A Case of Abnormal Postures in the Left Extremities after Pontine Hemorrhage: Dystonia or Pseudodystonia?

It is difficult to determine the pathoanatomical correlates of dystonia because of its complex pathophysiology, and most cases with secondary dystonia are associated with basal ganglia lesions. Moreover, it is a challenging issue that patients with abnormal postures accompanied by other neurological findings in the affected body part (e.g., sensory loss) can be diagnosed with true dystonia or pseudodystonia. Here, we report a case of abnormal postures with loss of proprioception in the left extremities after right dorsal pontine hemorrhage.ope

Enrichment of Exosome-Like Extracellular Vesicles from Plasma Suitable for Clinical Vesicular miRNA Biomarker Research

Exosome-like extracellular vesicles (ELVs) contain biomolecules that have potential as diagnostic biomarkers, such as proteins, micro-RNAs (miRNAs), and lipids. However, it is difficult to enrich ELVs consistently with high yield and purity from clinical samples, which hampers the development of ELV biomarkers. This is particularly true for miRNAs in protein-rich plasma. Hence, we modified ELV isolation protocols of three commercially available polymer-precipitation-based kits using proteinase K (PK) treatment to quantify ELV-associated miRNAs in human plasma. We compared the yield, purity, and characteristics of enriched plasma ELVs, and measured the relative quantity of three selected miRNAs (miR-30c, miR-126, and miR-192) in ELVs using six human plasma samples. Compared with the original protocols, we demonstrated that ELVs can be isolated with PK treatment with high purity (i.e., lack of non-exosomal proteins and homogeneous size of vesicles) and yield (i.e., abundancy of exosomal markers), which were dependent on kits. Using the kit with the highest purity and yield with PK treatment, we successfully quantified ELV miRNAs (levels of 45%-65% in total plasma) with acceptable variability. Collectively, ELV enrichment using the modified easy-to-use method appears suitable for the analysis of miRNAs, although its clinical applicability needs to be confirmed in larger clinical studies.ope

Subtypes of Sleep Disturbance in Parkinson's Disease Based on the Cross-Culturally Validated Korean Version of Parkinson's Disease Sleep Scale-2

BACKGROUND AND PURPOSE: This study aimed to determine the clinimetric properties of the Korean version of Parkinson's Disease Sleep Scale-2 (K-PDSS-2) and whether distinct subtypes of sleep disturbance can be empirically identified in patients with Parkinson's disease (PD) using the cross-culturally validated K-PDSS-2. METHODS: The internal consistency, test-retest reliability, scale precision, and convergent validity of K-PDSS-2 were assessed in a nationwide, multicenter study of 122 patients with PD. Latent class analysis (LCA) was used to derive subgroups of patients who experienced similar patterns of sleep-related problems and nocturnal disabilities. RESULTS: The total K-PDSS-2 score was 11.67±9.87 (mean±standard deviation) at baseline and 12.61±11.17 at the retest. Cronbach's α coefficients of the total K-PDSS-2 scores at baseline and follow-up were 0.851 and 0.880, respectively. The intraclass correlation coefficients over the 2-week study period ranged from 0.672 to 0.848. The total K-PDSS-2 score was strongly correlated with health-related quality of life measures and other corresponding nonmotor scales. LCA revealed three distinct subtypes of sleep disturbance in the study patients: "less-troubled sleepers," "PD-related nocturnal difficulties," and "disturbed sleepers." CONCLUSIONS: K-PDSS-2 showed good clinimetric attributes in accordance with previous studies that employed the original version of the PDSS-2, therefore confirming the cross-cultural usefulness of the scale. This study has further documented the first application of an LCA approach for identifying subtypes of sleep disturbance in patients with PD.ope

Rapid drug increase and early onset of levodopa-induced dyskinesia in Parkinson's disease

A higher levodopa dose is a strong risk factor for levodopa-induced dyskinesia (LID) in patients with Parkinson's disease (PD). However, levodopa dose can change during long-term medication. We explored the relationship between levodopa dose and time to onset of LID using longitudinal multicenter data. Medical records of 150 patients who were diagnosed with de novo PD and treated with levodopa until onset of LID were collected. Levodopa dose were assessed as the dose at 6 months from levodopa initiation and rate of dose increase between 6 months and onset of LID. The groups with earlier LID onset had higher levodopa and levodopa-equivalent dose at the first 6 months of treatment and rapid increase in both levodopa and levodopa-equivalent dose. Multivariable linear regression models revealed that female sex, severe motor symptom at levodopa initiation, and higher rate of increase in both levodopa and levodopa-equivalent dose were significantly associated with early onset of LID. The present results demonstrated that rapid increase in levodopa dose or levodopa-equivalent dose is associated with early onset of LID.ope

