Brain damage in National Hunt jockeys

Neurological consequences of traumatic brain injuries in sports

Traumatic brain injury (TBI) is common in boxing and other contact sports. The long term irreversible and progressive aftermath of TBI in boxers depicted as punch drunk syndrome was described almost a century ago and is now widely referred as chronic traumatic encephalopathy (CTE). The short term sequelae of acute brain injury including subdural haematoma and catastrophic brain injury may lead to death, whereas mild TBI, or concussion, causes functional disturbance and axonal injury rather than gross structural brain damage. Following concussion, symptoms such as dizziness, nausea, reduced attention, amnesia and headache tend to develop acutely but usually resolve within a week or two. Severe concussion can also lead to loss of consciousness. Despite the transient nature of the clinical symptoms, functional neuroimaging, electrophysiological, neuropsychological and neurochemical assessments indicate that the disturbance of concussion takes over a month to return to baseline and neuropathological evaluation shows that concussion-induced axonopathy may persist for years. The developing brains in children and adolescents are more susceptible to concussion than adult brain. The mechanism by which acute TBI may lead to the neurodegenerative process of CTE associated with tau hyperphosphorylation and the development of neurofibrillary tangles (NFTs) remains speculative. Focal tau-positive NFTs and neurites in close proximity to focal axonal injury and foci of microhaemorrhage and the predilection of CTE-tau pathology for perivascular and subcortical regions suggest that acute TBI-related axonal injury, loss of microvascular integrity, breach of the blood brain barrier, resulting inflammatory cascade and microglia and astrocyte activation are likely to be the basis of the mechanistic link of TBI and CTE. This article provides an overview of the acute and long-term neurological consequences of TBI in sports. Clinical, neuropathological and the possible pathophysiological mechanisms are discussed. This article is part of a Special Issue entitled 'Traumatic Brain Injury'.

Concomitant progressive supranuclear palsy and chronic traumatic encephalopathy in a boxer

We report the case of a 75-year-old ex-professional boxer who developed diplopia and eye movement abnormalities in his 60's followed by memory impairment, low mood and recurrent falls. Examination shortly before death revealed hypomimia, dysarthria, vertical supranuclear gaze palsy and impaired postural reflexes. Pathological examination demonstrated 4-repeat tau neuronal and glial lesions, including tufted astrocytes, consistent with a diagnosis of progressive supranuclear palsy. In addition, neurofibrillary tangles composed of mixed 3-repeat and 4-repeat tau and astrocytic tangles in a distribution highly suggestive of chronic traumatic encephalopathy were observed together with limbic TDP-43 pathology. Possible mechanisms for the co-occurrence of these two tau pathologies are discussed.

An analysis of injuries resulting from professional horse racing in France during 1991-2001: a comparison with injuries resulting from professional horse racing in Great Britain during 1992-2001

BACKGROUND

It has been previously shown that professional jockeys suffer high rates of fatal and non-fatal injuries in the pursuit of their occupation. Little is known, however, about differences in injury rates between countries.

AIM

To determine the rate of fatal and non-fatal injuries in flat and jump jockeys in France and to compare the injury rates with those in Great Britain and Ireland Method: Prospectively collected injury data on professional jockeys were used as the basis of the analysis.

RESULTS

Limb fractures occur four times more often in both flat and jump racing in France than in Great Britain. Similarly dislocations are diagnosed 20 times more often in flat and three times more often in jump racing. This difference is surprising given that French jockeys have fewer falls per ride than their British counterparts in flat racing, although they do have more falls than the British in jump racing. Similarly concussion rates seem to be higher in French jockeys, although there may be a difference in the diagnostic methods used in the different countries. By contrast, soft tissue injuries account for a far smaller percentage of injuries than in Great Britain.

CONCLUSION

There are striking differences in injury rates between countries which may be explained in part by a difference in track conditions-for example, harder tracks in France-or different styles of racing--for example, larger fields of horses per race in France.

Mild head injury in sports

Mild head injury has been recognized as producing numerous "postconcussive" symptoms that temporarily reduce an individual's ability to function. Controversy exists over the short-and long-term effects of mild head injuries, and the effects of repeated concussive blows to the head have not been sufficiently studied. Amateur and professional athletes provide an excellent population for the examination of many aspects of postconcussive syndrome. The nature, incidence, and cognitive and emotional symptoms of mild head injury, are reviewed within, the framework of professional and amateur sports. Particular attention is paid to the few available prospective studies of amateur boxers and collegiate football players.

Routine and quantitative EEG in mild traumatic brain injury

This article reviews the pathophysiology of mild traumatic brain injury, and the findings from EEG and quantitative EEG (QEEG) testing after such an injury. Research on the clinical presentation and pathophysiology of mild traumatic brain injury is reviewed with an emphasis on details that may pertain to EEG or QEEG and their interpretation. Research reports on EEG and QEEG in mild traumatic brain injury are reviewed in this setting, and conclusions are drawn about general diagnostic results that can be determined using these tests. QEEG strengths and weaknesses are reviewed in the context of factors used to determine the clinical usefulness of proposed diagnostic tests. Clinical signs, symptoms, and the pathophysiologic axonal injury and cytotoxicity tend to clear over weeks or months after a mild head injury. Loss of consciousness might be similar to a non-convulsive seizure and accompanied subsequently by postictal-like symptoms. EEG shows slowing of the posterior dominant rhythm and increased diffuse theta slowing, which may revert to normal within hours or may clear more slowly over many weeks. There are no clear EEG or QEEG features unique to mild traumatic brain injury. Late after head injury, the correspondence is poor between electrophysiologic findings and clinical symptoms. Complicating factors are reviewed for the proposed commercial uses of QEEG as a diagnostic test for brain injury after concussion or mild traumatic brain injury. The pathophysiology, clinical symptoms and electrophysiological features tend to clear over time after mild traumatic brain injury. There are no proven pathognomonic signatures useful for identifying head injury as the cause of signs and symptoms, especially late after the injury.

