Survey of the Knowledge, Attitudes, and Practices of Neurologists Regarding Exercise in Parkinson's Disease.

BACKGROUND AND PURPOSE: Exercise and physiotherapy can exert potentially beneficial effects on the motor and nonmotor features of Parkinson's disease (PD). We conducted an e-mail survey to assess the knowledge, attitudes, and practices of neurologists regarding exercise among patients with PD. METHODS: A total of 222 neurologists from the Korean Movement Disorder Society and the Korean Society of Neurologists completed the survey and were classified into 4 clusters using the k-means clustering algorithm based on their institute types, the proportions of PD patients in their clinics, and the number of years working as neurologists. RESULTS: Specialists working at referral hospitals (Clusters 1 and 2) were more confident than general neurologists (Clusters 3 and 4) about exercise improving the general motor features of PD. Specialists recommended more-frequent intense exercise compared with physicians not working at referral hospitals. The specialists in Cluster 1, representing >50% of PD patients in the clinics at referral hospitals, recommended exercise regardless of the disease stage, whereas the general neurologists in Clusters 3 and 4 recommended low-intensity exercise at an early stage of disease. Although most of the respondents agreed with the need for PD patients to exercise, less than half had prescribed rehabilitation or physiotherapy. More than 90% of the respondents answered that developing an exercise/physiotherapy protocol for PD would be helpful. CONCLUSIONS: Specialists were more confident than general neurologists about the effect of exercise and recommended more-intense activities regardless of the disease stage. These results highlight the need to develop clinical practice guidelines and PD-specialized exercise protocols to provide optimal care for PD patients.

Trends in Physiotherapy Interventions and Medical Costs for Parkinson's Disease in South Korea, 2011-2020.

Objective: Physiotherapy (PT), an effective strategy for managing Parkinson's disease (PD), can influence healthcare utilization. We analyzed trends in healthcare utilization, PT interventions, and medical costs among patients with PD. Methods: Using data from the Korean National Health Insurance Service from 2011 to 2020, we analyzed the number of patients with PD and their healthcare utilization and assessed the odds ratio (OR) for receiving regular PTs. Results: Over 10 years, 169,613 patients with PD were present. The number of patients with PD increased annually from 49,417 in 2011 to 91,841 in 2020. Patients with PD receiving PT increased from 4,847 (9.81%) in 2011 to 13,163 (14.33%) in 2020, and PT prescriptions increased from 81,220 in 2011 to 377,651 in 2019. Medical costs per patient with PD have increased from 1,686 United States Dollars (USD) in 2011 to 3,201 USD in 2020. Medical expenses for each patient with PD receiving PT increased from 6,581 USD in 2011 to 13,476 USD in 2020. Moreover, Regular PTs were administered to 31,782 patients (18.74%) and conducted only through hospitalization. Those in their 50s with disabilities demonstrated a high OR for regular PTs, while those aged 80 years or older and residing outside Seoul had a low OR. Conclusions: The PD burden increased in South Korea between 2011 and 2020, including an increase in healthcare utilization and medical costs. The significant rise in medical expenses can be associated with increased PD prevalence and PT interventions. Regular PT applications remain restricted and have barriers to access.

Impaired cognitive flexibility and disrupted cognitive cerebellum in degenerative cerebellar ataxias.

