Sympathetic dysfunction as an early indicator of autonomic involvement in Parkinson's disease

PURPOSE

The specific characteristics of autonomic involvement in patients with early Parkinson's disease (PD) are unclear. This study aimed to evaluate the characteristics of autonomic dysfunction in drug-naïve patients with early-stage PD without orthostatic hypotension (OH) by analyzing Valsalva maneuver (VM) parameters.

METHODS

We retrospectively analyzed drug-naïve patients without orthostatic hypotension (n = 61) and controls (n = 20). The patients were subcategorized into early PD (n = 35) and mid-PD (n = 26) groups on the basis of the Hoehn and Yahr staging. VM parameters, including changes in systolic blood pressure at late phase 2 (∆SBPVM2), ∆HRVM3, Valsalva ratio (VR), pressure recovery time, adrenergic baroreflex sensitivity, and vagal baroreflex sensitivity, were assessed.

RESULTS

In the early PD group, ∆SBPVM2, a marker of sympathetic function, was significantly lower compared with that in controls (risk ratio = 0.95, P = 0.027). Receiver operating characteristic (ROC) curve analysis showed an optimal cut-off value of -10 mmHg for ∆SBPVM2 [P = 0.002, area under the curve (AUC): 0.737]. VR exhibited an inverse relationship with Unified Parkinson's Disease Rating Scale Part 3 scores in the multivariable regression analysis (VR: P = 0.038, β = -28.61), whereas age showed a positive relationship (age: P = 0.027, β = 0.35).

CONCLUSION

The ∆BPVM2 parameter of the VM may help detect autonomic nervous system involvement in early-PD without OH. Our results suggest that sympathetic dysfunction is an early manifestation of autonomic dysfunction in patients with PD.

Evaluating the validity and reliability of the Korean version of Scales for Outcomes in Parkinson's Disease-Cognition

Objective

The Scales for Outcomes in Parkinson's Disease-Cognition (SCOPA-Cog) was developed to screen for cognition in PD. In this study, we aimed to evaluate the validity and reliability of the Korean version of the SCOPA-cog.

Methods

We recruited 129 PD patients from 31 clinics with movement disorders in South Korea. The original version of the SCOPA-cognition was translated into Korean using the translation-retranslation method. The test-rest method with an intraclass correlation coefficient (ICC) and Cronbach's alpha coefficient were used to assess reliability. The Spearman's Rank correlation analysis with Montreal Cognitive Assessment-Korean version (MOCA-K) and 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 showed a significant correlation with the K-MMSE and MOCA-K scores (r = 0.546 and r = 0.683, respectively).

Conclusions

Our results demonstrate that K-SCOPA-Cog exhibits good reliability and validity.

Association Between Baseline Gait Parameters and Future Fall Risk in Patients With De Novo Parkinson's Disease: Forward Versus Backward Gait

BACKGROUND AND PURPOSE

Falls are not uncommon even in patients with early stages of Parkinson's disease (PD). The aims of this study were to determine the relationships between gait parameters and falls and identify crucial gait parameters for predicting future falls in patients with de novo PD.

METHODS

We prospectively recruited patients with de novo PD, and evaluated their baseline demographics, global cognitive function on the Montreal Cognitive Assessment test, and parkinsonian motor symptoms including their subtypes. Both forward gait (FG) and backward gait (BG) were measured using the GAITRite system. The history of falls in consecutive patients with de novo PD was examined along with 1 year of follow-up data.

RESULTS

Among the 76 patients with de novo PD finally included in the study, 16 (21.1%) were classified as fallers. Fallers had slower gait and shorter stride for FG and BG parameters than did non-fallers, while stride-time variability was greater in fallers but only for BG. Multivariable logistic regression analysis revealed that slow gait was an independent risk factor in BG.

CONCLUSIONS

Among the patients with de novo PD, gait speed and stride length were more impaired for both FG and BG in fallers than in non-fallers. It was particularly notable that slow BG was significantly associated with future fall risk, indicating that BG speed is a potential biomarker for predicting future falls in patients with early-stage PD.

Fasting glucose variability and risk of dementia in Parkinson's disease: a 9-year longitudinal follow-up study of a nationwide cohort

Background

Diabetes is associated with an increased risk of Parkinson's disease dementia (PDD); however, it is unknown whether this association is dependent on continuous hyperglycemia, hypoglycemic events, or glycemic variability. We aimed to investigate the relationship between visit-to-visit fasting glucose variability and PDD development in patients with Parkinson's disease (PD).

Methods

Using data from the Korean National Health Insurance Service, we examined 9,264 patients aged ≥40 years with de novo Parkinson's disease (PD) who underwent ≥3 health examinations and were followed up until December 2019. Glucose variability was measured using the coefficient of variation, variability independent of the mean, and average real variability. Fine and Gray competing regression analysis was performed to determine the effect of glucose variability on incident PDD.

Results

During the 9.5-year follow-up period, 1,757 of 9,264 (19.0%) patients developed PDD. Patients with a higher visit-to-visit glucose variability had a higher risk of future PDD. In the multivariable adjusted model, patients with PD in the highest quartile (subdistribution hazard ratio [SHR] = 1.50, 95% CI 1.19 to 1.88), quartile 3 (SHR = 1.29, 95% CI 1.02 to 1.62), and quartile 2 (SHR = 1.30, 95% CI 1.04 to 1.63) were independently associated with a higher risk of PDD than those in the lowest quartile.

Conclusion

We highlighted the effect of long-term glucose variability on the development of PDD in patients with PD. Furthermore, our findings suggest that preventive measures for constant glucose control may be necessary to prevent PDD.

Hair Loss: A Well-Known Yet Understudied Symptom in Parkinson's Disease Patients During Dopaminergic Therapy

OBJECTIVE

Hair loss has been reported to occur during dopaminergic therapy in patients with Parkinson's disease. The mechanism by which dopaminergic therapy induces hair loss is not well understood. Dopamine receptors are present in the hair follicle, where they regulate melanin production. However, the role of dopamine receptors in hair growth is still not well understood. This study aimed to evaluate the prevalence of hair loss and identify factors associated with complaints of hair loss in patients with Parkinson's disease.

METHODS

A cross-sectional design involving 495 Parkinson's disease patients was applied to evaluate hair loss status. Patients completed a questionnaire, and scalp/hair examinations were performed. Patients with underlying conditions that could affect hair loss and those prescribed medications known to increase the risk of hair loss were excluded. Finally, 291 patients (58.8%) were included for analysis.

RESULTS

Among the 495 patients, 138 (27.9%) reported hair loss. Interestingly, more than half of the patients who complained of hair loss (79 out of 138) did not utilize treatments such as hair products, massage, dietary modifications, or alopecia medications. Hair inspection by a single investigator revealed objective hair loss in 263 patients (53.1%). An analysis of factors associated with hair loss complaints showed that the intake of dopaminergic medications with a levodopa-equivalent daily dose > 448 mg was associated with complaints of hair loss.

CONCLUSION

Dopaminergic medication is associated with hair loss complaints in Parkinson's disease patients.

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.

Distinct effects of cholesterol profile components on amyloid and vascular burdens

BACKGROUND

Cholesterol plays important roles in β-amyloid (Aβ) metabolism and atherosclerosis. However, the relationships of plasma cholesterol levels with Aβ and cerebral small vessel disease (CSVD) burdens are not fully understood in Asians. Herein, we investigated the relationships between plasma cholesterol profile components and Aβ and CSVD burdens in a large, non-demented Korean cohort.

METHODS

We enrolled 1,175 non-demented participants (456 with unimpaired cognition [CU] and 719 with mild cognitive impairment [MCI]) aged ≥ 45 years who underwent Aβ PET at the Samsung Medical Center in Korea. We performed linear regression analyses with each cholesterol (low-density lipoprotein cholesterol [LDL-c], high-density lipoprotein cholesterol [HDL-c], and triglyceride) level as a predictor and each image marker (Aβ uptake on PET, white matter hyperintensity [WMH] volume, and hippocampal volume) as an outcome after controlling for potential confounders.

RESULTS

Increased LDL-c levels (β = 0.014 to 0.115, p = 0.013) were associated with greater Aβ uptake, independent of the APOE e4 allele genotype and lipid-lowering medication. Decreased HDL-c levels (β =  - 0.133 to - 0.006, p = 0.032) were predictive of higher WMH volumes. Increased LDL-c levels were also associated with decreased hippocampal volume (direct effect β =  - 0.053, p = 0.040), which was partially mediated by Aβ uptake (indirect effect β =  - 0.018, p = 0.006).

