Post-concussion syndrome (PCS) is a condition characterized by prolonged cognitive and functional impairments following a traumatic brain injury (TBI) [1] . Symptoms such as memory deficits, impaired attention, and slowed cognitive processing often persist beyond the acute phase, significantly impacting quality of life. Current treatments for PCS typically focus on symptomatic relief but do not address the underlying neurophysiological dysfunctions, such as reduced neuroplasticity, mitochondrial dysfunction, and neuroinflammation [2] .

Recent advancements in therapeutic modalities have provided promising interventions for PCS. Hyperbaric therapy (HBT) is proposed to enhance neuroplasticity through changes in pressure dynamics rather than oxygenation [3] . HBT has historically been used to treat decompression sickness, carbon monoxide poisoning, and wound healing due to its capacity to improve tissue oxygenation and promote cellular repair. In neurological conditions, HBT has shown promise in improving neuroplasticity, reducing neuroinflammation, and enhancing cerebral blood flow, contributing to cognitive recovery.

Photobiomodulation (PBM) supports mitochondrial function and cellular resilience by enhancing adenosine triphosphate (ATP) production and reducing oxidative stress [4] [5] . Molecular hydrogen (MH) therapy, an emerging approach, reduces oxidative stress and inflammation, potentially augmenting recovery [6] [7] .

Emerging therapies like neurofeedback, transcranial magnetic stimulation (TMS), and vagus nerve stimulation (VNS) are also being explored for their potential in neurorehabilitation, offering additional avenues for addressing PCS. Neurofeedback, for instance, aims to train brain function by providing real-time feedback on neural activity, while TMS and VNS modulate neural circuits to promote recovery. Analogous cases in neurorehabilitation, where multimodal approaches have shown synergistic benefits, further substantiate the potential efficacy of combining these therapies.

This case report describes the application of HBT, PBM, and MH therapy in a patient with persistent PCS symptoms, demonstrating significant cognitive and neurophysiological improvements.

Following treatment, a notable reduction in P300 latency from 324 ms to 276 ms was observed, indicating improved cognitive processing speed [11] . Additionally, P300 voltage increased from 4.6 µV to 18.2 µV, suggesting enhanced attentional engagement and neurophysiological responsiveness [11] . These improvements reflect underlying enhancements in synaptic efficiency and neuroplasticity, which are critical for cognitive recovery in PCS patients. A dual-axis graph illustrates these changes, emphasizing the relationship between faster information processing and increased cortical activation.

Post-treatment results demonstrated a reduction in TMT Part A completion time from 56 seconds to 52 seconds, suggesting improved visual scanning and motor speed [12] . TMT Part B, which evaluates cognitive flexibility and executive function, showed a substantial improvement, with completion time decreasing from 127 seconds to 57 seconds [12] . A bar graph visualizes these reductions, reinforcing the observed cognitive benefits. All post-treatment assessments were conducted within one week of completing the 10-session protocol.

The observed improvements in cognitive function, illustrated in Figure 1 and Figure 2 , provide objective evidence that HBT, PBM, and MH therapy may enhance neurophysiological recovery in PCS patients. The reduction in P300 latency from 324 ms to 276 ms ( Figure 1 ) correlates with faster cognitive processing, reinforcing the potential neuroplastic benefits of this intervention [11] . Similarly, the increase in P300 voltage from 4.6 µV to 18.2 µV suggests greater cognitive engagement [11] . The enhanced performance in TMT Part A and Part B ( Figure 2 ) highlights comprehensive cognitive recovery across multiple domains [12] .

While the improvements observed are promising, it is important to consider other factors that may have contributed to these outcomes. The natural recovery trajectory post-concussion, the passage of time since injury, and potential placebo effects may have influenced the results. However, the magnitude of improvement across multiple objective measures suggests that the multimodal intervention played a significant role.

Future research should focus on validating these findings in larger, controlled studies to establish standardized protocols and investigate the long-term efficacy of these interventions. Extending the follow-up period to 3- and 6-month post-treatment would provide insights into the sustainability of cognitive improvements. Additionally, exploring biomarkers, such as inflammatory cytokines and mitochondrial activity, may further elucidate the mechanisms underlying recovery.

Given the potential costs associated with multimodal therapy, future studies should also aim to identify which individual treatments or combinations yield the most significant benefits. Understanding the relative contributions of HBT, PBM, and MH therapy will help optimize treatment protocols, making them more accessible and cost-effective for broader clinical applications.

This case demonstrates the efficacy of combining HBT, PBM, and MH therapy for post-concussion syndrome. Significant improvements in cognitive function and neurophysiological markers were observed, highlighting the potential for these therapies to address key aspects of PCS recovery. While sleep disturbances showed minimal improvement, the findings suggest that a multimodal approach may offer comprehensive benefits in managing PCS. Further research is warranted to optimize treatment protocols, determine the most effective components, and broaden clinical applications.