Evaluating neural activation changes following figure of eight walk training in parkinson's disease using fNIRS Pre-post observational study

Abstract

Background: Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by impaired motor control, particularly during complex gait activities. Figure-of-eight walking (infinity walk) is a dynamic locomotor task that challenges balance, coordination, and motor planning. Functional near-infrared spectroscopy (fNIRS) enables real-time assessment of cortical hemodynamic responses during such functional movements.

Objective: To evaluate the immediate effect of figure-of-eight walking on cortical activation, measured through changes in oxygenated (HbO) and deoxygenated hemoglobin (HbR), in individuals with Parkinson’s disease.

Methods: A single-group, within-subject experimental study was conducted on 11 participants diagnosed with Parkinson’s disease. Baseline cortical activity was recorded using fNIRS during rest, followed by recording during and after the figure-of-eight walking task. Hemodynamic parameters including HbO, HbR, and total hemoglobin were analyzed. Normality of data was assessed using the Shapiro–Wilk test, and paired sample t-tests were applied to compare pre- and post-intervention values.

Results: All variables were normally distributed (p > 0.05). Paired t-test analysis revealed no statistically significant differences between pre- and post-intervention values for HbO (p = 0.378), HbR (p = 0.397), and total hemoglobin (p = 0.627). Effect size analysis indicated small effect sizes across all variables. However, qualitative observation of fNIRS topographical maps demonstrated increased and more symmetrical cortical activation patterns following the intervention.

Conclusion: Figure-of-eight walking did not produce statistically significant changes in cortical hemodynamics in this sample. However, observed trends in cortical activation suggest potential neural engagement and compensatory cortical recruitment. Further studies with larger sample sizes and longer intervention durations are recommended to better elucidate the neurophysiological effects of complex gait training in Parkinson’s disease.

Keywords: Parkinson’s disease, fNIRS, figure-of-eight walking, cortical activation, oxyhemoglobin, gait analysis