A man from the 19th Century who survived a horrific brain injury, and became a notorious case study for neuroscience because of the personality change he underwent, has been the subject of yet more research.
The University of California at Los Angeles last week boasted that for the first time its researchers used “brain-imaging data that was lost to science for a decade” to explore the damage that Phineas Gage suffered to the so-called white matter that links different parts of the brain.
In 1848 Gage, a railroad supervisor in Vermont, used a rod to pack blasting powder into a rock, inadvertently setting off an explosion. The 13-pound, 3-foot-7-inch rod he was using shor forward and traveled through his left cheek, and then out of the top of his head.
Despite that traumatic brain injury (TBI), Gage survived. But he wasn’t the same man he was before the accident, which damaged most of his left frontal lobe. Gage, 25, was no longer a happy-go-lucky fellow. He became moody and “profane,” according to UCLA’s press release.
“Over the years, various scientists have studied and argued about the exact location and degree of damage to Gage’s cerebral cortex and the impact it had on his personality,” according to UCLA.
In last Wednesday’s issue of the journal PLoS ONE, ” Jack Van Horn, a UCLA assistant professor of neurology, and his colleagues note that while approximately 4 percent of the cerebral cortex was intersected by the rod’s passage, more than 10 percent of Gage’s total white matter was damaged. The passage of the tamping iron caused widespread damage to the white matter connections throughout Gage’s brain, which likely was a major contributor to the behavioral changes he experienced,” UCLA said in its press release.
“Because white matter and its myelin sheath — the fatty coating around the nerve fibers that form the basic wiring of the brain — connect the billions of neurons that allow us to reason and remember, the research not only adds to the lore of Phineas Gage but may eventually lead to a better understanding of multiple brain disorders that are caused in part by similar damage to these connections,” the university said.
“What we found was a significant loss of white matter connecting the left frontal regions and the rest of the brain,” Van Horn, who is a member of UCLA’s Laboratory of Neuro Imaging (LONI), said in a statement. “We suggest that the disruption of the brain’s ‘network’ considerably compromised it. This may have had an even greater impact on Mr. Gage than the damage to the cortex alone in terms of his purported personality change.”
LONI is a joint effort with Massachusetts General Hospital and the National Institutes of Health to document the trillions of microscopic links between every one of the brain’s 100 billion neurons — the so-called “connectome,”according to UCLA.
“And because mapping the brain’s physical wiring eventually will lead to answers about what causes mental conditions that may be linked to the breakdown of these connections, it was appropriate, as well as historically interesting, to take a new look at the damage to Gage’s brain,” the university said in its press release.
Gage’s 189-year-old skull is on display at Harvard Medical School, but is too fragile to undergo medical imaging again.
So UCLA’s researchers set out to find the last imaging data, from 2001, which had been lost due to various circumstances at Brigham and Women’s Hospital, a teaching affiliate of Harvard, for a decade.
“The authors were able to recover the computed tomographic data files and managed to reconstruct the scans, which revealed the highest-quality resolution available for modeling Gage’s skull,” UCLA said. ” Next, they utilized advanced computational methods to model and determine the exact trajectory of the tamping iron that shot through his skull. Finally, because the original brain tissue was, of course, long gone, the researchers used modern-day brain images of males that matched Gage’s age and (right) handedness, then used software to position a composite of these 110 images into Gage’s virtual skull, the assumption being that Gage’s anatomy would have been similar.”
Using that methodology, researcher determined that almost 11 percent of Gage’s white matter had been damaged, as well as 4 percent of his cortex.
“Our work illustrates that while cortical damage was restricted to the left frontal lobe, the passage of the tamping iron resulted in the widespread interruption of white matter connectivity throughout his brain, so it likely was a major contributor to the behavioral changes he experienced,” Van Horn said.
“Connections were lost between the left frontal, left temporal and right frontal cortices and the left limbic structures of the brain, which likely had considerable impact on his executive as well as his emotional functions,” he added.
After his accident, Gage worked as a stagecoach driver for several years in South America. He died in San Francisco a dozen years after his freak accident.
Van Horn compared Gage’s condition to that of others with TBI.
“The extensive loss of white matter connectivity, affecting both hemispheres, plus the direct damage by the rod, which was limited to the left cerebral hemisphere, is not unlike modern patients who have suffered a traumatic brain injury,” he said. “And it is analogous to certain forms of degenerative diseases, such as Alzheimer’s disease or frontal temporal dementia, in which neural pathways in the frontal lobes are degraded, which is known to result in profound behavioral changes.”