nephrologist, a gastroenterologist. Dozens of blood tests were done. An echocardiogram of his heart was normal. The EEG was normal. By every measure, the boy seemed fine.
And yet over the course of that fall, the attacks became more frequent. Once a week, sometimes twice, his mother would get a call from school saying that her son was being sent to the hospital. One neurologist thought these might be seizures and started the teenager on an antiseizure medication. But the attacks kept coming.
Harbaugh was stumped and frustrated, especially after the boy had spent a week in the hospital and was discharged — still without a diagnosis. At that point, Harbaugh mentioned to the family that perhaps they might need to find experts outside Atlanta. After much discussion, Harbaugh referred the boy to the Diagnostic Center at the Children's Hospital of Philadelphia, which specializes in diagnosing baffling illnesses in children. Harbaugh said he thought it seemed extreme to send this family from suburban Atlanta to a group of doctors in Philadelphia. Extreme but appealing. Coming at it with fresh eyes, a different perspective, these doctors might be able to find the answer.
And so, late that fall, the patient and his mother headed to the Children's Hospital of Philadelphia. They trooped from specialist's office to specialist's office, carrying the thick files of notes and tests that made up the boy's medical history. On their fourth and last day there, the boy and his mother went to see Dr. Rebecca Ichord, a young pediatric neurologist with a specialty in childhood stroke. Ichord greeted them in the waiting room. She was soft-spoken, with a serious but kind face. She sat down with mother and son and went through his thick chart — page by page — asking about each episode. Initially, Ichord, like the doctors before her, thought these "spells," as the boy called them, sounded like T.I.A.'s — ministrokes. But given the extensive work-up that had been done, it seemed clear that this had been ruled out. So what else could this be?
As Ichord went through each of the attacks with the teenager and his mother, she began to notice a pattern. "Were you always sitting down when these spells came on?" she asked. The patient thought for a moment. Yes, at the time of each of these episodes he had been sitting for a long time. They never occurred when he was active. It was the answer she was hoping for. "I think you have something called postural orthostatic tachycardia syndrome," she told the boy. This is a disorder that has only recently been described, but one she had seen a number of times during her years in practice. POTS, as it's called, is seen mostly in adolescents and is characterized by lightheadedness and confusion, usually upon standing up. Normally when you're sitting, blood pools in the legs. The blood vessels there constrict to help the blood return to the heart and stay in circulation. In patients with POTS, the vessels aren't constricting properly, and so too much blood stays in the legs, causing a decrease in the amount in circulation. An inadequate supply of blood to the brain causes the lightheadedness and confusion.
But what about these strokelike symptoms, the mother asked. That wasn't classic for POTS, but Ichord had seen it before too. She said she thought that in these patients the inadequate supply of blood triggered sensitive regions in the brain to overreact and cause these strange localized symptoms. And these symptoms, like the rest of them, got better when the patient lay down.
3. Resolution
A simple test could help her determine if her hunch was right. She had the lanky youth lie down on the examining table. She checked his pulse and his blood pressure. Both were normal. Then she had him sit up and measured his pulse and blood pressure again. Normally blood pressure doesn't change much and heart rate increases slightly as the body tries to get all the blood from the lower body, where it is pooled, to the rest of the body, which now needs more blood. In this patient, though his blood pressure remained normal, his heart began to race as his body tried to force the blood from his legs all the way up to his brain. Based on this test, Ichord thought it was quite likely that the teenager had POTS. She ordered a study, which confirmed her diagnosis.
POTS is often seen following a growth spurt. The thinking is that the nerves that tell the blood vessels to constrict haven't kept up with the rest of the body. Her patient had grown six inches over the last two years. Adolescents often grow out of this disease. Until then it is treated with a drug that constricts the blood vessels and salt tablets that increase the amount of fluid in the body. The boy was started on this regimen, and two years later, he is doing well.
"What's amazing to me," the patient told me recently, "is that I went to dozens of doctors, had hundreds of tests, had gallons of blood taken, and Ichord made this diagnosis with just one question and a blood-pressure cuff. I couldn't believe it." The difference was that, unlike the other doctors who had seen this patient, Ichord knew what she was looking for.
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