There is a clinically unmet need for a neuropsychological tool that reflects the pathophysiology of cognitive dysfunction in cerebellar degeneration. We investigated cognitive flexibility in degenerative cerebellar ataxia patients and aim to identify the pathophysiological correlates of cognitive dysfunction in relation to cerebellar cognitive circuits. We prospectively enrolled degenerative cerebellar ataxia patients with age-matched healthy controls who underwent 3 T 3D and resting-state functional MRI. All 56 participants were evaluated with the Scale for Assessment and Rating of Ataxia and neuropsychological tests including the Wisconsin Card Sorting Test, Trail Making Test, Montreal Cognitive Assessment and Mini-Mental State Examination. From MRI scans, we analysed the correlation of whole-brain volume and cortico-cerebellar functional connectivity with the Wisconsin Card Sorting Test performances. A total of 52 participants (29 ataxia patients and 23 healthy controls) were enrolled in this study. The Wisconsin Card Sorting Test scores (total error percentage, perseverative error percentage, non-perseverative error percentage and categories completed), Trail Making Test A and Montreal Cognitive Assessment were significantly impaired in ataxia patients (P < 0.05) compared to age-matched healthy controls. The Wisconsin Card Sorting Test error scores showed a significant correlation with the ataxia score (P < 0.05) controlling for age and sex. In volumetric analysis, the cerebellar right crus I, II, VIIb and VIII atrophy correlated with non-perseverative error percentage in the ataxia group. In functional connectivity analysis, the connectivity between crus I, II and VIIb of the cerebellum and bilateral superior parietal and superior temporal gyrus was significantly altered in ataxia patients. The functional connectivity between left crus II and VIIb of the cerebellum and dorsolateral prefrontal and superior frontal/parietal cortices showed a positive correlation with perseverative error percentage. The connectivity between left crus VIIb and pontine nucleus/middle cerebellar peduncle showed a significant negative correlation with non-perseverative error percentage in the ataxia group. The impaired cognitive flexibility represented by the Wisconsin Card Sorting Test was significantly impaired in degenerative cerebellar ataxia patients and correlated with disease severity. The Wisconsin Card Sorting Test performance reflects hypoactivity of the cognitive cerebellum and disrupted cortico-cerebellar connectivity in non-demented patients with degenerative cerebellar ataxia.

Ocular motor and vestibular dysfunction in central nervous system lymphoma.

BACKGROUND AND PURPOSE: Diagnosis of lymphoma involving the central nervous system (CNS) is challenging. This study aimed to explore the abnormal vestibular and ocular motor findings in CNS lymphoma. METHODS: A retrospective search of the medical records identified 30 patients with CNS lymphoma presenting ocular motor and vestibular abnormalities from four neurology clinics of university hospitals in South Korea (22 men, age range 14-81 years, mean 60.6 ± 15.2). The demographic and clinical features and the results of laboratory, radiological and pathological evaluation were analyzed. RESULTS: Patients presented with diplopia (13/30, 43%), vestibular symptoms (15/30, 50%) or both (2/30, 7%). In 15 patients with diplopia, abnormal ocular motor findings included ocular motor nerve palsy (n = 10, 67%), internuclear ophthalmoplegia (n = 2, 13%), external ophthalmoplegia (n = 2, 13%) and exophoria (n = 1, 7%). The vestibular abnormalities were isolated in 14 (82%) of 17 patients with vestibular symptoms and included combined unilateral peripheral and central vestibulopathy in three from lesions involving the vestibular nuclei. CNS lymphoma involved the brainstem (53%), cerebellum (33%), leptomeninges (30%), deep gray nuclei (23%) or cranial nerves (17%). Two patients showed the "double-panda" sign by involving the midbrain. CONCLUSIONS: This study expands the clinical and radiological spectra of CNS lymphoma. Neuro-ophthalmological and neuro-otological evaluation may guide the early diagnosis of CNS lymphoma.

Profiling Analysis of Tryptophan Metabolites in the Urine of Patients with Parkinson's Disease Using LC-MS/MS.

