Neuropsychological tests in sport-related concussion – are they worthwhile?

May 27, 2012 by 1 Comment

The article by Shrier in the current edition of CJSM revisits the issue of neuropsychological testing in the setting of sport-related concussion, and poses some searching questions in relation to the use of these tools in the diagnosis and management of sport-related concussion. In particular, he asks ‘…do the results of neuropsychological testing change patient management or provide other clinical benefit to the patient?’ and ‘Is there sufficient evidence to mandate it (neuropsychological testing) as standard of medical care?’ (Shrier, 2012).

Whilst it is clear that sport-related concussion is a hot topic in Sports Medicine, with an ever-increasing literature on the subject, and following three expert consensus panellist group meetings since 2001, controversy surrounding the diagnosis, management, and return to play protocols continues to rage amongst academics and clinicians alike.

In his article, Shrier concentrates on the application of neuropsychological tests to the sport-related concussion setting. Whilst it is accepted that neuropsychological tests alone are not adequate to confirm the diagnosis and dictate the ongoing management of concussion, they are currently widely used in the rehabilitation and return-to-play setting as a part of an overall neuropsychological assessment for players in elite sport suffering from a concussion – especially in hockey, and college football.

Shrier points out that neuropsychological tests are designed to give an objective assessment of brain function, but that ‘the objective in concussion management is to measure brain injury’ and points out that ‘brain injury is only one cause of decreased brain function,’ mentioning that there are several other factors that may affect brain function such as the presence or absence of other injuries or mood disorders (Shrier, 2012). The author does not point out exactly when he means by ‘brain function,’ however, nor discusses in detail any of the other multidimensional tools that may be used to assess this such as EEG and fMRI.

There are clearly limitations in using neuropsychological tests in the setting of sports-related concussion related to the issues Shrier points out in his article. However, it is important to remember that it is the application of these tests in the overall clinical context that perhaps assists the practitioner in making an informed and reasoned judgement as to whether impairment in brain function is likely to be secondary to concussion.

Further on in the article, Shrier goes on to argue that neuropsychological tests have ‘minimal value for an individual athlete and does not support mandating (their) use,’ (Shrier, 2012) and then examines the arguments for using the tests related to asymptomatic athletes at rest, athletes who are asymptomatic at rest but symptomatic on exertion, and athletes who are asymptomatic on exertion.

Whilst there is still academic debate surrounding the clinical usefulness of neuropsychological tests in the setting of sport-related concussions, doubt must also be levelled at their applicability and cost-effectiveness, a point also argued by Shrier in his conclusion. He also mentions that there are not enough neuropsychologists with appropriate expertise available to be able to warrant mandatory neuropsychological testing on a population level for them to be considered as standard of care, which is certainly true.

In his conclusion, Shrier argues that ‘NP testing provides only a small increase in prognostic information and does not change the management of athletes who are symptomatic at rest or with exercise,’ and points out that ‘There is no evidence that abnormal NP testing is associated with increased risk of further injury or delayed recovery in athletes who are asymptomatic at rest and exertion.’ (Shrier, 2012). 

The Concussion in Sport group, however,  in their last consensus statement mentioned that ‘the application of neuropsychological testing in concussion has been shown to be of clinical value and continues to contribute significant information in concussion evaluation.’ (McCrory et al, 2009).

No doubt Shrier’s article will fuel much continuing academic debate on the use of neuropsychological tests in the setting of sport-related concussion.

Are you using these tests as part of your overall concussion management programme?

CJSM would like to hear your thoughts on the debate.

References

1) Shrier i. 2012. Neuropsychological testing and Concussions: A Reasoned Approach. CJSM 22(3): 211-213

2) McCrory  P et al. 2009. Consensus Statement on Concussion in Sport 3rd International Conference on Concussion in Sport Held in Zurich, November 2008. CJSM 19(3): 185-200

Leave a Comment

Leave a Comment

Filed under Concussion in Sport, Elite sport, General Interest, Injury Prevention, Preparticipation Evaluation and Screening Tagged with

The Larks and the Owls – chronotypes and desynchronosis. Time for an individual approach with MEQ-SA analysis?

May 20, 2012 by

The practical management article in this month’s edition of the Clinical Journal of Sport Medicine by Charles H Samuels highlights a difficult problem facing athletes and their support staff that is commonly encountered during air travel, that of the issue of jet lag. Samuels makes the point about the difference between travel fatigue and jet lag (desynchronosis), defining the former as a  constellation of physical, psychological and environmental factors that impact over time on an athlete’s capacity to recover and perform, and the latter being defined as a number of symptoms occurring following travel between time zones.

The key to the understanding of these concepts lies within the study of Chronobiology – the field of biological science that examines cyclical phenomena in living organisms and their adaptation to solar and lunar rhythms. Human beings are normally diurnal creatures, usually being active in the day and sleeping at night. However, as many night and shift-pattern workers will attest, many of us are required to adapt to different patterns of activity and sleep as part of our everyday lives. Some of us are able to cope with these pattern shifts better than others, whereas extremes of sleep-activity outside the normal range may cause a person difficulty in participating in normal work, school and social activities.

