Tag: concussion

Categories : Injury & TraumaTags :

Experts Revise Consensus Statement on Management of Concussion in Sport

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Latest Consensus Statement on Concussion in Sport includes:

  • New and updated age appropriate tools to aid identification and management of condition
  • New versions of return to active sport and education strategies
  • Stronger evidence for benefits of light intensity exercise within first 48 hours to aid recovery
  • New targeted approach to rehabilitation
  • Call for interdisciplinary working group to guide research into potential long term effects

A group of more than 100 expert researchers and clinicians from around the world, co-chaired by Professor Jon Patricios of Wits Sport and Health (WiSH), University of the Witwatersrand (Wits University), has distilled and synthesised new scientific evidence and updated existing recommendations with the aim of optimising the care of athletes at all levels of participation who have, or who are at risk of, concussion.

Based on the outcomes from the International Conference on Concussion in Sport, held in Amsterdam in October 2022, and published in the British Journal of Sports Medicine (BJSM), the Statement is informed by 10 systematic reviews and methodology outlining the new consensus process. The entire process more than 4 years to complete. 

In a bid to be more transparent and inclusive than in previous years, the process adopted anonymous voting, alternative viewpoints, open declarations of potential conflicts of interest, and included the views of athletes, a focus on para-athletes, and ethical perspectives.  

The Statement includes a series of new (SCOAT6, Child SCOAT6) and updated (CRT6, SCAT6, Child SCAT6) age-appropriate tools for clinicians and sports organisations to help them better identify and manage sports related concussion in the short and longer term.

It features new evidence-based strategies for returning to active sport and education after concussion; early exercise and treatment recommendations; approaches to prevention; targeted rehabilitation; and a call for a working group to be set up to guide further research on the potential long term effects of concussion on health. 

Among the key recommendations:

Prevention

  • Policy or rule changes to minimise collisions, such as disallowing body checking in ice hockey – a defensive move in which the player tries to separate the puck from his/her opponent 
  • Neuromuscular training – aerobic, balance, strength, agility exercises +/-neck-specific components – in warm ups 
  • Mouthguard use in ice hockey (all ages)
  • Implementing laws and protocols, such as mandatory removal from play after actual or suspected concussion; healthcare professional clearance to return to play; and education of coaches, parents, and athletes on the signs and symptoms of concussion

Early interventions

  • Strict rest isn’t recommended. There’s now stronger evidence that light intensity physical activity, such as routine activities of daily living, and aerobic exercise, such as walking and stationary cycling, can aid recovery, as can limiting screen time during the first 48 hours.

Rehabilitation

  • For those experiencing dizziness, neck pain and/or headaches for more than 10 days, the Statement recommends cervico-vestibular rehabilitation – physiotherapy exercises to reduce symptoms and improve function.
  • Rehabilitation should be targeted to the needs of the individual.

Persisting symptoms 

  • Multidisciplinary team assessment to identify the types, pattern, and severity of symptoms and any other contributory factors is advised for those with symptoms lasting more than 4 weeks. 

Recovery

  • Advanced neuroimaging, biomarkers (chemical signals from nerves or blood vessels), genetic tests, and other emerging technologies to assess recovery are useful for research into the diagnosis, outlook, and recovery from sports related concussion. But as yet, they are some way off from being used in clinical practice, says the Statement.

Return to education and sport

  • Academic support may be needed for some athletes in the form of a return to learn strategy: this can include modified school attendance, limiting screen time, avoiding any contact sports or game play, extra time to complete assignments/homework or tests.
  • Light intensity activity in the early phases of the return to sport strategy is now recommended, with full sports participation usually occurring within 1 month of injury.
  • But it’s best to manage athletes on an individual basis, accounting for specific factors that may affect their recovery, such as a history of migraine, anxiety, and social factors.

Potential long term effects

  • The Statement notes the “increasing societal concern about possible problems with later in life brain health in former athletes, such as mental health problems, cognitive impairment and neurological diseases.”
  • Studies tracking the mental health of people over time (cohort studies) have found that former amateur and professional athletes don’t seem to be at heightened risk of depression or suicidality later in life.
  • Similarly, no heightened risk of neurological disease has been reported in former amateur athletes in these types of study. But some studies of former professional athletes have reported an association between playing professional American football and professional soccer and neurological disease in later life.
  • But the studies to date on the links between early sports participation and later life dementia and neurological disease are limited because they haven’t been able to adjust for a range of potentially highly influential factors, says the Statement.
  • It recommends setting up an interdisciplinary working group to guide appropriate research into the potential long term effects of concussion on health.

