Early-Onset Parkinsonism and Early-Onset Parkinson's Disease: A Population-Based Study (2010-2015)

NFKB1 variants were associated with the risk of Parkinson´s disease in male

The NF-κB pathway is involved in the pathogenesis of neurological disorders that have inflammation as a hallmark, including Parkinson's disease (PD). Our objective was to determine whether common functional variants in the NFKB1, NFKBIA and NFKBIZ genes were associated with the risk of PD. A total of 532 Spanish PD cases (61% male; 38% early-onset, ≤ 55 years) and 300 population controls (50% ≤55 years) were genotyped for the NFKB1 rs28362491 and rs7667496, NFKBIA rs696, and NFKBIZ rs1398608 polymorphisms. We compared allele and genotype frequencies between early and late-onset, male and female, and patient's vs. controls. We found that the two NFKB1 alleles were significantly associated with PD in our population (p = 0.01; total patients vs. controls), without difference between Early and Late onset patients. The frequencies of the NFKB1 variants significantly differ between male and female patients. Compared to controls, male patients showed a significantly higher frequency of rs28362491 II (p = 0.02, OR = 1.52, 95%CI = 1.10-2.08) and rs28362491 C (p = 0.003, OR = 1.62, 95%CI = 1.18-2.22). The two NFKB1 variants were in strong linkage disequilibrium and the I-C haplotype was significantly associated with the risk of PD among male (p = 0.002). In conclusion, common variants in the NF-kB genes were associated with the risk of developing PD in our population, with significant differences between male and female. These results encourage further studies to determine the involvement of the NF-kB components in the pathogenesis of Parkinson´s disease.

Global prevalence and incidence of Young Onset Parkinson's disease: A systematic review and meta-analysis

BACKGROUND

There is a lack of enough evidence regarding the epidemiology of Young-onset Parkinson's disease (YOPD) which is needed by clinicians and healthcare policymakers.

AIM

Herein, in this systematic review and meta-analysis, we aimed to estimate the global prevalence and incidence rates of YOPD.

METHODS

We searched the literature in PubMed, Scopus, and Web of Science in May 2022. We included retrospective, prospective, cross-sectional observational population-based studies that reported the prevalence or incidence of PD in individuals younger than 40 years with known diagnostic criteria.

RESULTS

After two-step screening, 50 studies were eligible to be included in our study. The age-standardized prevalence of YOPD was 10.2 per 100,000 persons globally while it was 14.7 per 100,000 population in European countries. Age-standardized prevalence estimates for 5-year age bands showed that the YOPD prevalence estimates varied from 6.1 per 100,000 population in the group aged 20-24 to 16.1 per 100,000 population in the group aged 35-39. Also, the age-standardized incidence of YOPD was 1.3 per 100,000 person-years population worldwide and 1.2 per 100,000 person-years in the European population.

CONCLUSION

Based on this systematic review and meta-analysis, the overall prevalence of YOPD is 10.2 per 100,000 population, although estimates of the prevalence and incidence in low-income countries remain scarce. To improve monitoring and certain diagnoses of YOPD, healthcare providers and policymakers should be aware that much more effective tools are required.

Motor cortex transcranial direct current stimulation improves non-motor symptoms in early-onset Parkinson's disease: a pilot study

Early-onset Parkinson's Disease (EOPD) demands tailored treatments. The younger age of patients might account for a higher sensitivity to transcranial direct current stimulation (tDCS) based non-invasive neuromodulation, which may raise as an integrative therapy in the field. Accordingly, here we assessed the safety and efficacy of the primary left motor cortex (M1) anodal tDCS in EOPD. Ten idiopathic EOPD patients received tDCS at 2.0 mA per 20 min for 10 days within a crossover, double-blind, sham-controlled pilot study. The outcome was evaluated by measuring changes in MDS-UPDRS part III, Non-Motor Symptoms Scale (NMSS), PD-cognitive rating scale, and PD Quality of Life Questionnaire-39 scores. We showed that anodal but not sham tDCS significantly reduced the NMSS total and "item 2" (sleep/fatigue) scores. Other parameters were not modified. No adverse events occurred. M1 anodal tDCS might thus evoke plasticity changes in cortical-subcortical circuits involved in non-motor functions, supporting the value as a therapeutic option in EOPD.

