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.

Erratum to: The KMDS-NATION Study: Korean Movement Disorders Society Multicenter Assessment of Non-Motor Symptoms and Quality of Life in Parkinson's Disease NATION Study Group.

This corrects the article on p. 393 in vol. 12, PMID: 27819413.

The KMDS-NATION Study: Korean Movement Disorders Society Multicenter Assessment of Non-Motor Symptoms and Quality of Life in Parkinson's Disease NATION Study Group.

BACKGROUND AND PURPOSE: Nonmotor symptoms (NMS) in Parkinson's disease (PD) have multisystem origins with heterogeneous manifestations that develop throughout the course of PD. NMS are increasingly recognized as having a significant impact on the health-related quality of life (HrQoL). We aimed to determine the NMS presentation according to PD status, and the associations of NMS with other clinical variables and the HrQoL of Korean PD patients. METHODS: We surveyed patients in 37 movement-disorders clinics throughout Korea. In total, 323 PD patients were recruited for assessment of disease severity and duration, NMS, HrQoL, and other clinical variables including demographics, cognition, sleep scale, fatigability, and symptoms. RESULTS: In total, 98.1% of enrolled PD subjects suffered from various kinds of NMS. The prevalence of NMS and scores in each NMS domain were significantly higher in the PD group, and the NMS worsened as the disease progressed. Among clinical variables, disease duration and depressive mood showed significant correlations with all NMS domains (p<0.001). NMS status impacted HrQoL in PD (rS=0.329, p<0.01), and the association patterns differed with the disease stage. CONCLUSIONS: The results of our survey suggest that NMS in PD are not simply isolated symptoms of degenerative disease, but rather exert significant influences throughout the disease course. A novel clinical approach focused on NMS to develop tailored management strategies is warranted to improve the HrQoL in PD patients.

Effects of repetitive transcranial magnetic stimulation on freezing of gait in patients with Parkinsonism.

PURPOSE: The aim of this study was to investigate the site-specific effects of repetitive transcranial magnetic stimulation (rTMS) on freezing of gait (FOG) in patients with parkinsonism. METHODS: Twenty patients with parkinsonism and FOG were included. A single session of 10 Hz rTMS was applied over three different cortical regions of the dominant hemisphere: the primary motor cortex of the lower leg (M1-LL), the supplementary motor area (SMA), and the dorsolateral prefrontal cortex (DLPFC). We also performed sham stimulation as a control. The Timed Up and Go (TUG) test, Turn Steps and Turn Time in 180° turning, Unified Parkinson's Disease Rating Scale (UPDRS) part III, FOG Questionnaire (FOG-Q), and motor evoked potential (MEP) studies were performed before and after each intervention. RESULTS: There were significant improvements in TUG test times after rTMS over the M1-LL and the DLPFC. Improvement was significantly greater after the M1-LL stimulation than sham condition. The M1-LL and DLPFC stimulation also resulted in significant improvements in both the number of Turn Steps and Turn Time. UPDRS-III scores were significantly decreased after the M1-LL and DLPFC stimulation. CONCLUSIONS: Use of 10 Hz rTMS on the M1-LL and DLPFC is therapeutically effective for FOG in patients with parkinsonism.

Translation and validation of the korean version of the 39-item Parkinson's disease questionnaire.

BACKGROUND AND PURPOSE: The importance of health-related quality of life (HrQoL) has been increasingly emphasized when assessing and providing treatment to patients with chronic, progressive, degenerative disorders. The 39-item Parkinson's disease questionnaire (PDQ-39) is the most widely used patient-reporting scale to assess HrQoL in Parkinson's disease (PD). This study evaluated the validity and reliability of the translated Korean version of the PDQ-39 (K-PDQ-39). METHODS: One hundred and two participants with PD from 10 movement disorder clinics at university-affiliated hospitals in South Korea completed the K-PDQ-39. All of the participants were also tested using the Unified Parkinson's Disease Rating Scale (UPDRS), Korean version of the Mini-Mental State Examination (K-MMSE), Korean version of the Montgomery-Asberg Depression Scale (K-MADS), Epworth Sleepiness Scale (ESS) and non-motor symptoms scale (NMSS). Retests of the K-PDQ-39 were performed over time intervals from 10 to 14 days in order to assess test-retest reliability. RESULTS: Each K-PDQ-39 domain showed correlations with the summary index scores (rS=0.559-0.793, p<0.001). Six out of eight domains met the acceptable standard of reliability (Cronbach's α coefficient ≥0.70). The Guttman split-half coefficient value of the K-PDQ-39 summary index, which is an indicator of test-retest reliability, was 0.919 (p<0.001). All of the clinical variables examined except for age, comprising disease duration, levodopa equivalent dose, modified Hoehn and Yahr stage (H&Y stage), UPDRS part I, II and III, mood status (K-MADS), cognition (K-MMSE), daytime sleepiness (ESS) and (NMSS) showed strong correlations with the K-PDQ-39 summary index (p<0.01). CONCLUSIONS: The K-PDQ-39 has been validated for use in the Korean-speaking PD population. The questionnaire is a valid and reliable assessment tool for assessing the HrQoL of Korean PD patients.