Although Parkinson's disease (PD) is a representative neurodegenerative disorder and shows characteristic motor impediments, the pathophysiological mechanisms and treatment targets for PD have not yet been clearly identified. Since several tryptophan metabolites produced by gut microbiota could pass the blood-brain barrier and, furthermore, might influence the central nervous system, tryptophan metabolites within the indole, kynurenine, and serotonin metabolic pathways might be the most potent targets for PD development. Furthermore, most metabolites are circulated via the blood, play roles in and/or are metabolized via the host organs, and finally are excreted into the urine. Therefore, profiling the overall tryptophan metabolic pathways in urine samples of patients with PD is important to understanding the pathological mechanisms, finding biomarkers, and discovering therapeutic targets for PD. However, the development of profiling analysis based on tryptophan metabolism pathways in human urine samples is still challenging due to the wide physiological ranges, the varied signal response, and the structural diversity of tryptophan metabolites in complicated urine matrices. In this study, an LC-MS/MS method was developed to profile 21 tryptophan metabolites within the indole, kynurenine, and serotonin metabolic pathways in human urine samples using ion-pairing chromatography and multiple reaction monitoring determination. The developed method was successfully applied to urine samples of PD patients (n = 41) and controls (n = 20). Further, we investigated aberrant metabolites to find biomarkers for PD development and therapeutic targets based on the quantitative results. Unfortunately, most tryptophan metabolites in the urine samples did not present significant differences between control and PD patients, except for indole-3-acetic acid. Nonetheless, indole-3-acetic acid was reported for the first time for its aberrant urinary levels in PD patients and tentatively selected as a potential biomarker for PD. This study provides accurate quantitative results for 21 tryptophan metabolites in biological samples and will be helpful in revealing the pathological mechanisms of PD development, discovering biomarkers for PD, and further providing therapeutic targets for various PD symptoms. In the near future, to further investigate the relationship between gut microbial metabolites and PD, we will employ studies on microbial metabolites using plasma and stool samples from control and PD patients.

Ocular Motor Findings Aid in Differentiation of Spinocerebellar Ataxia Type 17 from Huntington's Disease.

Differentiation of spinocerebellar ataxia type 17 (SCA17) from Huntington's disease (HD) is often challenging since they share the clinical features of chorea, parkinsonism, and dystonia. The ocular motor findings remain to be elucidated in SCA17, and may help differentiating SCA17 from HD. We retrospectively compared the ocular motor findings of 11 patients with SCA17 with those of 10 patients with HD. In SCA17, abnormal ocular motor findings included impaired smooth pursuit (9/11, 82%), dysmetric saccades (9/11, 82%), central positional nystagmus (CPN, 7/11, 64%), abnormal head-impulse tests (4/11, 36%), and horizontal gaze-evoked nystagmus (GEN, 3/11, 27%). Among these, CPN was more frequently observed in SCA17 than in HD (7/11 (64%) vs. 0/10 (0%), p = 0.004) while saccadic slowing was more frequently observed in HD than in SCA17 (8/10 (80%) vs. 2/11 (18%), p = 0.009). Of six patients with follow-up evaluation, five later developed bilateral saccadic hypermetria (n = 4), GEN (n = 1), CPN (n = 1), bilaterally abnormal smooth pursuit (n = 1), and hyperactive head-impulse responses (n = 1) along with a clinical decline. Ocular motor abnormalities can be utilized as a diagnostic marker for differentiation of SCA17 from HD as well as a surrogate marker for clinical decline in SCA17.

Lambert-Eaton myasthenic syndrome (LEMS) in a patient with lung cancer under treatment with pembrolizumab: a case study.

Pembrolizumab is an immune checkpoint inhibitor (ICI) against the programmed death-1 receptor. Herein, we introduce a rare adverse effect during using pembrolizumab. We present the case of an 80-year-old man with biopsy-proven unresectable double primary squamous cell carcinoma and large cell neuroendocrine carcinoma of the lung. After using pembrolizumab for 10 months, he complained of muscle weakness of both upper and lower extremities. In a nerve conduction study, the repetitive nerve stimulation test in the abductor digiti minimi was diagnostic of Lambert-Eaton myasthenic syndrome (LEMS): low in the amplitude of compound muscle action potential (1.4 mV), 28.6% decrement in the 5-Hz stimulation, and 579% increment in the 50-Hz stimulation. The disease did not progress after the discontinuation of pembrolizumab, even without any anti-cancer treatment for 12 months. We believe our clinical experience of this rare and unexpected adverse effect should be shared.

Diagnostic value of α-synuclein seeding amplification assays in α-synucleinopathies: A systematic review and meta-analysis.