Assessing the impact of novel risk loci on Alzheimer's and Parkinson's diseases in a Chinese Han cohort

Background

Overwhelming evidence points to that genetic factors contributing to the development of Alzheimer's disease (AD) and Parkinson's disease (PD). Genome-Wide Association Study (GWAS) has come a long way in the last decade. So far, a large number of GWAS studies have been published on neurological diseases and many other diseases, providing us with a wealth of genetic information and unique biological insights.

Methods

Genomic DNA was extracted from both patients' and controls' peripheral blood samples utilizing the Blood Genome Extraction Kit. Single nucleotide polymorphisms (SNPs) were genotyped employing the enhanced multiple ligase detection reaction (iMLDR) technology.

Results

A case-control study was conducted, involving 211 AD patients, 508 PD patients (including 117 with dementia), and 412 healthy individuals. Age and sex stratification analysis revealed that rs871269/TNIP1 was associated with LOAD (p = 0.035), and rs5011436/TMEM106B was associated with AD in males (p = 0.044) in the genotype model. In the allele model, rs871269/TNIP1 was found to be associated with PD in the Chinese Han population (p = 0.0035, OR 0.741, 95% CI 0.559-0.983), and rs708382/GRN was identified as a risk factor for Parkinson's disease dementia (PDD) in the Chinese Han population (p = 0.004, odds ratio (OR) 0.354, 95% confidence interval (CI) 0.171-0.733). However, no significant associations with AD or PD were observed for the remaining four loci (rs113020870/AGRN, rs6891966/HAVCR2, rs2452170/NTN5, rs1761461/LILRB2) in terms of allele or genotype frequencies.

Conclusion

This study identifies rs871269/TNIP1 as a potential risk factor for both LOAD and PD, rs708382/GRN as a risk factor for PDD, and rs5011436/TMEM106B as associated with AD in males when stratified by age.

Emergency department visits in Parkinson's disease: The impact of comorbid conditions

INTRODUCTION

Older adults have complex, often overlapping, medical conditions requiring careful management that may lead to increased emergency department usage compared to younger adults. Parkinson's disease (PD), a progressive neurodegenerative disorder characterized by distinct motor and nonmotor features, frequently occurs with additional comorbid disease. Classifying comorbid conditions into clinical subgroups allows for further understanding of the heterogeneity in outcomes in patients with PD. The current study examines the reasons for emergency department (ED) visits in a cohort of patients with PD and identifies comorbidities that are potential risk factors for specific ED presenting conditions.

METHODS

Using data from Optum's de-identified Integrated Claims-Clinical dataset years 2010-2018, patients with PD were identified based on ICD-9/10 diagnosis codes. We identified all ED visits occurring after the first observed diagnosis code for PD. Comorbid conditions were classified using the AHRQ Clinical Classification Software (CCS). We classified patients using Latent Class Analysis (LCA) and conducted multiple logistic regression models with the outcome of reason-for-visit to examine the associations with comorbidity-profile class, patient demographics, and socio-economic characteristics.

RESULTS

The most common reasons for ED admission were injuries such as fractures and contusions, diseases of the circulatory system, and general signs and symptoms, including abdominal pain, malaise, and fatigue. Comorbid medical conditions often observed in this patient population include depression, diabetes mellitus, and chronic pulmonary disease. Patients in the "Poorest Health" classification of the LCA had greater odds for ED admission for diseases related to the gastrointestinal system, musculoskeletal system, and injury/poisoning categories and reduced odds for admission for diseases of the circulatory system.

DISCUSSION

Patients with PD who present to the emergency department with injuries are more likely to be in poor health overall with a high comorbidity burden. Clarifying the complex medical needs of patients with PD is the first step to further individualize care, which may reduce ED visits in this population, improve quality of life, and lessen the footprint on the healthcare system.

Comparison of disability level between Early and Late Onset Parkinson's Disease using WHODAS 2

Background

Parkinson's disease (PD) is a degenerative neurological disorder that usually affects people over the age of 60. However, 10%-20% of patients have an early onset of PD (EOPD).

Objectives

To compare disability levels according to the World Health Organization Disability Assessment Schedule 2.0 (WHODAS-2) between people with EOPD and those with late-onset PD (LOPD).

