The risk of chronic traumatic brain injury in professional boxing: change in exposure variables over the past century

Abstract

Objectives:To determine if boxing exposure has changed over time and hence if current professional boxers are at the same risk of developing chronic traumatic brain injury (CTBI) as historical controls.Design:Literature review of published studies and analysis of data of active professional boxers.Subjects:Professional boxers in the United Kingdom and Australia.Main outcome measures:Boxing history and participation in sparring and professional bouts.Results:Since the 1930s, the average duration of a professional boxer’s career has dropped from 19 years to five years, and the mean number of career bouts has reduced from 336 to 13. This is despite no significant decline in participation rates from 1931 until 2002.Conclusions:The incidence of boxing related CTBI will diminish in the current era of professional boxing because of the reduction in exposure to repetitive head trauma and increasing medical monitoring of boxers, with preparticipation medical and neuroimaging assessments resulting in the detection of early and potentially pre-symptomatic cases of CTBI.

Membrane trauma and Na+ leak from Nav1.6 channels

“…The link between repeated head injury and chronic TBI in professional boxing is known (11), but the immediate efficacy of knock-out punches remains mysterious. Boxers drop unconscious as if the punch itself delivered an instantaneous nerve block to midbrain (55) axon tracts carrying consciousness-sustaining action potential traffic.…”

Chronic traumatic encephalopathy in sport: a systematic review

“…The ‘modern’ form of CTE, since 2005, encompasses a broad spectrum of clinical symptoms and pathological findings in former athletes 24 40. When compared with the classical CTE entity, there are differences in exposure rates, clinical presentation, cognitive and neurobehavioural features, diagnostic criteria, age of symptom onset, disease progression and putative neuropathological characteristics (see table 1).…”

Boxing-Related Head Injuries

“…The observed decline in boxing-related deaths after 1983 is reflective of these methods, but is also likely due in part to the reduction in a boxer's career from 19 to 5 years and in career bouts, from 336 to 13 matches. 68 In this regard, stringent enforcement of boxing rules and regulations, certification of trainers and managers, and mandatory hospital assessment with neuroimaging for boxers who are unresponsive for > 1 minute as well as those who sustain a knockout or technical knockout could lead to timely diagnosis and intervention. Further, it is likely that with close certified medical supervision and greater match control to the ringside physician, there will be a further reduction in the incidence of concussions and serious head injury.…”

“…It is estimated that between 15% and 40% of boxers demonstrate symptoms of chronic brain injury. 68 Punch drunk syndrome was first described by Martland 69 in 1928 as being characteristic of boxers who had sustained frequent, repetitive head trauma of concussive or subconcussive force. In this article, Martland 69 described the early symptoms of punch drunk syndrome as "mental confusion, slowness of muscle movements, speech hesitancy, and tremors of the hands. "…”