Appendectomy and the Risk of Parkinson's Disease: A Korean Nationwide Study.

BACKGROUND: The vermiform appendix is considered a potential reservoir for the abnormal α-synuclein aggregate in Parkinson's disease (PD). Previous epidemiologic evidence on the association between appendectomy and PD risk remains inconclusive, especially outside the Western world. OBJECTIVES: To investigate the association between appendectomy and PD risk in Korea. METHODS: Among 703,831 eligible adult subjects in the National Health Insurance Service sample cohort, we identified 16,122 patients who underwent appendectomy. The rest formed the control group. PD risk was assessed using time-dependent Cox regression analyses. RESULTS: The appendectomy group did not have altered risk of PD compared with the control group in either unadjusted [hazard ratio (HR) 1.32, 95% confidence interval (CI) 0.97-1.80, P = 0.08] or adjusted model (HR 1.42, CI 0.88-2.30, P = 0.15). No further statistical difference appeared when stratified by sex. CONCLUSIONS: Appendectomy is not associated with altered risk of PD in the Korean population.

Clinical and Genetic Characteristics Associated With Survival Outcome in Late-Onset Huntington's Disease in South Korea.

BACKGROUND AND PURPOSE: The onset of Huntington's disease (HD) usually occurs before the age of 50 years, and the median survival time from onset is 15 years. We investigated survival in patients with late-onset HD (LoHD) (age at onset ≥60 years) and the associations of the number of mutant CAG repeats and age at onset (AAO) with survival in patients with HD. METHODS: Patients with genetically confirmed HD at six referral centers in South Korea between 2000 and 2020 were analyzed retrospectively. Baseline demographic, clinical, and genetic characteristics and the survival status as at December 2020 were collected. RESULTS: Eighty-seven patients were included, comprising 26 with LoHD (AAO=68.77±5.91 years, mean±standard deviation; 40.54±1.53 mutant CAG repeats) and 61 with common-onset HD (CoHD) (AAO=44.12±8.61 years, 44.72±4.27 mutant CAG repeats). The ages at death were 77.78±7.46 and 53.72±10.86 years in patients with LoHD and CoHD, respectively (p<0.001). The estimated survival time was 15.21±2.49 years for all HD patients, and 10.74±1.95 and 16.15±2.82 years in patients with LoHD and CoHD, respectively. More mutant CAG repeats and higher AAO were associated with shorter survival (hazard ratio [HR]=1.05, 95% confidence interval [CI]=1.01-1.09, p=0.019; and HR=1.17, 95% CI=1.03-1.31, p=0.013; respectively) for all HD patients. The LoHD group showed no significant factors associated with survival after disease onset, whereas the number of mutant CAG repeats had a significant effect (HR=1.12, 95% CI=1.01-1.23, p=0.034) in the CoHD group. CONCLUSIONS: Survival after disease onset was shorter in patients with LoHD than in those with CoHD. More mutant CAG repeats and higher AAO were associated with shorter survival in patients with HD.

Increasing incidence of Parkinson's disease in patients with epilepsy: A Nationwide cohort study.

BACKGROUND: Although epilepsy is an uncommon comorbidity of Parkinson's disease (PD), the exact incidence of PD among the patients with epilepsy is not clarified yet. OBJECTIVES: We aimed to estimate the incidence of PD in patients with epilepsy and explore the association between epilepsy and PD. METHODS: Epilepsy patients enrolled in the National Health Insurance Service Health Screening Cohort (NHIS-HealS) (2002-2013) between 2003 and 2007 were set up as the experimental group. The major outcome was the occurrence of PD. Non-epilepsy patients were obtained through Propensity Score Matching of 'greedy nearest neighbor' algorithm in 1:1 ratio. The Cox Proportional Hazards model was used to calculate PD incidence and hazard ratio (HR). RESULTS: A total of 10,510 patients were finally included in the study, which contained 5255 patients in epilepsy and non-epilepsy groups, respectively. During the follow-up period, 85 patients with Parkinson's disease among 5255 patients with epilepsy and 57 patients with Parkinson's disease among 5255 patients without epilepsy occurred. The 10,000 Person-Year (PY), representing the number of PD patients per 10,000 per year, was 21.38 in the epilepsy group and 11.18 in the non-epilepsy group. When all variables were adjusted, it was found that the epilepsy group had a 2.19 times significantly higher risk of developing Parkinson's disease than the control group (The adjusted HR: 2.19 (95% CI, 1.55-3.12)). CONCLUSION: This study indicates an increased risk of PD in patients with epilepsy. However, further research is needed to prove an exact causal relationship between these two brain disorders.