Methods

We conducted a cross-sectional study with 95 EOPD patients (mean-age 44.51 ± 4.63, H&Y 1.93 ± 0.93) and 255 LOPD patients (mean-age 63.01 ± 7.99, H&Y 2.02 ± 0.95). Demographic information, clinical characteristics, cognitive evaluation by Telephone-Montreal-Cognitive-Assessment (T-MoCA), functionality self-evaluation by WHODAS-2 and the Unified-Parkinson's-Disease-Rating-Scale (MDS-UPDRS), parts I and II, were documented for each patient by an individual remote interview.

Results

Analysis showed a statistically significant difference between EOPD and LOPD in two domains of WHODAS-2 only: cognition (Z-adjusted = 2.60; p-value adjusted <0.009) and activities of daily living related to work/school (Z-adjusted = 2.34; p-value adjusted <0.01). T-MoCA scores confirmed more impaired cognition capacity in LOPD (Z-adjusted = 2.42; p-value adjusted <0.01). The two groups had no significant differences in levodopa daily dosage, Hoehn and Yahr (H&Y) stages, disease time duration, and MDS-UPDRS I and II scores.

Conclusion

People living with EOPD face similar disability levels as those with LOPD, except for cognition, where LOPD patients exhibited higher levels of disability than EOPD and for work activities where the EOPD exhibited higher levels of disability than LODP. These results highlight the challenges faced by people with EOPD in interacting with society and living with the disease for a longer time. The WHODAS-2 can be a useful tool to assess disability and tailor interventions for people with PD of different age groups.

Ethnicity and Parkinson's Disease: Motor and Nonmotor Features and Disease Progression in Latino Patients Living in Rural California

BACKGROUND

Parkinson's disease (PD) is the second most common neurodegenerative disorder among older adults worldwide. Currently, studies of PD progression rely primarily on White non-Latino (WNL) patients. Here, we compare clinical profiles and PD progression in Latino and WNL patients enrolled in a community-based study in rural Central California.

METHOD

PD patients within 5 years of diagnosis were identified from 3 counties between 2001 and 2015. During up to 3 visits, participants were examined by movement disorders specialists and interviewed. We analyzed cross-sectional differences in PD clinical features severity at each study visit and used linear mixed models and Cox proportional hazards models to compare motor, nonmotor, and disability progression longitudinally and to assess time to death in Latinos compared to WNL patients.

RESULTS

Of 775 patients included, 138 (18%) self-identified as Latino and presented with earlier age at diagnosis (63.6 vs 68.9) and death (78.6 vs 81.5) than WNL. Motor (hazard ratio [HR] = 1.17 [0.71, 1.94]) and nonmotor symptoms did not progress faster in Latino versus WNL patients after accounting for differences in baseline symptom severity. However, Latino patients progressed to disability stages according to Hoehn and Yahr faster than WNL (HR = 1.81 [1.11, 2.96]). Motor and nonmotor symptoms in Latino patients were also medically managed less well than in WNL.

CONCLUSIONS

Our PD study with a large proportion of Latino enrollees and progression data reveals disparities in clinical features and progression by ethnicity that may reflect healthcare access and structural socioeconomic disadvantages in Latino patients with PD.

Beta-propeller protein-associated neurodegeneration: A clinical update with a case report

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Shared molecular genetic factors influence subcortical brain morphometry and Parkinson's disease risk

Parkinson's disease (PD) is a late-onset and genetically complex neurodegenerative disorder. Here we sought to identify genes and molecular pathways underlying the associations between PD and the volume of ten brain structures measured through magnetic resonance imaging (MRI) scans. We leveraged genome-wide genetic data from several cohorts, including the International Parkinson's Disease Genomics Consortium (IPDG), the UK Biobank, the Adolescent Brain Cognitive Development (ABCD) study, the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE), the Enhancing Neuroimaging Genetics through Meta-Analyses (ENIGMA), and 23andMe. We observed significant positive genetic correlations between PD and intracranial and subcortical brain volumes. Genome-wide association studies (GWAS) - pairwise analyses identified 210 genomic segments with shared aetiology between PD and at least one of these brain structures. Pathway enrichment results highlight potential links with chronic inflammation, the hypothalamic-pituitary-adrenal pathway, mitophagy, disrupted vesicle-trafficking, calcium-dependent, and autophagic pathways. Investigations for putative causal genetic effects suggest that a larger putamen volume could influence PD risk, independently of the potential causal genetic effects of intracranial volume (ICV) on PD. Our findings suggest that genetic variants influencing larger intracranial and subcortical brain volumes, possibly during earlier stages of life, influence the risk of developing PD later in life.

