Validity and Reliability of the Korean Versions of the 9- and 19-Item Wearing-Off Questionnaires in Parkinson's Disease.

BACKGROUND AND PURPOSE: The wearing-off (WO) phenomenon is the most common motor complication in advanced Parkinson's disease (PD), but its identification remains challenging. The 9- and 19-item Wearing-off Questionnaires (WOQ-9 and WOQ-19) are self-assessment tools for motor and nonmotor symptoms that are widely used for WO screening. We produced Korean versions of the WOQ-19 and WOQ-9 (K-WOQ-19 and K-WOQ-9) and investigated their validity and reliability. METHODS: We used the translation-back translation method to produce K-WOQ-19 and K-WOQ-9, which were self-administered by 124 patients with PD. We conducted in-depth 10-minute interviews for confirming the presence of the WO phenomenon, and then stratified the participants into groups with and without WO. Diagnostic accuracy was assessed byanalyzing receiver operating characteristic curves. Concurrent validity was assessed using the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) andthe Hoehn and Yahr stage with Spearman's rank correlation analysis. Reliability was assessedbased on test-retest Cohen's kappa (κ) values and intraclass correlation coefficients (ICCs). RESULTS: The optimal cutoff scores on the K-WOQ-19 and K-WOQ-9 for WO screening were 4 and 2, respectively. The test-retest ICCs of K-WOQ-19 and K-WOQ-9 were 0.943 and 0.938, respectively. Nineteen of the combined 20 items in K-WOQ-19 and K-WOQ-9 showed moderate-to-substantial agreement (κ=0.412-0.771, p<0.001). The scores on the translated scales were significantly correlated with MDS-UPDRS IV scores. CONCLUSIONS: K-WOQ-19 and K-WOQ-9 are reliable and valid tools for detecting WO, with optimal cutoff scores of 4 and 2, respectively.

Clinico-physiological correlates of Parkinson's disease from multi-resolution basal ganglia recordings.

Parkinson's disease (PD) has been associated with pathological neural activity within the basal ganglia. Herein, we analyzed resting-state single-neuron and local field potential (LFP) activities from people with PD who underwent awake deep brain stimulation surgery of the subthalamic nucleus (STN; n = 125) or globus pallidus internus (GPi; n = 44), and correlated rate-based and oscillatory features with UPDRSIII off-medication subscores. Rate-based single-neuron features did not correlate with PD symptoms. STN single-neuron and LFP low-beta (12-21 Hz) power and burst dynamics showed modest correlations with bradykinesia and rigidity severity, while STN spiketrain theta (4-8 Hz) power correlated modestly with tremor severity. GPi low- and high-beta (21-30 Hz) power and burst dynamics correlated moderately with bradykinesia and axial symptom severity. These findings suggest that elevated single-neuron and LFP oscillations may be linked to symptoms, though modest correlations imply that the pathophysiology of PD may extend beyond resting-state beta oscillations.

Establishment of a registry of clinical data and bioresources for rare nervous system diseases.

Rare diseases are predominantly genetic or inherited, and patients with these conditions frequently exhibit neurological symptoms. Diagnosing and treating many rare diseases is a complex challenge, and their low prevalence complicates the performance of research, which in turn hinders the advancement of therapeutic options. One strategy to address this issue is the creation of national or international registries for rare diseases, which can help researchers monitor and investigate their natural progression. In the Republic of Korea, we established a registry across 5 centers that focuses on 3 rare diseases, all of which are characterized by gait disturbances resulting from motor system dysfunction. The registry will collect clinical information and human bioresources from patients with amyotrophic lateral sclerosis, spinocerebellar ataxia, and hereditary spastic paraplegia. These resources will be stored at ICreaT and the National Biobank of Korea. Once the registry is complete, the data will be made publicly available for further research. Through this registry, our research team is dedicated to identifying genetic variants that are specific to Korean patients, uncovering biomarkers that show a strong correlation with clinical symptoms, and leveraging this information for early diagnosis and the development of treatments.

Evaluating the Validity and Reliability of the Korean Version of the Scales for Outcomes in Parkinson's Disease-Cognition.

