Medical Management of Movement Disorders

A secret that underlies Parkinson's disease: The damaging cycle

Parkinson's disease (PD) is a movement disorder, and its common characteristics include the loss of dopaminergic neurons and the accumulation of a special type of cytoplasmic inclusions called Lewy bodies in the substantia nigra pars compacta, which are more prevalent in the elderly. However, the pathophysiology of PD is still elusive. In this review, we summarized five common factors involved in PD, namely, (i) oxidative stress, (ii) mitochondrial dysfunction, (iii) inflammation, (iv) abnormal α-synuclein, and (v) endogenous neurotoxins, and proposed a hypothesis involving a damaging cycle. Oxidative stress-triggered aldehydes react with biogenic amines to produce endogenous neurotoxins. They cause mitochondrial dysfunction and the formation of inflammasomes, which induce the activation of neuroglial cells and the infiltration of T lymphocytes. The synergistic effect of these processes fosters chronic inflammation and α-synuclein aggregation and further exacerbates the impact of oxidative stress to establish a damaging cycle that eventually results in the degeneration of dopaminergic neurons. This damaging cycle provides an explanation of progressive neuronal death during the pathogenesis of PD and provides new potential targets beneficial for developing new drugs and approaches for clinical neuroprotection.

Large-Scale Assessment of Function and Disability in Patients with Parkinson's Disease Using the Functioning Disability Evaluation Scale-Adult Version

This study assesses the functioning and disability related to Parkinson's disease using the Functioning Disability Evaluation Scale-Adult Version (FUNDES-Adult), based on the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) in a large-scale database; this study describes, discusses and clarifies the predictive factor of not being in an ambulatory status. Of 7455 patients included in this study, 3561 were not ambulatory and 3894 were ambulatory or assisted ambulatory. Patients with poor walking status revealed higher FUNDES-Adult scores in all domains. Age, modified Hoehn⁻Yahr stage, living in an institution and the standardized score of FUNDES-Adult domains 1 and 2 were positive independent predictors of the not ambulatory status. The FUNDES-Adult could evaluate multifaceted disability and predict the walking status in patients with Parkinson's disease.