The impact of China's zero markup drug policy on drug costs for managing Parkinson's disease and its complications: an interrupted time series analysis

Background

In April 2009, the Chinese government launched Zero Markup Drug Policy (ZMDP) to adjust medical institutions' revenue and expenditure structures.

Objective

This study evaluated the impact of implementing ZMDP (as an intervention) on the drug costs for managing Parkinson's disease (PD) and its complications from the healthcare providers' perspective.

Methods

The drug costs for managing PD and its complications per outpatient visit or inpatient stay were estimated using electronic health data from a tertiary hospital in China from January 2016 to August 2018. An interrupted time series analysis was conducted to evaluate the immediate change following the intervention (step change, β₁) and the change in slope, comparing post-intervention with the pre-intervention period (trend change, β₂). Subgroup analyses were conducted in outpatients within the strata of age, patients with or without health insurance, and whether drugs were listed in the national Essential Medicine List (EML).

Results

Overall, 18,158 outpatient visits and 366 inpatient stays were included. Outpatient (β₁ = -201.7, 95%CI: -285.4, -117.9) and inpatient (β₁ = -372.1, 95% CI: -643.6, -100.6) drug costs for managing PD significantly decreased when implementing ZMDP. However, for outpatients without health insurance, the trend change in drug costs for managing PD (β₂ = 16.8, 95% CI: 8.0, 25.6) or PD complications (β₂ = 12.6, 95% CI: 5.5, 19.7) significantly increased. Trend changes in outpatient drug costs for managing PD differed when stratifying drugs listed in EML (β₂ = -1.4, 95% CI: -2.6, -0.2) or not (β₂ = 6.3, 95%CI: 2.0, 10.7). Trend changes of outpatient drug costs for managing PD complications significantly increased in drugs listed in EML (β₂ = 14.7, 95% CI 9.2, 20.3), patients without health insurance (β₂ = 12.6, 95% CI 5.5, 19.7), and age under 65 (β₂ = 24.3, 95% CI 17.3, 31.4).

Conclusions

Drug costs for managing PD and its complications significantly decreased when implementing ZMDP. However, the trend in drug costs increased significantly in several subgroups, which may offset the decrease at the implementation.

[Muscle activation times facing to a perturbation in patients with early-stage Parkinson's disease]

OBJECTIVES

Parkinson's disease (PD) generates a high incidence of falls, however, there is little evidence of instabilities in the initial stages. This investigation sought to compare the muscle activation times in patients with initial PD against a postural disturbance vs. a control group.

MATERIALS AND METHODS

The electromyographic activity (EMG) of 10 patients with PD in early stages (61.3 ±3.8 years) and a control group of 10 adults (62.2 ±3.0 year) was evaluated. The participants were subjected to a surface disturbance, which generated a stabilization response. The test was performed under 2conditions: eyes open (OA) v/s eyes closed (OC). Trunk (spinal erector) and lower extremity (soleus, tibialis anterior, femoral biceps, femoral rectus, adductor magnus, gluteus medius) muscle activation time was analyzed using surface EMG.

RESULTS

The PD group showed faster response times compared to the control group in the soleus muscle in OC (P=.04). This same muscle showed differences when comparing OA vs. OC only in the PD group (P=.04), showing a shorter response time in the OC condition. When comparing the spinal erector muscle, the PD group showed slower response times in the OA (P=.02) and OC (P=.04) conditions compared to the control group.

CONCLUSIONS

Muscle activation times show that people with PD respond slower in the trunk muscles, while activation times decrease at the distal level. In the early stages, the slower responses at the trunk level could explain the onset of instability postural in these patients.

Louis EK, Boeve BF, Savica R. Sleep Disorders in Early-Onset Parkinsonism: A Population-Based Study

BACKGROUND

Sleep disturbances are common in parkinsonian disorders; however, whether sleep disorders affect individuals with early-onset parkinsonism and whether they differ from individuals with typical-onset parkinsonism is unknown.