Evidence gaps still to be filled

  • There’s limited evidence on the management of sports related concussion in 5-12 year olds and in para sport athletes, who are known to be at heightened risk of sports related concussion.
  • And little research on concussion exists for certain regions of the world, diverse cultural contexts, sex and genders.

Commenting on the Statement, Consensus Statement co-chair, Dr Kathryn Schneider of the University of Calgary, Canada, says: “This Statement sets out a range of new evidence-based recommendations, including those for concussion prevention as well as new versions of the concussion assessment tools and return to sport and school/learning strategies”. 

“We encourage clinicians and sports organisations around the globe to adapt these recommendations to their own geographic and cultural environments to optimise the care of athletes who have sustained, or who are at risk of, concussion,” she adds.

“The differentiating aspects of this latest Concussion Consensus are the rigorous methodological process we adopted, the new generation of tools available to clinicians, and the emphasis on the positive impact of exercise and targeted rehabilitation as effective interventions,” explains Consensus Statement co-chair, Professor Jon Patricios of Wits University, Johannesburg, South Africa.

“These have the potential to positively change the management of sport-related concussion.”

Source: Wits University

Categories : Injury & Trauma NeurologyTags :

Up to Half of Concussions May Have Long-lasting Effects

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Even mild concussion can cause long-lasting effects to the brain, according to a University of Cambridge analysis published in Brain. The study researchers showed that for almost a half of all people who receive a concussion, there are changes in how regions of the brain communicate with each other. This could potential cause long term symptoms such as fatigue and cognitive impairment.

Concussion, a mild traumatic brain injury, can occur as a result of a fall, a sports injury or from a cycling accident or car crash, for example. But despite the ‘mild’ label, it is commonly linked with persistent symptoms and incomplete recovery. Such symptoms include depression, cognitive impairment, headaches, and fatigue.

While some clinicians in recent studies predict that 9 out of 10 individuals who experience concussion will have a full recovery after six months, evidence is emerging that only a half achieve a full recovery. This means that a significant proportion of patients may not receive adequate post-injury care.

Predicting which patients will have a fast recovery and who will take longer to recover is challenging, however. At present, patients with suspected concussion will typically receive either a CT or MRI brain scan to look for structural problems, such as inflammation or bruising. Yet even if these scans show no obvious structural damage, a patient’s symptoms may still persist.

Dr Emmanuel Stamatakis from the Department of Clinical Neurosciences and Division of Anaesthesia at the University of Cambridge said: “Worldwide, we’re seeing an increase in the number of cases of mild traumatic brain injury, particularly from falls in our ageing population and rising numbers of road traffic collisions in low- and middle-income countries.

“At present, we have no clear way of working out which of these patients will have a speedy recovery and which will take longer, and the combination of over-optimistic and imprecise prognoses means that some patients risk not receiving adequate care for their symptoms.”

Dr Stamatakis and colleagues studied functional MRI (fMRI) brain scans taken from 108 patients with mild traumatic brain injury and compared them with scans from 76 healthy volunteers. Patients were also assessed for ongoing symptoms.

The patients and volunteers had been recruited to CENTER-TBI, a large European research project which aims to improve the care for patients with traumatic brain injury.

The team found that just under half (45%) were still showing symptoms resulting from their brain injury, with the most common being fatigue, poor concentration and headaches.

The researchers found that these patients had abnormalities in a region of the brain known as the thalamus, which integrates all sensory information and relays this information around the brain. Counter-intuitively, concussion was associated with increased connectivity between the thalamus and the rest of the brain – in other words, the thalamus was trying to communicate more as a result of the injury – and the greater this connectivity, the poorer the prognosis for the patient.