CONCLUSIONS

Our findings highlight that increased LDL-c and decreased HDL-c levels are important risk factors for Aβ and CSVD burdens, respectively. Furthermore, considering that plasma cholesterol profile components are potentially modified by diet, exercise, and pharmacological agents, our results provide evidence that regulating LDL-c and HDL-c levels is a potential strategy to prevent dementia.

Independent effect of Aβ burden on cognitive impairment in patients with small subcortical infarction

BACKGROUND

The effect of amyloid-β (Aβ) on cognitive impairment in patients with small subcortical infarction remains controversial, although a growing body of evidence shows a substantial overlap between Alzheimer's disease (AD) and subcortical ischemic vascular dementia, another form of cerebral small vessel disease (cSVD). Therefore, we investigated the relationships between Aβ positivity and the development of post-stroke cognitive impairment (PSCI) in patients with small subcortical infarction.

METHODS

We prospectively recruited 37 patients aged ≥ 50 years, with first-ever small subcortical infarction, who underwent amyloid positron emission tomography, 3 months after stroke at Korea University Guro Hospital. We also enrolled CU participants matched for age and sex with stroke patients for comparison of Aβ positivity. Patients were followed up at 3 and 12 months after the stroke to assess cognitive decline. Logistic and linear mixed-effect regression analyses were performed to identify the effect of Aβ positivity on PSCI development and long-term cognitive trajectories.

RESULTS

At 3 months after stroke, 12/37 (32.4%) patients developed PSCI, and 11/37 (29.7%) patients had Aβ deposition. Aβ positivity (odds ratio [OR] = 72.2, p = 0.024) was predictive of PSCI development regardless of cSVD burden. Aβ positivity (β = 0.846, p = 0.014) was also associated with poor cognitive trajectory, assessed by the Clinical Dementia Rating-Sum of Box, for 1 year after stroke.

CONCLUSIONS

Our findings highlight that Aβ positivity is an important predictor for PSCI development and cognitive decline over 1 year. Furthermore, our results provide evidence that anti-AD medications may be a strategy for preventing cognitive decline in patients with small subcortical infarctions.

Sex-specific relationship between non-alcoholic fatty liver disease and amyloid-β in cognitively unimpaired individuals

Background

Non-alcoholic fatty liver disease (NAFLD) is known to be associated with a high risk of clinically diagnosed Alzheimer's disease (AD). Additionally, the prevalence of NAFLD and AD is higher in elderly females than in males. However, a sex-specific association between NAFLD and amyloid-beta (Aβ) deposition remains unclear. Therefore, we investigated the sex-specific relationship between NAFLD and Aβ deposition in a large-sized cohort of cognitively unimpaired (CU) individuals.

Methods

We enrolled 673 (410 [60.9%] females and 263 [39.1%] males) CU individuals aged ≥45 years who underwent Aβ positron emission tomography (PET). The presence of NAFLD, assessed using the hepatic steatosis index, and the severity of NAFLD, assessed using the Fibrosis-4 index, were considered predictors. Aβ deposition on PET was considered as an outcome.

Results

Females had a higher frequency of NAFLD than males (48 and 23.2%, p < 0.001). Among females, the presence of NAFLD (β = 0.216, p < 0.001) was predictive of increased Aβ deposition, whereas among males, the presence of NAFLD (β = 0.191, p = 0.064) was not associated with Aβ deposition. Among females, the presence of NAFLD with low (β = 0.254, p = 0.039), intermediate (β = 0.201, p = 0.006), and high fibrosis (β = 0.257, p = 0.027) was predictive of increased Aβ deposition. Aβ deposition also increased as the severity of NAFLD increased in females (p for trend = 0.001).

Conclusion

We highlight the marked influence of NAFLD and its severity on the risk of Aβ deposition in relation to sex. Furthermore, our findings suggest that sex-specific strategies regarding the management of NAFLD are necessary for the prevention of Aβ deposition.

Ethnicity- and sex-specific genome wide association study on Parkinson's disease

Most previous genome-wide association studies (GWASs) on Parkinson's disease (PD) focus on the European population. There are several sex-specific clinical differences in PD, but little is known about its genetic background. We aimed to perform an ethnicity-specific and sex-specific GWAS on PD in the Korean population. A total of 1050 PD patients and 5000 controls were included. For primary analysis, we performed a GWAS using a logistic additive model adjusted for age and sex. The same statistical models were applied to sex-specific analyses. Genotyping was performed using a customized microarray chip optimized for the Korean population. Nine single nucleotide polymorphisms (SNPs) including four in the SNCA locus and three from the PARK16 locus were associated with PD in Koreans. The rs34778348 in the LRRK2 locus showed a strong association, though failed to pass cluster quality control. There were no notable genome-wide significant markers near the MAPT or GBA1 loci. In the female-only analysis, rs34778348 in LRRK2 and the four other SNPs in the SNCA showed a strong association with PD. In the male-only analysis, no SNP surpassed the genome-wide significance threshold under Bonferroni correction; however, the most significant signal was rs708726 in the PARK16 locus. This ethnicity- and sex-specific GWAS on PD implicate the pan-ethnic effect of SNCA, the universal but East-Asian inclined effect of PARK16, the East Asian-specific role of LRRK2 G2385R variants, and the possible disproportionate effect of SNCA and PARK16 between sexes for PD susceptibility. These findings suggest the different genetic contributions to sporadic PD in terms of ethnicity and sex.

Effect of Tablet-based Cognitive Intervention on Cognition in Patients With Mild Cognitive Impairment: A Pilot Study

Background and Purpose

Growing evidence has shown that cognitive interventions can mitigate cognitive decline in patients with mild cognitive impairment (MCI). However, most previous cognitive interventions have been group-based programs. Due to their intrinsic limitations, group-based programs are not widely used in clinical practice. Therefore, we have developed a tablet-based cognitive intervention program. This preliminary study investigated the feasibility and effects of a 12-week structured tablet-based program on cognitive function in patients with MCI.

Methods

We performed a single-arm study on 24 patients with MCI. The participants underwent a tablet-based cognitive intervention program 5 times a week over a 12-week period. The primary outcome was changes in cognitive function, measured using the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K). Outcomes were evaluated at baseline, within two weeks of the last program (post-intervention), and at the six-month follow-up session.

Results

The completion rate of the tablet-based program was 83.3% in patients with MCI. The program improved cognitive function based on the CERAD-K total score (p=0.026), which was maintained for at least three months (p=0.004). There was also an improvement in the depression scale score (p=0.002), which persisted for three months (p=0.027).

Conclusions

Our 12-week structured tablet-based program is feasible for patients with MCI. Furthermore, although further studies with a double-arm design are required, the program appears to be an effective strategy to prevent cognitive decline in patients with MCI.

Independent effect of cardiometabolic syndromes and depression on dementia in Parkinson's disease: A 12-year longitudinal follow-up study of a nationwide cohort

BACKGROUND

We aimed to investigate the incidence rate of Parkinson's disease dementia (PDD) according to age and disease duration by sex. Furthermore, we explored the effect of each cardiometabolic syndrome and depression on the incidence of PDD.

METHODS

Using data from the Korean National Health Insurance Service, 79,622 patients with de novo Parkinson's disease (PD) aged ≥40 years between January 2002 and December 2010 were followed to December 2019. We analyzed the incidence of PDD according to age at PD diagnosis and disease duration. To determine cardiometabolic syndromes and depression that affected PDD, we used Fine and Gray competing regression after controlling for age and sex.

RESULTS

During the 12.5-year follow-up period, the incidence of PDD increased with age at PD diagnosis (0.81-45.31 per 1000 person-years among those aged 40-44 and over 80 years, respectively) and longer disease duration (22.68 per 1000 person-years in 1-2 years to 34.16 per 1000 person-years in 15-16 years). Hypertension (subdistribution hazard ratio [SHR] = 1.11; 95% confidence interval [CI] 1.07-1.16), diabetes (SHR = 1.09; 95% CI 1.05-1.14), dyslipidemia (SHR = 1.15; 95% CI 1.11-1.20), and depression (SHR = 1.36; 95% CI 1.30-1.41) independently increased the risk for PDD.

CONCLUSIONS

Our findings provide insights into cardiometabolic syndromes as modifiable risk factors for incident PDD. Furthermore, our results will help in designing public health policies with respect to controlling cardiometabolic syndromes and depression to prevent incident PDD in patients with PD.

