Cortical activation during fine motor movement of Parkinson’s disease patients using fNIRS
Francisco Rivas1, Edgar Guevara2, Ildefonso Rodríguez1
1Neurology department, Hospital Central "Ignacio Morones Prieto", 2CIACYT, Universidad Autónoma de San Luis Potosí
Objective:
Objective: To determine if there is functional differences in activation of motor cortex measured by funciontal near-infrared spectroscopy (fNIRS) on Parkinson's disease (PD) patients compared to healthy people.
Background:
PD is one of the age-related diseases that represent more than half of the total global disease burden. Finger tapping has been validated to study the progression of the disease. However, affordable and portable techniques to assess cerebral activity are often missing. The main aim of this work is to characterize the motor cortex response of PD patients in a finger tapping task using fNIRS
Design/Methods:
Data was acquired from 10 PD patients (4 female, median age 69) and 5 age-matched controls (2 female, median age 67) using a portable system (Brite MKII, Artinis MS) that covered bilaterally the premotor and motor cortices. Participants were presented with 20 randomly assigned blocks of either left or right finger tapping that were interspersed with 20-23s of fixation. The hemodynamic response functions (HRF) was obtained by averaging 4 channels covering each region of interest. 4 features of the group-averaged HRF (peak amplitude, peak latency τ, AUC, and mean) were compared between groups with a Wilcoxon-Mann-Whitney test.
Results:
Group-averaged HRF revealed a greater peak amplitude and shorter latency in the control group. Between-group comparisons focused on the region of interest (ROI) specific to the dominant hand revealed a significant increase in peak latency (p=0.04) in the PD group. Although peak ΔHbO, integrated AUC, and mean ΔHbO were smaller in the PD group, no significant differences were found (p=0.44,0.31 and 0.31 respectively). These preliminary results suggest that PD patients show a significantly delayed time to peak and attenuated HRF, as compared to controls.
Conclusions:
Our findings showcase the application of fNIRS for the quantification of motor impairment in PD patients and the primary motor cortex is involved in its pathophysiology.