Rebecca Woodrow, a PhD student in the Department of Clinical Neuroscience and Hughes Hall, Cambridge, said: “Despite there being no obvious structural damage to the brain in routine scans, we saw clear evidence that the thalamus – the brain’s relay system – was hyperconnected. We might interpret this as the thalamus trying to over-compensate for any anticipated damage, and this appears to be at the root of some of the long-lasting symptoms that patients experience.”

Using positron emission tomography (PET) scans, the researchers were able to make associations with key neurotransmitters depending on which long-term symptoms a patient displayed. For example, patients experiencing cognitive problems such as memory difficulties showed increased connectivity between the thalamus and areas of the brain rich in the neurotransmitter noradrenaline; patients experiencing emotional symptoms, such as depression or irritability, showed greater connectivity with areas of the brain rich in serotonin.

Dr Stamatakis added: “We know that there already drugs that target these brain chemicals so our findings offer hope that in future, not only might we be able to predict a patient’s prognosis, but we may also be able to offer a treatment targeting their particular symptoms.”

Source: University of Cambridge

Categories : Injury & Trauma PaediatricsTags :

After Concussion, Kids Returning to School Sooner is Better

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Contrary to popular belief, rest may not always be the best treatment after a concussion, according to the results of a large multi-centre study published in JAMA Network Open. In fact, an early return to school may be associated with a lower symptom burden after suffering a concussion and, ultimately, faster recovery.

“We know that absence from school can be detrimental to youth in many ways and for many reasons,” says study lead author Christopher Vaughan, PsyD, neuropsychologist at Children’s National Hospital. “The results of this study found that, in general, an earlier return to school after a concussion was associated with better outcomes. This helps us feel reassured that returning to some normal activities after a concussion – like going to school – is ultimately beneficial.”

In this cohort study, data from over 1600 youths aged five to 18 were collected across nine paediatric emergency departments in Canada. Because of the large sample size, many factors associated with greater symptom burden and prolonged recovery were first accounted for through the complex statistical approach used to examine the data. The authors found that an early return to school was associated with a lower symptom burden 14 days post-injury in the 8 to 12 and 13 to 18-year-old age groups.

“Clinicians can now confidently inform families that missing at least some school after a concussion is common, often between 2 and 5 days, with older kids typically missing more school,” Dr Vaughan says. “But the earlier a child can return to school with good symptom management strategies and with appropriate academic supports, the better that we think that their recovery will be.”

The results suggest a possible mechanism of therapeutic benefit to the early return to school. This could be due to:

  • Socialisation (or avoiding the deleterious effects of isolation).
  • Reduced stress from not missing too much school.
  • Maintaining or returning to a normal sleep/wake schedule.
  • Returning to light-to-moderate physical activity sooner (also consistent with previous literature).

Source: Children’s National Hospital 

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Slower Concussion Recovery for Athletes not All Bad News

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Rugby players
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Athletes who recover more slowly from concussion may be able to return to play with an additional month of recovery beyond the typical recovery time, according to a new study published in the journal Neurology. Slow recovery was defined as taking more than 14 days for symptoms to resolve or taking more than 24 days to return to play, both of which are considered the typical recovery times for about 80% of athletes with concussion.

“Although an athlete may experience a slow or delayed recovery, there is reason to believe recovery is achievable with additional time and injury management,” said study author Thomas W. McAllister, MD, of the Indiana University School of Medicine in Indianapolis. “This is an encouraging message that may help to relieve some of the discouragement that athletes can feel when trying to return to their sport. While some athletes took longer than 24 days to return to play, we found that three-quarters of them were able to return to sports if given just one more month to recover.”

The study looked at 1751 American college athletes diagnosed with a concussion by a team physician. Of Male athletes (63%) participated primarily in football, soccer and basketball. Female athletes (37%) participated primarily in soccer, volleyball and basketball.

Participants were evaluated five times: within six hours after their injury, one to two days later, once free of symptoms, once cleared to return to play and at six months.

Participants reported symptoms daily to medical staff, up to 14 days following injury and then weekly if they had not yet returned to play.

A total of 399 athletes, or 23%, had a slow recovery.

Researchers found that of the athletes who took longer than 24 days to return to play, more than three-fourths, or 78%, were able to return to play within 60 days of injury, and four-fifths, or 83%, were able to return to play within 90 days of injury. Only 11% had not returned to play six months after injury.

