A researcher at the University of Missouri has helped identify a new sign that could help diagnose concussions.
Dr. Ross Zafonte, Executive Vice Dean for the University of Missouri School of Medicine, contributed to the study published in October which identified a new concussion sign known as SHAAKE. The acronym stands for Spontaneous Headshake After a Kinematic Event.
“That individual is shaking their head usually between two to eight times per second. And we believe there are many reasons why that can be occurring,” Zafonte said. “Could be visual - could be people are trying to stabilize their visual field. It could be they're simply trying to clear their sensorium or get a sense of where am I and what's going on.”
The study found that people who displayed the head shake behavior after a head injury were more likely to have a concussion – suggesting it could be a diagnostic tool.
“What is very cool about this - it's another thing that can be used by those people on the sidelines, as well as in some ways, the players themselves, to identify individuals who would benefit from a screening,” Zafonte said.
Research showed that the sign had a sensitivity of 49.6% and a positive predictive value of 72.4% for diagnosing concussions. That means nearly half of subjects in the study who displayed SHAAKE were positive for a concussion, and that researchers estimate just over 72% of people who display SHAAKE will test positive for a concussion.
The study showed a higher predictive value for football players at 91.9%. Researchers on the study pointed to Miami Dolphins quarterback Tua Tagovailoa’s movements after an undiagnosed concussion during a September 2022 game as a visible example of SHAAKE and how it can present.
Zafonte said the numbers indicate that SHAAKE can be a good diagnostic tool for concussions in football, but also said it has potential to be used to identify concussions in many contexts, including non-athletic fields.
“A place we are looking for it is in our military service members after blast related injury, specifically those individuals who are doing door blast breaching on a continual basis,” Zafonte said.
Zafonte says the team plans to share their research with medical and sports organizations moving forward and encourage them to include SHAAKE as a concussion screening protocol.
