A 64-year-old Swiss woman has reported the presence of a pale, milky-white and translucent third arm. – swissinfo

By | April 13, 2009

A 64-year-old woman has reported to doctors at Geneva University Hospital the presence of a pale, milky-white and translucent third arm.

After examining the case, the woman’s neurologist, Asaid Khateb of the hospital’s experimental neurophysiology laboratory, called the rare phenomenon credible.

The arm appeared to the woman a few days after suffering a stroke, doctors said.

But this case of what is known as a supernumerary phantom limb (SPL) is a genuine head-scratcher.

The upshot is that the woman can use the apparitional extremity to relieve very real itches on the cheek. It cannot penetrate solid objects.

She does not always perceive the arm but “retrieves” it when needed, doctors told the Swiss news agency.

It is nevertheless the first case known to doctors of a person being able to feel, see and deliberately move a limb that doesn’t exist. The findings are published in the Annals of Neurology.

Khateb and his colleagues examined the patient’s brain using functional magnetic resonance imaging (MRI), a tool that allows doctors to see whether the brain is truly stimulated, and to pinpoint where. In this case, the investigations revealed that the woman actually experienced what she described.

Researchers instructed the woman to move her right hand. As expected, the motor cortex and visual processing areas in the left side of her brain became mobilised.

The same effects were observed to a lesser extent when the woman simply imagined moving her right hand. Imaginary movements of the woman’s paralysed left hand prompted the same activity in the brain, but on the right side.

But when doctors asked her to move her phantom arm, her brain reacted as though the arm really existed and could be moved. In addition, the patient’s visual cortex was also activated, indicating the she actually saw the imaginary limb.

And when she was instructed to scratch her cheek, regions of the brain relating to touch were activated.

… Khateb said the exact cause of the imaginary arm remains a mystery. Supernumerary limbs are rare. There are only nine known cases of a patient both feeling and seeing an arm.

via A 64-year-old Swiss woman has reported the presence of a pale, milky-white and translucent third arm. – swissinfo.

One thought on “A 64-year-old Swiss woman has reported the presence of a pale, milky-white and translucent third arm. – swissinfo

  1. James

    Have you ever read “Phantoms in the Brain”? The author goes into good detail as to why phantom limbs probably exist and he has also developed treatments for people whose phantom limbs are stuck in a position of clenching or squeezing to the point where it hurts them (yes, pain emanating from a phantom limb. More specifically pain emanating from the brain due to a malfunction)

    Phantom limbs almost always develop after a stroke and/or an amputation. Damage to the primary visual cortex caused by a stroke has in rare cases caused vivid and constant hallucinations in patients. The fact that she can see it most likely means that her stroke paralyzed the left side of her body and she developed a phantom afterword. Or perhaps even more rarely the stroke simply damaged her left visual field and she developed a blind spot with hallucinations hallucinations. Speculation is rampant.

    The article does not give enough information! It would be interesting to know if she also had hemispatial neglect (http://en.wikipedia.org/wiki/Hemispatial_neglect) or denied paralysis (http://sandrablakeslee.com/articles/paralysis_denial_aug05.php) Both of which may be more frequent than we realize but tend to not be diagnosed because doctors think it is a psychological problem and not a neurological problem.

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