INTRODUCTION: Alpha-synuclein(αSyn) aggregates are definite pathological hallmarks of α-synucleinopathies. Seeding amplification assays (SAAs) have been developed to detect trace amounts of αSyn oligomers in vivo.. Herein, we assessed the diagnostic accuracy of the αSyn-SAAs across biospecimens, diagnostic references, methods, and subtypes. METHODS: A systematic literature search yielded 36 eligible studies for a meta-analysis of the sensitivity and specificity of αSyn-SAAs in patients with α-synucleinopathies(n = 2722) and controls(n = 2278). Pooled sensitivities and specificities with 95% confidence intervals (CIs) were calculated using bivariate random-effects models and a meta-regression analysis was performed. RESULTS: The summary sensitivity and specificity of αSyn-SAAs positivity for the diagnosis of α-synucleinopathies were 0.88(95% CIs = 0.84-0.91) and 0.95(0.93-0.97), respectively. Two covariates (biospecimen and diagnostic reference) were significant in fitting the meta-regression model (likelihood-ratio test for sensitivity and specificity, p < 0.01, p = 0.01, respectively). Skin αSyn-SAAs exhibited the highest sensitivity 0.92(0.87-0.95), which was not different from that of cerebrospinal fluid (CSF)(0.90(0.86-0.93), p = 0.39). Olfactory mucosa αSyn-SAAs exhibited a lower sensitivity 0.64(0.49-0.76) than those of the other two specimens(p = 0.02, 0.01, compared to CSF and skin, respectively). Application of pathological diagnostic standards were associated with a higher specificity of αSyn-SAAs compared to clinical diagnosis (p < 0.01). The diagnostic sensitivity and specificity of CSF αSyn-SAAs were 0.91(0.87-0.94) and 0.96(0.93-0.98) for Lewy body disease, 0.90(0.79-0.95) and 0.96(0.90-0.98) for prodromal α-synucleinopathies, and 0.63(0.24-0.90) and 0.97(0.93-0.99) for multiple system atrophy. CONCLUSIONS: αSyn-SAAs are promising in vivo detectors of abnormal αSyn aggregates and may aid the early diagnosis of α-synucleinopathies.

Brain Metabolism Related to Mild Cognitive Impairment and Phenoconversion in Patients With Isolated REM Sleep Behavior Disorder.

BACKGROUND AND OBJECTIVES: Mild cognitive impairment (MCI) in isolated REM sleep behavior disorder (iRBD) is a risk factor for subsequent neurodegeneration. We aimed to identify brain metabolism and functional connectivity changes related to MCI in patients with iRBD and the neuroimaging markers' predictive value for phenoconversion. METHODS: This is a prospective cohort study of patients with iRBD with a mean follow-up of 4.2 ± 2.6 years. At baseline, patients with iRBD and age- and sex-matched healthy controls (HCs) underwent 18F-fluorodeoxyglucose (FDG)-PET and resting-state fMRI scans and a comprehensive neuropsychological test battery. Voxel-wise group comparisons for FDG-PET data were performed using a general linear model. Seed-based connectivity maps were computed using brain regions showing significant hypometabolism associated with MCI in patients with iRBD and compared between groups. A Cox regression analysis was applied to investigate the association between brain metabolism and risk of phenoconversion. RESULTS: Forty patients with iRBD, including 21 with MCI (iRBD-MCI) and 19 with normal cognition (iRBD-NC), and 24 HCs were included in the study. The iRBD-MCI group revealed relative hypometabolism in the inferior parietal lobule, lateral and medial occipital, and middle and inferior temporal cortex bilaterally compared with HC and the iRBD-NC group. In seed-based connectivity analyses, the iRBD-MCI group exhibited decreased functional connectivity of the left angular gyrus with the occipital cortex. Of 40 patients with iRBD, 12 patients converted to Parkinson disease (PD) or dementia with Lewy bodies (DLB). Hypometabolism of the occipital pole (hazard ratio [95% CI] 6.652 [1.387-31.987]), medial occipital (4.450 [1.143-17.327]), and precuneus (3.635 [1.009-13.093]) was associated with higher phenoconversion rate to PD/DLB. DISCUSSION: MCI in iRBD is related to functional and metabolic changes in broad brain areas, particularly the occipital and parietal areas. Moreover, hypometabolism in these brain regions was a predictor of phenoconversion to PD or DLB. Evaluation of cognitive function and neuroimaging characteristics could be useful for risk stratification in patients with iRBD.