OBJECTIVE

To compare the prevalence and incidence of sleep disorders before and after parkinsonian motor symptom onset between individuals with early onset parkinsonism (age ≤50 at motor symptom onset) and typical-onset parkinsonism (age >50 at motor symptom onset).

METHODS

We used a population-based, 1991 to 2015 incident-cohort study of parkinsonism including 38 patients with early-onset and 1,001 patients with typical-onset parkinsonism. Presence or absence and type of sleep disorder as well as the relationship between motor and sleep symptoms were abstracted from the medical records. Rates of sleep disorders before and after onset of parkinsonism were compared with logistic regression and Cox proportional hazards models.

RESULTS

The prevalence of sleep disorders prior to the onset of parkinsonism in early vs. typical parkinsonism (24% vs. 16% p = 0.19) and incidence of sleep disorders after parkinsonism onset (5.85 cases per 100 person-years vs. 4.11 cases per 100 person-years; HR 1.15 95% CI: 0.74-1.77) were similar between the two groups. Early-onset parkinsonism had a higher risk for developing post-motor insomnia compared with typical-onset parkinsonism (HR 1.73, 95% CI: 1.02-2.93); the risk for developing all other sleep disorders considered was similar between groups.

CONCLUSION

Sleep disorders are common in individuals with early-onset parkinsonism and occur with similar frequency to those with typical-onset parkinsonism, except for insomnia, which was more frequent in the early-onset group.

40-Year Incidence of Early-Onset Parkinson's Disease in Southeast Minnesota

BACKGROUND

Parkinson's disease (PD) most commonly surfaces at middle age. An earlier onset is named early-onset Parkinson's disease (EOPD), but the exact definition is a matter of ongoing scientific debate.

OBJECTIVE

To investigate 40-year EOPD incidence trends in a population-based cohort of parkinsonism in Olmsted County, Minnesota.

METHODS

We used the Rochester Epidemiology Project (REP) to identify all incident EOPD cases in Olmsted County, 1976-2015. A movement-disorder specialist reviewed all cases to confirm the EOPD diagnosis. For EOPD definition, we used two age cut-offs: motor-symptom onset at or before 50 and 55 years.

RESULTS

EOPD incidence was 1.43/100,000 person-years for ≤55 and 0.55/100,000 for ≤50 years. Men had a higher incidence in both groups [1.84 vs. 1.03 (p = 0.04); and 0.70 vs. 0.40 (p = 0.24), respectively]. EOPD incidence of patients with motor-symptom onset before age 55 increased from 1.02/100.000 person-year 1976-1985, to 1.32/100.000 person-year 2006-2015. A similar trend was observed when ≤50 years cut-off was used (0.28/100,000 person-years 1976-1985, to 0.59/100,000 person-year 2006-2015). However, negative binomial regression found no significant change in incidence per 10 years (RR = 1.04 and 1.24 in the two groups). Incidence was consistently higher in men than women. Median time from EOPD-symptom onset to death was shorter in the EOPD ≤55 group (21.9 years) compared to the EOPD ≤50 group (25.6 years).

CONCLUSION

We observed an increased trend in the incidence of EOPD with both cut-off ages. Overall, incidence of EOPD was 1.43 (≤55) and 0.55 (≤50) cases per 100,000 person-years, higher in men.

Early-Onset Parkinson's Disease: Creating the Right Environment for a Genetic Disorder

Parkinson's disease (PD) by its common understanding is a late-onset sporadic movement disorder. However, there is a need to recognize not only the fact that PD pathogenesis expands beyond (or perhaps to) the brain but also that many early-onset patients develop motor signs before the age of 50 years. Indeed, studies have shown that it is likely the protein aggregation observed in the brains of patients with PD precedes the motor symptoms by perhaps a decade. Studies on early-onset forms of PD have shown it to be a heterogeneous disease with multiple genetic and environmental factors determining risk of different forms of disease. Genetic and neuropathological evidence suggests that there are α-synuclein centric forms (e.g., SNCA genomic triplication), and forms that are driven by a breakdown in mitochondrial function and specifically in the process of mitophagy and clearance of damaged mitochondria (e.g., PARKIN and PINK1 recessive loss-of-function mutations). Aligning genetic forms with recognized environmental influences will help better define patients, aid prognosis, and hopefully lead to more accurately targeted clinical trial design. Work is now needed to understand the cross-talk between these two pathomechanisms and determine a sense of independence, it is noted that autopsies studies for both have shown the presence or absence of α-synuclein aggregation. The integration of genetic and environmental data is critical to understand the etiology of early-onset forms of PD and determine how the different pathomechanisms crosstalk.

