Brain health concerns in former rugby players: clinical and cognitive phenotypes

Abstract

Epidemiological studies have shown that elite rugby players are at greater risk of neurodegenerative disease in later life, with post-mortem studies conducted in ex-players demonstrating the presence of neuropathologies related to repetitive head impacts, such as chronic traumatic encephalopathy. However, detailed prospective data establishing the clinical presentation of former rugby players with brain health concerns are lacking. In particular, the rates of traumatic encephalopathy syndrome, the clinical correlate of chronic traumatic encephalopathy, and the relationship between clinical outcomes and repetitive head impacts are unknown. Two hundred former elite rugby players with brain health concerns and 33 matched healthy control subjects were assessed. Self-reported concussion history, career duration, player position, self-rated scales of depression, anxiety, sleep quality, post-concussion symptoms and quality of life, self and informant ratings of neuropsychiatric symptoms and executive function behaviours, were obtained. Formal cognitive testing, traumatic encephalopathy syndrome classification and 3 T MRI were performed. Former players had a median age of 44 years (90.5% male, median career length = 10.5 years, median self-reported career concussions = 7); 63% were forwards and 37% were backs. Ex-players had elevated scores compared to controls on all symptom scales except sleep quality. Despite frequent subjective memory complaints, performance on cognitive testing did not significantly differ from controls. No players fulfilled criteria for dementia. Twenty-four former players fulfilled research criteria for traumatic encephalopathy syndrome (seven with cognitive impairment, 12 with neurobehavioral dysregulation, five with both). Provisional levels of certainty for chronic traumatic encephalopathy were relatively low (21 'suggestive', three 'possible', zero 'probable/definite'). Forwards and those with higher self-reported concussions were more likely to be classified as having traumatic encephalopathy syndrome based on neurobehavioral disturbance. Symptom burden (depressive and anxiety symptoms, post-concussion symptoms, behaviour rating of executive dysfunction, and neuropsychiatric symptom severity) was higher in those with higher self-reported concussions but was unrelated to years of play or position played. Cavum septum pellucidum was visible on structural imaging in 24% of players (12% in controls) and was more common in the high compared to low concussion group (32% versus 16%). In summary, former elite rugby players in mid-life had significant symptom burden, especially those self-reporting more concussions. In contrast, objective cognitive impairments and traumatic encephalopathy syndrome were relatively uncommon and there was no evidence of dementia. These results provide insights into the clinical presentations of former elite rugby players with brain health concerns during mid-life and highlight the complex relationship between symptoms, cognition and head impact exposure.

Keywords: TBI; TES; behaviour; cognition; concussion; rugby.