The Influence of Body Mass Index at Diagnosis on Cognitive Decline in Parkinson's Disease

Background and purpose: Associations between alterations in body mass index (BMI) and cognitive function have been reported in Parkinson's disease (PD). We investigated whether the BMI at a PD diagnosis is associated with cognitive decline and the future development of dementia. Methods: We recruited 70 patients with de novo PD who underwent neuropsychological testing every 3 years and were followed up for more than 6 years. We classified patients into the following three groups based on their BMI at the diagnosis: under-/normal weight (n=21), overweight (n=22), and obese (n=27). We evaluated differences in the rate of cognitive decline over time among the groups using linear mixed models and the conversion rate to dementia using survival analysis. Results: The obese patients with PD showed a slower deterioration of global cognitive function as well as language and memory functions than did the under-/normal-weight group during the 6-year follow-up. The three BMI groups showed different rates of conversion to dementia (log-rank test: p=0.026). The combined overweight and obese group showed a lower risk of developing dementia compared with the under-/normal-weight group (hazard ratio= 0.36, 95% CI=0.12-0.82, p=0.046). Conclusions: We have demonstrated that a higher-than-normal BMI at the time of a PD diagnosis has a protective effect against the deterioration of cognitive function and the conversion to dementia.ope

Heterogeneous Patterns of Striatal Dopamine Loss in Patients with Young- versus Old-Onset Parkinson's Disease: Impact on Clinical Features

OBJECTIVE: Ample evidence has suggested that age at onset of Parkinson's disease (PD) is associated with heterogeneous clinical features in individuals. We hypothesized that this may be attributed to different patterns of nigrostriatal dopamine loss. METHODS: A total of 205 consecutive patients with de novo PD who underwent 18F-FP-CIT PET scans (mean follow-up duration, 6.31 years) were divided into three tertile groups according to their age at onset of parkinsonian motor symptoms. Striatal dopamine transporter (DAT) availability was compared between the old- (n = 73) and young-onset (n = 66) groups. In addition, the risk of developing freezing of gait (FOG) and longitudinal requirements for dopaminergic medications were examined. RESULTS: The old-onset PD group (mean age at onset, 72.66 years) exhibited more severe parkinsonian motor signs than the young-onset group (52.58 years), despite comparable DAT availability in the posterior putamen; moreover, the old-onset group exhibited more severely decreased DAT availability in the caudate than the young-onset group. A Cox regression model revealed that the old-onset PD group had a higher risk for developing FOG than the young-onset group [hazard ratio 2.523, 95% confidence interval (1.239-5.140)]. The old-onset group required higher doses of dopaminergic medications for symptom control than the young-onset group over time. CONCLUSION: The present study demonstrated that the old-onset PD group exhibited more severe dopamine loss in the caudate and were more likely to develop gait freezing, suggesting that age at onset may be one of the major determinants of the pattern of striatal dopamine depletion and progression of gait disturbance in PD.ope

Feasibility and Efficacy of Intra-Arterial Administration of Mesenchymal Stem Cells in an Animal Model of Double Toxin-Induced Multiple System Atrophy.

Multiple system atrophy (MSA) is a sporadic neurodegenerative disease of the central and autonomic nervous system. Because no drug treatment consistently benefits MSA patients, neuroprotective strategy using mesenchymal stem cells (MSCs) has a lot of concern for the management of MSA. In this study, we investigated the safety and efficacy of intra-arterial administration of MSCs via internal carotid artery (ICA) in an animal model of MSA. The study was composed of feasibility test using a ×10 and ×50 of a standard dose of MSCs (4 × 107 MSCs) and efficacy test using a ×0.2, ×2, and ×20 of the standard dose. An ultrasonic flow meter and magnetic resonance imaging (MRI) showed that no cerebral ischemic lesions with patent ICA blood flow was were observed in animals receiving a ×10 of the standard dose of MSCs. However, no MSA animals receiving a ×50 of the standard dose survived. In efficacy test, animals injected with a ×2 of the standard dose increased nigrostriatal neuronal survival relative to a ×0.2 or ×20 of the standard dose. MSA animals receiving MSCs at ×0.2 and ×2 concentrations of the standard dose exhibited a significant reduction in rotation behavior relative to ×20 of the standard dose of MSCs. Cerebral ischemic lesions on MRI were only observed in MSA animals receiving a ×20 of the standard dose. The present study revealed that if their concentration is appropriate, intra-arterial injection of MSCs is safe and exerts a neuroprotective effect on striatal and nigral neurons with a coincidental improvement in motor behavior. Stem Cells Translational Medicine 2017;6:1424-1433.ope

