3 November 1999

Pacman type attacks to the human brain

by Kate Melville

A good belt to the head can trigger a "Pacman-like" enzyme that can eating important structural proteins in the brain for up to one month afterward the initial blow!

According to a University of Florida Brain Institute researcher Ronald Hayes, director of the Center for Traumatic Brain Injury Studies. His finding based on studies in rats, suggests treatment for traumatic brain injury must consider tissue damage that can continues to occur long after the initial incident.

While there have been many recent studies that have assessed traumatic brain injury therapies, no effective treatment actually exists. Hays says that, "Emergency room medical personnel often talk about a golden hour, that if you don't get a person into treatment within the first hour or so after an injury, a lot of damage has been done to the patient. With traumatic brain injury, the thought has been that treatment within the first two days is critical." But Hayes' data suggests that this critical period may actually be much longer (up to a month) and so has implications for longer term patients treatment.

In the United States, according to the National Institutes of Health automobile accidents, shooting and sporting accidents cause an estimated 52,000 brain injury deaths each year (men outnumbering women 2 to 1) and an estimated 5.3 million people are permanently disabled! The bad guys are Calpains a type of protein-destroying enzyme found in cells throughout the body. Experiments indicate that calpains switch on when calcium floods cells after brain injury with the activation of the calpains associated with the death of brain cells that may could contribute to the extensive atrophy and shrinkage of the brain seen after traumatic injury.

"In the past several years, there have been a large number of clinical trials testing treatments for brain injury that have shown no effect," said Professor Hayes, a neuroscientist at the UF's College of Medicine. "Researchers thought they had an effective therapy, but when they tried it, the people didn't get better. One reason may be that they didn't treat the patient long enough because the biochemical storm lasted longer than two days. We may have to completely redefine our approach to therapy, because if you try to get in there too early and for too brief a time with a treatment, you might not block the damage that lies ahead," Hayes said. "But if you give a treatment for too long, you might block some of the self- repair that will make the patient better. Understanding these relationships is critical, and our research is a necessary first step in this effort. "To complicate matters, some level of calpain activity may actually be a necessary part of a "resculpting" effort that can repair damage.