What is prosopometamorphopsia, this rare disorder which leads to seeing “demonic” forms?

What is prosopometamorphopsia, this rare disorder which leads to seeing “demonic” forms?


He thought he was going crazy. Victor Sharrah, a 58-year-old American, remembers the day when all the faces of passers-by appeared distorted to him while he was walking his dog in the street. “My first thought was that I had woken up in a world of demons,” he told AFP. I started to panic. » The chef has not “completely lost his mind” as he first thought.

He actually suffers from a rare visual disorder, prosopometamorphopsia (PMO), like around ten other people around the world.

Symptoms of prosopometamorphopsia

The symptoms are mainly characterized by distortions of visual perception. They concern the shape as well as the size, color and even the position of facial features. Some see one half of a face beneath the other, others see faces in constant motion, still others see green or purple figures.

Unlike other patients who suffer from the same disorder, Victor Sharrah manages to see objects such as cars or objects without distortion. It also correctly distinguishes faces when they are in two dimensions, in photos or on screen.

It is thanks to this that scientists from Dartmouth College (United States) were able to create images of its perceptions. His case was the subject of a publication in the prestigious journal Lancet. Concretely, the researchers asked the patient to describe the differences he saw between the face of a person physically present and the associated photo presented to him on the computer screen.

Little-known causes

If we see a little better from the side of the symptoms, this is not the case with the origin. The causes of prosopometamorphopsia are still very poorly understood. In most cases, “something happened in the brain that correlated with this abnormal experience,” says Jason Barton, a neurologist at the University of British Columbia.

In any case, the study sheds light on a little-known and poorly diagnosed disorder. “Many patients with PMO are in fact wrongly diagnosed as suffering from schizophrenia by psychiatrists and receive antipsychotics, even though their condition affects the visual system,” regrets Brad Duchaine, an author of the study. The equally terrifying symptoms for patients require different treatments.


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