Rethinking recovery in adolescent concussions: Network‐level functional connectivity alterations associated with motor deficits

Abstract

Adolescents who are clinically recovered from concussion continue to show subtle motor impairment on neurophysiological and behavioral measures. However, there is limited information on brain–behavior relationships of persistent motor impairment following clinical recovery from concussion. We examined the relationship between subtle motor performance and functional connectivity of the brain in adolescents with a history of concussion, status post‐symptom resolution, and subjective return to baseline. Participants included 27 adolescents who were clinically recovered from concussion and 29 never‐concussed, typically developing controls (10–17 years); all participants were examined using the Physical and Neurologic Examination of Subtle Signs (PANESS). Functional connectivity between the default mode network (DMN) or dorsal attention network (DAN) and regions of interest within the motor network was assessed using resting‐state functional magnetic resonance imaging (rsfMRI). Compared to controls, adolescents clinically recovered from concussion showed greater subtle motor deficits as evaluated by the PANESS and increased connectivity between the DMN and left lateral premotor cortex. DMN to left lateral premotor cortex connectivity was significantly correlated with the total PANESS score, with more atypical connectivity associated with more motor abnormalities. This suggests that altered functional connectivity of the brain may underlie subtle motor deficits in adolescents who have clinically recovered from concussion. More investigation is required to understand the persistence and longer‐term clinical relevance of altered functional connectivity and associated subtle motor deficits to inform whether functional connectivity may serve as an important biomarker related to longer‐term outcomes after clinical recovery from concussion.

Concussion history and virtual reality metrics predict core or lower extremity injury occurrence among high school athletes

“…Rapid reconfigurations of network connectivity patterns generate neural signals that are highly variable, which produce consistency in behavioral responses ( 37 , 38 ). Conversely, reduced default mode network deactivation is believed to result in attention lapses that produce inconsistency in motor output ( 14 ). Our finding of an association between elevated Step RT-IIV with CLEI (males ≥0.282 and females ≥0.301) is consistent with evidence for the interpretation of high RT-IIV as a behavioral correlate of neural impairment ( 20 , 27 – 29 , 39 ).…”

“…We have demonstrated that VR testing can detect a potentially modifiable contributor to elevated injury susceptibility through documentation of a prospective association between pre-participation perceptual–motor performance and subsequent injury occurrences. A substantial body of evidence has established that concussion effects can persist for months or years beyond clinical recovery and return to sport participation ( 7 , 14 , 17 , 21 ). Numerous researchers have presented evidence supporting a need for more stringent criteria to determine post-concussion readiness for return to sport ( 2 , 3 , 5 , 24 , 30 ) and a need for periodic risk screening of all athletes with a test that imposes sufficient cognitive and motor challenge to reveal subtle deficits ( 12 , 14 , 23 , 31 , 58 ).…”

“…A substantial body of evidence has established that concussion effects can persist for months or years beyond clinical recovery and return to sport participation ( 7 , 14 , 17 , 21 ). Numerous researchers have presented evidence supporting a need for more stringent criteria to determine post-concussion readiness for return to sport ( 2 , 3 , 5 , 24 , 30 ) and a need for periodic risk screening of all athletes with a test that imposes sufficient cognitive and motor challenge to reveal subtle deficits ( 12 , 14 , 23 , 31 , 58 ). Some evidence exists to support the potential for mitigation of injury risk through targeted training ( 34 , 60 ).…”

“…Although the exact mechanism responsible for the elevation of post-concussion injury risk is unknown ( 21 , 22 ), neuromechanical responsiveness to changing environmental conditions may be delayed by deficits in visual–spatial attention and cognitive–motor integration (i.e., perceptual–motor processing) ( 12 , 23 – 25 ). Because the self-reported resolution of concussion symptoms is currently the primary criterion for return to sport participation, there exists an urgent need for a clinical test that can identify individual athletes who possess an elevated risk for further injury ( 12 , 14 , 15 ).…”

Test-Retest Reliability of Immersive Virtual Reality Measures of Perceptual-Motor Performance

“…Non-immersive VR methods project a simulated environment onto a screen or computer monitor that is viewed within the surrounding real environment, whereas immersive VR methods project the user into a simulated three-dimensional environment through a head-mounted display that completely removes visual awareness of the real environment (Müller et al, 2023; Santos et al, 2020). A growing awareness of the limitations of existing clinical tests for detecting subtle performance deficiencies among athletes has created a critical need for new clinical measures that will identify those with elevated injury risk (Crasta et al, 2023; Wong et al, 2023). Compared to standard clinical tests of neurocognitive and neuromuscular function, VR can provide greater control of visual stimuli (e.g., location, duration, speed of movement and closer coupling between perceptual and motor responses) (Harris et al, 2020; Müller et al, 2023).…”