Different effects of cardiometabolic syndrome on brain age in relation to gender and ethnicity

BACKGROUND

A growing body of evidence shows differences in the prevalence of cardiometabolic syndrome (CMS) and dementia based on gender and ethnicity. However, there is a paucity of information about ethnic- and gender-specific CMS effects on brain age. We investigated the different effects of CMS on brain age by gender in Korean and British cognitively unimpaired (CU) populations. We also determined whether the gender-specific difference in the effects of CMS on brain age changes depending on ethnicity.

METHODS

These analyses used de-identified, cross-sectional data on CU populations from Korea and United Kingdom (UK) that underwent brain MRI. After propensity score matching to balance the age and gender between the Korean and UK populations, 5759 Korean individuals (3042 males and 2717 females) and 9903 individuals from the UK (4736 males and 5167 females) were included in this study. Brain age index (BAI), calculated by the difference between the predicted brain age by the algorithm and the chronological age, was considered as main outcome and presence of CMS, including type 2 diabetes mellitus (T2DM), hypertension, obesity, and underweight was considered as a predictor. Gender (males and females) and ethnicity (Korean and UK) were considered as effect modifiers.

RESULTS

The presence of T2DM and hypertension was associated with a higher BAI regardless of gender and ethnicity (p < 0.001), except for hypertension in Korean males (p = 0.309). Among Koreans, there were interaction effects of gender and the presence of T2DM (p for T2DM*gender = 0.035) and hypertension (p for hypertension*gender = 0.046) on BAI in Koreans, suggesting that T2DM and hypertension are each associated with a higher BAI in females than in males. In contrast, among individuals from the UK, there were no differences in the effects of T2DM (p for T2DM*gender = 0.098) and hypertension (p for hypertension*gender = 0.203) on BAI between males and females.

CONCLUSIONS

Our results highlight gender and ethnic differences as important factors in mediating the effects of CMS on brain age. Furthermore, these results suggest that ethnic- and gender-specific prevention strategies may be needed to protect against accelerated brain aging.

Incidence of Parkinson's disease and modifiable risk factors in Korean population: A longitudinal follow-up study of a nationwide cohort

Introduction

We aimed to investigate the incidence of Parkinson's disease (PD) by age and year for each sex as well as the modifiable risk factors for PD. Using data from the Korean National Health Insurance Service, 938,635 PD and dementia-free participants aged ≥40 years who underwent general health examinations were followed to December 2019.

Methods

We analyzed the PD incidence rates according to age, year and sex. To investigate the modifiable risk factors for PD, we used the Cox regression model. Additionally, we calculated the population-attributable fraction to measure the impact of the risk factors on PD.

Results

During follow-up, 9,924 of the 938,635 (1.1%) participants developed PD. The incidence of PD increased continuously from 2007 to 2018, reaching 1.34 per 1,000 person-years in 2018. The incidence of PD also increases with age, up to 80 y. Presence of hypertension (SHR = 1.09, 95% CI 1.05 to 1.14), diabetes (SHR = 1.24, 95% CI 1.17 to 1.31), dyslipidemia (SHR = 1.12, 95% CI 1.07 to 1.18), ischemic stroke (SHR = 1.26, 95% CI 1.17 to 1.36), hemorrhagic stroke (SHR = 1.26, 95% CI 1.08 to 1.47), ischemic heart disease (SHR = 1.09, 95% CI 1.02 to 1.17), depression (SHR = 1.61, 95% CI 1.53 to 1.69), osteoporosis (SHR = 1.24, 95% CI 1.18 to 1.30), and obesity (SHR = 1.06, 95% CI 1.01 to 1.10) were independently associated with a higher risk for PD.

Discussion

Our results highlight the effect of modifiable risk factors for PD in the Korean population, which will help establish health care policies to prevent the development of PD.

Validity and Reliability of the Korean-Translated Version of the International Cooperative Ataxia Rating Scale in Cerebellar Ataxia

OBJECTIVE

The International Cooperative Ataxia Rating Scale (ICARS) is a semiquantitative clinical scale for ataxia that is widely used in numerous countries. The purpose of this study was to investigate the validity and reliability of the Korean-translated version of the ICARS.

METHODS

Eighty-eight patients who presented with cerebellar ataxia were enrolled. We investigated the construct validity using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). We also investigated the internal consistency using Cronbach's α and intrarater and interrater reliability using intraclass correlation coefficients.

RESULTS

The Korean-translated ICARS showed satisfactory construct validity using EFA and CFA. It also revealed good interrater and intrarater reliability and showed acceptable internal consistency. However, subscale 4 for assessing oculomotor disorder showed moderate internal consistency.

CONCLUSION

This is the first report to investigate the validity and reliability of the Korean-translated ICARS. Our results showed excellent construct and convergent validity. The reliability is also acceptable.

Mild cognitive impairment is associated with poor gait performance in patients with Parkinson’s disease

Cognitive impairment may be commonly accompanied by gait disturbance in patients with Parkinson’s disease (PD). However, it is still controversial whether gait disturbance is associated with mild cognitive impairment (MCI) and which cognitive function has a more important effect on specific gait parameter. Our objective was to investigate the association of gait parameters with MCI and the correlation between performance on comprehensive neuropsychological tests and gait parameters in PD patients. We enrolled 257 patients with de novo PD (111 PD-normal cognition and 146 PD-MCI). All patients underwent comprehensive neuropsychological tests and gait evaluation using the GAITRite system. We used logistic regression analysis and partial correlation to identify the association between gait parameters and MCI and correlations between neuropsychological performance and gait parameters. Gait velocity (odds ratio [OR] = 0.98, 95% confidence interval [CI] = 0.97−0.99) and stride length (OR = 0.98; 95% CI = 0.97−0.99) were associated with MCI in patients with PD. Specifically, gait velocity, stride length, and double support ratio were only associated with attention and frontal-executive function performance in patients with PD. Our findings provide insight into the relationship between gait disturbance and MCI in patients with PD. Furthermore, the evaluation of gait disturbance is necessary for PD patients with cognitive impairment.

Gender-specific relationship between thigh muscle and fat mass and brain amyloid-β positivity

BACKGROUND

The relationship of specific body composition in the thighs and brain amyloid-beta (Aβ) deposition remained unclear, although there were growing evidence that higher muscle and fat mass in thighs had a protective effect against cardiometabolic syndromes. To determine whether muscle mass and fat mass in the thighs affected amyloid-beta (Aβ) positivity differently in relation to gender, we investigated the association of muscle mass and fat mass with Aβ positivity using positron emission tomography (PET) in individuals without dementia.

METHODS

We recruited 240 participants (134 [55.8%] males, 106 [44.2%] females) without dementia ≥45 years of age who underwent Aβ PET, bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DEXA) scans of the hip in the health promotion center at Samsung Medical Center in Seoul, Korea. Lower extremity skeletal muscle mass index (LASMI) was measured using BIA, and gluteofemoral fat percentage (GFFP) was estimated using DEXA scans of the hip. We investigated the associations of LASMI and GFFP with Aβ positivity using logistic regression analyses after controlling for age, APOE4 genotype, and cognitive stage.

RESULTS

Higher muscle mass in the thighs, measured as LASMI (odds ratio [OR]=0.27, 95% confidence interval [CI] 0.08 to 0.84, p=0.031) was associated with a lesser risk of Aβ positivity in only females. Higher fat mass in the thighs, measured as GFFP (OR=0.84, 95% CI 0.73 to 0.95, p=0.008) was associated with a lesser risk of Aβ positivity in only males. However, the association between LAMSI (p for interaction= 0.810), GFFP (p for interaction= 0.075) and Aβ positivity did not significantly differ by gender. Furthermore, LAMSI only negatively correlated with centiloid (CL) values in females (r=-0.205, p=0.037), and GFFP only negatively correlated with CL values only in males (r=-0.253, p=0.004).

CONCLUSIONS

Our findings highlight the importance of recognizing that gender differences exist with respect to the specific body composition to potentially protect against Aβ deposition. Therefore, our results may help in designing gender-specific strategies for controlling body composition to prevent Aβ deposition.

Cortical neuroanatomical changes related to specific language impairments in primary progressive aphasia

Objective

Language function test-specific neural substrates in Korean patients with primary progressive aphasia (PPA) might differ from those in other causes of dementia and English-speaking PPA patients. We investigated the correlation between language performance tests and cortical thickness to determine neural substrates in Korean patients with PPA.

Materials and methods

Ninety-six patients with PPA were recruited from the memory clinic. To acquire neural substrates, we performed linear regression using the scores of each language test as a predictor, cortical thickness as an outcome and age, sex, years of education, and intracranial volume as confounders.

