Abstract T P78: Neurovascular Changes Characterize Split-belt Adaptation in Chronic Stroke Survivors: Preliminary Results
Background & Purpose: While previous studies have implicated localized cortical regions in the recovery of locomotor function in stroke survivors, very little is known about the mechanisms that underlie the recovery of locomotor adaptation in stroke survivors. Locomotor adaptation in stroke survivors is hampered due to the deterioration in bilateral coordination during gait. In an ongoing study, bilateral incoordination in gait was targeted with a split-belt paradigm and cortical neurovascular changes during the adaptation task were recorded with Functional Near Infrared Spectroscopy (fNIRS).
Subjects & Methods: In this study, chronic stroke survivors walked on a split-belt treadmill while wearing an fNIRS device. In a series of trials participants walked in baseline, split-belt, and catch conditions. A continuous wave fNIRS system, the ETG-4000 Optical System (Hitachi Medical Corporation, Tokyo, Japan) utilizing two different wavelengths (~695 and ~830 nm) sampling at 10 Hz, was used to measure cortical activity. Task-related cortical activity was computed based on the amount of oxygenated (OxyHb) hemoglobin during the locomotor adaptation task. Our paradigm yielded 24 channels on each side of head. Baseline levels of oxyhemoglobin were calculated for 30 seconds before starting each trial with the subjects standing in quiet stance. The differences from baseline were calculated during the first and last 30 seconds of each trial to determine initial changes and changes due to adaptation.
Results: Preliminary results from the study demonstrated the following for the primary motor and associated cortices: 1) higher levels of oxyhemoglobin on the non-affected side in comparison to the affected side, 2) Increased oxyhemoglobin during initial adaptation in comparison to baseline, 3) early to late split-belt adaptation was characterized by a reduction in oxyhemoglobin and 4) In the catch trial, there was an increase in oxyhemoglobin.
Conclusion: Characteristic neurovascular changes were demonstrated in chronic stroke survivors during locomotor adaptation that enhance our mechanistic understanding of adaptive changes after stroke and can potentially impact neuro-rehabilitation.
Author Disclosures: T. Rand: None. P. Fayad: None. M. Mukherjee: None.
- © 2015 by American Heart Association, Inc.