Brain Damage May Have Contributed to Former Wrestler's Violent Demise

ARTICLE IN BRIEF

✓ Autopsied brain tissue from Chris Benoit showed evidence of chronic traumatic encephalopathy.

NEW YORK CITY-Professional wrestler Christopher Benoit is the fifth former athlete with extensive brain damage believed to be caused by multiple concussions, neurosurgeons said here at a news conference on Sept. 5th.

Robert Cantu, MD, told reporters that of the former athletes they have studied, the former World Wrestling Entertainment wrestler had by far and away the greatest amount of tau protein accumulation in his brain, a marker of brain trauma. Dr. Cantu is chief of neurosurgery service and director of sports medicine at Emerson Hospital in Concord, MA, and co-director of the neurology sports injury center at Brigham and Women's Hospital in Boston.

University of Pittsburgh neuropathologist Bennet Omalu led the research on behalf of the Sports Legacy Institute, an organization he, Dr. Cantu, and other concussion experts formed this summer to study the effects of sports concussions on athletes. Dr. Omalu has reported this type of brain damage - known as chronic traumatic encephalopathy - in former National Football League players Terry Long (Neurosurgery 2005;57:128-134), Mike Webster (Neurosurgery 2006;59:1086-1093), Andre Waters, and Justin Strzelczyk.

Chronic traumatic encephalopathy, or CTE, is a progressive condition marked by neurofibrillary tangles and neuritic threads, starting in the neocortex and progressing to the hippocampus. It was first identified in 1928 and attributed to repetitive cerebral trauma. In boxers, the condition is referred to dementia pugilistica or punchdrunk syndrome.

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With permission from the Benoit family, neurosurgeons used immunostains to examine tau protein in slices of Benoit's brain. They found neurofibrillary tangles, neuritic threads, and dead neurons throughout the neocortex, basal ganglia, substantia nigra, and brainstem. According to the researchers, tau becomes phosphorylated and visible after prior traumatic brain injury.

These areas of tau protein deposits are dead neurons, dead brain cells, ghosts of old neurons. They are a footprint of a past injury, Julian E. Bailes, MD, chair of neurosurgery at West Virginia University, and a former team physician for the Pittsburgh Steelers, said. We think this would correlate with the nature of the sport of wrestling and his medical history, having sustained multiple concussions during his career.

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Dr. Cantu said the findings have been confirmed by neuropathologists at the University of Pittsburgh and West Virginia University. Dr. Bailes said the group plans to submit the findings for publication.

VIOLENT ENDINGS

In June, Benoit, his wife, and his seven-year-old son were discovered dead in their suburban Atlanta home. Law enforcement officials believe 40-year-old Benoit asphyxiated his son and wife, leaving copies of the Bible next to each of their bodies, before hanging himself with a cord from one of his gym weight machines.

The researchers said it's possible that Benoit's CTE could have led to the killings. Dr. Omalu said in an interview with Neurology Today that the pathology of CTE involves the limbic system, which controls emotions, and could therefore lead to uncharacteristic behavior. They all have behavioral impairment, impairment of executive function, he said. When you lose executive functioning you lose your inhibitions.

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The lives of two of the other athletes diagnosed by Dr. Omalu also came to tragic, violent ends. Long, who played for the Philadelphia Eagles, committed suicide at age 44 by drinking antifreeze. Thirty-six-year-old Strzelczyk, a former Pittsburgh Steeler, led police on a high-speed chase on the wrong side of the highway before he collided with a tanker truck and died. According to reports from families gathered by Dr. Omalu, both Long and Webster had exhibited cognitive impairment, major depression, paranoia, and aggressive behavior.

Michael Benoit, Christopher Benoit's father, said at the press conference that he had not personally noticed his son acting strangely, but emphasized that their contact was limited to short weekly to biweekly phone calls. He also said that after the killings he had discovered a diary that showed his son was having problems. …I would have thought it was written by someone who was extremely disturbed at the time, Michael Benoit said.

His father said he knows of no documented concussions but that he'd told him that he had experienced numerous concussions. I think it's the extreme that is in the wrestling industry today that it's not unusual to get hit by a table or chair, he added.

Though toxicology reports determined Benoit had steroids in his system at the time of death, the researchers said it is unclear how the drugs could have affected his behavior, and they couldn't have caused CTE. The state of the science today is we don't associate abnormal protein accumulation with steroid use, Dr. Cantu said.

OUTSIDE EXPERTS RESPOND

James Kelly, MD, professor of neurosurgery and physical medicine and rehabilitation at the University of Colorado School of Medicine, said it is unlikely that Benoit's murderous behavior could be explained by CTE alone. He said in an e-mail to Neurology Today that the violence associated with CTE tends to be impulsive, which would be at odds with reports suggesting that the Benoit killings involved time and planning.

I would look to explanations such as the high levels of testosterone reportedly found in his blood, and possible anabolic steroid abuse, said Dr. Kelly, who has co-authored a consensus statement on the neurobehavioral aspects of violence (Neuropsychiatry Neuropsychol Behav Neurol 2001;14:1-14). This behavior is similar to others in which a psychosis is the likely cause without underlying CTE.

Another expert, who is not affiliated with the Sports Legacy Institute, Barry Jordan, MD, chief medical officer for the New York State Athletic Commission, said Benoit's brain pathology is not consistent with classic CTE, which he said must also include amyloid deposition. Benoit could have had frontotemporal dementia, which is also marked by neurofibrillary tangles and behavioral problems, he said.

Robert A. Stern, PhD, associate professor of neurology and co-director of the Alzheimer's Disease Clinical and Research Program at Boston University, said CTE is different from Alzheimer disease pathology in that it does not always involve amyloid deposition.

Dr. Bailes said head injuries should not be taken lightly. As a neurosurgeon, if you see an individual experiencing emotionally aberrant behavior who has had past brain injuries, you can suspect this problem and for sure keep them away from further damage.