Results

Poor performance in each language function test was associated with lower cortical thickness in specific cortical regions: (1) object naming and the bilateral anterior to mid-portion of the lateral temporal and basal temporal regions; (2) semantic generative naming and the bilateral anterior to mid-portion of the lateral temporal and basal temporal regions; (3) phonemic generative naming and the left prefrontal and inferior parietal regions; and (4) comprehension and the left posterior portion of the superior and middle temporal regions. In particular, the neural substrates of the semantic generative naming test in PPA patients, left anterior to mid-portion of the lateral and basal temporal regions, quite differed from those in patients with other causes of dementia.

Conclusion

Our findings provide a better understanding of the different pathomechanisms for language impairments among PPA patients from those with other causes of dementia.

Independent effect of body mass index variation on amyloid-β positivity

Objectives

The relationship of body mass index (BMI) changes and variability with amyloid-β (Aβ) deposition remained unclear, although there were growing evidence that BMI is associated with the risk of developing cognitive impairment or AD dementia. To determine whether BMI changes and BMI variability affected Aβ positivity, we investigated the association of BMI changes and BMI variability with Aβ positivity, as assessed by PET in a non-demented population.

Methods

We retrospectively recruited 1,035 non-demented participants ≥50 years of age who underwent Aβ PET and had at least three BMI measurements in the memory clinic at Samsung Medical Center. To investigate the association between BMI change and variability with Aβ deposition, we performed multivariable logistic regression. Further distinctive underlying features of BMI subgroups were examined by employing a cluster analysis model.

Results

Decreased (odds ratio [OR] = 1.68, 95% confidence interval [CI] 1.16–2.42) or increased BMI (OR = 1.60, 95% CI 1.11–2.32) was associated with a greater risk of Aβ positivity after controlling for age, sex, APOE e4 genotype, years of education, hypertension, diabetes, baseline BMI, and BMI variability. A greater BMI variability (OR = 1.73, 95% CI 1.07–2.80) was associated with a greater risk of Aβ positivity after controlling for age, sex, APOE e4 genotype, years of education, hypertension, diabetes, baseline BMI, and BMI change. We also identified BMI subgroups showing a greater risk of Aβ positivity.

Conclusion

Our findings suggest that participants with BMI change, especially those with greater BMI variability, are more vulnerable to Aβ deposition regardless of baseline BMI. Furthermore, our results may contribute to the design of strategies to prevent Aβ deposition with respect to weight control.

Movement Disorders Associated With Cerebral Artery Stenosis: A Nationwide Study

Background

Studies of secondary movement disorder (MD) caused by cerebrovascular diseases have primarily focused on post-stroke MD. However, MD can also result from cerebral artery stenosis (CAS) without clinical manifestations of stroke. In this study, we aimed to investigate the clinical characteristics of MD associated with CAS.

Materials and Methods

A nationwide multicenter retrospective analysis was performed based on the data from patients with CAS-associated MDs from 16 MD specialized clinics in South Korea, available between January 1999 and September 2019. CAS was defined as the >50% luminal stenosis of the major cerebral arteries. The association between MD and CAS was determined by MD specialists using pre-defined clinical criteria. The collected clinical information included baseline demographics, features of MD, characteristics of CAS, treatment, and MD outcomes. Statistical analyses were performed to identify factors associated with the MD outcomes.

Results

The data from a total of 81 patients with CAS-associated MD were analyzed. The mean age of MD onset was 60.5 ± 19.7 years. Chorea was the most common MD (57%), followed by tremor/limb-shaking, myoclonus, and dystonia. Atherosclerosis was the most common etiology of CAS (78%), with the remaining cases attributed to moyamoya disease (MMD). Relative to patients with atherosclerosis, those with MMD developed MD at a younger age (p < 0.001) and had a more chronic mode of onset (p = 0.001) and less acute ischemic lesion (p = 0.021). Eight patients who underwent surgical treatment for CAS showed positive outcomes. Patients with acute MD onset had a better outcome than those with subacute-to-chronic MD onset (p = 0.008).

Conclusions

This study highlights the spectrum of CAS-associated with MD across the country. A progressive, age-dependent functional neuronal modulation in the basal ganglia due to CAS may underlie this condition.

Independent effect of neurogenic orthostatic hypotension on mild cognitive impairment in Parkinson's disease

PURPOSE

Orthostatic hypotension (OH) is an associative or causative factor of cognitive impairment in Parkinson's disease (PD). However, the association between mild cognitive impairment (MCI) and neurogenic OH directly associated with the presence of alpha-synuclein in PD remains unclear. We aimed to evaluate the relationship between MCI and neurogenic OH in patients with de novo PD. We also investigated the patterns of neuropsychological performance according to neurogenic OH.

METHODS

A total of 456 patients with PD-normal cognition (PD-NC, n = 204) or PD-MCI (n = 252) were recruited from multiple centers in Korea. All patients underwent comprehensive neuropsychological tests and tilt-table tests to evaluate cognitive function and neurogenic OH. We used logistic regression analysis and multivariate analysis of covariance to determine the association between MCI and neurogenic OH and the pattern of neuropsychological performance according to neurogenic OH.

RESULTS

Neurogenic OH (odds ratio = 3.66, 95% confidence interval 2.06 to 6.47) was independently associated with MCI in patients with de novo PD, regardless of orthostatic symptoms, while nonneurogenic OH was not. Patients with PD with neurogenic OH exhibited worse performance in frontal-executive function and visual memory function than those without neurogenic OH.

CONCLUSION

Our findings provide insight into neurogenic OH as an important clinical factor with cognitive impairment in individuals with PD and vice versa. Therefore, the evaluation of cognitive function is necessary in PD patients with neurogenic OH.

Constipation is Associated With Mild Cognitive Impairment in Patients With de novo Parkinson's Disease

Objective

The association between gastrointestinal (GI) symptoms and cognitive profile in patients with Parkinson's disease (PD) at diagnosis remains unclear, although GI symptoms and cognitive impairment are highly prevalent in patients with PD. We investigated the relationship between constipation and cognitive status. We also aimed to identify the correlation between constipation and each neuropsychological dysfunction.

Methods

A total of 427 patients with de novo Parkinson's disease with normal cognition (PD-NC, n = 170) and Parkinson's disease with mild cognitive impairment (PD-MCI, n = 257) at Korea University Guro Hospital in Seoul, Korea were included. All patients underwent comprehensive neuropsychological tests and completed the Non-Motor Symptoms Scale (NMSS). The frequency and severity of constipation were assessed using the NMSS GI symptoms scale, we used logistic regression analysis and partial correlation analysis to determine the associations between constipation score, MCI, and each neuropsychological dysfunction.

Results

Frequent and severe constipation was associated with MCI in patients with PD at diagnosis regardless of disease severity. Specifically, constipation was related to poor performance in frontal-executive and visuospatial functions after controlling for age and sex.

Conclusion

Our findings may provide an understanding of constipation as a marker associated with cognitive impairment in individuals with PD. Therefore, the evaluation of cognitive function is warranted in PD patients with constipation, while further studies are necessary to investigate the detailed mechanism of our results.

Dance Intervention Using the Feldenkrais Method Improves Motor, and Non-Motor Symptoms and Gait in Parkinson's Disease: A 12-Month Study

Objective

The aim of this study was to assess the effects of dancing (using the Feldenkrais method) on motor and non-motor symptoms, quality of life (QoL), and objective parameters of gait at the time of intervention and at the end of the 1-year study period.

Methods

This was a single-arm study in which 12 subjects with Parkinson’s disease (PD) received dance intervention during a 6-month period. Objective motor scales, gait analysis, and questionnaires on non-motor symptoms were evaluated at baseline and at 3, 6, and 12 months.

Results

Dance intervention decreased motor scale (Unified Parkinson’s Disease Rating Scale and Tinetti scale) scores and improved gait disturbance (gait velocity and step length) without increasing levodopa equivalent dose. Furthermore, dancing decreased non-motor scale (Non-Motor Symptoms Scale and Montgomery-Asberg Depression Rating Scale) scores and improved QoL.

Conclusion

Our findings suggest that dance intervention can be a complementary management method for PD patients.

Independent effects of amyloid and vascular markers on long-term functional outcomes: An 8-year longitudinal study of subcortical vascular cognitive impairment

BACKGROUND AND PURPOSE

Subcortical vascular cognitive impairment (SVCI) is characterized by the presence of cerebral small vessel disease (CSVD) markers. Some SVCI patients also show Alzheimer's disease and cerebral amyloid angiopathy markers. However, the effects of these imaging markers on long-term clinical outcomes have not yet been established. The present study, therefore, aimed to determine how these imaging markers influence functional disability and/or mortality.