Case report: Early-onset Parkinson's disease with initial spastic paraparesis and hyperreflexia caused by compound heterozygous PRKN-gene exon 2 and 4 deletions

Pathogenic variants in the Parkin-gene (PRKN) are among the most common genetic causes of early onset Parkinson's disease (EOPD). Patients with EOPD can present with atypical clinical features and misdiagnosis is frequent. Here, we report a clinical phenotype with atypical signs and symptoms of a 35-year-old male patient with EOPD caused by a compound heterozygous PRKN-gene deletion of exons 2 and 4. After the initial diagnosis of stiff person syndrome, the patient was admitted to our department for a second opinion after 8 years of untreated disease progression. The patient presented with prominent spastic paraparesis pronounced on the right side and hyperreflexia as well as Parkinsonism with rigidity predominantly affecting the upper limbs, bradykinesia, and resting tremor. In the diagnostic assessment, magnetic evoked potentials to the anterior tibial muscles showed a low amplitude on the right side, compatible with pyramidal tract disturbance. However, an MRI of the head and the spine did not show any pathologies or atrophy. A [123I] FP-CIT SPECT scan revealed profoundly and left-pronounced reduced striatal uptake suggesting a neurodegenerative Parkinson's syndrome. Even though an acute levodopa challenge did not show marked improvement of symptoms, the chronic levodopa challenge with up to 450 mg/day significantly reduced the rigidity and bradykinesia. Surprisingly, spastic paraparesis and hyperreflexia diminished under dopaminergic treatment. Finally, genetic analysis by next-generation sequencing via copy number variant analysis (CNV) and multiplex ligation-dependent probe amplification (MLPA) confirmed compound heterozygous deletions of exons 2 and 4 in the PRKN-gene. As presented in this case, the awareness of atypical clinical symptoms of EOPD is essential to prevent misdiagnosis in young patients.

Clinical differences between early-onset and mid-and-late-onset Parkinson's disease: Data analysis of the Hellenic Biobank of Parkinson's disease

BACKGROUND

Age at onset is one of the most critical factors contributing to the clinical heterogeneity of Parkinson's disease (PD), and available evidence is rather conflicting.

OBJECTIVE

The aim of this study is to investigate the clinical differences between early-onset PD (EOPD) and mid-and-late-onset PD (MLOPD) in the Greek population, based on the existing data of the Hellenic Biobank of PD (HBPD).

METHODS

HBPD contains information of PD cases from two centers in Greece during 2006-2017. Patients with the A53T mutation in the SNCA gene or mutations in the GBA1 gene were excluded. Associations between clinical characteristics (motor and non-motor symptoms, side of onset, first symptom, motor complications) and MLOPD versus EOPD were explored with a single logistic regression model adjusting for gender, family history of PD, disease and dopaminergic therapy duration, disease severity (UPDRS III), levodopa equivalent daily dose, as well as each of the other clinical characteristics.

RESULTS

675 patients (129 EOPD, 546 MLOPD) were included. EOPD was more frequently associated with dystonia (OR 0.19, 95% CI 0.08-0.50, p < 0.01) and motor complications (0.23, 0.07-0.76, 0.02), compared to MLOPD. Bilateral onset (9.38, 1.05-84.04, 0.045) and autonomic dysfunction (2.31, 1.04-5.11, 0.04) were more frequently associated with MLOPD.

CONCLUSIONS

EOPD and MLOPD display distinct clinical profiles, regarding motor and non-motor symptoms, side of onset and motor complications in the Greek population. These differences may reflect diverse pathophysiological backgrounds, potentially attributed to genetic or age-related epigenetic influences.

WITHDRAWN: 40-Year incidence of early-onset Parkinson's disease (EOPD) in Southeast Minnesota

This article has been withdrawn: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been withdrawn at the request of the editor and publisher. The publisher regrets that an error occurred which led to the premature publication of this paper. This error bears no reflection on the article or its authors. The publisher apologizes to the authors and the readers for this unfortunate error.

