Hysteria, where sufferers complain of a specific ailment with no discernible cause, is not an imaginary disorder, according to a group of Canadian researchers.

The team used brain imaging scans to detect evidence of cerebral dysfunction in three women suffering from the condition, more formally known as “sensory conversion disorder.”

The findings, published in the December 12 issue of the journal Neurology, will help to improve understanding of conversion disorder, a neurological disorder in which a person displays symptoms, but doctors are unable to determine a specific medical cause for the discomfort.

The three women involved in the study complained of numbness in their left hand or foot. The researchers used MRI machines to observe how the women’s brains responded to stimulation of the numb body parts.

In all three, stimulation of the numb body part failed to activate the part of the brain that responds to touch. However, the monitored brain area did respond when the researchers simultaneously stimulated both the numb appendage and the opposite one not affected by the disorder.

“The principal finding is that stimulation of the numb body part did not activate the somatosensory region of the brain, while stimulating both limbs did,” wrote study author Dr. Omar Ghaffar, of Sunnybrook Health Sciences Center in Toronto, in a prepared statement.

The researchers concluded that stimulating both the numb and normal-sensing limbs may act as distraction, shifting the patient’s focus, and thereby overcoming the inhibition.

“Future studies plan to build on these findings by scanning more subjects and health controls,” Ghaffar said. “In addition, a study examining the role of distraction in conversion disorder is underway.”