Injuries in professional horse racing in Great Britain and the Republic of Ireland during 1992-2000

Professional horse racing is an exciting and demanding sport with high injury rates. Surprisingly few epidemiological studies have been published and no prospective studies have been reported. This paper reviews the literature and provides a detailed breakdown of injuries in Great Britain and the Republic of Ireland for 1992-2000. The introduction of protective equipment is discussed and evidence for its effectiveness put forward.

Recurrent traumatic brain injury

This article reviews, analyses and provides commentary on the most recent literature concerning recurrent traumatic brain injury (RTBI) case histories. It is revealed that a significant proportion of TBI sufferers survive and recover most of the functions of daily living. However, relatively little is known about the epidemiology, effects, or causes of a new phenomenon: recurrent TBI.

Performance of horse-riding helmets in frontal and side impacts

Cases of head injury are reviewed in which riders wearing jockey skull caps have suffered impacts to the front, back or side of their helmets. The design and constructional materials of such helmets are assessed. Impact tests that simulate the accidents confirm the low energy absorption potential of some helmets for lateral impacts. Most pedal or motorcycle helmet designs afford better lateral impact protection.

Nervous system sports-related injuries

With the evolution of sports medicine as a subspecialty comes a redirection of attention to the medical and athletic communities to the prompt recognition and timely treatment of many potentially serious conditions. Nervous system complications of sports injuries have gone largely unaddressed in the literature. It is the goal of this communication to review the wide range of nervous system injuries due to sports activities, discuss the mechanisms of such injuries, and focus attention on their prevention and management. The role of the neurologist and neurosurgeon as a sports medicine team member will be discussed, as will their roles in planning and development of programs and equipment at the secondary school, collegiate, and professional levels.

For Jockeys, Injuries Are Not a Long Shot

No mere lightweights, jockeys are a tough breed of athlete. Their sport subjects them to the risk of serious injury, the stress of extreme competition, and the strain of making weight.

Horse riding and head injury: admissions to a regional head injury unit

A retrospective survey has been carried out of 59 patients who suffered head injury related to horse riding out of 7172 cases of head and spinal injury admitted to a regional head injury unit in the 5-year period 1980-85. Most (85%) were female, against the usual 80% male predominance of head injury, 56 were minor injuries and 3 severe, of whom 2 died. Skull fracture was present in 10 patients (17%) of whom at least 5 had been wearing headgear at impact, and scalp trauma was noted in 22 (37%) with a predominance of occipital injuries. All the severely injured cases had an occipital skull fracture. One fifth of the patients suffered additional significant injuries. While most patients (90%) made a good recovery, 2 remained moderately and one severely disabled. Horse riding posed a significant risk of head injury to the population of riders, mainly young women. This survey suggests that the wearing of amateur riding headgear does not adequately protect the rider from scalp and skull injury, particularly in the occipital region.

Equestrian Injuries

In brief: It has always been assumed that participants in equestrian sports are at high risk of serious injury and that minor injuries are common. This study of American Horse Shows Association and United States Pony Clubs horse shows tried to determine if shows are as safe as or safer than other sports, what the accident rate is for horse shows, if any factors influence the accident rate, and what types of accidents and injuries occur. There were 290 reported injuries and two deaths in the 984 responding shows. The accident rate per entry was 0.0003. There was no statistically significant relationship between any external factors and the accident rate. Anecdotes usually indicate a preponderance of shoulder injuries, but the statistics did not find this to be so. Bruises and being "shook up" accounted for 45.5% of the injuries, and fractures 15.5%.

Serious head injury in sport

Of 1900 head injuries serious enough to be admitted to the neurosurgical unit in Glasgow over a five year period, 52 (2.7%) were due to "sport." Golf, horse-riding, and Association football were the sports most commonly linked with serious head injury. Golfing injuries were all compound depressed fractures, and all these patients made a good recovery; horse-riding produced more severe injuries, three of the eight patients being left with residual disability. Much attention has been directed to preventing repeated minor head injury in boxing, but this study emphasises the need for preventing both the primary head injury and secondary complications associated with other sports.

Equestrian injuries--a one year prospective study

A one year prospective study of equestrian injuries was carried out in an area where horse riding is a popular pursuit. 115 persons suffered injury--eighty females and thirty-five males of whom sixty were under fifteen years of age. No fatalities were recorded and there were 0.2 injuries per 100 rides. Most injuries were minor and to the musculo-skeletal system. Visceral and cerebral injuries were not common but the former were life threatening in all cases. It is concluded that young riders should be supervised.