OBJECTIVE: The Scales for Outcomes in Parkinson's Disease-Cognition (SCOPA-Cog) was developed to assess cognition in patients with Parkinson's disease (PD). In this study, we aimed to evaluate the validity and reliability of the Korean version of the SCOPACog (K-SCOPA-Cog). METHODS: We enrolled 129 PD patients with movement disorders from 31 clinics in South Korea. The original version of the SCOPA-Cog was translated into Korean using the translation-retranslation method. The test-retest method with an intraclass correlation coefficient (ICC) and Cronbach's alpha coefficient were used to assess reliability. Spearman's rank correlation analysis with the Montreal Cognitive Assessment-Korean version (MOCA-K) and the Korean Mini-Mental State Examination (K-MMSE) were used to assess concurrent validity. RESULTS: The Cronbach's alpha coefficient was 0.797, and the ICC was 0.887. Spearman's rank correlation analysis revealed a significant correlation with the K-MMSE and MOCA-K scores (r = 0.546 and r = 0.683, respectively). CONCLUSION: Our. RESULTS: demonstrate that the K-SCOPA-Cog has good reliability and validity.

Increasing exercise with a mobile app in people with Parkinson's disease: a pilot study.

Background Exercise is crucial for the well-being of people with Parkinson's disease (PD). Although there are challenges to exercising with PD, mobile apps are seen as potential solutions, though their impact is not yet fully understood. We developed a mobile app and a home-based exercise program specialised for people with PD and investigated the effect of the mobile exercise app for the people with PD. Methods Participants from the Movement Disorder Clinic were prompted to download and actively use our app for a duration of 2 weeks. Before commencing, we assessed their self-rated smartphone proficiency. Both at the start and after the 2-week period, we employed the International Physical Activity Questionnaire-Short Form and the PD Questionnaire-39 (PDQ-39) to evaluate their physical activity and overall quality of life (QoL). Exercise metrics were quantified in terms of metabolic equivalent minutes per week (MET-min/week). Furthermore, we gathered feedback on user satisfaction with the app at the end of the study. Results Out of 41 recruited patients, 25 completed the 2-week program and 16 dropped out. Median MET-min/week rose from 1386.0 to 3210.0 (P = 0.009), primarily in moderate activities (P = 0.049) and walking (P = 0.002). Median PDQ-39 scores showed improvement from 17.2 to 8.5 (P = 0.005) after the program. Conclusion The mobile app holds potential to enhance exercise and QoL for people with PD. For optimal benefits, future studies should focus on e-health literacy education, app quality enhancements, and a broader exercise program variety.

Effectiveness of Live-Streaming Tele-Exercise Intervention in Patients With Parkinson's Disease: A Pilot Study.

OBJECTIVE: Exercise can improve both motor and nonmotor symptoms in people with Parkinson's disease (PwP), but there is an unmet need for accessible and sustainable exercise options. This study aimed to evaluate the effect, feasibility, and safety of a regularly performed live-streaming tele-exercise intervention for PwP. METHODS: A live-streaming exercise intervention for PwP was implemented twice a week for 12 weeks. We measured the motor and nonmotor symptom scores of the included patients before and after the intervention. Changes in clinical scores from baseline to postintervention were analyzed using paired t-tests. Factors associated with improvements in clinical scores and compliance were analyzed using Pearson's correlation analysis. RESULTS: Fifty-six participants were enrolled in the study. There were significant improvements in Hospital Anxiety and Depression Scale (HADS)-anxiety (p = 0.007), HADS-depression (p < 0.001), Unified Parkinson's Disease Rating Scale (UPDRS) part III (p < 0.001), UPDRS total (p = 0.015), Hoehn and Yahr stage (p = 0.027), and Parkinson's Disease Fatigue Scale-16 (p = 0.026) scores after the intervention. Improvements in motor symptoms were associated with improvements in mood symptoms and fatigue. Higher motor impairment at baseline was associated with a greater compliance rate and better postintervention composite motor and nonmotor outcomes (ΔUPDRS total score). Overall, the 12-week tele-exercise program was feasible and safe for PwP. No adverse events were reported. The overall adherence rate was 60.0% in our cohort, and 83.4% of the participants were able to participate in more than half of the exercise routines. CONCLUSION: The live-streaming tele-exercise intervention is a safe, feasible, and effective nonpharmacological treatment option that can alleviate fatigue and improve mood and motor symptoms in PwP.