METHODS

We recruited 194 participants with SVCI from the memory clinic and followed them up. All participants underwent brain magnetic resonance imaging at baseline, and 177 (91.2%) participants underwent beta-amyloid (Aβ) positron emission tomography. We examined the occurrence of ischemic or hemorrhagic strokes. We also evaluated functional disability and mortality using the modified Rankin scale. To determine the effects of imaging markers on functional disability or mortality, we used Fine and Gray competing regression or Cox regression analysis.

RESULTS

During a 8.6-year follow-up period, 46 of 194 patients (23.7%) experienced a stroke, 110 patients (56.7%) developed functional disabilities and 75 (38.6%) died. Aβ positivity (subdistribution hazard ratio [SHR] = 2.73), greater white matter hyperintensity (WMH) volume (SHR = 3.11) and ≥3 microbleeds (SHR = 2.29) at baseline were independent predictors of functional disability regardless of the occurrence of stroke. Greater WMH volume (hazard ratio = 2.07) was an independent predictor of mortality.

CONCLUSIONS

Our findings suggest that diverse imaging markers may predict long-term functional disability and mortality in patients with SVCI, which in turn may provide clinicians with a more insightful understanding of the long-term outcomes of SVCI.

Clinical Characteristic in Primary Progressive Aphasia in Relation to Alzheimer's Disease Biomarkers

BACKGROUND

Primary progressive aphasia (PPA) is associated with amyloid-β (Aβ) pathology. However, clinical feature of PPA based on Aβ positivity remains unclear.

OBJECTIVE

We aimed to assess the prevalence of Aβ positivity in patients with PPA and compare the clinical characteristics of patients with Aβ-positive (A+) and Aβ-negative (A-) PPA. Further, we applied Aβ and tau classification system (AT system) in patients with PPA for whom additional information of in vivo tau biomarker was available.

METHODS

We recruited 110 patients with PPA (41 semantic [svPPA], 27 non-fluent [nfvPPA], 32 logopenic [lvPPA], and 10 unclassified [ucPPA]) who underwent Aβ-PET imaging at multi centers. The extent of language impairment and cortical atrophy were compared between the A+ and A-PPA subgroups using general linear models.

RESULTS

The prevalence of Aβ positivity was highest in patients with lvPPA (81.3%), followed by ucPPA (60.0%), nfvPPA (18.5%), and svPPA (9.8%). The A+ PPA subgroup manifested cortical atrophy mainly in the left superior temporal/inferior parietal regions and had lower repetition scores compared to the A-PPA subgroup. Further, we observed that more than 90% (13/14) of the patients with A+ PPA had tau deposition.

CONCLUSION

Our findings will help clinicians understand the patterns of language impairment and cortical atrophy in patients with PPA based on Aβ deposition. Considering that most of the A+ PPA patents are tau positive, understanding the influence of Alzheimer's disease biomarkers on PPA might provide an opportunity for these patients to participate in clinical trials aimed for treating atypical Alzheimer's disease.

Hippocampal volume is related to olfactory impairment in Parkinson's disease

BACKGROUND AND PURPOSE

Recent evidence has suggested that hyposmia in patients with Parkinson's disease (PD) may be due to impaired central processing. Furthermore, the hippocampus has been regarded as a critical structure linking olfactory impairment and cognitive impairment in PD patients. This study aimed to identify significant structural alterations of the hippocampus in PD patients with hyposmia, and to determine whether these structural changes are significantly associated with olfactory impairment severity.

METHODS

Eighteen idiopathic PD patients with hyposmia and 18 age- and sex-matched PD patients without hyposmia were enrolled. Hippocampal volume and its subfields were measured using FreeSurfer software and compared between hyposmic and normosmic PD patients. We also compared hippocampal substructures' volumes and correlated the hippocampal volumes with hyposmia severity.

RESULTS

PD patients with hyposmia had significantly smaller hippocampal volumes. Among the three components of the hippocampus, the hippocampal body showed a markedly lower volume, which correlated significantly with the cross-cultural smell identification test score that represents olfactory function status. Hippocampal subfield analysis showed that substructures (subiculum, molecular layer) that constitute the hippocampal body showed the most significant volume difference.

CONCLUSIONS

We suggest that atrophy of the bilateral hippocampus implies underlying problems in the central olfaction process in PD patients. In particular, the hippocampus might not only play a critical role in olfaction but could also be important for elucidating possible mechanisms of broad nonmotor symptoms in PD patients.

Correlating Beta Oscillations from Intraoperative Microelectrode and Postoperative Implanted Electrode in Patients Undergoing Subthalamic Nucleus Deep Brain Stimulation for Parkinson Disease; A Feasibility Study

OBJECTIVE

We sought to investigate the feasibility of intraoperative local field potential (LFP) recording from the microelectrode during deep brain stimulation surgery for patients with Parkinson disease.

METHODS

Sixteen subthalamic nucleus recordings from 10 Parkinson disease patients who underwent deep brain stimulation surgery were included in this study. Signals from microelectrodes were amplified and differently filtered to display real-time single-unit neuronal activity and LFP simultaneously during surgery. LFP recordings were also recorded postoperatively from the implanted macroelectrodes and, power spectral density and peak frequency of beta oscillation of LFP (beta LFP) between 2 conditions were compared.

RESULTS

Stable intraoperative beta LFP were observed in 68.75% (11 of 16) cases. There was no significant difference of peak frequency between intraoperative and postoperative beta-LFP but significant difference of mean percentage of beta LFP was noted between 2 conditions.

CONCLUSIONS

Despite low signal-to-noise ratio and susceptibility to noises from external sources, this study shows that intraoperative recording of beta LFP using microelectrode is feasible. And, given that no significant difference in peak frequency of beta LFP between intraoperative and postoperative LFP was found, we suggest that not only intraoperative beta LFP can be used as a reliable surrogate for postoperative beta LFP, but it can also provide us an information for estimating the location with maximal power of beta oscillation within the subthalamic nucleus.

The Four Square Step Test for Assessing Cognitively Demanding Dynamic Balance in Parkinson's Disease Patients

Objective

The Four Square Step Test (FSST) is a tool that assesses dynamic balance during obstacle step-over. To date, few studies have used the FSST to measure balance in patients with Parkinson’s disease (PD). This study aimed to verify that patients with PD, even at the de novo early stage, take more time to perform the FSST and identify which factors, cognitive status or cardinal motor symptoms, are related most to FSST scores.

Methods

Thirty-five newly diagnosed drug-naïve patients with PD and 17 controls completed the FSST. The Unified Parkinson’s Disease Rating Scale (UPDRS), Hoehn and Yahr (H&Y) stage, spatiotemporal gait parameters, and neuropsychological test battery were also assessed in the PD group.

Results

Mean FSST performance time was 8.20 ± 1.61 seconds in patients with PD, which was significantly more than the control group (7.13 ± 1.10 seconds, p = 0.018). UPDRS part III total score and H&Y stage were not significantly associated with FSST, but among the UPDRS subscores, only the postural instability/gait disturbance subscore showed a significant association. Regarding the association between FSST and cognition, the Trail Making Test-B and the Color Word Stroop Test showed strongly inverse correlations with FSST (rho = -0.598 and -0.590, respectively). With respect to gait parameters, double support time was significantly associated with FSST score (rho = 0.342, p = 0.044); however, other parameters, including velocity and step length, were not associated with the FSST.

Conclusion

The FSST can be used in the clinic to assess dynamic balance with cognitive demands even in the early stages of PD.

A novel variant of dehydrodolichol diphosphate synthase (DHDDS) mutation with adult-onset progressive myoclonus ataxia

We report a novel variant of DHDDS mutation in a patient with progressive adult-onset myoclonus ataxia. The mutation in our patient was different from previous reports of denovo mutations in DHDDS in 6 patients who showed tremor-like myoclonus and generalized epilepsy.

Cortical neuroanatomical changes related to specific neuropsychological deficits in subcortical vascular cognitive impairment

•

Poor performances in neuropsychological tests were associated with cortical atrophy.

•

Neural substrates in Aβ (−) SVCI differed from those in ADCI.

•

Neural substrate of episodic memory was frontal regions in Aβ (−) SVCI.

•

Neural substrates of three neuropsychological tests showed laterality.