Caregiver Burden of Patients With Huntington's Disease in South Korea.

OBJECTIVE: This is the first prospective cohort study of Huntington's disease (HD) in Korea. This study aimed to investigate the caregiver burden in relation to the characteristics of patients and caregivers. METHODS: From August 2020 to February 2022, we enrolled patients with HD from 13 university hospitals in Korea. We used the 12-item Zarit Burden Interview (ZBI-12) to evaluate the caregiver burden. We evaluated the clinical associations of the ZBI-12 scores by linear regression analysis and investigated the differences between the low- and high-burden groups. RESULTS: Sixty-five patients with HD and 45 caregivers were enrolled in this cohort study. The average age at onset of motor symptoms was 49.3 ± 12.3 years, with an average cytosine-adenine-guanine (CAG)n of 42.9 ± 4.0 (38-65). The median ZBI-12 score among our caregivers was 17.6 ± 14.2. A higher caregiver burden was associated with a more severe Shoulson-Fahn stage (p = 0.038) of the patients. A higher ZBI-12 score was also associated with lower independence scale (B = -0.154, p = 0.006) and functional capacity (B = -1.082, p = 0.002) scores of patients. The caregiving duration was longer in the high- than in the low-burden group. Caregivers' demographics, blood relation, and marital and social status did not affect the burden significantly. CONCLUSION: HD patients' neurological status exerts an enormous impact on the caregiver burden regardless of the demographic or social status of the caregiver. This study emphasizes the need to establish an optimal support system for families dealing with HD in Korea. A future longitudinal analysis could help us understand how disease progression aggravates the caregiver burden throughout the entire disease course.

Dietary quality and the gut microbiome in early-stage Parkinson's disease patients.

BACKGROUND: The prevalence of Parkinson's disease (PD) has increased steadily with the increase of the elderly population. PD may influence dietary intake and quality, and the gut microbiome composition. The present study examined differences in dietary intake and quality between PD patients and controls according to sex. In addition, we assessed the gut microbiome composition. METHODS: This cross-sectional study was conducted at A Medical Center, Seoul, South Korea. PD severity, swallowing function, olfactory function, and constipation status were examined by a skilled nurse. Dietary data were collected through a semi-quantitative food frequency questionnaire. Stool samples were subjected to microbiome analysis. To examine dietary quality, the Dietary Quality Index-International (DQI-I), Healthy Eating Index (HEI), Index of Nutritional Quality (INQ), Dietary Diversity Score (DDS), and Mediterranean Diet Score (MDS) were used. An independent t-test was used to determine differences between patients and controls. A chi-square test was used to examine frequency differences. RESULTS: Dietary intake did not differ between the PD patient and control groups. Regarding dietary quality, the patients consumed more saturated fat compared to controls. Overall, the dietary differences between the groups were minor. The composition of the gut microbiome differed between PD patients and controls. Lactobacillus and Bifidobacterium genus were most abundant in PD patients. Prevotella VZCB and other Faecalibacterium were most abundant in controls. CONCLUSIONS: Our results indicated that PD patients may experience gut microbiome change even in the early stage, while nutritional needs can be met when a balanced diet including various food groups are consumed.

Plasma neurofilament light-chain and phosphorylated tau as biomarkers of disease severity in Huntington's disease: Korean cohort data.