For the slow recovery group, the average time for returning to play was 35 days after injury, compared to 13 days in the overall group.

“The results of this study provide helpful information for athletes and medical teams to consider in evaluating expectations and making difficult decisions about medical disqualification and the value of continuing in their sport,” McAllister said.

A limitation of the study is that participants were all collegiate varsity athletes and may not be representative of other age groups or levels of sport, and the results may not apply to other types of mild brain injuries.

Source: American Academy of Neurology

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Repeated Concussions can Result in Skull Thickening

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Published in the journal Scientific Reports, a study led by Associate Professor Bridgette Semple from Monash University, found that repeated concussions resulted in thicker, denser bones in the skull.

Although bones are considered a mostly structural component of the human body, bones are in fact active living tissues that can respond to applied mechanical forces. For example, martial arts training, with its kicks, punches and throws, has been shown to increase bone mineral density in the arms, legs and spines of practitioners.

At present, it is unclear whether this thickening of the skull is beneficial or detrimental: theoretically, a thicker skull is a stronger skull, suggesting that this may be the bone’s attempt to protect the brain from subsequent impacts.

“This is a bit of a conundrum,” Assoc Prof Semple said. “As we know, repeated concussions can have negative consequences for brain structure and function. Regardless, concussion is never a good thing.”

The team hopes that the microstructural skull alterations caused by concussion are now considered by researchers in the field to better understand how concussions affect the whole body.

A form of mild traumatic brain injury, concussion have been linked to long-term neurological consequences if they happen repetition.

While most studies focus on its effect on the brain and its function, they largely ignore the overlying skull bones.

Study collaborator Professor Melinda Fitzgerald, from Curtin University and the Perron Institute in Western Australia, has previously shown that repeated concussive impacts lead to subtle problems with memory, and evidence of brain damage.

In this new study, high-resolution neuroimaging and tissue staining techniques were used in a pre-clinical animal model, and revealed an increase in bone thickness and density, in close proximity to the site of injury.

“We have been ignoring the potential influence of the skull in how concussive impacts can affect the brain,” Associate Professor Semple said. “These new findings highlight that the skull may be an important factor that affects the consequences of repeated concussions for individuals.”

Future studies are planned, with collaborator and bone expert Professor Natalie Sims from St Vincent’s Institute of Medical Research in Melbourne, to understand if a thickened skull resulting from repeated concussions alters the transmission of impact force through the skull and into the vulnerable brain tissue underneath.

Source: Monash University

Categories : Injury & Trauma PaediatricsTags :

A Tangled Web of Brain Damage from Concussions in Children

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Concussion may cause different types of brain damage which lead to similar symptoms in children, according to research published in eLife. A new way of studying concussions could help inform the development of future treatments.

While most children fully recover after a concussion, some will have lasting symptoms. The findings help explain the complex relationships that exist between symptoms and the damage caused by the injury.

The researchers found that certain combinations of brain damage were associated with specific symptoms such as attention difficulties. Other symptoms, such as sleep problems, occurred in children with multiple types of injuries. For example, damage to areas of the brain that are essential for controlling sleep and wakefulness could cause challenges with sleeping, as could damage to brain regions that control mood.

The brain’s white matter holds clues

To do this, they examined how damage to the brain resulting from concussion affected its structural connection network, known as white matter. They then used statistical modelling techniques to see how these changes related to 19 different symptoms reported by the children or their caregivers.

Analysing symptoms may advance treatment

“Despite decades of research, no new treatment targets and therapies for concussions have been identified in recent years,” said lead author Guido Guberman, a Vanier Scholar and MDCM Candidate at McGill University. “This is likely because damage to the brain caused by concussions, and the symptoms that result from it, can vary widely across individuals. In our study, we wanted to explore the relationships that exist between the symptoms of concussion and the nature of the injury in more detail.”

Guberman and his colleagues analysed data collected from 306 children, aged nine to 10 years old, who had previously had a concussion. The children were all participants in the Adolescent Brain Cognitive Development (ABCD) Study.

