A joint US and Norwegian study has shown that many people who have sustained a concussion report cognitive difficulties such as problems with memory and attention, yet they perform normally on the tests that measure these tasks.
Each year, thousands of people end up in hospital with a concussion, often from a fall or sporting injury. Many people who suffer minor head injuries rest up and then continue life as usual after a few days. But some are plagued by symptoms for a long time afterward.
PhD candidate, psychologist Jonas Stenberg, from the Norwegian University of Science and Technology (NTNU) has collaborated with researchers from Harvard Medical School in a study that has been published in the journal Neuropsychology.
Stenberg found that the patients who experience difficulty thinking, remembering and planning are not the same ones who struggle with thinking, remembering and planning on the tests.
“The results were a bit surprising,” says Stenberg.
“If someone reports significant memory problems, we expect them to also have poor results on the memory tests. But that wasn’t the case.”
The researchers examined 135 people aged 16 to 59 years. They arrived at St. Olav’s Hospital or urgent care in Trondheim with minor head injuries, and were asked to participate in the study. Half of them had been briefly unconscious after the injury. The average age was 33, and most were men.
They were checked two weeks after the injury, and then again three months after the injury.
Even after three months, the follow-up showed no clear association between the symptoms experienced by the study participants and their test results.
Stenberg believes that the surprising results of the study could be because of several reasons. Tests and self-reporting may be measuring different problems, or the tests may not be succeeding in capturing patients’ symptoms, or it may be difficult for patients to assess their own functioning and symptoms.
“It’s important for people who’ve suffered mild concussions to be thoroughly examined with several different methods to ensure they get the help they need,” Stenberg says.
He said it was also important to remember that most people quickly become symptom-free after a minor head injury. In several studies, researchers are now trying to figure out who would benefit the most from good follow-up care.
The emotional link
These studies take into account both personal factors and factors related to the injury itself, such as MRI findings of smaller injuries to the brain.
Although the relationship between perceived symptoms and test results was weak, the association between perceived cognitive, emotional and physical ailments was all the stronger.
“Patients who reported improvement in cognitive symptoms also reported improvement in their physical and emotional symptoms. This finding may be a clue that treating one type of symptom, such as the emotional, can also improve cognitive symptoms,” Stenberg says.
In other words, helping people reduce their sadness after an injury could improve their memory.
“This is promising information for treatment, and right now studies are under way at NTNU that are looking at the effectiveness of rehabilitation after concussions,” Stenberg says.
Stenberg J, Karr JE, Terry DP, et al. Change in self-reported cognitive symptoms after mild traumatic brain injury is associated with changes in emotional and somatic symptoms and not changes in cognitive performance. Neuropsychology. 2020;34(5):560-568. doi:10.1037/neu0000632