Nouchine Hadjikhani

Streamlining Neuroimaging

By Dustin Driver

Dr. Nouchine Hadjikhani reads minds. As a radiologist at the Martinos Center for Biomedical Imaging at Massachusetts General Hospital (MGH), a teaching hospital affiliated with the Harvard Medical School (HMS), she seeks through the use of MRI to unravel the mystery of migraines and to understand how people perceive and process body language.

Hadjikhani recently started using NeuroLens, a powerful Mac-only 3D neuroimaging application, which she runs on a Power Mac G5 desktop system and which has become a vital tool for her research. “I look at everything I do with NeuroLens,” she says. She currently uses NeuroLens to get an almost instant preview of her functional MRI results before doing additional analyses using established UNIX packages like FS-FAST and Freesurfer.

“The first time I saw NeuroLens on the Mac I was so shocked. Normally it would take several days before I could look at the results. Now I come back from the scanner with a CD loaded with files and put it in the Power Mac computer and click on NeuroLens and in less than 10 minutes I have the results.”

From Positron Emission to MRI

During her post-doctoral work in Sweden, Hadjikhani used positron emission tomography to scan the visual cortex of the brain. It was the first time she got to peek into someone’s head. “I was trying to understand how vision and touch are connected,” she says. “When you put your hand in your pocket and you feel your key, you know which one it is even though you don’t see it. The question was, how can you visualize what you feel with your hand?”

In 1995, she had her first encounter with MRI. “That was quite something,” she says. “I was in the magnet myself and they showed me an image of my own brain. It was a very impressive moment. Suddenly you can have somebody alive and look at different things in the brain. There’s no danger and you can repeatedly get data about how the brain is organized.”

She now uses her skills in her role as an assistant professor in radiology at HMS, where she has been working since 1996. Her knowledge of the visual cortex and expertise with MRI machines would lead her to one of the most mundane, yet mysterious, of human ailments: the migraine.

Using MRI to Study Migraines

Most migraines arise without warning, but about 10 percent of migraine victims see flickering lights, called scintillations or aura, 20 minutes before an attack. Hadjikhani’s task was to capture some of these auras using MRI. Luckily, she had a patient who could reliably induce an aura and the following migraine — by playing basketball. “We have a little court next to the lab,” says Hadjikhani. “He agreed to play for us. We rushed him into the magnet and started to image. It was one of the first times that anybody had seen a migraine in an MRI.”

The image was surprising. Hadjikhani and her peers now think that migraines with aura are triggered by a phenomenon called cortical spreading depression. Essentially, something lights a fuse that sets off a cascade of neural fireworks in and around the visual cortex. Hadjikhani and others believe that cortical spreading depression leaves chemical fallout that aggravates the meninges, which contain a network of nerves and blood vessels that surround the brain. This fallout may trigger migraine pain.

In the future, Hadjikhani’s migraine work could lead to drugs that squelch cortical spreading depression. “There’s evidence that if you use drugs that stabilize the neural membrane you can actually diminish migraine with aura,” she says. “Right now they are anti-epileptic drugs, but they’re a bit too strong and may have many side effects. Now the way is open to develop drugs that really look at the source of the problem and not the consequences of it.”

Reading Bodies

Hadjikhani also studies the brain’s perception of facial and body expressions. What part of the brain recognizes fear, aggravation or anger in someone’s stance? Hadjikhani and Dr. Beatrice de Gelder, a colleague at Tilburg University in the Netherlands, are trying to find out.

“There are more people looking at faces now and the amount of literature is amazing,” says Hadjikhani. “But you don’t normally see a face alone, you see whole bodies.”

Hadjikhani and de Gelder compiled a complex library of body expressions — the first one ever — to use in their experiment. Using MRI, they discovered that the same chunks of gray matter — the amygdala and fusiform cortex — are responsible for processing both facial and body expressions.

The information will come in handy for doctors who are studying autism, Williams syndrome, Huntington’s disease or Parkinson’s disease — patients with those ailments have trouble telling the difference between a grimace and a coy smile. “If you can’t recognize facial expressions, how bad are you at looking at body expressions?” asks Hadjikhani. She doesn’t have the answer yet, but she hopes that her research will lead to new treatments and therapies.

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