Relationship between Neural Rhythm Generation Disorders and Physical Disabilities in Parkinson’s Disease Patients’ Walking
Miyake Y (2014) Relationship between Neural Rhythm Generation Disorders and Physical Disabilities in
Parkinson's Disease Patients' Walking. PLoS ONE 9(11): e112952. doi:10.1371/journal.pone.0112952
Relationship between Neural Rhythm Generation Disorders and Physical Disabilities in Parkinson's Disease Patients' Walking
Leo Ota 0
Hirotaka Uchitomi 0
Ken-ichiro Ogawa 0
Satoshi Orimo 0
Yoshihiro Miyake 0
Oscar Arias-Carrion, Hospital General Dr. Manuel Gea Gonzalez, Mexico
0 1 Department of Computational Intelligence and Systems Science, Tokyo Institute of Technology , Yokohama, Kanagawa , Japan , 2 Department of Neurology, Kanto Central Hospital , Setagaya, Tokyo , Japan
Walking is generated by the interaction between neural rhythmic and physical activities. In fact, Parkinson's disease (PD), which is an example of disease, causes not only neural rhythm generation disorders but also physical disabilities. However, the relationship between neural rhythm generation disorders and physical disabilities has not been determined. The aim of this study was to identify the mechanism of gait rhythm generation. In former research, neural rhythm generation disorders in PD patients' walking were characterized by stride intervals, which are more variable and fluctuate randomly. The variability and fluctuation property were quantified using the coefficient of variation (CV) and scaling exponent a. Conversely, because walking is a dynamic process, postural reflex disorder (PRD) is considered the best way to estimate physical disabilities in walking. Therefore, we classified the severity of PRD using CV and a. Specifically, PD patients and healthy elderly were classified into three groups: no-PRD, mild-PRD, and obvious-PRD. We compared the contributions of CV and a to the accuracy of this classification. In this study, 45 PD patients and 17 healthy elderly people walked 200 m. The severity of PRD was determined using the modified Hoehn-Yahr scale (mH-Y). People with mH-Y scores of 2.5 and 3 had mild-PRD and obvious-PRD, respectively. As a result, CV differentiated no-PRD from PRD, indicating the correlation between CV and PRD. Considering that PRD is independent of neural rhythm generation, this result suggests the existence of feedback process from physical activities to neural rhythmic activities. Moreover, a differentiated obvious-PRD from mildPRD. Considering a reflects the intensity of interaction between factors, this result suggests the change of the interaction. Therefore, the interaction between neural rhythmic and physical activities is thought to plays an important role for gait rhythm generation. These characteristics have potential to evaluate the symptoms of PD.
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Funding: This work was supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) Grant-in-Aid for Scientific Research (B) to Dr.
Miyake (MEXT KAKENHI Grant Number 23300209, URL: http://www.mext.go.jp/english/). The funders had no role in study design, data collection and analysis,
decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
Walking is one of the most fundamental factors in our daily
behaviors. The gait dynamics is thought to be generated by the
interaction between neural rhythmic activity and physical activity
[1,2]. However, because this interaction is difficult to estimate in
healthy gait dynamics, we focused on the patients with Parkinsons
disease (PD) (as a typical example of neurodegenerative disease)
[3], which causes not only neural rhythm generation disorders, but
also physical disabilities. To identify the mechanism of gait rhythm
generation, we attempted to examine the relationship between
neural rhythmic activity and physical activity in PD patients.
In previous studies, two symptoms were reported as neural
rhythm generation disorders in PD patients walking. One
symptom was the increase in the variability of gait rhythm [4,5],
and the other symptom was a change in the fluctuation property of
gait rhythm from the normal 1/f-like fluctuation property [68].
In healthy young people, gait rhythm is not constant; rather, it
changes subtly. This change can be described by a pair of physical
measures. One is the coefficient of variation (CV), which
represents the variability of gait rhythm. The other is the scaling
exponent a, which represents the fluctuation property of gait
rhythm and can be calculated by detrended fluctuation analysis
(DFA). In particular, the fluctuation in gait rhythm is an important
feature of walking. In healthy young people, the gait rhythm
exhibits small variation and 1/f-like fluctuation properties [9].
For each of these symptoms, two types of gait rehabilitation
methods using sensory cues have been proposed. One is gait
training with rhythmic stimuli, which is based on forced
entrainment for human, including rhythmic auditory stimulation
(RAS) gait training [10] and treadmill training [11]. Th (...truncated)