Nathan Schilaty

BACKGROUND: Traumatic brain injury (TBI), particularly mild forms resulting from blast exposure, remains a diagnostic challenge among veterans due to delayed symptom onset and overlapping psychological conditions such as posttraumatic stress disorder. Current diagnostic methods rely heavily on subjective assessments, contributing to underdiagnosis and inconsistent care. Electroencephalography (EEG) offers a non-invasive, real-time measure of cortical activity with high temporal resolution, making it a promising tool for objective TBI assessment. This sub-study, nested within a randomized controlled trial evaluating hyperbaric oxygen therapy (HBOT) for veterans with TBI, investigates EEG as both a diagnostic modality and a therapeutic monitor.

METHODS: This sub-study adopts the same triple-blinded, randomized, parallel-group design as the parent trial. Participants are veterans with mild to moderate TBI, randomized to receive either HBOT or a sham treatment. EEG data are collected at three time points: baseline (pre-treatment), midpoint (18-21 dives), and post-treatment (2 weeks after completion). EEG recordings are performed during standardized cognitive and motor tasks using a 32-channel wireless headset. Primary outcomes include event-related potential amplitudes and alpha-band spectral power, analyzed for longitudinal changes and group differences. Secondary outcomes include latency measures, spectral power across additional frequency bands, and functional connectivity metrics. Data are modeled using repeated measures analysis to assess treatment effects and individual trajectories.

DISCUSSION: This sub-study aims to validate EEG as a scalable and objective tool for diagnosing and monitoring TBI in clinical settings. By identifying electrophysiological signatures associated with injury severity and treatment response, EEG may enhance diagnostic precision and support personalized care strategies. The integration of EEG within a larger therapeutic trial framework allows for comprehensive evaluation of its clinical utility. Findings may inform future protocols for TBI assessment and contribute to the development of neurophysiological biomarkers that complement existing symptom-based approaches.

TRIAL REGISTRATION: ClinicalTrials.gov NCT06581003. Registered on 30 August 2024.

BACKGROUND: Anterolateral ligament and medial collateral ligament injuries could happen concomitantly with anterior cruciate ligament ruptures. The anterolateral ligament is injured more often than the medial collateral ligament during concomitant anterior cruciate ligament ruptures although it offers less restraint to knee movement. Comparing the material properties of the medial collateral ligament and anterolateral ligament helps improve our understanding of their structure-function relationship and injury risk before the onset of injury.

METHODS: Eight cadaveric lower extremity specimens were prepared and mechanically tested to failure in a laboratory setting using a hydraulic platform. Measurements of surface strains of superficial surface of each medial collateral ligament and anterolateral ligament specimen were found using three-dimensional digital image correlation. Ligament stiffness was found using ultrasound shear-wave elastography. t-tests were used to assess for significant differences in strain, stress, Young's modulus, and stiffness in the two ligaments.

FINDINGS: The medial collateral ligament exhibited greater ultimate failure strain along its longitudinal axis (p = 0.03) and Young's modulus (p < 0.0018) than the anterolateral ligament. Conversely, the anterolateral ligament exhibited greater ultimate failure stress than the medial collateral ligament (p < 0.0001). Medial collateral ligament failure occurred mostly in the proximal aspect of the ligament, while most anterolateral ligament failure occurred in the distal or midsubstance aspect (P = 0.04).

INTERPRETATION: Despite both being ligamentous structures, the medial collateral ligament and anterolateral ligament exhibited separate material properties during ultimate failure testing. The weaker material properties of the anterolateral ligament likely contribute to higher rates of concomitant injury with anterior cruciate ligament ruptures.