OBJECTIVE: To investigate neurofilament light chain (NfL), phosphorylated tau (p-Tau) and total tau (t-Tau) as plasma markers for clinical severity in Korean Huntington's disease (HD) cohort. METHODS: Genetically-confirmed 67 HD patients participated from 13 referral hospitals in South Korea. The subjects were evaluated with the Unified Huntington's Disease Rating Scale (UHDRS), total motor score (TMS) and total functional capacity (TFC), Mini-Mental Status Examination (K-MMSE), Montreal Cognitive Assessment (MoCA-K), and Beck's depression inventory (K-BDI). We measured plasma NfL, p-Tau and t-Tau concentrations using single-molecule array (SIMOA) assays. Stages of HD were classified based on UHDRS-TFC score and plasma markers were analyzed for correlation with clinical severity scales. RESULTS: Plasma NfL was elevated in both 6 premanifest and 61 full manifest HD patients compared to the reference value, which increased further from premanifest to manifest HD groups. The NfL level was not significantly correlated with UHDRS TMS or TFC scores in manifest HD patients. Plasma p-Tau was also elevated in HD patients (p = 0.038). The level was the highest in stage III-V HD (n = 30) group (post-hoc p < 0.05). The p-Tau was correlated with UHDRS TFC scores (adjusted p = 0.002). Plasma t-Tau neither differed among the groups nor associated with any clinical variables. CONCLUSIONS: This study supports plasma NfL being a biomarker for initial HD manifestation in Korean cohort, and a novel suggestion of plasma p-Tau as a potential biomarker reflecting the clinical severity in full-manifest HD.

Bidirectional association between Parkinson's disease and obstructive sleep apnea: a cohort study.

STUDY OBJECTIVES: Chronic intermittent hypoxia due to obstructive sleep apnea (OSA) causes oxidative stress, which may contribute to the pathophysiology of Parkinson's disease (PD). However, the bidirectional relationship between PD and OSA has not been satisfactorily established. The objective of this study was to try to estimate whether there is a bidirectional relationship between PD and OSA through a retrospective cohort study in the South Korean population. METHODS: This study used data from the Korean National Health Information Database of the National Health Insurance Service, which contains data from 3.5 million individuals evenly distributed. In study 1, patients with OSA were matched in a 1:2 ratio with non-OSA controls. In study 2, patients with PD were matched in a 1:2 ratio with non-PD controls. A stratified Cox proportional hazards model was used to calculate hazard ratios. RESULTS: In study 1, which included 6,396 patients with OSA and 12,792 non-OSA controls, the incidence of PD per 10,000 person-years was 11.59 in the OSA group and 8.46 in the non-OSA group. The OSA group demonstrated a 1.54-fold higher incidence of PD than the non-OSA group (95% confidence interval, 1.14-2.07; P < .05). In study 2, which included 3,427 patients with PD and 6,854 non-PD controls, the incidence of OSA per 10,000 person-years was 14.97 in the PD group and 7.72 in the non-PD group. The PD group demonstrated a 1.92-fold higher incidence of OSA than the non-PD group (95% confidence interval, 1.32-2.78; P < .05). CONCLUSIONS: This study supports a possible bidirectional relationship between PD and OSA. CITATION: Jeon S-H, Hwang YS, Oh S-Y, et al. Bidirectional association between Parkinson's disease and obstructive sleep apnea: a cohort study. J Clin Sleep Med. 2023;19(9):1615-1623.

Whole-genome sequencing reveals an association between small genomic deletions and an increased risk of developing Parkinson's disease.

Single-nucleotide variants (SNVs) associated with Parkinson's disease (PD) have been investigated mainly through genome-wide association studies. However, other genomic alterations, including copy number variations, remain less explored. In this study, we conducted whole-genome sequencing of primary (310 PD patients and 100 healthy individuals) and independent (100 PD patients and 100 healthy individuals) cohorts from the Korean population to identify high-resolution small genomic deletions, gains, and SNVs. Global small genomic deletions and gains were found to be associated with an increased and decreased risk of PD development, respectively. Thirty significant locus deletions were identified in PD, with most being associated with an increased PD risk in both cohorts. Small genomic deletions in clustered loci located in the GPR27 region had high enhancer signals and showed the closest association with PD. GPR27 was found to be expressed specifically in brain tissue, and GPR27 copy number loss was associated with upregulated SNCA expression and downregulated dopamine neurotransmitter pathways. Clustering of small genomic deletions on chr20 in exon 1 of the GNAS isoform was detected. In addition, we found several PD-associated SNVs, including one in the enhancer region of the TCF7L2 intron, which exhibited a cis-acting regulatory mode and an association with the beta-catenin signaling pathway. These findings provide a global, whole-genome view of PD and suggest that small genomic deletions in regulatory domains contribute to the risk of PD development.

