Magnetic resonance spectroscopic study of parkinsonism related to boxing

Review: Contact sport-related chronic traumatic encephalopathy in the elderly: clinical expression and structural substrates

Professional boxers and other contact sport athletes are exposed to repetitive brain trauma that may affect motor functions, cognitive performance, emotional regulation and social awareness. The term of chronic traumatic encephalopathy (CTE) was recently introduced to regroup a wide spectrum of symptoms such as cerebellar, pyramidal and extrapyramidal syndromes, impairments in orientation, memory, language, attention, information processing and frontal executive functions, as well as personality changes and behavioural and psychiatric symptoms. Magnetic resonance imaging usually reveals hippocampal and vermis atrophy, a cavum septum pellucidum, signs of diffuse axonal injury, pituitary gland atrophy, dilated perivascular spaces and periventricular white matter disease. Given the partial overlapping of the clinical expression, epidemiology and pathogenesis of CTE and Alzheimer's disease (AD), as well as the close association between traumatic brain injuries (TBIs) and neurofibrillary tangle formation, a mixed pathology promoted by pathogenetic cascades resulting in either CTE or AD has been postulated. Molecular studies suggested that TBIs increase the neurotoxicity of the TAR DNA-binding protein 43 (TDP-43) that is a key pathological marker of ubiquitin-positive forms of frontotemporal dementia (FTLD-TDP) associated or not with motor neurone disease/amyotrophic lateral sclerosis (ALS). Similar patterns of immunoreactivity for TDP-43 in CTE, FTLD-TDP and ALS as well as epidemiological correlations support the presence of common pathogenetic mechanisms. The present review provides a critical update of the evolution of the concept of CTE with reference to its neuropathological definition together with an in-depth discussion of the differential diagnosis between this entity, AD and frontotemporal dementia.

The Evidence for Chronic Traumatic Encephalopathy in Boxing

The sport of boxing has been the source of much debate, with concerns about the neurological risks of participating having led to many calls to ban the sport. This review seeks to establish an evidence base for the development of boxing-related chronic traumatic encephalopathy (CTE) and to determine the relevance of this information to the modern day sport.The clinical features of CTE include various symptoms affecting the pyramidal and extrapyramidal systems, which manifest most often as disturbed gait and coordination, slurred speech and tremors, as well as cerebral dysfunction causing cognitive impairments and neurobehavioural disturbances. Both amateur and professional boxers are potentially at risk of developing CTE. No current epidemiological evidence exists to determine the prevalence of this condition in modern day boxing, despite 17% of professional boxers in Britain with careers in the 1930-50s having clinical evidence of CTE. As medical presence within the sport increases and with modern boxers likely to have shorter careers, a reduced exposure to repetitive head trauma, and improved treatment and understanding of the development of CTE will occur. This should lead to the incidence of CTE diminishing in boxing populations.