A prospective multi-centre study of susceptibility map-weighted MRI for the diagnosis of neurodegenerative parkinsonism.

OBJECTIVES: This study aimed to compare susceptibility map-weighted imaging (SMwI) using various MRI machines (three vendors) with N-3-fluoropropyl-2-ß-carbomethoxy-3-ß-(4-iodophe nyl)nortropane (18F-FP-CIT) PET in the diagnosis of neurodegenerative parkinsonism in a multi-centre setting. METHODS: We prospectively recruited 257 subjects, including 157 patients with neurodegenerative parkinsonism, 54 patients with non-neurodegenerative parkinsonism, and 46 healthy subjects from 10 hospitals between November 2019 and October 2020. All participants underwent both SMwI and 18F-FP-CIT PET. SMwI was interpreted by two independent reviewers for the presence or absence of abnormalities in nigrosome 1, and discrepancies were resolved by consensus. 18F-FP-CIT PET was used as the reference standard. Inter-observer agreement was tested using Cohen's kappa coefficient. McNemar's test was used to test the agreement between the interpretations of SMwI and 18F-FP-CIT PET per participant and substantia nigra (SN). RESULTS: The inter-observer agreement was 0.924 and 0.942 per SN and participant, respectively. The diagnostic sensitivity of SMwI was 97.9% and 99.4% per SN and participant, respectively; its specificity was 95.9% and 95.2%, respectively, and its accuracy was 97.1% and 97.7%, respectively. There was no significant difference between the results of SMwI and 18F-FP-CIT PET (p > 0.05, for both SN and participant). CONCLUSIONS: This study demonstrated that the high diagnostic performance of SMwI was maintained in a multi-centre setting with various MRI scanners, suggesting the generalisability of SMwI for determining nigrostriatal degeneration in patients with parkinsonism. KEY POINTS: • Susceptibility map-weighted imaging helps clinicians to predict nigrostriatal degeneration. • The protocol for susceptibility map-weighted imaging can be standardised across MRI vendors. • Susceptibility map-weighted imaging showed diagnostic performance comparable to that of dopamine transporter PET in a multi-centre setting with various MRI scanners.

Data-driven subtype classification of patients with early-stage multiple system atrophy.

INTRODUCTION: Patients with multiple system atrophy (MSA) are conventionally identified as having MSA-P (prominent parkinsonism) or MSA-C (prominent cerebellar ataxia) based on their predominant motor manifestations. The objective of the present study was to conduct latent class analysis (LCA) of various motor and nonmotor symptoms in early MSA to characterize data-driven subgroups. METHODS: Sixty-one probable or possible MSA patients with disease durations of 3 years or less were included prospectively. LCAs were performed to identify similar clinical subgroups giving even weights to a wide range of MSA motor and nonmotor features. We ran latent models of up to 6 class solutions; the overall model fit was evaluated based on the parsimony of the derived classes, the fit indices, and clinical interpretability. RESULTS: The LCA outcome supported categorization of at least three subgroups of patients with early MSA: the largest class 1, labeled "moderate parkinsonism + extensive dysautonomia", included approximately half of our study patients and showed marked autonomic dysfunction with a burden of parkinsonism. The two other classes, class 2 "predominant parkinsonism + limited dysautonomia" and class 3 "predominant cerebellar symptoms + limited dysautonomia", showed marked core motor features (parkinsonism or cerebellar symptoms) with generally mild dysautonomia. CONCLUSIONS: To our knowledge, this is the first data-driven identification of disease subtypes covering various symptom constellations in early MSA (<3 years from motor symptom onset). The present LCA result did not replicate the conventional motor classification and supported the heterogeneity within MSA-P and MSA-C subtypes.

A Novel TFG Mutation in a Korean Family with α-Synucleinopathy and Amyotrophic Lateral Sclerosis.

