ImPact Test-Retest Reliability: Reliably Unreliable?

This study is an observational study of the reliability of follow up tests. In my personal opinion, ANY patient who is SYMPTOMATIC but has a normal test AND any ASYMPTOMATIC patient with an abnormal test should have an expert evaluation .

Do experts review all these baseline tests and provide an interpretation?

Do parents get results and an option to evaluate their child?
Are schools  putting students with abnormal tests in the game?

hmmm...

 JR

ImPact Test-Retest Reliability: Reliably Unreliable?

Jacob Resch , PhD, ATC*; Aoife Driscoll , BSc†; Noel McCaffrey , MD†; Cathleen Brown , PhD, ATC‡; Michael S. Ferrara , PhD, ATC, FNATA‡; Stephen Macciocchi , PhD, ABPP§; Ted Baumgartner , PhD‡; Kimberly Walpert , MD‖

*University of Texas at Arlington;

†Dublin City University, Ireland;

‡University of Georgia, Athens;

§Shepherd Center, Atlanta, GA;

‖Georgia Neurological Surgery, Athens

Context: Computerized neuropsychological testing is commonly used in the assessment and management of sport-related concussion. Even though computerized testing is widespread, psychometric evidence for test-retest reliability is somewhat limited. Additional evidence for test-retest reliability is needed to optimize clinical decision making after concussion.

Objective: To document test-retest reliability for a commercially available computerized neuropsychological test battery (ImPACT) using 2 different clinically relevant time intervals.

Design: Cross-sectional study.

Setting: Two research laboratories.

Patients or Other Participants: Group 1 (n = 46) consisted of 25 men and 21 women (age = 22.4 ± 1.89 years). Group 2 (n = 45) consisted of 17 men and 28 women (age = 20.9 ± 1.72 years).

Intervention(s): Both groups completed ImPACT forms 1, 2, and 3, which were delivered sequentially either at 1-week intervals (group 1) or at baseline, day 45, and day 50 (group 2). Group 2 also completed the Green Word Memory Test (WMT) as a measure of effort.

Main Outcome Measures: Intraclass correlation coefficients (ICCs) were calculated for the composite scores of ImPACT between time points. Repeated-measures analysis of variance was used to evaluate changes in ImPACT and WMT results over time.

Results: The ICC values for group 1 ranged from 0.26 to 0.88 for the 4 ImPACT composite scores. The ICC values for group 2 ranged from 0.37 to 0.76. In group 1, ImPACT classified 37.0% and 46.0% of healthy participants as impaired at time points 2 and 3, respectively. In group 2, ImPACT classified 22.2% and 28.9% of healthy participants as impaired at time points 2 and 3, respectively.

Conclusions: We found variable test-retest reliability for ImPACT metrics. Visual motor speed and reaction time demonstrated greater reliability than verbal and visual memory. Our current data support a multifaceted approach to concussion assessment using clinical examinations, symptom reports, cognitive testing, and balance assessment.

Key Words:  intraclass correlation, concussions, mild traumatic brain injuries, neuropsychological 
testing, athletes

FULL study here

Address correspondence to Jacob Resch, PhD, ATC, University of Texas at Arlington, Box 19259, 113 Maverick Activities Center, Arlington, TX 76102. Address e-mail to resch@uta.edu.

What are the NFL players being told about concussions by their own Players' Association?

I think its fascinating that the teams have physicians but that the Players' Association is advocating the use of IMPARTIAL specialists: neurologists. JR


What is a concussion?

A concussion is a type of brain injury. It occurs when the brain moves quickly enough to interrupt its function. Most concussions result in full recovery, but some can lead to more severe injuries if not recognized and treated properly.

The source of the injury is not always clear. It can come from a blow to the head or even from a blow to the body. It can come from one big hit  or from several smaller ones.

You may not always be aware that you are concussed. It is common that  concussed people do not know they are injured. Look out for the health of your teammates. Be aware of these signs and symptoms in yourself  and fellow players:
What is interesting is that the NFL plaers' association is teaming up with neurologists (the American Academy of Neurologists)


WHAT IS A CONCUSSION?

• Disorientation or confusion
• Memory loss
• Behavior or personality change
• Trouble concentrating
• Feeling sleepy or groggy
• Sensitive to light or sound
• Dizziness or nausea
• Headache

If you or a teammate have any of these symptoms, tell your medical staff immediately. Trying to play with a concussion puts  you at serious risk for further injury
.
WHAT SHOULD I EXPECT FROM MY TEAM?

IMMEDIATE EVALUATION OF A SUSPECTED CONCUSSION.
If a concussion is suspected (in either a game or practice), you should
be evaluated immediately. There is an NFL protocol for this evaluation
that can be done in under 10 minutes. If you think you may have a
concussion, report your symptoms and request this exam. DO NOT
TRY TO PLAY THROUGH THIS INJURY.


THOROUGH EVALUATION TO DETERMINE PRESENCE OF
CONCUSSION.

