Onset Of Parkinson's Disease Motor Symptoms Research Articles

Profiling Non-motor Symptoms in Monogenic Parkinson's Disease.

Parkinson’s disease (PD) is the second most common neurodegenerative disease in the elder population, pathologically characterized by the progressive loss of dopaminergic neurons in the substantia nigra. While the precise mechanisms underlying the pathogenesis of PD remain unknown, various genetic factors have been proved to be associated with PD. To date, at least 23 loci and 19 disease-causing genes for PD have been identified. Although monogenic (often familial) cases account for less than 5% of all PD patients, exploring the phenotypes of monogenic PD can help us understand the disease pathogenesis and progression. Primary motor symptoms are important for PD diagnosis but only detectable at a relatively late stage. Despite typical motor symptoms, various non-motor symptoms (NMS) including sensory complaints, mental disorders, autonomic dysfunction, and sleep disturbances also have negative impacts on the quality of life in PD patients and pose major challenges for disease management. NMS is common in all stages of the PD course. NMS can occur long before the onset of PD motor symptoms or can present in the middle or late stage of the disease accompanied by motor symptoms. Therefore, the profiling and characterization of NMS in monogenic PD may help the diagnosis and differential diagnosis of PD, which thereby can execute early intervention to delay the disease progression. In this review, we summarize the characteristics, clinical phenotypes, especially the NMS of monogenic PD patients carrying mutations of SNCA, LRRK2, VPS35, Parkin, PINK1, DJ-1, and GBA. The clinical implications of this linkage between NMS and PD-related genes are also discussed.

Past appendectomy may be related to early cognitive dysfunction in Parkinson's disease.

The vermiform appendix is a potential site of initiation of Parkinson's disease (PD) pathology. We hypothesized that the appendectomy earlier in life may alter the clinical expression of PD. To explore the effects of appendectomy prior to onset of PD motor symptoms on patients' symptoms, in particular on cognitive dysfunction. Two hundred and sixty-two consecutive PD patients were asked about past history of appendectomy and underwent an evaluation, which included the Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn & Yahr scale (H&Y), Schwab & England Independence Scale (S&E), Dementia Rating Scale-2 (DRS-2), Apathy Evaluation Scale, Hospital Anxiety and Depression Scale, and Brief Smell Identification Test. Motor symptoms were evaluated in OFF and ON states. Non-parametric group comparisons and logistic regressions were used for data analyses. Thirty-one patients (11.8%) had history of appendectomy prior to PD onset. These patients had more severe motor symptoms (UPDRS-III and H&Y) and lower functional independence (S&E) in ON and had higher frequency of cognitive dysfunction (DRS-2 Initiation/Perseveration, Conceptualization, and Memory subscales) (p < 0.05). The association between history of appendectomy and cognitive dysfunction was evident only in patients with late onset PD (≥ 55years) and with disease duration ≤ 5years. History of appendectomy remained statistically associated with impairment on DRS-2 Conceptualization and Memory subscales, when demographic and clinical variables were considered. History of appendectomy appears to alter the clinical expression of late onset PD, with early cognitive impairment, more severe motor symptoms in ON, and poorer functional independence under anti-parkinsonian medication.

Altered Gut Microbiome and Intestinal Pathology in Parkinson's Disease.

Parkinson’s disease (PD) is a common neurodegenerative disorder arising from an interplay between genetic and environmental risk factors. Studies have suggested that the pathological hallmarks of intraneuronal α-synuclein aggregations may start from the olfactory bulb and the enteric nervous system of the gut and later propagate to the brain via the olfactory tract and the vagus nerve. This hypothesis correlates well with clinical symptoms, such as constipation, that may develop up to 20 years before the onset of PD motor symptoms. Recent interest in the gut–brain axis has led to vigorous research into the gastrointestinal pathology and gut microbiota changes in patients with PD. In this review, we provide current clinical and pathological evidence of gut involvement in PD by summarizing the changes in gut microbiota composition and gut inflammation associated with its pathogenesis.

The clinical spectrum of anxiety in Parkinson's disease.