Nonarteritic anterior ischemic optic neuropathy and incidence of Parkinson's disease based on a nationwide population based study.

This study aimed to investigate the association between nonarteritic anterior ischemic optic neuropathy (NAION) and Parkinson's disease (PD) using a retrospective, nationwide, population-based cohort in South Korea. This study utilized data from the Korean National Health Insurance database, including 43,960 NAION patients and 219,800 age- and sex-matched controls. Cox proportional hazards regression models were used to assess the risk of developing PD in the NAION group compared to the control group after adjusting for various confounding factors. Subgroup analyses were conducted based on sex, age, and comorbidities. The incidence rate of PD was higher in the NAION group (1.326 per 1000 person-years) than in the control group (0.859 per 1000 person-years). After adjusting for confounding factors, the risk of developing PD was significantly higher in the NAION group (adjusted hazard ratio [aHR] 1.516, 95% confidence interval [CI] 1.300-1.769). Subgroup analyses did not reveal a significant difference in the risk of PD development based on sex, age, or comorbidities. This retrospective, nationwide, population-based cohort study revealed a significant association between NAION and an increased risk of developing PD in a South Korean population. The incidence rate of PD was observed to be higher in individuals diagnosed with NAION than in age- and sex-matched controls even after adjusting for potential confounding variables, with the risk being approximately 51.6% higher in the NAION group. Further research is necessary to elucidate the underlying pathophysiological mechanisms linking NAION to PD and to determine whether similar associations exist in other ethnic and geographical populations.

Risk of Parkinson disease in stroke patients: A nationwide cohort study in South Korea.

BACKGROUND AND PURPOSE: Previous studies have examined the risk of stroke in patients with Parkinson disease (PD), but the incidence of PD onset among stroke patients and its risk according to severity of poststroke disabilities have scarcely been investigated. This study aims to determine whether the risk of PD is increased among stroke patients using a retrospective cohort with a large population-based database. METHODS: We used data collected by the Korean National Health Insurance Service from 2010 to 2018 and examined 307,361 stroke patients and 380,917 sex- and age-matched individuals without stroke to uncover the incidence of PD. Cox proportional hazards regression was used to calculate the hazard ratio (HR) and 95% confidence interval (CI), and the risk of PD was compared according to presence and severity of disability. RESULTS: During 4.31 years of follow-up, stroke patients had a 1.67 times higher risk of PD compared to individuals without stroke (adjusted HR = 1.67, 95% CI = 1.57-1.78). The risk of PD was greater among stroke patients with disabilities than among those without disabilities, even after adjustment for multiple covariates (adjusted HR = 1.72, 95% CI = 1.55-1.91; and adjusted HR = 1.66, 95% CI = 1.56-1.77, respectively). CONCLUSIONS: Our study demonstrated an increased risk of PD among stroke patients. Health professionals need to pay careful attention to detecting movement disorders as clues for diagnosing PD.

Subjective cognitive complaints in patients with progressive supranuclear palsy.

Introduction: Subjective cognitive complaints (SCC) refer to self-reported cognitive decline that may or may not be reflected in objective neuropsychological evaluations. Such SCC are prevalent in neurodegenerative diseases, including Parkinson's disease (PD), but the prevalence and clinical features in patients with progressive supranuclear palsy (PSP) have not been investigated. Methods: We recruited 83 PSP patients without dementia and investigated their SCC using a semi-structured interview. Comprehensive neuropsychological test results and patient clinical features were compared according to presence of SCC and underlying cognitive state. Results: Among the 83 patients, 16 had normal cognition (NC), 67 had mild cognitive impairment (MCI), and 36 (43.4%) reported SCC. Among NC patients, 37.5% (6/16) had SCC, while 44.8% (30/67) of MCI patients reported SCC. There were no differences between the neuropsychological test results or demographic and clinical characteristics of PSP patients with or without SCC in the NC group. The demographic and clinical characteristics of the MCI+SCC (MCI with SCC)and MCI-SCC (MCI without SCC) groups were comparable, but the MCI+SCC group had significantly worse neuropsychological scores than the MCI-SCC group, particularly in tests assessing attention, language, visual memory, and fronto-executive function domains. Discussion: While SCC are commonly reported by PSP patients, patients with PSP and MCI+SCC had worse cognitive function than those who did not report SCC. These findings suggest that SCC in PSP patients with MCI could be a worsening sign of cognitive function. Therefore, it is crucial for physicians to assess SCC in PSP patients and to provide timely diagnosis and management of cognitive decline.