Effect of Home-Based Self-Management Intervention for Community-Dwelling Patients with Early Parkinson's Disease: A Feasibility Study.

PURPOSE: This study aimed to evaluate the effect of a home-based self-management intervention in community-dwelling patients with early Parkinson's diseases (PD). DESIGN: A randomized-controlled design. METHODS: Thirty-two patients participated (15=intervention, 17=control), and the intervention group received 16 weeks of the intervention. FINDINGS: Physical activity and non-motor symptoms improved more in the intervention group than in the control group. CONCLUSION: Home-based self-management intervention was effective in improving physical activity and non-motor symptoms for them. CLINICAL EVIDENCE: Home-based intervention - comprising education, telephone counseling, smartphone-based message and information, and smart wearable devices - was feasible for patients with early PD.

The Effect of Blood Lipids, Type 2 Diabetes, and Body Mass Index on Parkinson's Disease: A Korean Mendelian Randomization Study.

OBJECTIVE: Associations between various metabolic conditions and Parkinson's disease (PD) have been previously identified in epidemiological studies. We aimed to investigate the causal effect of lipid levels, type 2 diabetes mellitus (T2DM), and body mass index (BMI) on PD in a Korean population via Mendelian randomization (MR). METHODS: Two-sample MR analyses were performed with inverse-variance weighted (IVW), weighted median, and MR-Egger regression approaches. We identified genetic variants associated with lipid concentrations, T2DM, and BMI in publicly available summary statistics, which were either collected from genome-wide association studies (GWASs) or from meta-analyses of GWAS that targeted only Korean individuals or East Asian individuals, including Korean individuals. The outcome dataset was a GWAS on PD performed in a Korean population. RESULTS: From previous GWASs and meta-analyses, we selected single nucleotide polymorphisms as the instrumental variables. Variants associated with serum levels of low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides, as well as with T2DM and BMI, were selected (n = 11, 19, 17, 89, and 9, respectively). There were no statistically significant causal associations observed between the five exposures and PD using either the IVW, weighted median, or MR-Egger methods (p-values of the IVW method: 0.332, 0.610, 0.634, 0.275, and 0.860, respectively). CONCLUSION: This study does not support a clinically relevant causal effect of lipid levels, T2DM, and BMI on PD risk in a Korean population.

Monochorea after acute contralateral pontine infarction: A case report.

RATIONALE: Chorea is a hyperkinetic movement characterized by random, brief, and involuntary muscle contractions. In stroke, a common cause of chorea, basal ganglia are anatomical locations that can cause chorea when a stroke occurs, and chorea is less frequently triggered by a stroke in other anatomical brain regions. Herein, we report a rare case of monochorea after acute contralateral pontine infarction. PATIENT CONCERNS: A 32-year-old man visited the emergency room due to dysarthria and right hemiparesis that occurred approximately 6 hours and 30 minutes before the visit. A brain magnetic resonance image confirmed a diffusion restriction lesion in the left pons. The patient was initially diagnosed with acute infarction at the left pons and began to receive medical treatment with an antiplatelet agent and statin with admission. DIAGNOSIS: Approximately 14 hours after the onset of the initial stroke symptoms, the patient complained of involuntary movement in the right arm for the first time. Intermittent, irregular involuntary movements were observed in the distal part of the right arm. This symptom was unpredictable and random, and a similar symptom was not observed in other parts of the patient's body. Clinically, post-stroke monochorea was suspected. INTERVENTIONS AND OUTCOMES: The symptom improved from day 5 without specific medical treatment for chorea. LESSONS: The monochorea caused by the pontine lesion in this case was triggered by the direct lesions of the corticospinal tract, and its underlying pathophysiology remains unclear. However, abnormal movements can occur due to inadequate downstream activation or inhibition of the corticospinal tract, which is induced by functional abnormalities of the motor cortex. This case suggests that further investigation is needed on the mechanisms of direct corticospinal tract lesions for chorea.

Two cases of Ramsay-Hunt syndrome following varicella zoster viral meningitis in young immunocompetent men: case reports.

