Cerebral Perfusion Effects of Cognitive Training and Transcranial Direct Current Stimulation in Mild-Moderate TBI

Area of Science:

• Neuroscience
• Neuroimaging
• Rehabilitation

Background:

• Persistent post-traumatic symptoms (PPS) following traumatic brain injury (TBI) cause chronic functional impairment.
• Pseudocontinuous arterial spin labeling (pCASL) is a neuroimaging technique used to study cerebral blood flow (CBF) changes in TBI.
• pCASL shows promise for assessing therapeutic responses in TBI patients.

Purpose of the Study:

• To investigate the effects of computerized executive function training combined with anodal transcranial direct current stimulation (tDCS) on cognitive PPS in mild-moderate TBI (mmTBI).
• To assess changes in cerebral blood flow (CBF) using pCASL before and after the intervention.
• To explore the relationship between cognitive/behavioral improvements and CBF changes.

Main Methods:

• A pilot study involved 24 subjects with chronic mmTBI.
• Participants underwent 10 days of computerized executive function training with either active or sham anodal tDCS.
• Assessments included behavioral surveys, neuropsychological testing, and MRI with pCASL for CBF measurement.

Main Results:

• Both active and sham groups showed significant improvements in depression, anxiety, attention, and executive function.
• Global CBF decreased over time; regional CBF changes were noted in the right inferior frontal gyrus (IFG).
• Active tDCS was linked to stable or increased CBF in the right IFG, while sham stimulation led to reduced CBF; no direct association was found between neuropsychological performance and CBF changes.

Conclusions:

• The study indicates a complex interaction between mmTBI, cerebral perfusion, and recovery.
• Observed CBF changes may stem from the intervention's physiological effects, compensatory neural mechanisms, or confounding factors.
• Findings support further research into cognitive training paradigms for mmTBI, despite limitations like small sample size.