Sahar Sattari with Dr. Naznin Virji-Babul
Concussion is common among adolescents, particularly in those who play sports like hockey, rugby and football, yet clinicians still lack objective, brain-based tools to detect and monitor injury. Diagnosis still relies heavily on symptoms, which can be subjective and inconsistent.
In a new study published in Scientific Reports, first author Sahar Sattari, a PhD student under the supervision of Dr. Naznin Virji-Babul, investigated whether a concussion leaves a measurable “signature” in the resting brain.
Even when we are resting quietly, the brain does not stay still. It rapidly shifts between very brief, stable patterns of activity that last only fractions of a second. These patterns are called microstates.
“You can think of them as the brain’s ‘snapshots’ or ‘building blocks’ of thought,” Sahar explains. “They are short moments when different brain networks are temporarily working together.”
By measuring how long these patterns last and how often they occur, researchers can get insight into how efficiently the brain’s networks are communicating and coordinating.
In this study, Sahar and her team studied adolescent male athletes within two weeks of a sport-related concussion and compared them to healthy peers using electroencephalography (EEG). Previous research has only examined microstates in adults with long-term concussion effects, but this study is the first to investigate whether EEG microstate patterns change in adolescent males during the acute phase of injury.
Adolescents are particularly vulnerable because their brains are undergoing rapid development, so when a concussion occurs during this age, symptoms can be more severe and longer-lasting compared to younger children or adults.
“We wanted to know whether concussion changes the brain’s normal rhythms, even when someone is not performing a task,” says Dr. Virji-Babul, Professor in UBC Medicine’s Department of Physical Therapy. “What we found is that the injured brain behaves differently at rest.”
The brain’s unique “signatures”
“Think of the brain like an orchestra. Each section — strings, brass, percussion — represents a different brain network responsible for attention, movement, self-awareness and other functions,” Dr. Virji-Babul explains. “These sections smoothly take turns leading and supporting one another to create balanced, flexible music.”
After a concussion, the orchestra is still playing, but the timing is off.
In this study, the research team found that one important “section” — the one that helps you focus, detect important information and switch between tasks — did not stay active as long as it normally would. It stepped back too quickly. This suggests the brain may have more difficulty sustaining attention or efficiently shifting between mental tasks.
They also observed that another section involved in movement and body awareness played less often. This may help explain why some individuals experience dizziness, balance problems, or feel physically “off” after a concussion.
At the same time, a different section — linked to mind-wandering and internal thoughts — seemed to play more strongly and for longer than usual. This may relate to the distracted or “brain fog” feeling that many people report.
So concussion does not stop the music. Instead, it temporarily changes how the sections coordinate and take turns.
“The overall harmony becomes less balanced, even though the orchestra is still functioning,” says Dr. Virji-Babul. “Our EEG measurements allowed us to detect these subtle shifts in coordination, even while the athletes were simply resting.”
This image shows the EEG topographies of seven different microstates. The first row shows the maps generated using data from both groups combined. The second and third rows show the maps generated separately for the control and concussed groups.
Toward better detection
“Our findings suggest that concussion disrupts the dynamic balance between major brain networks,” says Sahar. “These changes were detectable in simple resting-state EEG recordings, which is encouraging for real-world applications.”
Although exploratory and based on a small sample, the study highlights EEG microstate analysis as a promising, portable tool for objective concussion assessment, particularly in youth sports and remote settings.
“It opens the door to tracking recovery using neural dynamics rather than symptoms alone,” notes Dr. Virji-Babul.