BACKGROUND: Ramsay-Hunt syndrome (RHS) due to varicella zoster virus (VZV) infection is commonly reported in individuals aged at least 50 years or immunocompromised individuals. VZV infection may invade the central nervous system (CNS) and cause meningitis or encephalitis, which are more likely to occur in patients with chronic diseases such as diabetes and chronic renal failure. However, cases with VZV-induced concurrent RHS and CNS infections are rare. CASE PRESENTATION: Two young male patients, aged 32 and 43 years, with no underlying disease developed VZV meningitis, followed by RHS involving cranial nerves VII and VIII. Both patients presented with symptoms of peripheral facial palsy, and dizziness accompanied by tinnitus and hearing loss, which appeared several days after the onset of fever and headache. These symptoms were documented as facial neuropathy and sensorineural hearing loss in the electrophysiologic studies. Lymphocyte-dominant pleocytosis and VZV positivity were confirmed from cerebrospinal fluid examination and polymerase chain reaction, respectively. The patients were treated with intravenous acyclovir and oral steroids simultaneously. Following the treatment completion, both patients were relieved of their headaches and fever; however, facial palsy, dizziness, and tinnitus persisted. They were followed up at the outpatient clinic. CONCLUSION: These cases confirmed that RHS and CNS infections can co-exist even in young adults with normal immune function and more importantly, that CNS infection can precede RHS. Since early detection and treatment of RHS improve the prognosis, it is critical to closely monitor patients with VZV meningitis or encephalitis considering the possible superimposition of RHS.

Long-term motor outcomes of deep brain stimulation of the globus pallidus interna in Parkinson's disease patients: Five-year follow-up.

BACKGROUND: Deep brain stimulation (DBS) of globus pallidus interna (GPi) is an established treatment for advanced Parkinson's disease (PD). However, in contrast to subthalamic nucleus (STN)-DBS, long-term outcomes of GPi-DBS have rarely been studied. OBJECTIVE: We investigated the long-term motor outcomes in PD patients at 5 years after GPi-DBS. METHODS: We retrospectively analyzed the clinical data for PD patients who underwent GPi-DBS. Longitudinal changes of UPDRS scores from baseline to 5 years after surgery were assessed. RESULTS: Forty PD patients with a mean age of 59.5 ± 7.9 years at DBS surgery (mean duration of PD: 11.4 ± 3.4 years) were included at baseline and 25 patients were included in 5-year evaluation after DBS. Compared to baseline, sub-scores for tremor, levodopa-induced dyskinesia (LID), and motor fluctuation indicated improved states up to 5 years after surgery (p < 0.001). However, UPDRS Part 3 total score and sub-score for postural instability and gait disturbance (PIGD) gradually worsened over time until 5 years after surgery (p > 0.017 after Bonferroni correction). In a logistic regression model, only preoperative levodopa response was associated with the long-term benefits on UPDRS Part 3 total score and PIGD sub-score (OR = 1.20; 95% CI = 1.04-1.39; p = 0.015 and OR = 4.99; 95% CI = 1.39-17.89; p = 0.014, respectively). CONCLUSIONS: GPi-DBS provides long-term beneficial effects against tremor, motor fluctuation and LID, but PIGD symptoms gradually worsen. This selective long-term benefit has implications for the optimal application of DBS in PD patients.

Association of Depression With Early Occurrence of Postural Instability in Parkinson's Disease.

OBJECTIVE: Depression in Parkinson's disease (PD) affects the quality of life of patients. Postural instability and gait disturbance are associated with the severity and prognosis of PD. We investigated the association of depression with axial involvement in early-stage PD patients. METHODS: This study involved 95 PD patients unexposed to antiparkinsonian drugs. After a baseline assessment for depression, the subjects were divided into a depressed PD group and a nondepressed PD group. Analyses were conducted to identify an association of depression at baseline with the following outcome variables: the progression to Hoehn and Yahr scale (H-Y) stage 3, the occurrence of freezing of gait (FOG), levodopa-induced dyskinesia, and wearing-off. The follow-up period was 53.40 ± 16.79 months from baseline. RESULTS: Kaplan-Meier survival curves for H-Y stage 3 and FOG showed more prominent progression to H-Y stage 3 and occurrences of FOG in the depressed PD group than in the nondepressed PD group (log-rank p = 0.025 and 0.003, respectively). Depression in drug-naïve, early-stage PD patients showed a significant association with the progression to H-Y stage 3 (hazard ratio = 2.55; 95% confidence interval = 1.32-4.93; p = 0.005), as analyzed by Cox regression analyses. In contrast, the occurrence of levodopa-induced dyskinesia and wearing-off did not differ between the two groups (log-rank p = 0.903 and 0.351, respectively). CONCLUSION: Depression in drug-naïve, early-stage PD patients is associated with an earlier occurrence of postural instability. This suggests shared nondopaminergic pathogenic mechanisms and potentially enables the prediction of early development of postural instability.

