Brain Vital Signs Detect Cognitive Improvements During Combined Physical Therapy and Neuromodulation in Rehabilitation From Severe Traumatic Brain Injury: A Case Report

Abstract

Using a longitudinal case study design, we have tracked the recovery of motor function following severe traumatic brain injury (TBI) through a multimodal neuroimaging approach. In 2006, Canadian Soldier Captain (retired) Trevor Greene (TG) was attacked with an axe to the head while on tour in Afghanistan. TG continues intensive daily rehabilitation, which recently included the integration of physical therapy (PT) with neuromodulation using translingual neurostimulation (TLNS) to facilitate neuroplasticity. Recent findings with PT + TLNS demonstrated that recovery of motor function occurred beyond conventional time limits, currently extending past 14-years post-injury. To investigate whether PT + TLNS similarly resulted in associated cognitive function improvements, we examined event-related potentials (ERPs) with the brain vital signs framework. In parallel with motor function improvements, brain vital signs detected significant increases in basic attention (as measured by P300 response amplitude) and cognitive processing (as measured by contextual N400 response amplitude). These objective cognitive improvements corresponded with TG's self-reported improvements, including a noteworthy and consistent reduction in ongoing symptoms of post-traumatic stress disorder (PTSD). The findings provide valuable insight into the potential importance of non-invasive neuromodulation in cognitive rehabilitation, in addition to initial indications for physical rehabilitation.

Keywords: brain vital signs; case report; electroencephalography (EEG); neuroplasticity; post-traumatic stress disorder (PTSD); translingual neurostimulation (TLNS); traumatic brain injury (TBI).

Figure 1

Overview of the experimental design and clinical timelines for the overall and current studies (B: Baseline; and T: Treatment).

Figure 2

Radar plots of brain vital signs amplitudes and latencies from central electrodes for all three event-related potentials (ERPs) transformed into standardized scores (6 total). Increased ERP amplitudes equate to higher scores, and decreased ERP latencies equate to higher scores.

Figure 3

N100, P300, and N400 ERP amplitudes in microvolts at each assessment across Central Left Temporal, and Right Temporal electrode groups. Gray area indicates PT + TLNS treatment. *Indicates p < 0.05 relative to pooled-baseline [False-Discovery Rate (FDR) corrected].