Flight travel over different time zones presents a challenge for the individual as the body seeks adjusts its circadian rhythms to these different  zones. A number of different modalities may be used in order to prevent athletes developing jet-lag, including the use of melatonin, preflight adjustment to travel, timed light exposure and avoidance, and changes in training schedules. However, it is interesting to observe that some individuals seem to suffer from jet lag more than others, and that there is variability in the efficacy of preventative and treatment strategies for desynchronosis amongst athletes.

Why is it that some of us seem to cope better with time zone changes and shift pattern working? Perhaps the answer lies in an individual’s chronotype.

Sleep researchers refer to ‘Larks’ as individuals who naturally wake up in the morning, contrasting with the ‘Owls’ who wake up and go to sleep late. These groups are also described as being comprised by individuals with ‘morning-ness’ and ‘evening-ness’ tendencies. Most people lie somewhere in between. However, there are some interesting differences between the groups with some researchers going as far as to suggest that disease processes may be directly influenced by morning-ness and evening-ness. This news feature in Nature, published in 2009, discusses some of these concepts in greater detail for those readers who may be interested to know more.

Horne & Ostberg in 1976 presented a self-assessment morningness-eveningness questionnaire and this has been modified by others to produce an MEQ-SA. Those of you who may wish to objectively assess your lark-ish and owl-ish tendencies can find the modified MEQ-SA questionnaire and scoring table here. 

It is unclear which factors contribute to an individual’s chronotype, as there seems to be no clear correlation to gender, ethnicity, or socio-environmental factors. However, perhaps chronotype variation may go some way to explaining why there is such variability in the effect of different preventative strategies for jet-lag between individuals. If so, then the assessment of an individual’s chronotype may form an important part of an overall primary preventative strategy for travelling athletes and support staff, which may be best conducted as part of an individual approach rather than a team approach.

Unfortunately, there is currently a paucity of literature on chronotype analysis in elite athletes in relation to jet-lag prevention representing an opportunity for further research in this area.

Are any readers using chronotype analysis as part of a jet-lag prevention strategy? CJSM would like to know.

References –

Samuels, Charles H. 2012. Jet Lag and Travel Fatigue: A Comprehensive Management Plan for Sport Medicine Physicians and High-Performance Support Teams. Clin.J.Sport Med. 22(3): 268-273

Phillips, Melissa Lee. 2009. Of owls, larks and alarm clocks. Nature 458 

Horne JA & Ostberg O.1976. A self-assessment questionnaire to determine morningness-eveningness in human circadian rhythms. Int. J. Chronobiol. 4(2):97-110 

 

Leave a Comment

Leave a Comment

Filed under Basic Sciences in SEM, Elite sport, General Interest, Travel Medicine Tagged with , ,

Exercise-associated hyponatremia; drinking oneself to death….. Guest blog by Dr Jonathan Williams

April 9, 2012 by

A 22 year old male fitness instructor finished the 2007 London Marathon, collapsed, and despite immediate emergency medical care, died. His serum sodium was markedly low, and the cause of death was found to be hyponatremia. Subsequent investigations established that he had been concerned about becoming dehydrated, and had therefore drunk a large volume of fluid en route. Several other athletes have died from hyponatremia due to drinking excessively, and many others have required hospital care. Studies from the 2002 Boston Marathon and 2006 London Marathon found that 13% and 12.5% of finishers, respectively, had asymptomatic hyponatremia. Our paper in this month’s CJSM explored the 2010 London Marathon runners’ knowledge about fluid intake, their drinking strategies and knowledge about exercise-associated hyponatremia (EAH).

City marathons were established around the world in the 1970s and 1980s. Elite marathon runners of the time rarely drank much during races; when Mike Gratton won London Marathon in 1983, he drank nothing. However, in 1975, the American College of Sports Medicine published a position statement advocating regular fluid intake during endurance events, suggesting this would reduce the risk of heat stroke. During the 1980s and 1990s, increasing numbers of endurance athletes experienced EAH.  International EAH Consensus Development Conferences of 2005 and 2007 reviewed the available evidence about EAH, and advocated drinking “to thirst” rather than the higher volumes recommended by ACSM. In 2007, ACSM revised its position statement advising that fluid intake during exercise should not exceed sweat loss.

In our study, a representative sample of 217 runners was questioned. More than 93% of the runners had read or been told about drinking fluid on marathon day. However, 12% planned to drink a volume large enough to put them at higher risk of EAH, and only 25.3% planned to drink according to their thirst. Although 68% had heard of hyponatremia or low sodium, only 35.5% had a basic understanding of its cause and effects. These findings suggest that runners lack knowledge about appropriate fluid intake on race day. Effective education is needed to prevent overdrinking during marathons.

