A Dutch woman recovering from a stroke had an unusual response to seeing her family:

The faces of her closest family members looked strange and distorted to her -- even repulsive.

But at the same time, strangers' faces seemed normal. In fact, she had much less trouble recognizing the faces of strangers and celebrities than she did her own flesh and blood.

This fascinating case of a 62-year-old woman referred to as JS is described in a recent issue of the journal Neurocase.

Hospitalized after having an ischemic stroke, JS was unable to recognize one of her daughters with whom she had regular contact. But she immediately recognized her other daughter, whom she hadn't seen in eight years.

When her grandchildren visited, she wouldn't let them sit on her lap because she thought they looked repulsive.

"Of course, JS felt bad and ashamed about not recognizing family members or perceiving them as ugly," says Dr. Joost Heutink, the lead author of the case study.

"As soon as we established that JS had a problem recognizing faces, we informed her family that a perceptual disorder prevented her from recognizing people she loved," he explains.

During neuropsychological testing, JS was given a facial recognition task. She was shown a series of photographs of her close family members, celebrities, and unfamiliar people and asked whether she recognized the person.

She correctly identified strangers 96 percent of the time and correctly identified a celebrity  -- whether it was Elvis, Albert Einstein, Oprah Winfrey, or Julia Roberts -- 76 percent of the time.

When shown photos of Osama bin Laden and Adolf Hitler, JS responded that these were pictures of "pathetic look-alikes who should have made more effort to look like the 'real' people." (They were the real people, though.)

While she found it easy to identify famous people and strangers, she had much more difficulty with her friends and family. She was the slowest and least accurate at placing familiar faces and correctly recognized them only 49% of the time.

When shown snapshots of her family, the facial proportions seemed distorted. She was even more critical of her grandkids' photos. To her, they appeared overweight and extremely tan.

"I have seen hundreds of cases with visual complaints after stroke in the posterior brain regions," says Heutink, an assistant professor of clinical neuropsychology at the University of Groningen in the Netherlands. "Several had problems recognizing familiar faces but I never encountered anything like this."

"It's an extremely rare case," he admits. As for why it occurred, Heutink and his colleagues write that "mild prosopometamorphopsia might explain this unusual clinical picture."

This mouthful of a word --  prosopometamorphopsia -- refers to a difficulty recognizing faces because they look contorted or warped in some way.

Heutink suspects that the areas of JS's brain damaged by stroke made it difficult for her to process and interpret information about facial identity along with its emotional context and meaning.

As a result, her facial distortions seem to be limited to close family and other emotionally relevant people in her life  -- perhaps explaining her reaction to seeing bin Laden and Hitler's photos.  She also has trouble recognizing basic emotional expressions on faces.

JS continues to have problems recognizing faces, but she has been taught how to compensate for it.  "We teach patients how to recognize people by specific details, such as their hair, clothes, voice, or posture," Heutink explains.

They also trained JS's family to call minutes before arriving at her home. That way she knows exactly who is there when the doorbell rings. It works every time. 

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