The Cleavage Effect of Mesenchymal Stem Cell and Its Derived Matrix Metalloproteinase-2 on Extracellular α-Synuclein Aggregates in Parkinsonian Models

Ample evidence has suggested that extracellular α-synuclein aggregates would play key roles in the pathogenesis and progression of Parkinsonian disorders (PDs). In the present study, we investigated whether mesenchymal stem cells (MSCs) and their derived soluble factors could exert neuroprotective effects via proteolysis of extracellular α-synuclein. When preformed α-synuclein aggregates were incubated with MSC-conditioned medium, α-synuclein aggregates were disassembled, and insoluble and oligomeric forms of α-synuclein were markedly decreased, thus leading to a significant increase in neuronal viability. In an animal study, MSC or MSC-conditioned medium treatment decreased the expression of α-synuclein oligomers and the induction of pathogenic α-synuclein with an attenuation of apoptotic cell death signaling. Furthermore, we identified that matrix metalloproteinase-2 (MMP-2), a soluble factor derived from MSCs, played an important role in the degradation of extracellular α-synuclein. Our data demonstrated that MSCs and their derived MMP-2 exert neuroprotective properties through proteolysis of aggregated α-synuclein in PD-related microenvironments. Stem Cells Translational Medicine 2017;6:949-961.ope

Diffusion tensor imaging in patients with essential tremor

BACKGROUND AND PURPOSE: The traditional paradigm has regarded essential tremor (ET) as a benign disorder. However, recent clinical, neuroimaging, and neuropathologic studies suggest that ET may be a progressive neurologic disorder. Based on clinicopathologic findings that cerebellum and its outflow are the key structures in ET and degeneration of gray matter in cerebellum is followed by consequent wallerian degeneration of white matter (WM) fibers, the aim of the present study was to investigate changes in anisotropy in patients with ET. MATERIALS AND METHODS: Fractional anisotropy (FA) images were generated from DTI data acquired at 1.5T in 10 patients with ET compared with 8 control subjects by using statistical parametric mapping to make voxel-by-voxel comparisons. RESULTS: Compared with the control subjects, the patients with ET exhibited significantly reduced FA (P(uncorrected) < .005) in the anterolateral portion of the right pons and decreased FA in the bilateral cerebellum, left retrorubral area of the midbrain, and bilateral deep WM, including the orbitofrontal, lateral frontal, parietal, and temporal WM. CONCLUSION: This study demonstrates that structural changes in the WM are extensive in patients with ET, supporting the findings of previous functional neuroimaging and pathologic studiesope

Changes in cerebral glucose metabolism in patients with Parkinson disease with dementia after cholinesterase inhibitor therapy

We investigated changes in cerebral glucose metabolism after cholinesterase inhibitor (ChEI) therapy in patients with Parkinson disease dementia (PDD) to determine whether cognitive improvements would be reflected in changes of cerebral metabolic patterns, thus offering insight into the neural substrate of cognitive dysfunction in patients with PDD. METHODS: We performed a serial PET study before (baseline) and after ChEI therapy on 10 patients with PDD, using statistical parametric mapping. Additionally, covariance analysis was performed to extract regions in which increased change in regional cerebral metabolism correlated significantly with increased Mini-Mental State Examination scores. RESULTS: The statistical parametric mapping analysis indicated that significantly increased cerebral metabolism after ChEI therapy, compared with at baseline, was most evident in the left angular gyrus extending to the supramarginal area and left superior and middle frontal gyri. Additionally, cerebral metabolism was significantly increased in the right superior frontal and left middle orbitofrontal gyri. In contrast, the right fusiform gyrus showed significantly decreased metabolism after ChEI, compared with at baseline. In the correlation analysis, improvements in Mini-Mental State Examination scores after ChEI treatment were significantly associated with increased cerebral metabolism in the left supramarginal, orbitofrontal, and cingulate areas. CONCLUSION: Our data suggest that prefrontal and parietal association areas may be relevant structures for the pharmacologic response to ChEI in patients with PDD.ope