Age Cutoff for Early-Onset Parkinson's Disease: Recommendations from the International Parkinson and Movement Disorder Society Task Force on Early Onset Parkinson's Disease

Background

Early-onset Parkinson's disease (EOPD)/young-onset Parkinson's disease (YOPD) is defined as Parkinson's disease (PD) with an age at onset (AAO) after age 21 years but before the usual AAO for PD. Consensus is lacking, and the reported maximal age for EOPD/YOPD has varied from 40 to 60 years, leading to a lack of uniformity in published studies and difficulty in harmonization of data. EOPD and YOPD have both been used in the literature, somewhat interchangeably.

Objective

To define the nomenclature and AAO cutoff for EOPD/YOPD.

Methods

An extensive review of the literature and task force meetings were conducted. Conclusions were reached by consensus.

Results

First, the literature has seen a shift from the use of YOPD toward EOPD. This seems motivated by an attempt to avoid age-related stigmatization of patients. Second, in defining EOPD, 56% of the countries use 50 or 51 years as the cutoff age. Third, the majority of international genetic studies in PD use an age cutoff of younger than 50 years to define EOPD. Fourth, many studies suggest that changes in the estrogen level can affect the predisposition to develop PD, making the average age at menopause of 50 years an important factor to consider when defining EOPD. Fifth, considering the differential impact of the AAO of PD on professional and social life, using 50 years as the upper cutoff for the definition of EOPD seems reasonable.

Conclusions

This task force recommends the use of EOPD rather than YOPD. It defines EOPD as PD with AAO after 21 years but before 50 years.

Real-World Prescription Patterns For Patients With Young-Onset Parkinson’s Disease in China: A Trend Analysis From 2014 to 2019

Introduction Pharmacotherapy is one of the main treatments for patients with young-onset Parkinson’s disease (YOPD). Although numerous studies on the treatment of YOPD have been published, the real-world prescription patterns of these populations remain unclear in China.

Methods A national comprehensive evaluation was performed to reveal the pharmacological treatment patterns in Chinese patients with Parkinson’s disease from 1 January 2014 to 31 December 2019, with patients aged 21–50 years classified as having YOPD for the subgroup analysis. Information on patients and drugs was extracted to analyse the demographic characteristics, prescription patterns, and levodopa equivalent daily dose (LED) during disease progression.

Results A total of 1,134 patients with YOPD were included, and the majority were aged 41–50 years. Prescription of L-DOPA/benserazide and pramipexole accounted for more than 30 and 20%, respectively, in each year from 2014 to 2019. There was no difference in prescription patterns in terms of age, sex and geographical areas. Half of the patients with YOPD were on monotherapy, but the proportion decreased from 2016. Correspondingly, the proportion of patients receiving polytherapy increased, especially those who were prescribed more than two anti-Parkinson’s disease drugs. During the disease course, LED showed high variability, which increased over time.

Conclusion L-DOPA/benserazide and pramipexole were the most frequently prescribed anti-PD drugs for patients with YOPD in China. There was a slight trend in the transition from monotherapy to polytherapy. LED increased with disease duration. Thus, we provided an overview of the prescription patterns for patients with YOPD in China.

Deep Brain Stimulation and Treatment Outcomes of Young- and Late-Onset (≤55 Years) Parkinson's Disease: A Population-Based Study

Background: No studies have reported the rate of motor complications (MC) and response to medical and surgical treatment in a population-based cohort of young-onset Parkinson's Disease (YOPD) patients and a cohort of sex-matched late-onset Parkinson's Disease (LOPD).

Objective: To assess the outcomes of dopaminergic treatment in YOPD and LOPD, explore treatment-induced MC, medical adjustment, and rate of deep brain stimulation (DBS).

Methods: We used the expanded Rochester Epidemiology Project (eREP) to investigate a population-based cohort of YOPD between 2010 and 2015 in 7 counties in Minnesota. Cases with onset ≤55 years of age were included as YOPD. An additional sex-matched cohort of LOPD (onset at ≥56 years of age) was included for comparison. All medical records were reviewed to confirm the diagnoses.

