Extremely rare syndrome causes people to see 'demon faces'

For the first time, scientists have recreated what patients with prosopometamorphopsia (PMO) experience when looking at other people's faces.

One winter morning three years ago, Victor Sharrah woke up and saw his roommate going into the bathroom. However, when Sharrah looked at his friend's face, he was very frightened because the lines stretched out like a "devil's face". In Sharrah's eyes, the corners of his friend's mouth and eyes were elongated, his ears were pointed and there were many deep wrinkles on his forehead. In fact, nothing changed in his friend's face. Instead, a syndrome changed the way Sharrah saw him. He was extremely scared because the same thing happened when he looked at other people's faces.

The deformed face that Sharrah saw when looking at everyone. (Photo: Antônio Mello).

"I tried to explain to my roommate what I saw and he thought I was crazy," Sharrah shared. "Imagine waking up one morning and suddenly everyone in the world looks like a character in a horror movie."

Sharrah, now 59 years old and living in Clarksville, Tennessee, was diagnosed with prosopometamorphopsia (PMO) , an extremely rare neurological disorder that causes the human face to appear deformed. Since 1904, fewer than 100 cases of the disease have been recorded, and many doctors have never heard of it. But Sharrah's case could raise awareness of the mysterious syndrome and provide insight into the lives of people with PMO. For the first time, researchers were able to create a digital simulation of what a disfigured face would look like for someone with PMO like Sharrah and published their findings in The Lancet on March 23, according to Smithsonian .

Sharrah's face only deformed when she looked at people directly. When he looked at the face on a photo or computer screen, the image seemed completely normal. This difference allowed researchers to use photo editing software to recreate what Sharrah saw. They did so by showing Sharrah a picture of a person's face while that person stood in the room with him. As he described the differences between the photo and the real person, the team adjusted the photo until it matched Sharrah's description.

Symptoms of PMO vary significantly from person to person. Faces may appear puffy, pale, or have odd patterns, and distinctive features may shift to other areas of the face. When looking in the mirror, the patient's own face may be deformed. So while digitally edited photos represent what Sharrah sees when looking at people's faces, they may not match the experiences of other PMO patients. Still, images are useful for people to understand the type of deformity a patient might see, said Jason Barton, a neurologist at the University of British Columbia in Canada, who was not involved in the study.

Doctors often confuse PMO with mental health syndromes such as schizophrenia or psychosis. Although there is some overlap in symptoms, one big difference is that patients with PMO don't think the world is really distorted, they perceive their perspective to be different, according to study co-author Antônio Mello, cognitive psychologist and neuroscientist at Dartmouth College.

"Many people are afraid to talk about their symptoms because they fear others will think the deformities are a sign of a mental disorder ," says Brad Duchaine, a psychologist and brain scientist at Dartmouth College. For many people, PMO symptoms disappear within a few days or weeks. But for some people like Sharrah, they can last for years.

Researchers are not sure what causes PMO, although they suspect it results from problems in the part of the brain that processes facial images. Some patients develop PMO after a stroke, infectious disease, tumor, or head injury, while others have a sudden illness that cannot be clearly explained.

As for Sharrah, 4 months before his symptoms began, he suffered from carbon monoxide poisoning. More than a decade earlier, he suffered a serious head injury when he fell backwards and hit his head on the floor. However, in his case, adjusting the light color to a particular green tone would help him see the actual face.

Researchers hope the new paper will help doctors accurately diagnose PMO. They also hope the study results will help PMO patients feel less alone.