“The methods used in our study provide a novel way of conceptualising and studying concussions,” says senior author Maxime Descoteaux, a Professor of Computer Science at Université de Sherbrooke. “Once our results are validated and better understood, they could be used to explore potential new treatment targets for individual patients. More broadly, it would be interesting to see if our methods could also be used to gather new insights on neurological diseases that likewise cause varied symptoms among patients.”

Source: McGill University

Categories : Injury & TraumaTags :

Greater Concussion Risk in Fighters Who Cut Weight for a Bout

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There is more risk of suffering concussions or being misdiagnosed with head trauma is greater among fighters who rapidly cut weight before bouts, usually by dehydrating, researchers have revealed for the first time.

More than 60% of athletes in combat sports such as boxing and mixed martial arts (MMA) reported that their symptoms worsened after they dehydrated to make strict weight classes.

These controversial weight cutting techniques involve stop drinking water and endure long periods in saunas.

MMA athletes reported concussion severity to be 40% higher compared to other sports, particularly boxing – believed to be due to the mix of striking and contact with the ground.

Published in the Clinical Journal of Sports Medicine, the study comes after a series of tragedies associated with weight cuts, with some athletes even dying in the attempt to achieve a perceived competitive edge, by competing in a smaller weight class.

They found that as competitors dramatically dehydrate themselves to meet stringent weight classes, the associated symptoms may ‘muddy the waters’ of baseline concussion testing, due to similar symptoms.

This is because the symptoms of hypohydration – where competitors enter a water deficit – match concussive signs, such as dizziness, headaches, and lethargy.

This study has spurred further probes into the neurological implications of rapid weight loss. The researchers have called on governing bodies to check fighters’ hydration levels before fights.

Researcher Nasir Uddin, from St Mary’s University, said: “This study shows that current concussion testing does not account for the crossover of symptoms from being dehydrated, and is potentially putting fighters at risk.

“Not only is cutting weight through dehydration in and of itself dangerous, but it might actually exacerbate concussion symptoms and, even more concerningly, means medical professionals may actually misdiagnose it.

“Going forward, governing bodies should ensure hydration and baseline concussion symptoms are taken into account before and after bouts.”

The study surveyed more than 130 anonymous athletes representing six combat sports, all aged 18 or above and who had previously cut weight.

It also found that 65% of the fighters had an experience of a weight cut “not going to plan”, suffering a lack of energy, strength, power, coordination or increased susceptibility to being ‘rocked’ during a bout.

This means the dangerous practice may not offer a competitive advantage after all.

Dr Jamie Tallent, from the University of Essex, said: “This is perhaps the most surprising finding that not only are weight cuts dangerous – they leave fighters at a disadvantage more often than not and may exacerbate the risks of being further injured.”

Source: University of Essex

Categories : Injury & TraumaTags :

Long-term Symptoms of Concussion Tied to Vestibular Nerve Damage

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A clinical study from Lund University in Sweden has shown that long-term problems such as dizziness and difficulty focusing after a concussion originate in an injury to the vestibular nerve. The researchers published their findings in the Journal of Neurotrauma.

Concussion resulting from a blow to the head is a hazard in many sports. In American football, where players who have suffered from repeated concussions have developed dementia, severe depression and cognitive impairment.

Concussion usually has only temporary symptoms, but an increasing number of athletes experience long-term problems that make it difficult to work, go to school or play sports. The symptoms are aggravated by activity or impressions and include headaches, depression, anxiety, nausea, difficulty focusing and problems with balance.

“It has been unclear what causes the symptoms, and it is difficult for healthcare professionals to help these athletes. We wanted to investigate this further to find out what really causes the symptoms,” said Professor Niklas Marklund, one of the study’s researchers.

The study included 21 healthy athletes without previous trauma to the head, and 21 athletes who all suffered from sports-related concussions and who had experienced persisting symptoms for more than six months. The researchers used a 7-Tesla MRI, to study the athletes’ brains to understand more about what caused the symptoms. They discovered impaired function of the balance organs in the inner ear of 13 athletes in the group with long-term problems. In the group of healthy athletes three people had similar findings.

“The test results show that the injury is located to the vestibular nerve, which is connected to the semicircular canals in a cavity inside the skull, and which is directly adjacent to the cochlea in the ear. These injuries lead to the inward nerve impulses not working properly, and the brain therefore does not receive important information about body movements and sensory impressions required to maintain a good balance,” said Anna Gard, doctoral student at Lund University and first author of the study.