BACKGROUND: Tropomyosin-receptor kinase fused gene (TFG) functions as a regulator of intracellular protein packaging and trafficking at the endoplasmic reticulum exit sites. TFG has recently been proposed as a cause of multisystem proteinopathy. OBJECTIVES: Here, we describe a Korean family presenting with Parkinson's disease or amyotrophic lateral sclerosis caused by a novel variant of TFG (c.1148 G > A, p.Arg383His). METHODS: We collected clinical, genetic, dopamine transporter imaging, nerve conduction, and electromyography data from the seven subjects. To verify the pathogenicity of the R383H variant, we studied cell viability and the abnormal aggregation of α-synuclein and TAR DNA-binding protein 43 (TDP-43) in HeLa cells expressing R383H-TFG. RESULTS: The clinical phenotypes of the R383H-TFG mutation varied; of the five family members, one had Parkinson's disease, three had subclinical parkinsonism, and one (the proband) had amyotrophic lateral sclerosis. The individual with multiple system atrophy was the proband's paternal cousin, but the TFG genotype was not confirmed due to unavailability of samples. Our in vitro studies showed that R383H-TFG overexpression impaired cell viability. In cells co-expressing R383H-TFG and α-synuclein, insoluble α-synuclein aggregates increased in concentration and were secreted from the cells and co-localized with R383H-TFG. The levels of cytoplasmic insoluble aggregates of TDP-43 increased in HeLa cells expressing R383H-TFG and co-localized with R383H-TFG. CONCLUSIONS: Clinical and in vitro studies have supported the pathogenic role of the novel TFG mutation in α-synucleinopathy and TDP-43 proteinopathy. These findings expand the phenotypic spectrum of TFG and suggest a pivotal role of endoplasmic reticulum dysfunction during neurodegeneration. © 2021 International Parkinson and Movement Disorder Society.

Parainfectious Anti-Glial Fibrillary Acidic Protein-Associated Meningoencephalitis.

Movement disorders associated with glial fibrillary acidic protein (GFAP) autoantibodies have rarely been reported as ataxia or tremors. A 32-year-old man with headache and fever, initially diagnosed with viral meningoencephalitis, showed gradual improvement with empirical treatment. Two weeks after the illness, he suddenly developed orofacial, tongue, and neck dyskinesia accompanied by oculomotor abnormalities, which developed into severe generalized choreoballism. Brain magnetic resonance imaging (fluid-attenuated inversion recovery) showed signal hyperintensities in the bilateral globus pallidus interna. The clinical picture suggested an acute inflammatory trigger of secondary autoimmune encephalitis. The autoimmune antibody test was positive for GFAP, with the strongest reactivity in the cerebrospinal fluid (CSF) before treatment and decreased reactivity in serial CSF examinations during immunotherapy. Dyskinesia gradually improved to the extent that it could be controlled with only oral medications. This patient presented with parainfectious GFAP meningoencephalitis with distinctive clinical features and imaging findings.

Diagnostic usefulness of 10-step tandem gait test for the patient with degenerative cervical myelopathy.

Tandem gait is considered one of the most useful screening tools for gait impairment. The aim of this study is to evaluate diagnostic usefulness of 10-step tandem gait test for the patients with degenerative cervical myelopathy (DCM). Sixty-two DCM patients were compared to 55 persons without gait abnormalities as control. We counted the number of consecutive steps and graded into five according the number of steps and stability. Five grades of tandem gait were investigated for association with clinical parameters including qualitative Japanese orthopedic association (JOA) sub-score for lower extremities and Nurick scale and quantitative balance and gait assessments. The number of tandem steps were reduced and the grades of tandem gait were differently distributed in the DCM patients compared to controls (steps, 7.1 ± 3.6 versus 9.9 ± 0.4, p < 0.001; grades of 0/1/2/3/4/5, 1/13/14/15/19 versus 0/0/2/15/38, p < 0.001 in patients with DCM and control respectively). Patients with DCM showed more unstable balance and abnormal gait features including slower velocity, shorter strides, wider bases with increased stance phase of a gait cycle compared to the control group. The grades of tandem gait were correlated with JOA sub-score (r = 0.553, p < 0.001) and the Nurick scale (r = - 0.652, p < 0.001) as well as both balance and gait parameters. In DCM patients, tandem gait was impaired and correlated with severity of gait abnormality. The authors believe that 10-step tandem gait test is an objective and useful screening test for evaluating gait disturbance in patients with DCM.