Results: In the seven counties 2010–15, there were 28 YOPD patients, which were matched with a LOPD cohort. Sixteen (57%) YOPD had MC, as compared to 9 (32%) LOPD. In YOPD, 9 had motor fluctuations (MF) and Levodopa-induced dyskinesia (LID) together, whereas 3 had LID only and 4 MF only. In LOPD, 3 had MF and LID, 3 MF only, and 3 LID only. Following medical treatment for MC, 6/16 YOPD (38%) and 3/9 (33%) LOPD had symptoms resolution. In YOPD, 11/16 (69%) were considered for DBS implantation, in LOPD they were 2/9 (22%), but only 7 (6 YOPD and 1 LOPD) underwent the procedure. YOPD had significantly higher rates in both DBS candidacy and DBS surgery (respectively, p = 0.03 and p = 0.04). Among DBS-YOPD, 5/6 (83%) had positive motor response to the surgery; the LOPD case had a poor response. We report the population-based incidence of both YOPD with motor complications and YOPD undergoing DBS, which were 1.17 and 0.44 cases per 100,000 person-years, respectively.

Conclusion: Fifty-seven percent of our YOPD patients and 32% of the LOPD had motor complications. Roughly half of both YOPD and LOPD were treatment resistant. YOPD had higher rates of DBS candidacy and surgery. Six YOPD and 1 LOPD underwent DBS implantation and most of them had a positive motor response after the surgery.

Comprehensive methylation profile of CSF cfDNA revealed pathogenesis and diagnostic markers for early-onset Parkinson's disease

Background: Early-onset Parkinson's disease (EOPD) is one uncommon Parkinson's disease subtype with characteristic clinicopathological features. The full epigenomic profile of EOPD is largely unknown. Methods: We performed the first study to investigate the EOPD full methylation profile of cerebrospinal fluid (CSF) cell-free DNA (cfDNA) from 26 EOPD patients and 10 control patients. Results: 2220 differentially methylated genes were identified in EOPD. Hypermethylation far outweighed hypomethylation in gene numbers. Clustering and enrichment analyses identified aberrant neuronal function and immune response. Weighted correlation network analysis demonstrated significant correlation between methylation signatures and clock drawing test (CDT), mini-mental state examination (MMSE), education, working status, alcohol drinking history and Hamilton anxiety scale (HAMA). Several key networking genes in EOPD aberrant methylation were also identified. Conclusions: The methylation profile and signatures of CSF cfDNA were revealed for the first time in EOPD. Aberrant methylation signatures were correlated with education, working status, alcohol drinking history, CDT, MMSE and HAMA.

A Practical Approach to Early-Onset Parkinsonism

Early-onset parkinsonism (EO parkinsonism), defined as subjects with disease onset before the age of 40 or 50 years, can be the main clinical presentation of a variety of conditions that are important to differentiate. Although rarer than classical late-onset Parkinson’s disease (PD) and not infrequently overlapping with forms of juvenile onset PD, a correct diagnosis of the specific cause of EO parkinsonism is critical for offering appropriate counseling to patients, for family and work planning, and to select the most appropriate symptomatic or etiopathogenic treatments. Clinical features, radiological and laboratory findings are crucial for guiding the differential diagnosis. Here we summarize the most important conditions associated with primary and secondary EO parkinsonism. We also proposed a practical approach based on the current literature and expert opinion to help movement disorders specialists and neurologists navigate this complex and challenging landscape.

Gene therapy strategies for rare monogenic disorders with nuclear or mitochondrial gene mutations

Rare monogenic disorders are a group of single-gene-mutated diseases that have a low incidence rate (less than 0.5‰) and eventually lead to patient disability and even death. Due to the relatively low number of people affected, these diseases typically fail to attract a great deal of commercial investment and research interest, and the affected patients thus have unmet medical needs. Advances in genomics biology, gene editing, and gene delivery can now offer potentially effective options for treating rare monogenic diseases. Herein, we review the application of gene therapy strategies (traditional gene therapy and gene editing) against various rare monogenic diseases with nuclear or mitochondrial gene mutations, including eye, central nervous system, pulmonary, systemic, and blood cell diseases. We summarize their pathologic features, address the barriers to gene delivery for these diseases, discuss available therapies in the clinic and in clinical trials, and sum up in-development gene delivery systems for various rare monogenic disorders. Finally, we elaborate the possible directions and outlook of gene therapy for rare monogenic disorders.