Concussion often results from the head rotating too fast.

“We have not examined athletes with short-term problems after blows to the head, so we cannot say anything about them. This study applies to athletes with prolonged symptoms after concussion. The rotation of the head that occurs in connection with a concussion could lead to a stretch of the vestibular nerve, which then leads to impaired function. Now that we have more knowledge about where the problems are located, it is easier to find possible therapies that could help these athletes,” concluded Prof Marklund.

Source: Lund University

Categories : Neurodegenerative DiseasesTags :

No Overall Link of Concussions to Cognitive Decline in Older Ex-rugby Players

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Elite ex-rugby players aged 50+ who suffered three or more rugby-related concussions in their career have similar cognitive function to those who had experienced fewer concussions, according to a new study in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

The BRAIN study worked with nearly 150 retired elite male players now aged 50+ who played for either England, Oxford University or Cambridge University in the pre-professional era.

While no worsening of cognitive function was seen in the group overall and in the under 75s, the study did find that over 75s with three or more rugby-related concussions during their career (14/48) had significantly worse cognitive function on average than those who had experienced fewer concussions, and may be at risk of future cognitive problems.

The findings have implications for the clinical management of older ex-rugby players, and possibly ex-players of other contact sports who may be at risk of impaired cognition, the team noted.

Given the age of the 75+ participants, these findings therefore primarily relate to the pre-professional era in rugby. Additional work is needed for younger players, particularly when reaching older ages when more cognitive problems manifest.

This study marks the first to attempt to measure cognitive function in a large number of former players and to link this to their concussion and playing history. Previous studies which have focussed on younger players have found little or no association between concussions and reduced cognitive function.

The study’s last author, Professor Neil Pearce from the London School of Hygiene & Tropical Medicine, said: “Evidence is accumulating on the possible long-term health risks in former contact sport athletes. However, each sport is different and there is currently little evidence from rugby players. This study adds to this knowledge gap, and shows that playing elite rugby may affect cognitive function in older age. It’s important more research is conducted to confirm this, and on those who played in the early years of professional rugby.”

One partial explanation for the reduced cognition in the 75+ groups could be that the former elite rugby players in this study were mostly highly educated, therefore having a higher average cognitive function at the start of their playing careers.

Dr Valentina Gallo, from the University of Groningen in the Netherlands (formerly at Queen Mary University of London), another of the Principal Investigators of the BRAIN study, and study first author, said: “Our findings are in line with those of previous studies, and perhaps highlight that the high cognitive reserve in this study group may have masked the initial phases of any cognitive problems they experience. We’ll be following up on this group of players to shed further light on our findings.”

Participants took part in an extensive set of tests capturing physical and cognitive capabilities. with cognitive function measured using the Pre-clinical Alzheimer Cognitive Composite (PACC) score, which combines tests that assess episodic memory, timed executive function, and global cognition.

After adjusting for possible confounding factors including age, smoking and player playing position, participants over 75 with three or more concussions scored about two points lower on the PACC score. This indicates a difference in cognitive function that can only be detectable with this sort of detailed testing, but which may indicate an increased risk of developing neuro-degenerative conditions.

A total of 116 (80%) respondents reported at least one rugby-related concussion. Among the concussed, the number of rugby-related concussion ranged between one and 25, with a median of two. The number of rugby-related concussions was not associated with the position they played or with length of rugby career.

Dr Simon Kemp, RFU Medical Services Director, said: “This study, that started in 2017, adds to our developing understanding of the potential long term consequences of head impacts and concussions.  The agreed group of participants were aged 50+ principally because of the greater likelihood that we might detect any neurocognitive decline if present.  It is important to also conduct research with younger retired players.

Source: London School of Hygiene & Tropical Medicine

Categories : Injury & TraumaTags :

CT Scans Improve Outcomes for Concussion Patients

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A study found that CT scans for concussion patients provide crucial information on their risk for long-term impairment and their potential to make a complete recovery, and points to the need for more follow-up.

