A Los Angeles-based company has found that its “advanced version” of a transcranial Doppler (TCD) device is able to pick up changes in blood flow in the brains of recently concussed athletes, potentially increasing the likelihood of a useful ultrasound device that can be available on the sidelines of sporting events to diagnose concussions in real time. The abstract of the study is being presented at the American Academy of Neurology’s annual meeting, and the association issued this news release as part of its conference outreach. The news release does an admirable job of explaining the experimental design that led to this finding, getting specific about the nature of the participants and using language understandable to lay audiences. Its omission of information about potential costs, harms and conflicts of interest is less ideal. Journalists, of course, will also need to be sensitive to the fact that the research has not yet undergone peer review.
[Editor’s note: Kathlyn Stone, one of three reviewers on this news release, worked for the American Academy of Neurology from 2000-2004 as senior manager of media relations. She has no current relationship with the AAN.]
According to the release, more than 1 million athletes in the United States sustain concussions each year. Detecting those “hits” early—ideally on the field of play—and determining which require medical intervention would be valuable.
That being said, there really is no medical intervention to prevent sports-related concussion except to abstain from more contact. If the test were sensitive enough to detect early signs of concussion, it could prevent some additional damage that could result from continuing to play.
While the study’s principle investigator notes that the device may be “less expensive” than MRI, costs are not broached in the text. To have one of these devices at all sport events, say, starting at high school and beyond, would be quite expensive. Plus, staff would need to be trained to use the device and interpret the results. Dopplers are not used and interpreted by the lay public. The practicality of this was not mentioned.
The release states that the TCD ultrasound device “was able to differentiate between healthy and concussed athletes 83 percent of the time” compared to lower success rates for other procedures. But that is not the only important statistic.
While the concordance between the clinical criteria and the ultrasound was 83 percent, the test has a sensitivity of only 70 percent, suggesting that 30 percent of concussions are missed. In addition, there is a 17 percent false positive rate, It was not made clear by the news release when the test was performed. It appears that the test was well after the traumatic event, so we do not know what the test performance is at the time of injury.
The release also makes clear that physicians do not yet know what to “make” of this ability when it comes to clinical care.
Possible harmful effects, most notably false positive and false negative results, of the ultrasound procedure are not mentioned. A false positive could result in unnecessary follow-up tests and treatments while a false-negative result could lead to an athlete resuming on-field play too soon, greatly increasing their risk of head injury complications and severity.
The experiment is carefully explained in the news release, using language that will be accessible to non-scientists. But we are not told when the test was performed in relation to the trauma, which has bearing on the results and diagnostic accuracy. We think the release earns a satisfactory here for adding a caution that doctors have not yet forged a clear link between documenting changes in blood flow in the brain after a concussion and treatment.
The release doesn’t engage in disease mongering. Concussions among athletes is an increasingly recognized health risk.
While the news release makes clear that the National Institutes of Health and the National Science Foundation funded the study, it does not illuminate the potential conflict of interest of the lead investigator. The lead investigator is identified in the release as the co-founder of Neural Analytics which developed the technology, and a journalist or other reader must then infer that the company may well be a beneficiary of the adoption of this technology. At minimum, some acknowledgement of the financial prospects for the company would be appropriate.
Existing strategies to detect changes in blood flow in the brain—magnetic resonance imaging (MRI) and “traditional” transcranial Doppler devices—are compared to the advanced version of TCD ultrasound tested here.
However, we think the criteria here was just marginally met. An alternative for diagnosing concussion not discussed is evaluating clinical signs and symptoms, the typical method for classifying a head trauma as a concussion or not. We do not know whether doppler ultrasound is a better predictor of long-term problems than clinical signs and symptoms.
The second half of the news release discusses through comments of sources the need for further research to explore the utility of the device. That type of content sends the message to readers that the technology is not yet available. We do have concerns with the language suggesting that this technology should be readily available at sporting events.
The closest the release comes to claiming novelty is its assertions that the TCD ultrasound device is more accurate than other devices and that its application “may be a less expensive and portable way to measure these changes.” We’ll give that a satisfactory.
Although the text does not shy away from demonstrating that the technology under study does a better job of detecting changes in blood flow among concussed athletes than do other diagnostic strategies, it also offers cautionary comments that make clear the device is still very much in the testing phase.