Anxiety is common in Parkinson's disease (PD), and contributes to increased disability and poorer quality of life. In spite of its significant impact, the symptomatology, chronology, and neurobiology of anxiety in PD are all poorly understood, and this hinders accurate diagnosis and development of effective treatment strategies. This review investigates and updates literature related to the clinical spectrum of anxiety in PD. The reported prevalence of anxiety in PD varies considerably, with emerging interest in the frequency of the DSM-IV residual category of "Anxiety disorder, not otherwise specified" (Anxiety disorder NOS), which is observed in up to 25% of PD patients. By design, there are no standardized diagnostic criteria for Anxiety disorder NOS, because this is the category applied to individuals who do not meet diagnostic criteria for any other current anxiety disorder. Anxiety rating scales incompletely capture anxiety symptoms that relate specifically to PD symptoms and the complications arising from PD therapy. Consequently, these scales have been deemed inappropriate for use in PD, and there remains a need for the development of a new PD-specific anxiety scale. Research establishing accurate symptom profiles of anxiety in PD is sparse, although characterizing such symptomatology would likely improve clinical diagnosis and facilitate targeted treatment strategies. Research into the neurobiological and psychological underpinnings of anxiety in PD remains inconclusive. Anxiety can precede the onset of PD motor symptoms or can develop after a diagnosis of PD. Further investigations focused on the chronology of anxiety and its relationship to PD diagnosis are required.

REM sleep behavior disorder in Japanese patients with Parkinson’s disease: a multicenter study using the REM sleep behavior disorder screening questionnaire

REM sleep behavior disorder (RBD) is known to be observed more frequently in patients with an α-synucleinopathy such as Parkinson's disease (PD) than in the general population. The precise prevalence of RBD in Japanese PD patients is not known. Therefore, we investigated the prevalence and the clinical characteristics of patients with RBD in a large population of Japanese patients with PD. We investigated various clinical features and employed the Japanese version of the RBD screening questionnaire on 469 non-demented Japanese PD patients in this multicenter study. Probable or possible RBD was detected in 146 patients (31.1%) and was significantly associated with longer PD duration, higher Hoehn and Yahr stage, higher Unified Parkinson's Disease Rating Scale part III subscale (7 items), more motor fluctuations, and a higher levodopa-equivalent daily dose (p < 0.01). As to the major autonomic dysfunctions, severe constipation was significantly more frequent in PD patients with RBD than in those without it (p < 0.01). The RBD symptoms of 53 patients (39.0%) preceded the onset of PD motor symptoms. The median interval from the onset of RBD symptoms to PD motor symptoms was 17.5 years, and 3 patients had intervals of over 50 years. This large-scale multicenter study revealed that RBD is a frequent non-motor symptom in Japanese patients with PD, which may precede the onset of motor symptoms. Moreover, RBD that increases with the duration and severity of PD may be associated with autonomic dysfunction.

Effects of early and delayed treatment with an mGluR5 antagonist on motor impairment, nigrostriatal damage and neuroinflammation in a rodent model of Parkinson's disease

The loss of nigrostriatal dopaminergic neurons that characterizes Parkinson's disease (PD) causes complex functional alterations in the basal ganglia circuit. Increased glutamatergic activity at crucial points of the circuit may be central to these alterations, thereby contributing to the onset of PD motor symptoms. Signs of neuroinflammation accompanying the neuronal loss have also been observed; also in this case, glutamate-mediated mechanisms may be involved. Glutamate may therefore intervene at multiple levels in PD pathophysiology, possibly through the modulation of metabotropic receptors. To address this issue, we evaluated the effects of systemic treatment with MPEP (2-methyl-6-(phenylethynyl)-pyridine), an antagonist of metabotropic receptor mGluR5, in a rodent model of progressive nigrostriatal degeneration based on the intrastriatal injection of 6-hydroxydopamine (6-OHDA). Following 6-OHDA injection, Sprague-Dawley rats underwent a 4-week, daily treatment with MPEP (1.5 mg/kg, i.p.). To investigate whether the effects varied with the progression of the lesion, subgroups of lesioned animals started the treatment at different time-points: (1) immediately, (2) 1 week, or (3) 4 weeks after the neurotoxin injection. Akinesia, dopaminergic nigrostriatal damage and neuroinflammatory response (microglial and astroglial activation) were investigated. MPEP prompted immediate amelioration of 6-OHDA-induced akinesia, as measured by the Adjusting step test, in all subgroups, regardless of the degree of nigrostriatal damage. Conversely, MPEP did not modify neuronal survival or neuroinflammatory response in the nigrostriatal pathway. In conclusion, chronic treatment with MPEP exerted a pure symptomatic effect, further supporting that mGluR5 modulation may be a viable strategy to counteract the basal ganglia functional modifications underlying PD motor symptoms.