In the UC San Francisco-led study, researchers examined CT scans of 1935 patients, aged 17 and over, whose neurological exams met criteria for concussion, or mild traumatic brain injury (TBI). Outcomes for moderate and severe TBI have been linked to CT imaging features, but this may be the first time this link has been identified in patients with concussion. This contradicts previous research which had found no prognostic significance of specific types of CT abnormalities.

“Radiologists who routinely read trauma scans know intuitively that patterns of intracranial injury on CT are not random,” said first author Esther Yuh, MD, PhD, of the UCSF Department of Radiology and Biomedical Imaging. “We showed there are patterns of injury, that some of these are associated with worse outcome than others, and that they provide a window into mechanisms of injury that is reproducible across large studies.”

The study was published online in JAMA Neurology.

“Although concussions are referred to as mild traumatic brain injuries, there is nothing mild about some concussions,” explained senior author Geoffrey Manley, MD, PhD, professor and vice chair of neurological surgery at UCSF and chief of neurosurgery at Zuckerberg San Francisco General Hospital. “Patients with concussion may suffer from prolonged headache, poor sleep and impaired concentration, and they are at higher risk of self-medicating with drugs and alcohol. Concussion can also contribute to depression and anxiety, and increase the risk for suicide. We need to view concussion not as an event but as a disease requiring physician follow-up after a patient is discharged from the hospital.”

The participants were enrolled by the brain injury research initiative TRACK-TBI, of which Manley is the principal investigator. To enrich the number of so-called complicated concussions, the researchers drew exclusively from patients who had been seen at hospitals with level 1 trauma centres. This meant 37 percent of study participants had a positive CT, significantly more than the 9 percent of positive CTs from patients in US emergency departments.

The most common patterns of injury, affecting more than half of CT-positive patients, were combinations of subarachnoid haemorrhage (SAH), subdural haematoma (SDH), and/or contusion, which may be caused by injuries such as falls from standing. About 7 percent had intraventricular haemorrhage (IVH) or petechial haemorrhage, caused by head rotation as in some sporting, scooter and automobile accidents; and 5 percent had epidural haematoma (EDH), often seen in sports injuries such as being hit with a baseball.

Average age of the patients was 41 and 66 percent were male. They were followed-up at two weeks, and at three-, six- and 12 months following injury. Patients in the SAH/SDH/contusion group failed to make a complete recovery at 12 months post-injury and had a range of outcome impairments, from mild to more severe.

Patients in the IVH/petechial haemorrhage group tended toward more severe impairments, in the lower-moderate disability range, a level potentially affecting multiple areas of function, such as employment, social and leisure activities, up to 12 months post-injury. Patients with EDH fared significantly better and demonstrated complete recovery by their six-month assessment.

Results from CENTER-TBI, a parallel brain injury research group that had enrolled 2594 participants at European trauma centres. validated the findings. “The confirmation of the findings in an independent cohort confirms the fidelity of our results,” said Manley, adding that patients with EDH were one exception, with incomplete recovery lingering for months longer than those patients followed by TRACK-TBI. However, more severe outcomes were not seen at any point in either study.

The researchers noted that even among concussion patients with positive CT scans, only 39 percent get follow-up care, which should be routine. They also cautioned that their findings are not a call for increased CT use, which has radiation dose concerns and is restricted to known or suspected concussions.

Indeed, a recently approved rapid hand-held blood test may reduce the amount of CT scans. Manley found this test was more sensitive than CT in detecting concussion. The blood test measures biomarkers associated with TBI, which were nearly 52 times higher in MRI-identified concussion patients than in healthy participants.

In addition to challenging the belief that CT features in concussion are not relevant, the researchers are also challenging the idea that concussion is “what the patient brings to the injury,” said Manley, who is also affiliated with the UCSF Weill Institute for Neurosciences. “In moderate and severe TBI, it is anecdotally taught that outcome is determined by ‘what the injury brings to the patient,’ while concussion is determined by baseline characteristics like age, sex and years of education. While the study confirms the importance of these characteristics, we show that in some concussion cases, poor outcomes are also attributed to ‘what the injury brings to the patient.'”

Source: University of California, San Francisco

Journal information: Yuh EL et al., Pathological computed tomography features associated with adverse outcomes after mild traumatic brain injury, JAMA Neurology, July 19, 2021.