Objective

Neuropsychological test-specific neural substrates in subcortical vascular cognitive impairment (SVCI) are expected to differ from those in Alzheimer’s disease-related cognitive impairment (ADCI) but the details are unclear. To determine neural substrates related to cerebral small vessel disease, we investigated the correlations between cognitive dysfunctions measured by standardized neuropsychological tests and cortical thickness in a large sample of participants with amyloid negative (Aβ (−)) SVCI.

Methods

One hundred ninety-eight participants with Aβ (−) SVCI were recruited from the memory clinic between November 2007 to August 2018. To acquire neural substrates, we performed linear regression using the scores of each neuropsychological test as a predictor, cortical thickness as an outcome, and age, sex, education years, intracranial volume and white matter hyperintensity (WMH) as confounders.

Results

Poor performances in each neuropsychological test were associated with cortical atrophy in certain brain regions regardless of WMH. Especially, not the medial temporal but the frontal and posterior cingulate regions with cortical atrophy were mainly associated with memory impairment. Poor performance in animal fluency was more likely to be associated with cortical atrophy in the left hemisphere, while poor performance in the visuospatial memory test was more likely to be associated with cortical atrophy in the right hemisphere.

Conclusions

Our findings suggested that cortical atrophy was an important factor of cognitive impairment in Aβ (−) SVCI regardless of WMH. Furthermore, our findings might give clinicians a better understanding of specific neural substrates of neuropsychological deficits in patients with SVCI.

Genomic Association Study for Cognitive Impairment in Parkinson's Disease

Background: Cognitive impairment is very common in Parkinson's disease (PD) and constitutes the most debilitating complication of this disease. However, to date, few studies have investigated a genome-wide association in the development of cognitive impairment of PD. We aimed to identify the genetic loci associated with cognitive impairment in patients with sporadic PD by ethnicity-specific genotyping.

Materials and methods: We recruited 1,070 patients with PD and performed a genome-wide association study using the Korean Chip, a microarray chip containing 827,400 single-nucleotide polymorphisms (SNPs) optimized for the Korean population. Multiple logistic regression models adjusting for age, sex, years of education, and disease duration were used to compare between patients with and without cognitive impairment, which was defined using the Mini-Mental Status Examination (MMSE) score (MMSE score ≥ 26 vs. < 26) or the Montreal Cognitive Assessment (MoCA) score (MoCA score ≥24 vs. < 24).

Results:RYR2 SNP rs10495397 was most significantly associated with cognitive impairment based on the MMSE scores (OR = 3.21; 95% CI = 1.96–5.25, P = 3.36 × 10⁻⁶) and CASC17 showed the strongest association with cognitive impairment based on the MoCA scores. However, none of the SNPs were statistically significant after Bonferroni correction.

Conclusion:RYR2 may play a role in cognitive impairment in PD by the pathogenic mechanism of neuroinflammation. However, more studies are needed to replicate and validate the results of our functional study.

Regional Cerebral Cortical Atrophy is Related to Urinary Tract Symptoms in Parkinson's Disease

BACKGROUND AND PURPOSE

Lower urinary tract symptoms (LUTS) are the most common nonmotor symptoms usually occurring mid-stage of Parkinson's disease (PD); however, its underlying mechanisms are unknown. We aimed to assess whether corticometry or volumetry can identify a pattern of cerebral cortical changes in PD patients with LUTS.

METHODS

We recruited 85 idiopathic PD patients and performed corticometry and volumetry on various cortical regions using each patient's magnetic resonance imaging. To identify a correlation between the cortical thickness/volume and nonmotor symptoms scale domain 7 scores, which represent the severity of LUTS, we performed general linear model and region of interest analyses.

RESULTS

Significant regional thinning of the left precuneus, left temporal pole, left precentral, right precuneus, and right pars opercularis was correlated with nonmotor symptoms scale domain 7 scores. We also found that cortical volumes of left precuneus and left frontal pole were inversely correlated with the severity of urinary symptoms.

CONCLUSIONS

This study showed that the thicknesses and volumes of several cortical regions were significantly correlated with the severity of LUTS in PD patients. The findings of regional atrophy and thinning of specific cortical regions in this study provide additional evidence that multiple cortical regions, especially the precuneus cortex, not only may be involved in urinary dysfunctions of PD patients but also may help to elucidate the exact underlying mechanisms for LUTS in PD patients.

Double-Blind, Randomized, Placebo-Controlled Trial of DA-9701 in Parkinson's Disease: PASS-GI Study

Objectives

This study aimed to assess the efficacy of DA‐9701 on gastrointestinal symptom‐related quality of life in patients with Parkinson's disease on stable dopaminergic medications.

Methods

This multicenter, double‐blind, placebo‐controlled, phase 4 trial included a total of 144 patients with Parkinson's disease with gastrointestinal dysfunctions based on predefined criteria. Participants were randomized to take either DA‐9701 or placebo for 4 weeks, and then both groups were administered DA‐9701 for an additional 8 weeks while antiparkinsonian medications were unchanged. The primary outcome measure was gastrointestinal symptoms and related quality‐of‐life changes assessed on the Korean Nepean dyspepsia index after 4 and 12 weeks of therapy. We also evaluated the impact of DA‐9701 therapy on parkinsonian motor symptoms at each time point.

Results

The gastrointestinal symptom‐related quality‐of‐life score significantly improved in the DA‐9701‐treated group compared with the placebo‐treated group after 4weeks (adjusted P = 0.012 by linear mixed effect model analysis). The overall gastrointestinal symptom and dyspepsia sum scores improved at 12 weeks after intervention in the DA‐9701‐first treated group (adjusted P = 0.002 and 0.014, respectively) and also in the placebo‐first treated group (adjusted P = 0.019 and 0.039) compared with the baseline. Parkinsonian motor severity was not significantly affected by DA‐9701 treatment in both groups at 4 and 12 weeks after intervention. There were no drug‐related serious adverse events throughout the trial.

Conclusions

DA‐9701 therapy improved gastrointestinal symptom‐related quality of life, and 12 weeks of daily administration can relieve the overall severity of gastrointestinal symptoms in patients with Parkinson's disease without affecting motor symptoms. (Clinical trial identifier: NCT02775591.) © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Genomic Analysis Identifies New Loci Associated With Motor Complications in Parkinson's Disease

Background: Parkinson's disease (PD) is a common neurodegenerative disorder, characterized by a clinical symptomatology involving both motor and non-motor symptoms. Motor complications associated with long-term dopaminergic treatment include motor fluctuations and levodopa-induced dyskinesia (LID), which may have a major impact on the quality of life. The clinical features and onset time of motor complications in the disease course are heterogeneous, and the etiology remains unknown. Objective: We aimed to identify genomic variants associated with the development of motor fluctuations and LID at 5 years after the onset of PD. Methods: Genomic data were obtained using Affymetrix Axiom KORV1.1 array, including an imputation genome-wide association study (GWAS) grid and other GWAS loci; functional variants of the non-synonymous exome; pharmacogenetic variants; variants in genes involved in absorption, distribution, metabolism, and excretion of drugs; and expression quantitative trait loci in 741 patients with PD. Results: FAM129B single-nucleotide polymorphism (SNP) rs10760490 was nominally associated with the occurrence of motor fluctuations at 5 years after the onset of PD [odds ratio (OR) = 2.9, 95% confidence interval (CI) = 1.8-4.8, P = 6.5 × 10^-6]. GALNT14 SNP rs144125291 was significantly associated with the occurrence of LID (OR = 5.5, 95% CI = 2.9-10.3, P = 7.88 × 10^-9) and was still significant after Bonferroni correction. Several other genetic variants were associated with the occurrence of motor fluctuations or LID, but the associations were not significant after Bonferroni correction. Conclusion: This study identified new loci associated with the occurrence of motor fluctuations and LID at 5 years after the onset of PD. However, further studies are needed to confirm our findings.

Neuropsychiatric Traits Associated with Refractory Impulse Control Disorder in Parkinson's Disease

INTRODUCTION

Impulse control disorder (ICD) in Parkinson's disease (PD) is a critical nonmotor symptom with personality or neuropsychiatric traits contributing to ICD.

OBJECTIVE

This study aimed to identify predictive traits for persistent or paradoxical aggravation of ICD after dopamine agonist substitution therapy for ICD in PD.

METHODS

We conducted a case-control study using a database of a multicenter intervention trial for ICD in PD. The poor-outcome group was defined by showing paradoxical increases in ICD behaviors after the substitution of dopamine agonists with levodopa. We analyzed the pre-intervention personality traits associated with the poor outcome and also evaluated the risk traits for refractory ICD using a receiver-operating characteristic (ROC) curve analysis.

