Personalized high-definition transcranial direct current stimulation improves cognition following carbon monoxide poisoning induced amnesia: A case report.

Abstract

High-definition transcranial direct current stimulation (HD-tDCS) has the potential to improve cognitive functioning following neurological injury and in neurodegenerative conditions. In this case report, we present the first use of HD-tDCS in a person with severe anterograde amnesia following carbon monoxide poisoning. The participant underwent two rounds of HD-tDCS that were separated by 3 months (Round 1 = 30 sessions; Round 2 = 31 sessions). We used finite element modeling of the participant's structural MRI to develop an individualized montage that targeted multiple brain regions involved in memory encoding, as identified by Neurosynth. Overall, the participant's objective cognitive functioning improved significantly following Round 1, declined during the 2 months without HD-tDCS, and again improved following Round 2. Subjective informant reports from family and medical personnel followed this same pattern of improvement following each round with a decline in between rounds. We also provide preliminary evidence of altered brain activity during a learning/memory task using functional near-infrared spectroscopy, which may help establish the physiological effects of HD-tDCS in future work. Overall, these findings reinforce the potential value of HD-tDCS as a user-friendly method of enhancing cognition following anoxic/hypoxic brain injury.