Oral and gut dysbiosis leads to functional alterations in Parkinson's disease.

Although several studies have identified a distinct gut microbial composition in Parkinson's disease (PD), few studies have investigated the oral microbiome or functional alteration of the microbiome in PD. We aimed to investigate the connection between the oral and gut microbiome and the functional changes in the PD-specific gut microbiome using shotgun metagenomic sequencing. The taxonomic composition of the oral and gut microbiome was significantly different between PD patients and healthy controls (P = 0.003 and 0.001, respectively). Oral Lactobacillus was more abundant in PD patients and was associated with opportunistic pathogens in the gut (FDR-adjusted P < 0.038). Functional analysis revealed that microbial gene markers for glutamate and arginine biosynthesis were downregulated, while antimicrobial resistance gene markers were upregulated in PD patients than healthy controls (all P < 0.001). We identified a connection between the oral and gut microbiota in PD, which might lead to functional alteration of the microbiome in PD.

Effect of mobile health intervention for self-management on self-efficacy, motor and non-motor symptoms, self-management, and quality of life in people with Parkinson's disease: Randomized controlled trial.

OBJECTIVES: To evaluate the effects of a mobile health intervention for self-management on self-efficacy, motor and non-motor symptoms, self-management, and quality of life in people with Parkinson's disease. METHODS: A randomized controlled design was used. The participants were randomly assigned to an intervention or a control group. The intervention group (n = 20) received mobile health intervention comprising mobile applications, smartwatches, smartphone-based short text messages and information, and telephone counselling; whereas the control group (n = 23) received short text messages and telephone counselling for 16 weeks. RESULTS: After 16 weeks, self-efficacy and non-motor symptom scores in the intervention group significantly improved compared to those in the control group. However, no significant differences were observed in the motor symptoms, self-management, and quality of life between the groups. CONCLUSIONS: The mobile health intervention for self-management is effective for self-efficacy and non-motor symptoms in people with Parkinson's disease.

Factors correlated with therapeutic effects of globus pallidus deep brain stimulation on freezing of gait in advanced Parkinson's disease: A pilot study.

INTRODUCTION: Deep brain stimulation (DBS) has showed variable therapeutic effect on freezing of gait (FOG) in Parkinson's disease (PD). It is unclear which factors associated with the effect of DBS on FOG in patients with advanced PD. In this study, we investigated the correlation of pre and postoperative factors with the therapeutic effect of globus pallidus interna (GPi) DBS on FOG in PD patients. METHODS: We retrospectively analyzed PD patients with FOG (N = 20) who underwent GPi DBS surgery. Postoperatively, video-based analysis for FOG severity was performed at the first DBS programming and patients were categorized into two groups according to DBS effect on FOG (11 FOG responders and 9 FOG non-responders) at medication-off state. We analyzed preoperative clinical characteristics, cognitive function, striatal dopamine transporter availability, postoperative DBS programming parameters, lead locations, and volume of tissue activated in functional subregions of GPi. Bootstrap enhanced Elastic-Net logistic regression was used to select pre and postoperative factors associated with the effect of GPi DBS. RESULTS: Therapeutic effect of GPi DBS on FOG were correlated with the disease duration of PD before DBS surgery, preoperative improvement in FOG severity by levodopa medication, and the distance from active contact of DBS electrode to the prefrontal region of GPi anatomical site. CONCLUSIONS: Our study results suggest that the effect of GPi DBS on FOG is correlated with disease duration, levodopa responsiveness on FOG before DBS surgery and DBS electrode location, providing useful information to predict FOG outcome after GPi DBS in PD patients.