Waiting impulsivity in progressive supranuclear palsy-Richardson's syndrome.

Background: Waiting impulsivity in progressive supranuclear palsy-Richardson's syndrome (PSP-RS) is difficult to assess, and its regulation is known to involve nucleus accumbens (NAc) subregions. We investigated waiting impulsivity using the "jumping the gun" (JTG) sign, which is defined as premature initiation of clapping before the start signal in the three-clap test and compared clinical features of PSP-RS patients with and without the sign and analyzed neural connectivity and microstructural changes in NAc subregions. Materials and methods: A positive JTG sign was defined as the participant starting to clap before the start sign in the three-clap test. We classified participants into the JTG positive (JTG +) and JTG negative (JTG-) groups and compared their clinical features, microstructural changes, and connectivity between NAc subregions using diffusion tension imaging. The NAc was parcellated into core and shell subregions using data-driven connectivity-based methods. Results: Seventy-seven patients with PSP-RS were recruited, and the JTG + group had worse frontal lobe battery (FAB) scores, more frequent falls, and more occurrence of the applause sign than the JTG- group. A logistic regression analysis revealed that FAB scores were associated with a positive JTG sign. The mean fiber density between the right NAc core and right medial orbitofrontal gyrus was higher in the JTG + group than the JTG- group. Discussion: We show that the JTG sign is a surrogate marker of waiting impulsivity in PSP-RS patients. Our findings enrich the current literature by deepening our understanding of waiting impulsivity in PSP patients and introducing a novel method for its evaluation.

The Role of Levodopa Challenge in Predicting the Outcome of Subthalamic Deep Brain Stimulation.

Background: Deep brain stimulation of the subthalamic nucleus (STN-DBS) is an effective and evidence-based treatment for idiopathic Parkinson's disease (iPD). A minority of patients does not sufficiently benefit from STN-DBS. Objective: The predictive validity of the levodopa challenge for individual patients is analyzed. Methods: Data from patients assessed with a preoperative Levodopa-test and a follow-up examination (mean ± standard deviation: 9.15 months ±3.39) from Kiel (n = 253), Berlin (n = 78) and Toronto (n = 98) were studied. Insufficient DBS outcome was defined as an overall UPDRS-III reduction <33% compared to UPDRS-III in med-off at baseline or alternatively if the minimal clinically important improvement of 5 points was not reached. Single UPDRS-items and sub-scores were dichotomized. Following exploratory analysis, we trained supervised regression- and classification models for outcome prediction. Results: Data analysis confirmed significant correlation between the absolute UPDRS-III reduction during Levodopa challenge and after stimulation. But individual improvement was inaccurately predicted with a large range of up to 30 UPDRS III points. Further analysis identified preoperative UPDRS-III/med-off-scores and preoperative Levodopa-improvement as most influential factors. The models for UPDRS-III and sub-scores improvement achieved comparably low accuracy. Conclusions: With large prediction intervals, the Levodopa challenge use for patient counseling is limited, though remains important for excluding non-responders to Levodopa. Despite these deficiencies, the current practice of patient selection is highly successful and builds not only on the Levodopa challenge. However, more specific motor tasks and further paraclinical tools for prediction need to be developed.

Whole exome sequencing and clinical investigation of young onset dystonia: What can we learn?

