Altered neural recruitment during single and dual tasks in athletes with repeat concussion

Abstract

Sports-related concussions (SRCs) pose significant challenges to college-aged athletes, eliciting both immediate symptoms and subacute cognitive and motor function impairment. While most symptoms and impairments resolve within weeks, athletes with repeat SRCs may experience heightened risk for prolonged recovery trajectories, future musculoskeletal injuries, and long-term neurocognitive deficits. This study aimed to investigate the impact of repeat SRCs on dual task performance and associated neural recruitment using functional near-infrared spectroscopy (fNIRS). A total of 37 college-aged athletes (ages 18-24) participated in this cross-sectional observational study, 20 with a history of two or more SRCs, and 17 controls that had never sustained an SRC. Participants completed the Neuroimaging-Compatible Dual Task Screen (NC-DTS) while neural recruitment in the frontoparietal attention network and the primary motor and sensory cortices was measured using fNIRS. Athletes with repeat SRCs exhibited comparable single task and dual task performance to control athletes. Neuroimaging results indicated altered neural recruitment patterns in athletes with repeat SRCs during both single and dual tasks. Specifically, athletes with repeat SRCs demonstrated increased prefrontal cortex (PFC) activation during single motor tasks compared to controls (p < 0.001, d = 0.47). Conversely, during dual tasks, these same athletes exhibited reduced PFC activation (p < 0.001, d = 0.29) compared to their single task activation. These findings emphasize that while athletes with repeat SRCs demonstrate typical single and dual task performance, persistent alterations in neural recruitment patterns suggest ongoing neurophysiological changes, possibly indicating compensatory neural strategies and inefficient neural resource allocation, even beyond symptom resolution and medical clearance.

Keywords: compensation; dual task; functional near-infrared spectroscopy; neurophysiology; prefrontal cortex; sports related concussion.

Figure 1

Functional near-infrared spectroscopy (fNIRS) head probe. A priori established regions of interest (ROI) for the fNIRS head probe. For this study, 15 LED sources and 15 detectors were used to create 50 channels covering the right lateralized nodes of the frontoparietal attention network and over bilateral primary motor and primary sensory cortices. Additionally, eight short-separator channels (illustrated as blue rings around red circles) were distributed throughout the head probe to measure scalp perfusion.

Figure 2

Dual task performance in the repeat SRC and control groups. (A) Mean gait speed (m/s) during the lower extremity (LE) single motor and dual tasks for the repeat SRC and control groups. (B) Mean number of catches during the upper extremity (UE) single motor and dual tasks for the repeat SRC and control groups. Light gray lines indicate paired single task and dual task performance for each group. All Ps < 0.001 except for LE single motor to dual task for controls (p = 0.016).

Figure 3

Dual task effects (DTE) and interference. (A) Individual motor (gait speed) DTE plotted against cognitive (verbal fluency) DTE for the lower extremity (LE) subtask. (B) Individual motor (catches) DTE plotted against cognitive (serial sevens) DTE for the upper extremity (UE) subtask. For both LE and UE, most participants experienced mutual inference of motor and cognitive performance (lower left quadrant), with a portion of participants experiencing a cognitive priority trade off (lower right quadrant).

Figure 4

Lower extremity (LE) neural recruitment significance map for HbO beta change. (A) Dual task activation contrasted against single motor task activation for the repeat SRC group only. (B) Dual task activation contrasted against single motor task activation for the control group only. (C) Activation in the repeat SRC group contrasted against activation of the control group for the single motor task condition. (D) Activation in the repeat SRC group contrasted against activation of the control group for the dual task condition. The colored bars illustrate a random-effects t-score map with red indicating increased activation and blue indicating decreased activation.

Figure 5

Upper extremity (UE) neural recruitment significance map for HbO beta change. (A) Dual task activation contrasted against single motor task activation for the repeat SRC group only. (B) Dual task activation contrasted against single motor task activation for the control group only. (C) Activation in the repeat SRC group contrasted against activation of the control group for the single motor task condition. (D) Activation in the repeat SRC group contrasted against activation of the control group for the dual task condition. The colored bars illustrate a random-effects t-score map with red indicating increased activation and blue indicating decreased activation.