Recovery of clinical, cognitive and cortical activity measures following mild traumatic brain injury (mTBI): A longitudinal investigation

Working Memory Recovery in Adolescents with Concussion: Longitudinal fMRI Study

Background: Understanding the behavioral and neural underpinnings of the post-concussion recovery of working memory function is critically important for improving clinical outcomes and adequately planning return-to-activity decisions. Previous studies provided inconsistent results due to small sample sizes and the use of a mixed population of participants who were at different post-injury time points. We aimed to examine working memory recovery during the first 6 months post-concussion in adolescents. Methods: We used functional magnetic resonance imaging (fMRI) to scan 45 concussed adolescents [CONCs] at baseline (<10 days post-concussion) and at 6 months post-concussion. Healthy control adolescents [HCs; n = 32] without a history of concussion were scanned once. During the scans, participants performed one-back and two-back working memory tasks with letters as the stimuli and angry, happy, neutral, and sad faces as distractors. Results: All affected adolescents were asymptomatic and cleared to return to activity 6 months after concussion. Working memory recovery was associated with faster and more accurate responses at 6 months vs. baseline (p-values < 0.05). It was also characterized by significant difficulty-related activation increases in the left inferior frontal gyrus (LIFG) and the left orbitofrontal cortex (LOFC) at 6 months vs. baseline. Although the activation differences between one-back and two-back were comparable between HCs and CONCs at 6 months, HCs had more pronounced activation in the LIFG than concussed adolescents. Conclusions: Post-concussion recovery is associated with significant performance improvements in speed and accuracy, as well as the normalization of brain responses in the LIFG and LOFC during the n-back task. The observed patterns of LOFC activation might reflect compensatory strategies to distribute neural processing and reduce neural fatigue post-concussion.

Symptom presentation and evolution in the first 48 hours after injury are associated with return to play after concussion in elite Rugby Union

BACKGROUND

Return to play (RTP) in elite rugby is managed using a 6-stage graduated RTP protocol, which can result in clearance to play within 1 week of injury. We aimed to explore how symptom, cognitive, and balance presentation and evolution during concussion screens 2 h (head injury assessment (HIA) 2) and 48 h (HIA3) after injury were associated with time to RTP) to identify whether a more conservative graduated RTP may be appropriate.

METHODS

A retrospective cohort study was conducted in 380 concussed rugby players from elite men's rugby over 3 consecutive seasons. Players were classified as shorter or longer returns, depending on whether RTP occurred within 7 days (allowing them to be considered to play the match 1 week after injury) or longer than 8 days, respectively. Symptom, cognitive, and balance performance during screens was assessed relative to baseline (normal or abnormal) and to the preceding screen (improving or worsening). Associations between sub-test abnormalities and RTP time were explored using odds ratios (OR, longer vs. shorter). Median day absence was compared between players with abnormal or worsening results and those whose results were normal or improving.

RESULTS

Abnormal symptom results during screens 2 h and 48 h after concussion were associated with longer return time (HIA2: OR = 2.21, 95% confidence interval (95%CI): 1.39-3.50; HIA3: OR = 3.30, 95%CI: 1.89-5.75). Worsening symptom number or severity from the time of injury to 2 h and 48 h post-injury was associated with longer return (HIA2: OR = 2.49, 95%CI: 1.36-4.58; HIA3: OR = 3.34, 95%CI: 1.10-10.15. Median days absence was greater in players with abnormal symptom results at both HIA2 and HIA3. Cognitive and balance performance were not associated with longer return and did not affect median days absence.

CONCLUSION

Symptom presentation and evolution within 48 h of concussion were associated with longer RTP times. This may guide a more conservative approach to RTP, while still adhering to individualized concussion management principles.

Efficacy of rTMS combined with cognitive training in TBI with cognition disorder: a systematic review and meta-analysis

Post-traumatic brain injury cognitive disorder(PTBICD) is one of the common symptoms of TBI survivors, severely limiting their life and rehabilitation progress. Repetitive transcranial magnetic stimulation (rTMS) has been shown to modulate cognition in a non-invasive manner while there are inconsistencies in previous studies. A comprehensive systematic review of rTMS treatment in patients with PTBICD is warranted. To evaluate the efficacy and safety of rTMS + cognitive training(CT) in enhancing cognitive function among PTBICD patients. A comprehensive search was conducted in PubMed, EMBASE, Cochrane Library, WOS, CNKI, Wan Fang, VIP and CBM, to identify relevant randomized controlled trials(RCTs) published before December 20, 2023. The primary outcomes measured changes in global cognitive scales, while the secondary outcomes focused on improvements in attention, memory, event-related potentials, and activities of daily living. Meta-analysis of data was carried out using Stata 14.0. Fourteen studies including 820 PTBICD patients were included. The results showed that rTMS + CT significantly improved MoCA[WMD = 3.47, 95%CI (2.56, 4.38)], MMSE[WMD = 3.79, 95%CI (2.23, 5.35)], RBMT[WMD = 1.53, 95%CI (0.19, 2.87)], LOTCA[WMD = 5.68, 95%CI (3.11, 8.24)], and promoted MBI[WMD = 7.41, 95%CI (5.90, 8.92)] as well as reduced correlated potential P300 latency[WMD = -20.77, 95%CI (-38.08, -3.45)] and amplitude[WMD = 0.81, 95%CI (0.57, 1.06)] in PTBICD compared to sham rTMS or CT, while adverse reaction ratio was higher than that of control group [RR = 1.67, 95%CI (1.00, 2.77)]. The results demonstrated that rTMS + CT can improve the cognitive function, mental state and daily activity ability of PTBICD patients. Systematic Review Registration: [PROSPERO], identifier [No. CRD42024520596].

Maximizing the Clinical Value of Blood-Based Biomarkers for Mild Traumatic Brain Injury

Mild traumatic brain injury (TBI) and concussion can have serious consequences that develop over time with unpredictable levels of recovery. Millions of concussions occur yearly, and a substantial number result in lingering symptoms, loss of productivity, and lower quality of life. The diagnosis may not be made for multiple reasons, including due to patient hesitancy to undergo neuroimaging and inability of imaging to detect minimal damage. Biomarkers could fill this gap, but the time needed to send blood to a laboratory for analysis made this impractical until point-of-care measurement became available. A handheld blood test is now on the market for diagnosis of concussion based on the specific blood biomarkers glial fibrillary acidic protein (GFAP) and ubiquitin carboxyl terminal hydrolase L1 (UCH-L1). This paper discusses rapid blood biomarker assessment for mild TBI and its implications in improving prediction of TBI course, avoiding repeated head trauma, and its potential role in assessing new therapeutic options. Although we focus on the Abbott i-STAT TBI plasma test because it is the first to be FDA-cleared, our discussion applies to any comparable test systems that may become available in the future. The difficulties in changing emergency department protocols to include new technology are addressed.