Prefrontal Cortical Activation With Open and Closed-Loop Tactile Cueing When Walking and Turning in Parkinson Disease: A Pilot Study

Background and Purpose: Gait and turning impairments are common in people with Parkinson disease (PwPD). Tactile cues delivered in open- or closed-loop modalities may improve gait and turning in PwPD, but underlying mechanisms are unclear. Attention stemming from the prefrontal cortex (PFC) may play a role in cue response, but PFC contributions to specific cue modalities are unclear. Examining how open- and closed-loop cueing influences PFC activity during walking and turning in PwPD may elucidate mechanisms involved in cue response, which could advance development of effective therapeutics. We examined PFC activity during walking and turning in response to open- and closed-loop cueing in PwPD, and explored relationships between PFC activity and behavioral measures. Methods: A mobile functional near-infrared spectroscopy device measured PFC activity during walking and turning in 25 PwPD (n = 13 freezers, n = 12 nonfreezers). Participants performed 180 degrees and 360 degrees turns while walking, and a 2-minute walk under single- and dual-task (AX-CPT) conditions with and without an open- (metronome-like vibration) or closed-loop (biofeedback vibration) tactile cue. Results: PFC activity did not change when walking or turning in PwPD; freezing status or task demands did not influence PFC activity. With both open- and closed-loop cueing dual-task cost of gait significantly improved, whereas turning slowed. Discussion and Conclusions: Our preliminary results indicate that both open- and closed-loop cueing can improve gait without additional burden to the PFC beyond usual walking. However, turning while walking slowed with cueing with no PFC activity change. Further investigations are necessary to establish these findings in a larger cohort. Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, the Video, available at: ).