Think Like a Doctor: An Unusual Headache Solved

On Thursday, we challenged Well readers to puzzle their way through the case of a 23-year-old woman who started out with what seemed like her usual migraine but who then became more and more ill. By the time the diagnosis was made, she had double vision and she was shaking and confused. And despite the right diagnosis, there was worse to come.

But first, the correct diagnosis is…

Ovarian teratoma (dermoid cyst) encephalitis

Nearly 300 readers offered their thoughts on what was wrong with this patient. The first person to come up with the right diagnosis was Dr. Matthew Bevers, a neurology resident at Massachusetts General Hospital and the Brigham and Women’s Hospital in Boston.

Dr. Bevers studied with Dr. Josep O. Dalmau, the neurologist who published the first case series describing this rare disease. He also saw a case just like this one last year, he told me. As in that case, the patient — a young woman — had come from another hospital where the most common diseases had been considered and ruled out, pushing the new team to consider more unusual diagnoses.

The Diagnosis:

A dermoid cyst, or teratoma, is an unusual growth most commonly found in the ovary or testes. These strange cysts have been a source of fascination since their discovery in the 19th century because, although they are smooth and appear normal on the outside, on the inside they often contain hair, nails, teeth and other tissue not normally seen in the reproductive system.

Indeed, the name “teratoma” is derived from the Greek word for “monster,” because of their creepy contents. They are also called dermoid cysts because most of the time these growths are made up of cells that would normally be found in or on the skin (dermis). These cysts rarely cause trouble and are usually removed only if they get too large or cause pain.

In 2005, a paper published in The Annals of Neurology by Dr. Dalmau and colleagues described nine women who started off with a severe headache, then rapidly developed psychiatric and neurological symptoms, including psychosis, seizures and somnolence. Most eventually became unresponsive and comatose. All were found to have teratomas. Remarkably, most recovered fully once the tumor was removed, though three had some long-term deficits. One died, even after being treated. More recently a case series of 100 women diagnosed with this strange illness showed how very dangerous this disease can be. Nearly a quarter of those women died despite treatment.

The authors of the first case series theorized that these particular tumors — which have the potential to grow any type of cell in the body — grew some type of primitive brain cells. Then, for reasons that are not well understood, the women’s immune systems mistakenly identified these cells as “foreign” and did what they’re designed to do: make antibodies to destroy these presumed invaders. These antibodies attack the cells in the body and then go on to attack the same kind of cells in the brain.

Treatment usually starts with the surgical removal of the teratoma, followed by treatment with medications to neutralize the attacking antibodies. Earlier treatment appears to be associated with a better recovery.

How the Diagnosis Was Made:

Dr. Neil A. Busis, the chief of neurology at the teaching hospital where the patient was sent, says he made the diagnosis before he even saw the patient. He reviewed the data collected by the hospital where she’d originally been treated. As soon as he saw that this was a healthy young woman with rapidly progressive neurological deficits and a known teratoma, he recognized a pattern.

It was a new pattern for Dr. Busis. Just a few months earlier he’d been in a lecture where this entity was mentioned. It piqued his interest and he’d stored it away as something to consider in the right patient. This, he thought, was definitely the right patient.

Dr. Busis recommended that she be tested for the presence of the telltale anti-brain antibody — called anti-NMDA — and suggested getting a gynecologist involved to help manage the illness and remove the tumor. But the illness was moving too fast.

The next day, before the gynecologist even had a chance to see her, the patient began seizing. When the nurse found her, sprawled across her bed, jerking and twitching, she called for help. The young woman was intubated and transferred to the I.C.U. Over the course of the next 24 hours the seizures relented and she lapsed into a coma.

Dr. Busis was certain that this patient had this recently described disease. “It was a textbook case,” he told me recently. Still, other members of the team were not convinced.

There is an aphorism in medicine that reminds us of a basic mathematical truth: that an unusual presentation of a common disease is far more likely than even a textbook presentation of a rare disease. However, once the patient worsened, and ended up comatose and on a ventilator, Dr. Busis was able to persuade the other doctors on the team to treat her for ovarian teratoma encephalitis, even as they continued to look for other possible diagnoses. The cyst was removed, and she was given medications to tamp down her immune response.

A Slow Recovery:

The patient didn’t respond right away. Dr. Busis wasn’t worried. In the reported cases, it often took weeks before improvement was seen. In this case, it took two weeks for the patient to wake up. And once she did, she was quite weak and lethargic.

Her short-term memory was impaired. She couldn’t walk; she could barely talk. But slowly, over the course of the next weeks, she improved. She was discharged to a rehabilitation facility six weeks after she first came to the hospital. With a lot of help and hard work she got better. That was two years ago. She is now back at work and feeling great.

She tells me that she doesn’t remember much about her hospital stay. Going to the first hospital, she recalls being sent to a private room on the floor for palliative care. The doctors were worried she could have some infectious encephalopathy and that was the only single room available.

The patient didn’t know what the doctors were thinking. And so, as she was pushed through the hallways and saw where she was, she was scared. “Am I going to die?” she remembers asking her boyfriend, now fiancé. He shook his head, “I don’t think so,” he told her. The next thing she remembers, it was two months later and she was in a rehab hospital, hours from her home.

The Test of Time:

One of the difficulties of making a diagnosis of a rare disease is that even though our bodies have limited ways of going wrong, we still have rather primitive tools for investigating those wayward paths. One of the most powerful tools we have is time. Disease progression often clarifies the diagnosis. And far too often, response to therapy serves as our definitive diagnostic test.

In this case, there was a test for the anti-brain antibody that was causing the patient’s dire symptoms, but it’s not done often, and only performed at a few laboratories. By the time the test results confirming the diagnosis came back for this patient, she was already in rehab and getting better.

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