RESULTS

The poor-outcome group showed higher levels of anger expression (p =0.007) and obsessive-compulsive traits (p =0.009) compared with the good-outcome group at the pre-intervention state. In the ROC curve analysis, the Obsessive-Compulsive Inventory showed the highest area under the curve with 80.0% sensitivity and 74.3% specificity in discriminating against the poor-outcome group.

CONCLUSIONS

Our results suggest that assessment of obsessive compulsiveness may be useful for predicting the refractoriness of ICD behaviors in planning an interventional treatment for ICD in PD.

Augmented decision-making for acral lentiginous melanoma detection using deep convolutional neural networks

BACKGROUND

Several studies have achieved high-level performance of melanoma detection using convolutional neural networks (CNNs). However, few have described the extent to which the implementation of CNNs improves the diagnostic performance of the physicians.

OBJECTIVE

This study is aimed at developing a CNN for detecting acral lentiginous melanoma (ALM) and investigating whether its implementation can improve the initial decision for ALM detection made by the physicians.

METHODS

A CNN was trained using 1072 dermoscopic images of acral benign nevi, ALM and intermediate tumours. To investigate whether the implementation of CNN can improve the initial decision for ALM detection, 60 physicians completed a three-stage survey. In Stage I, they were asked for their decisions solely on the basis of dermoscopic images provided to them. In Stage II, they were also provided with clinical information. In Stage III, they were provided with the additional diagnosis and probability predicted by the CNN.

RESULTS

The accuracy of ALM detection in the participants was 74.7% (95% confidence interval [CI], 72.6-76.8%) in Stage I and 79.0% (95% CI, 76.7-81.2%) in Stage II. In Stage III, it was 86.9% (95% CI, 85.3-88.4%), which exceeds the accuracy delivered in Stage I by 12.2%p (95% CI, 10.1-14.3%p) and Stage II by 7.9%p (95% CI, 6.0-9.9%p). Moreover, the concordance between the participants considerably increased (Fleiss-κ of 0.436 [95% CI, 0.437-0.573] in Stage I, 0.506 [95% CI, 0.621-0.749] in Stage II and 0.684 [95% CI, 0.621-0.749] in Stage III).

CONCLUSIONS

Augmented decision-making improved the performance of and concordance between the clinical decisions of a diverse group of experts. This study demonstrates the potential use of CNNs as an adjoining, decision-supporting system for physicians' decisions.

Influences of elbow, shoulder, trunk motion and temporospatial parameters on arm swing asymmetry of Parkinson's disease during walking

Arm swing asymmetry is commonly observed in early Parkinson's disease (PD) and has been found to be useful for early diagnosis. However, there are uncertainties about the nature of its relationships with gait parameters, especially shoulder and elbow motions. Therefore, this study explored how these relationships are different between PD and controls. Forty one early PD and 23 controls were included. Participants walked at self-selected speed for 3D motion analysis. Arm swing at the wrist (AS), temporospatial parameters and kinematics in elbow, shoulder and trunk were obtained. Amplitudes and asymmetries of these variables were compared between PD and control groups. PD group showed increased AS asymmetry, compared to controls. Multiple hierarchical regression analysis on AS asymmetry was conducted in order to investigate how PD influences on the relationship between AS asymmetry and other variables. In pooled data (PD and control group), asymmetries in elbow and shoulder range of motion (RoM) were significant predictors for AS asymmetry but walking speed and asymmetries in temporospatial parameters were not significant. Group effect (PD effect) was significantly mediated by only elbow RoM asymmetry. Interaction between group and elbow RoM asymmetry was statistically significant, indicating that group was an effect modifier for elbow RoM asymmetry effect on AS asymmetry. Conclusively, arm swing asymmetry measured at the wrist represents the involvement of PD effect on the unilateral and distal upper limb in early stage. These findings are helpful for future researches related to clinical applications and mechanisms of arm swing asymmetry in PD.

Midbrain atrophy in patients with presymptomatic progressive supranuclear palsy-Richardson's syndrome

INTRODUCTION

In the present study, midbrain atrophy and the pons-to-midbrain area ratio (P/M ratio) were investigated as diagnostic markers for presymptomatic progressive supranuclear palsy-Richardson's syndrome (Pre-PSP-RS).

METHODS

The present study included 27 patients with probable PSP-RS who underwent brain MRI at least twice before and after the development of clinical symptoms, age- and sex-matched participants with Parkinson's disease (PD, n = 27), and healthy controls (n = 27). The midbrain area, pons area, and P/M ratio of the Pre-PSP-RS, PD, and control subjects were measured using midsagittal images from brain MRI, and the parameters were compared among the groups.

RESULTS

The midbrain area decreased and the P/M ratio increased significantly in the Pre-PSP-RS patients compared with both the PD and control subjects (midbrain, Pre-PSP-RS vs. PD = 1.01 cm²vs. 1.29 cm², p < 0.001, Pre-PSP-RS vs. controls = 1.01 cm²vs. 1.29 cm², p < 0.001; P/M ratio, Pre-PSP-RS vs. PD = 5.27 vs. 4.03, p < 0.001, Pre-PSP-RS vs. controls = 5.27 cm²vs. 4.06 cm², p < 0.001). The P/M ratio had high sensitivity (vs. PD, 96.3%, vs. control, 88.9%) and specificity (vs. PD, 81.5%, vs. control, 96.3%) in differentiating Pre-PSP-RS patients from PD and control subjects.

CONCLUSION

Midbrain atrophy precedes the clinical symptoms of PSP-RS and could be a useful diagnostic imaging biomarker for Pre-PSP-RS. Furthermore, this information could play an important role in the development of future treatment strategies.

Ultrasonography and electrophysiological study of median nerve in patients with essential tremor

Essential tremor (ET) is a common movement disorder characterized by postural or kinetic tremor. We aimed to evaluate median nerve enlargement in patients with ET using ultrasonography (USG). Thirty-eight hands from 19 patients with ET and 24 hands from 13 controls underwent nerve conduction studies (NCS) and USG at the wrist. Tremor severity was measured using the Fahn-Tolosa-Marin Tremor Rating Scale (FTM-TRS). The median nerve cross sectional area (mCSA) in USG and NCS parameters were compared using ANCOVA. We evaluated the correlation between mCSA and NCS parameters or FTM-TRS scores using linear regression analysis. mCSA was significantly larger (p<0.001) and NCS parameters were different in two groups. Also, mCSA was negatively correlated with part B and C scores of FTM-TRS (p<0.001 and p = 0.039, respectively). In conclusion, median nerve enlargement with the changes of NCS parameters was observed and correlated with the severity of tremor in patients with ET.

Behavioural and trait changes in parkinsonian patients with impulse control disorder after switching from dopamine agonist to levodopa therapy: results of REIN-PD trial

OBJECTIVE

In this multicentre open-label trial, we compared behavioural and neuropsychiatric symptoms in Parkinson's disease (PD) patients with impulse control disorders (ICD) treated with dopamine agonists before and 12 weeks after substituting dopamine agonists with an equivalent dose of levodopa/carbidopa slow-release formulation.

METHODS

Baseline characteristics of 50 PD patients with ICD were compared with those of 60 medicated and 40 drug-naive PD control groups. Neuropsychiatric trait changes in the PD-ICD group were investigated 12 weeks after the intervention. ICD behaviours were assessed via modified Minnesota Impulsive Disorders Interview (mMIDI), whereas parkinsonian severity and neuropsychiatric characters were systematically assessed with the Unified PD Rating Scale (UPDRS) and a predefined neuropsychological assessment battery.

RESULTS

At baseline, ICD patients showed higher scores in the Neuropsychiatric Inventory and anxiety, anger and obsessive-compulsive traits compared with both PD control groups. In contrast, the three PD groups showed indifference in the impulsivity scales. At 12 weeks post intervention, ICD behaviours significantly improved (p<0.001, Δ modified MIDI score=‒5.27 ± 5.75) along with the UPDRS II daily activity scores (p=0.02, Δ=‒2.07 ± 4.53). Behavioural disinhibition tended to improve (p=0.06), although no significant changes were observed in the Neuropsychiatric Inventory and personality trait scores. Dopamine agonist withdrawal syndrome developed in 5.3% of the PD-ICD group.

