In the emergency room, the young woman was sleepy and confused. She didn't remember the seizure. All she knew was that she felt bad earlier that day. Her shoulders ached and she had these strange shooting pains that ran up her neck, into her skull. She had a wicked headache too. Although she had this headache for months, it was much worse that day. At home she took a long hot bath and went to bed. She woke up in the ambulance.
She'd had no fever, she told the E.R. doctor, and hadn't felt sick — just sore. And now she felt fine. Her arm didn't hurt — in fact she couldn't remember that it had ever hurt. She still had the headache, though. She didn't smoke, didn't drink and took no medications. She moved to Boston from Bolivia several years earlier to get married and now had 15-month-old. Other than mild confusion, the patient's physical exam was normal. The E.R. doctor ordered blood tests to look for evidence of infection along with a CT scan of her head to look for a tumor.
Her headache started the year before, when she was pregnant. Before that she had the occasional headache, but back when her daughter was barely a bump, she got one that simply never went away. She told the midwife, who said it wasn't unusual to get headaches during pregnancy. But to the patient, this headache seemed different. It was like a vise on her head, just over her eyes. The pressure wasn't excruciating, just unrelenting. She took Tylenol, and that sometimes helped, but the headache always came back. Sometimes it even woke her up in the middle of the night. Finally the midwife sent her to her primary-care doctor.
Her doctor, a young internist in her first year of training (who asked that her name not be used), was worried about this headache. It had persisted for weeks and woke her patient up from sleep — that was unusual. The doctor recalled how happy the patient was when she called her with the news of her positive pregnancy test. And now barely showing at five months, she looked like the picture of expectant health. Had she had any weakness or numbness? Was there any loss of hearing or blurry vision? No, no and no. Well, she did have blurry vision, but that's only because she hated wearing her glasses.
The doctor focused her exam to look for any hint that this headache might be because of some kind of brain injury. She looked into the patient's eyes with the ophthalmoscope, scanning the retina for any signs of increased pressure inside the brain. She checked the patient's strength, coordination and reflexes. Nothing. Her exam was completely normal.
Headaches are common, accounting for some 18 million doctor visits a year. Most are completely benign, but up to 3 percent of patients with a headache severe enough to send them to the emergency room will have something worth worrying about. Doctors are taught to look for three types of potentially dangerous headaches: the first, the worst and the cursed. The first headache in someone who doesn't have headaches; the worst headache ever in someone who does; or a headache "cursed" by symptoms like weakness or numbness. A CT scan should be considered for these possibly life-threatening headaches. This headache fit into none of these informal categories.
This patient was woken up from sleep by her headaches — that's unusual, but the doctor knew that it was not one of the recommended reasons for getting a CT scan. And she was pregnant. A CT scan of the head requires a relatively high dose of radiation. Was the doctor's concern great enough to risk exposing the fetus based only on this somewhat unusual symptom? Not yet. Especially since there was another possible cause of the persistent headache — eyestrain. The patient was no longer wearing her glasses; she didn't even own a pair, she confessed. She should get new glasses, the doctor suggested, and see if wearing them helped her headache. If not, she should come back. Perhaps they would get a CT scan at that point.
It was more than a year later when the patient next came to see the doctor. She had gotten glasses, and though the headaches hadn't stopped, they seemed a bit better. It was no longer a constant pain. She had one maybe three to four times a week, and it lasted for a few hours and went away with a little ibuprofen. Besides, she was really too busy with the baby and her job to worry too much about them.
Then, six months after that last visit, she had this middle of the night seizure. In the E.R., the blood tests were all normal. Not so the CT scan. On the right side of the patient's brain, just over the eye, there was a bright circle of white, the size of a dime. Not a brain tumor. No, the radiologist said, this was a tiny worm, a larvae, the young offspring of a tapeworm. The parasite, known asTaenia solium, is transmitted through undercooked pork contaminated by tapeworm eggs. Once in the body, the eggs hatch and then attach themselves to the intestinal wall and within a few months can grow to up to 15 feet or more. A mature tapeworm will then release hundreds of eggs into the gut every day. If any of these are ingested, they can hatch, enter the bloodstream and, once there, can lodge almost anywhere in the body, although they usually end up in muscle and in the brain.
Although unusual in the United States, pork tapeworm is common in the developing world. And having these larvae in the brain, a condition known as neurocysticercosis, is the most common cause of adult epilepsy in South and Central America. The patient was probably infected with this tapeworm years earlier when she lived in Bolivia. This kind of infection can be asymptomatic for years. Once the doctors saw the CT scan, the patient was treated with an antiparasite medication for 30 days and started on antiseizure medications.
When her primary-care doctor heard that her patient had been diagnosed with neurocysticercosis, she scoured the patient's hospital chart and then her own notes. How had she missed that? What should she have done differently? She discussed the case with several of her teachers, who assured her that she had done everything properly. One of the frustrating truths in medicine is that it is possible to do everything right and still be wrong and miss the diagnosis.
The young doctor called the patient to see how she was doing and to schedule a follow-up visit. She was disappointed, though not completely surprised, when the patient chose to see a different doctor at the clinic.
In thinking about this case, the doctor's greatest regret is that she didn't get the chance to follow up on her patient and find out that her headaches didn't go away by just wearing glasses. When patients don't come back, the temptation is to assume they've gotten better. That is often not the case. Sometimes they've just given up. Now when she has a patient she is worried about, the doctor doesn't tell them to call her if they don't get better. Instead she has them make an appointment to come back in a couple of weeks. "If they are all better," the doctor told me, "they can cancel the appointment. But just in case they aren't — the way this woman wasn't — they can come back, and I can have another shot at the whole thing."
Lisa Sanders is the author of "Every Patient Tells a Story: Medical Mysteries and the Art of Diagnosis."
http://www.nytimes.com/2010/11/07/magazine/07FOB-Diagnosist-t.html?ref=magazine