Professor Tim Noakes has researched EAH for almost thirty years. He is due to publish a book in May 2012 called ‘Waterlogged’ in which he explores the influence sports drink manufacturers have on the science of hydration, and on runners’ drinking habits. ‘Waterlogged’ is likely to be thought-provoking, controversial and fascinating.

The cause of EAH is firmly established and it is entirely preventable. It is now the responsibility of race organizers, drinks manufacturers, running publications and us as sports physicians to educate runners effectively about safe drinking strategies.

Dr Jonathan Williams is a Sports Medicine Doctor and General Practitioner, as well as an avid runner.

The photograph is of the author having just completed a London Marathon

References :

1) Williams J et al. 2012. Hydration Strategies of Runners in the London Marathon. Clin J Sport Med 22 (2): 152-156

2) Hew-Butler et al. 2008. Statement of the Second International Exercise-Associated Hyponatremia Consensus Development Conference, New Zealand, 2007. Clin J Sport Med 18(2): 111-121

3) Hew-Butler et al. 2005. Consensus Statement of the First International Exercise-Associated Hyponatremia Consensus Development Conference, Cape Town, South Africa 2005. Clin J Sport Med 15(4): 208-213

4) Sawka MN et al. 2007. ACSM Position stand – Exercise and Fluid Replacement. Med Sci Sports Ex 39 (2): 377-390

Leave a Comment

Leave a Comment

Filed under Elite sport, Exercise Science, General Interest Tagged with ,

Sports pre-hospital immediate care training – not a Road Traffic Collision to be seen – Guest Blog by Dr Jonathan Hanson

March 7, 2012 by

Fortunately for athletes, the days of a medic in the bar in a suit are mostly behind us. The general advancement in pre-hospital care and in particular through primary care avenues has led to the recognition that there is “no place for a token Doctor” in the sporting environment.

Ethically and medico-legally, pitchside medical staff need to be trained and equipped for the service for which they provide. The exact level to which this training has taken place will vary from sport to sport, with motorsport and equestrian events requiring a level of training comparable to that of general pre-hospital care specialists dealing with immediate medical response to complex polytrauma.

However, therein lies the current problem of pre-hospital care teaching and the sporting environment – the injury profiles, or at least those that we know, of most sports are generally not comparable to the case load for which a pre-hospital care specialist would regularly manage. Although sports such as American football, Rugby, Australian rules football and ice hockey have particularly ferocious collisions, they do not cause the patterns of multiple injuries or tissue damage that one would see in a road traffic collision, a fall from a height or a blast injury. Hence, many training courses aimed at tackling standard pre-hospital care scenarios are not entirely appropriate for the pitchside sports physician or physiotherapist.

Within pre-hospital emergency care training there exists a niche for a separate entity of sports pre-hospital immediate care courses – courses that reflect not only the injury profiles of the sports for which they are designed, but also the speed of response of the pitchside responder, so that when they meet tachycardia, tachypneoa and distress on the pitch – they have “shock” at the back of their minds, but “recovering from sprinting” at the front. Indeed, the speed of response of pitchside medical staff means that many pre-hospital principals need viewing in a different light.

On-field trauma patients don’t really have time to bleed 2 litres of blood into the abdomen by the time they are initially assessed, unlike the patients being assessed by emergency services a few minutes following a car crash. Of course haemorrhagic shock does occur in sport so training needs to include the need to monitor and transfer those about which we are worried. Pelvic haematomas seldom have enough time to form during most sports, let alone be disrupted by particular manoeuvres, so some of the arguments about choice of equipment and techniques when pitchside staff extricate an athlete are more open for debate. Most athletes who compete in an environment with pitchside medical support are extremely fit and with massive physiological reserves – again another unique demographic for the expected caseload and training needs to reflect the physiological response in such individuals to trauma.  For some medics at least, every move can be live on TV – with both medical pressures and privacy issues for the athlete, and the pressures of a high media spotlight need also to be taken into consideration.

Fortunately the niche of sports pre-hospital immediate care courses has been recognised by the Faculties of Pre-hospital Care and of Sport and Exercise medicine of the Royal College of Surgeons of Edinburgh, and as a result excellent in-hospital courses such as ATLS are being replaced on the sports medicine curriculum by sports pre-hospital immediate care courses. This should lead to regulation about training standards and delivery and help regulate the recent explosion of sports trauma courses to a common standard for the good of the athlete and for the medics. Long may it continue.

Dr Jonathan Hanson FFSEM is a Sport and Exercise Medicine Physician / Rural Practitioner, at Broadford Hospital, Skye, Scotland

Image – Dr Jonathan Hanson (right) and a colleague in action

Leave a Comment

Leave a Comment

Filed under Elite sport, General Interest, Prehospital care Tagged with , ,

← Older posts

Newer posts →