CONCLUSIONS

This study provides class IV evidence suggesting that switching from dopamine agonists to levodopa/carbidopa slow-release formulations alleviated ICD behaviours in PD patients leading to improvement in daily activities whereas neuropsychiatric traits associated with ICD persisted after the 12-week therapy.

TRIAL REGISTRATION NUMBER

NCT01683253.

Clinical Characteristics of Involuntary Movement in Hospitalized Patients

OBJECTIVE

Neurological symptoms in hospitalized patients are not rare, and neurological consultation for movement disorders is especially important in evaluating or managing those with various movement disorders. Therefore, we investigated a clinical pattern of in-hospital consultations for various movement disorders in a tertiary care university hospital.

METHODS

Over two years, a total of 202 patients (70.7 ± 11.8 years of age) presenting with movement disorders referred to movement disorder specialists were investigated.

RESULTS

The main symptoms referred by nonneurologists were tremor (56.9%), parkinsonism (16.8%), and gait disturbance (8.9%). The most frequent diagnostic category was toxic/metabolic-caused movement disorder (T/MCMD) (35%) with regard to medications, followed by Parkinson's disease (PD) (16%). Regarding the mode of onset, T/MCMD was the leading cause for acute (68%) and subacute onset (46%), while PD was the leading disorder (31%) for chronic onset.

CONCLUSION

The current study showed a characteristic pattern of inpatients presenting with movement disorders. Furthermore, our findings highlighted the clinical significance of drug use or metabolic problems for treating this patient population.

Validity and Reliability Study of the Korean Tinetti Mobility Test for Parkinson's Disease

Objective

Postural instability and gait disturbance are the cardinal symptoms associated with falling among patients with Parkinson’s disease (PD). The Tinetti mobility test (TMT) is a well-established measurement tool used to predict falls among elderly people. However, the TMT has not been established or widely used among PD patients in Korea. The purpose of this study was to evaluate the reliability and validity of the Korean version of the TMT for PD patients.

Methods

Twenty-four patients diagnosed with PD were enrolled in this study. For the interrater reliability test, thirteen clinicians scored the TMT after watching a video clip. We also used the test-retest method to determine intrarater reliability. For concurrent validation, the unified Parkinson’s disease rating scale, Hoehn and Yahr staging, Berg Balance Scale, Timed-Up and Go test, 10-m walk test, and gait analysis by three-dimensional motion capture were also used. We analyzed receiver operating characteristic curve to predict falling.

Results

The interrater reliability and intrarater reliability of the Korean Tinetti balance scale were 0.97 and 0.98, respectively. The interrater reliability and intra-rater reliability of the Korean Tinetti gait scale were 0.94 and 0.96, respectively. The Korean TMT scores were significantly correlated with the other clinical scales and three-dimensional motion capture. The cutoff values for predicting falling were 14 points (balance subscale) and 10 points (gait subscale).

Conclusion

We found that the Korean version of the TMT showed excellent validity and reliability for gait and balance and had high sensitivity and specificity for predicting falls among patients with PD.

Recuperation of slow walking in de novo Parkinson's disease is more closely associated with increased cadence, rather than with expanded stride length

INTRODUCTION

Gait characteristics in the early stages of Parkinson's disease (PD) have been less investigated so far. Moreover, the levodopa effect on gait in early PD remains to be further elucidated. We prospectively designed the study to examine gait dynamics and effect of dopaminergic treatment in patients with de novo PD.

METHODS

Spatiotemporal parameters were measured in healthy controls and drug naïve patients with PD, using computerized analysis with GAITRite system during usual gait. In PD group, motor symptoms and gait parameters were examined in both drug naive and levodopa 100mg trial conditions.

RESULTS

Twenty four de novo PD patients and 27 healthy controls (matched for age, sex, and height) were selected for the study. Compared with the controls, patients with de novo PD showed the decrease in stride length, in both Med-OFF and Med-ON conditions. Notably, drug naïve patients with PD demonstrated slow walking velocity, whereas those with levodopa administration exhibited the increase of cadence by shortening stride time, which resulted in the improvement of gait speed. In addition, the stride length (gait hypokinesia) correlated with postural instability and gait difficulty subscore, but not with tremor, rigidity, bradykinesia, or total motor score.

CONCLUSION

As a compensatory mechanism of slow walking, we found that the increment in cadence (frequency) is more important than the increment in stride length (amplitude) in gait dynamics in de novo PD. Additionally, the results may indicate that gait hypokinesia in PD could be regarded as one of axial symptoms.

Sleepiness and Depression in Parkinson's Disease Patients Treated with Ropinirole and Levodopa

Objective

We aimed to investigate the effect of ropinirole on excessive daytime sleepiness (EDS) and depression in Parkinson’s disease (PD) with a large population.

Methods

We conducted a cross-sectional observational study at nine hospitals in Korea between April 24, 2013, and April 22, 2015. We analyzed the demographic and clinical features, other medical history, history of antiparkinsonian medication within 6 months, Hoehn and Yahr stage (HY stage), Unified Parkinson’s Disease Rating Scale (UPDRS) part II and III, Epworth Sleepiness Scale (ESS), and 30-item Geriatric Depression Scale (GDS-30).

Results

Four-hundred-thirteen patients with PD (mean age: 65.2 ± 9.0 years; men: 227 patients) were analyzed. Multivariate logistic regression analysis showed that age at examination, UPDRS II, and GDS-30 were independent risk factors for EDS and that sex, UPDRS II, and ESS were independent risk factors for depression.

Conclusion

Our large group study did not find any significant associations of ropinirole with EDS and depression in Korean PD patients.

Patients and Their Caregivers' Burdens for Parkinson's Disease in Korea

Objective

Many patients with Parkinson’s disease (PD) suffer from motor and non-motor symptoms. According to these variable symptoms of PD, patients or caregivers have a poorer quality of life than patients with other neurodegenerative diseases. Since the difficulties are varied for all patients, prioritizing their difficulties differs among all cases. The goal of this study was to investigate the burdens of PD among the caregivers as well as patients and to identify areas requiring aid from the government.

Methods

We surveyed the awareness and perceptions of PD in patients and caregivers of PD by a face-to-face questionnaire. The questionnaire was divided into three sections: symptoms of PD (part A), desire for policies (part B), and difficulties faced by their caregivers (part C). Part A comprised 8 questions, Part B had 2 questions, and Part C had 3 questions.

Results

In total, 853 subjects (702 patients and 151 caregivers) were enrolled in this study. The major difficulties experienced by PD patients were physical (67%), psychiatric (60%) and socio-economic (52%). Assessing the physical difficulties, more than half the patients experienced severe difficulties (29% very severe, 39% severe). Psychiatric difficulties were assessed as severe (35%) and very severe (21%) among the patients. Severe difficulties were also experienced socio-economically, at 52% in patients and 49% in caregivers, especially among patients in their fifties (58%) and those with their spouse (65%) as caregivers. The topmost need was the introduction of new technology for treatment of PD (62%), followed by relief of costs for treatment (38%) and a family support system (31%). The majority (91%) of the patients were diagnosed with PD within two years after onset of symptoms.

Conclusion

We know that the difficulties of PD and the needs for government assistance are different between patients and caregivers. These results emphasize that perceiving the difficulties and needs of patients and caregivers early can help to prevent and ameliorate the burden of disease.

Quantitative Gait Analysis in Patients with Huntington's Disease

Objective

Gait disturbance is the main factor contributing to a negative impact on quality of life in patients with Huntington’s disease (HD). Understanding gait features in patients with HD is essential for planning a successful gait strategy. The aim of this study was to investigate temporospatial gait parameters in patients with HD compared with healthy controls.

Methods

We investigated 7 patients with HD. Diagnosis was confirmed by genetic analysis, and patients were evaluated with the Unified Huntington’s Disease Rating Scale (UHDRS). Gait features were assessed with a gait analyzer. We compared the results of patients with HD to those of 7 age- and sex-matched normal controls.

Results

Step length and stride length were decreased and base of support was increased in the HD group compared to the control group. In addition, coefficients of variability for step and stride length were increased in the HD group. The HD group showed slower walking velocity, an increased stance/swing phase in the gait cycle and a decreased proportion of single support time compared to the control group. Cadence did not differ significantly between groups. Among the UHDRS subscores, total motor score and total behavior score were positively correlated with step length, and total behavior score was positively correlated with walking velocity in patients with HD.

Conclusion

Increased variability in step and stride length, slower walking velocity, increased stance phase, and decreased swing phase and single support time with preserved cadence suggest that HD gait patterns are slow, ataxic and ineffective. This study suggests that quantitative gait analysis is needed to assess gait problems in HD.