Brain neuron injury seen in amateur boxers

NEW YORK (Reuters Health) - Findings from a small study that measured neurochemical markers in the cerebral fluid of the spine suggest that amateur boxing can result in injury to the neuron and astrocyte cells in the brain.

If these results are verified in larger studies with longer follow-up periods to determine the physical effects of this damage, cerebrospinal fluid (CSF) analysis "may provide a scientific basis for medical counseling of athletes after boxing or head injury," Dr. Henrik Zetterberg, from Goteborg University in Sweden, and colleagues conclude.

As reported in the Archives of Neurology, CSF levels of various biomarkers for neuronal injury were measured in 14 amateur boxers and 10 healthy non-athletes.

Samples of the CSF were obtained from the boxers 7 to 10 days and again 3 months after a bout. In the non-athletic group, CSF samples were taken once.

Levels of two markers of nerve injury -- neurofilament light protein and total tau -- were higher in the days following a bout than 3 months later. A similar finding was noted with glial fibrillary acidic protein -- a marker for astroglial injury.

The number and severity of hits to the head were both directly linked to injury marker levels.

Compared with the nonathletes, the boxers had significantly elevated post-bout levels of neurofilament light protein and glial fibrillary acidic protein, but not total tau. After 3 months of no boxing, only the neurofilament light protein levels remained significantly elevated in the boxers.

"The molecular changes detected are likely to be even more pronounced in professional boxers and in boxers who have received a knockout punch," the researchers note.

SOURCE: Archives of Neurology, September 2006.