Not every hit that causes symptoms is a concussion and  only medical personnel can make the diagnosis. You should be evaluated  with a comprehensive neurological evaluation, ideally in a quiet, distractionfree place.

RETURN TO WORK. If you have a concussion, you should not participate  in a game or practice until you are (1) symptom free at rest and during physical exertion and (2) cleared by your team physician AND the team’s  independent neurological consultant.

 The return to work protocol should
involve several steps of increasing exertion – from a stationary bike, to
jogging, to agility work, to non-contact drills. With each step, a player must
be symptom free to move to the next step. You should never play football
after a concussion if you have not been evaluated appropriately or are still  experiencing symptoms.

WHAT ELSE CAN I DO?

You have the right to a second opinion.

It is your health and your brain. If  you are unsure about your medical condition and/or your medical care,
do not hesitate to seek additional care. There are many experts in sports  concussion that can provide the care you need.

Don’t let any question go unasked. You and your family deserve the best  information. If you would like help getting a second opinion, or have a question, call

Identifying conditions contributing to concussions and brain damage

A new computer model claims to help reduce concussions and brain injury in athletes and soldiers.

Concussions can occur in sports and in combat, but health experts do not know precisely which jolts, collisions and awkward head movements during these activities pose the greatest risks to the brain. To find out, Johns Hopkins engineers have developed a powerful new computer-based process that helps identify the dangerous conditions that lead to concussion-related brain injuries. This approach could lead to new medical treatment options and some sports rule changes to reduce brain trauma among players.

The research comes at a time when greater attention is being paid to assessing and preventing the head injuries sustained by both soldiers and athletes. Some kinds of head injuries are difficult to see with standard diagnostic imaging but can have serious long-term consequences. Concussions, once dismissed as a short-term nuisance, have more recently been linked to serious brain disorders.

"Concussion-related injuries can develop even when nothing has physically touched the head, and no damage is apparent on the skin," said K. T. Ramesh, the Alonzo G. Decker Jr. Professor of Science and Engineering who led the research at Johns Hopkins. "Think about a soldier who is knocked down by the blast wave of an explosion, or a football player reeling after a major collision. The person may show some loss of cognitive function, but you may not immediately see anything in a CT-scan or MRI that tells you exactly where and how much damage has been done to the brain. You don't know what happened to the brain, so how do you figure out how to treat the patient?"

To help doctors answer this question, Ramesh led a team that used a powerful technique called diffusion tensor imaging, together with a computer model of the head, to identify injured axons, which are tiny but important fibers that carry information from one brain cell to another. These axons are concentrated in a kind of brain tissue known as "white matter," and they appear to be injured during the so-called mild traumatic brain injury associated with concussions. Ramesh's team has shown that the axons are injured most easily by strong rotations of the head, and the researchers' process can calculate which parts of the brain are most likely to be injured during a specific event.

The team described its new technique in the Jan. 8 edition of the Journal of Neurotrauma. The lead author, Rika M. Wright, played a major role in the research while completing her doctoral studies in Johns Hopkins' Whiting School of Engineering, supervised by Ramesh. Wright is now a postdoctoral research fellow at Carnegie Mellon University. Ramesh is continuing to conduct research using the technique at Johns Hopkins with support from the National Institutes of Health.

Beyond its use in evaluating combat and sports-related injuries, the work could have wider applications, such as detecting axonal damage among patients who have received head injuries in vehicle accidents or serious falls. "This is the kind of injury that may take weeks to manifest," Ramesh said. "By the time you assess the symptoms, it may be too late for some kinds of treatment to be helpful. But if you can tell right away what happened to the brain and where the injury is likely to have occurred, you may be able to get a crucial head-start on the treatment."

Armed with this knowledge, Ramesh and his colleagues want to use their new technology to examine athletes, particularly football and hockey players, who are tackled or struck during games in ways that inflict that violent side-to-side motion on the head. In the recent journal article, the authors point out that many professional sports games are recorded in high-definition video from multiple angles. This, they write, could allow researchers to reconstruct the motions involved in sport collisions that lead to the most serious head injuries.

The authors also noted that some sports teams equip their players' helmets or mouth guards with instruments that can measure the acceleration of the head during an impact. Such data, entered into the researchers' computer model, could help determine the likely location of brain damage. These results, combined with neuropsychological tests, could be used to guide the athlete's treatment and rehabilitation, the authors said, and to help a sports team decide when an athlete should be allowed to resume playing. This strategy also may help reduce the risk to athletes arising from a degenerative disease linked to repeated concussions.

More research, testing and validation must be conducted before the computer model can become useful in a clinical setting. This will include animal experiments and the correlation of data from event reconstruction to make sure the model accurately identifies brain injuries.

Ideally, Ramesh would like to collect digital brain images from soldiers and athletes before they enter combat or join highly physical sports activities. "We would then be able to track a high-risk population and keep records detailing what types of head injuries they experience," he said. "Then, we could look at how their brains may have changed since the original images were collected. This will also help guide the physicians and health professionals who provide treatment after critical events."

Read more here