About 20 percent of professional boxers develop chronic traumatic brain injury, according to background information in the article. Some studies have suggested that amateur boxers also damage their nervous systems, but because their shorter bouts allow fewer blows to the head and because they must wear safety equipment, the effects tend to be less severe. These studies have been based on assessment of thinking, learning, memory and other brain functions long after boxing, rather than an immediate test performed soon after a fight.
Henrik Zetterberg, M.D., Ph.D., The Sahlgrenska Academy at Göteborg University, Göteborg, Sweden, and colleagues obtained spinal fluids (via spinal tap) from 14 amateur boxers (11 men and three women, average age 22 years) seven to 10 days after a bout and again three months later, after a rest from boxing. At the first assessment, the boxers reported how many hits to the head they received during the match and underwent physical and neurologic examinations; none showed signs of brain injury. The researchers also tested the cerebrospinal fluids of 10 healthy men who were not boxers as controls. Levels of several chemicals that indicate damage to brain cells (neurons) and their axons, the thread-like extensions of the cell that reach toward other brain cells to transmit electrical impulses, were measured.
Seven to 10 days after a boxing match, the group of boxers had higher average levels of chemicals known as neurofilament light protein and total tau than they did three months later. "The cerebrospinal fluid levels of these proteins increase in disorders with neuronal and axonal de
Source:JAMA and Archives Journals