Brain surgery is not rocket science. --Jerry 12/29/98
By Nicholas Keung, Toronto Star Staff Reporter 12/29/98

Laurier prof suggests flaws in accepted medical neuron diagram

A neuron map used to teach brain surgeons for the past 50 years is flawed, a Wilfrid Laurier University researcher says.

"This is the most widely reproduced map in neuroscience and to show that there's an error in it is inherently interesting," psychology professor Dr. Philip Servos said from his Waterloo laboratory yesterday.

Although Servos' study suggests the Penfield map - a rendering showing the corresponding brain structure and body sensations in pre-med textbooks - is generally accurate, the parts of the brain that react to chin and forehead should be reversed.

Montreal neurosurgeon Wilder Penfield came up with the illustration in the 1930s and 1940s while conducting research during operations on epilepsy patients.

Since Penfield's focus was on speech and movement of the right hand, Servos believed that some areas, including facial sensations, only received little attention.

"As we collect more research data in this area, we may find how brittle the current work is," Servos said.

He said currently, surgeons still have to open patients' skulls for presurgical planning and a more refined map of the brain will help neurosurgeons make the decisions necessary in highly technical operations.

Using magnetic resonance imaging technology, Servos tested the oxygen level of different cells in the brains of six human subjects when tiny jets of air were blown on to their chins and foreheads.

"What my study shows is the potential of the MRI technique to help us learn about how the brain is able to deal with what it does," he added.

While on a two-year postdoctoral fellowship at Stanford University, Servos attended a speech by neuroscientist Dr. Vilayanur Ramachandran on "phantom pain," complaints by amputees of pain and feeling in missing limbs.

He was surprised that amputees' missing arms would feel like they were being touched when they were actually stimulated on their chins, but not on their foreheads as predicted by the Penfield map.

"The only way that can be true is that the map is upside down," said Servos, who continued his research at Wilfrid Laurier in 1996.

Servos' study of the neuron map is currently under review and is expected to be published by the middle of next year.