BACKGROUND: Dystonia is a heterogeneous movement disorder involving various genetic backgrounds, and the implication of whole exome sequencing (WES) has yet to be clearly elucidated. In this study, we performed WES in Korean patients with young-onset dystonia. METHODS: We recruited patients with young-onset dystonia based on the new MDS dystonia classification at Samsung Medical Centre from 2015 to 2019. We excluded subjects diagnosed by single gene tests (GCH1, TOR1A, PANK2, PRRT2, and SGCE) or levodopa trials and subjects with focal or possible secondary dystonia. We performed WES in all enrolled subjects and confirmed the results with Sanger sequencing. RESULTS: Of the 43 patients, we detected 11 disease-causing variants, classified as either pathogenic or likely pathogenic, in 9 patients (20.9%). Generalized dystonia, infancy-childhood-onset dystonia, and other combined neurologic manifestations were related with PV/LPV. When we retrospectively reviewed the patients with PV/LPV, brain imaging was diagnostic in 3 subjects (HTRA1, SCL20A, and WDR45), clinical characteristics of paroxysmal presentation were observed in 2 (ADCY5 and ATP1A3), and microcephaly was noted in 1 patient (KMT2B). CONCLUSION: Clinical exome sequencing is helpful for the diagnosis of dystonia, especially for that with infancy-childhood onset, and generalized dystonia with other neurologic manifestations. Additionally, careful evaluations and examinations could provide information for selecting candidates for genetic testing.

Automatic stridor detection using small training set via patch-wise few-shot learning for diagnosis of multiple system atrophy.

Stridor is a rare but important non-motor symptom that can support the diagnosis and prediction of worse prognosis in multiple system atrophy. Recording sounds generated during sleep by video-polysomnography is recommended for detecting stridor, but the analysis is labor intensive and time consuming. A method for automatic stridor detection should be developed using technologies such as artificial intelligence (AI) or machine learning. However, the rarity of stridor hinders the collection of sufficient data from diverse patients. Therefore, an AI method with high diagnostic performance should be devised to address this limitation. We propose an AI method for detecting patients with stridor by combining audio splitting and reintegration with few-shot learning for diagnosis. We used video-polysomnography data from patients with stridor (19 patients with multiple system atrophy) and without stridor (28 patients with parkinsonism and 18 patients with sleep disorders). To the best of our knowledge, this is the first study to propose a method for stridor detection and attempt the validation of few-shot learning to process medical audio signals. Even with a small training set, a substantial improvement was achieved for stridor detection, confirming the clinical utility of our method compared with similar developments. The proposed method achieved a detection accuracy above 96% using data from only eight patients with stridor for training. Performance improvements of 4%-13% were achieved compared with a state-of-the-art AI baseline. Moreover, our method determined whether a patient had stridor and performed real-time localization of the corresponding audio patches, thus providing physicians with support for interpreting and efficiently employing the results of this method.

Increased risk of Parkinson's disease amongst patients with age-related macular degeneration and visual disability: A nationwide cohort study.

BACKGROUND AND PURPOSE: The association between Parkinson's disease (PD) and age-related macular degeneration (AMD) has been shown in previous reports. However, the association between the severity of AMD and PD development is unknown. The aim was to evaluate the association of AMD with/without visual disability (VD) with the risk of PD occurrence using the National Health Insurance data in South Korea. METHODS: A total of 4,205,520 individuals, 50 years or older and without a previous diagnosis of PD, participated in the Korean National Health Screening Program in 2009. AMD was verified using diagnostic codes, and participants with VD were defined as those with loss of vision or visual field defect as certified by the Korean Government. The participants were followed up until 31 December 2019, and incident cases of PD were identified using registered diagnostic codes. The hazard ratio was calculated for groups (control and AMD with/without VD) using multivariable adjusted Cox regression analysis. RESULTS: In total, 37,507 participants (0.89%) were diagnosed with PD. Amongst individuals with AMD, the risk of PD development was higher in individuals with VD (adjusted hazard ratio [aHR] 1.35, 95% confidence interval [CI] 1.09-1.67) than in those without (aHR 1.22, 95% CI 1.15-1.30) compared with controls. Additionally, an increased risk of PD was observed in individuals with AMD compared with controls, regardless of the presence of VD (aHR 1.23, 95% CI 1.16-1.31). CONCLUSIONS: Visual disability in AMD was associated with the development of PD. This suggests that neurodegeneration in PD and AMD may have common pathways.

Hemiatrophy-hemiparkinsonism and Poland syndrome: A causative or coincidental association?

Despite various neurologic symptoms of Poland syndrome (PS), parkinsonism was never reported in PS, and the response to the treatment of parkinsonism was not studied before. We report a case of ipsilateral parkinsonism in PS, similar to hemiatrophy-hemiparkinsonism, with a good response to levodopa and subthalamic deep brain stimulation.