Overnight switch from ropinirole to transdermal rotigotine patch in patients with Parkinson disease.

BACKGROUND: A recent trial involving predominantly Caucasian subjects with Parkinson Disease (PD) showed switching overnight from an oral dopaminergic agonist to the rotigotine patch was well tolerated without loss of efficacy. However, no such data have been generated for Korean patients. METHODS: This open-label multicenter trial investigated PD patients whose symptoms were not satisfactorily controlled by ropinirole, at a total daily dose of 3 mg to 12 mg, taken as monotherapy or as an adjunct to levodopa. Switching treatment from oral ropinirole to transdermal rotigotine was carried out overnight, with a dosage ratio of 1.5:1. After a 28-day treatment period, the safety and tolerability of switching was evaluated. Due to the exploratory nature of this trial, the effects of rotigotine on motor and nonmotor symptoms of PD were analyzed in a descriptive manner. RESULTS: Of the 116 subjects who received at least one treatment, 99 (85%) completed the 28-day trial period. Dose adjustments were required for 11 subjects who completed the treatment period. A total of 76 treatment-emergent adverse events (AEs) occurred in 45 subjects. No subject experienced a serious AE. Thirteen subjects discontinued rotigotine prematurely due to AEs. Efficacy results suggested improvements in both motor and nonmotor symptoms and quality of life after switching. Fifty-two subjects (46%) agreed that they preferred using the patch over oral medications, while 31 (28%) disagreed. CONCLUSIONS: Switching treatment overnight from oral ropinirole to transdermal rotigotine patch, using a dosage ratio of 1.5:1, was well tolerated in Korean patients with no loss of efficacy. TRIAL REGISTRATION: This trial is registered with the ClincalTrails.gov Registry (NCT00593606).

Differential genetic susceptibility in diphasic and peak-dose dyskinesias in Parkinson's disease.

To examine whether there is a differential genetic susceptibility in the diphasic and peak-dose forms of levodopa-induced dyskinesias (LID) in patients with Parkinson's disease (PD). The study cohort comprised 503 unrelated Korean PD patients who were treated with levodopa and had a disease duration of at least 5 years. The presence of LID was identified during a routine follow-up and special care was taken to separate the two distinct forms of LID into diphasic and peak-dose dyskinesias (PDSK). Genotyping was performed in the 503 patients and in 559 healthy controls to search for polymorphisms of DRD3 p.S9G, DRD2 Taq1A, GRIN2B c.2664C>T, c.366C>G, c.-200T>G, and the promoter region of SLC6A4. A total of 229 patients expressed LID (peak-dose in 205, diphasic in 57, and both in 33). The presence of diphasic dyskinesia (DDSK) was exclusively associated with the DRD3 p.S9G variant after adjusting for gender, age at PD onset, Hoehn & Yahr stage, and duration of levodopa treatment. Carrying the AA genotype was likely to shorten the onset of DDSK according to the duration of levodopa therapy (P = 0.02). The presence of PDSK was not significantly associated with any of the six genetic variants studied. There may be a genetic susceptibility in the development of DDSK in PD patients on chronic levodopa therapy, and its underlying pathophysiological mechanism might be distinct from that of PDSK.

Association between the dose of dopaminergic medication and the behavioral disturbances in Parkinson disease.

OBJECTIVES: To survey the point prevalence of impulse control and repetitive behavior disorders (ICRBs) in patients with Parkinson disease (PD) and to determine the relationship between PD medication dose and the risk of ICRBs. METHODS: A multicenter cross-sectional survey was applied to consecutive patients with PD over a 3-month period. The presence of ICRBs was screened using a modified version of the Minnesota Impulsive Disorders Interview that comprised five ICRB modules: compulsive buying, gambling, sexual behavior, eating, and punding. Data regarding the patients' clinical features and concurrent anti-PD drugs were also collected during the interview. Adjusted odds ratios (ORs) of the daily doses of dopamine agonist and L-dopa for the development of an ICRB were calculated after adjustment for clinical variables. RESULTS: Among the 1167 patients recruited, 118 (10.1%) exhibited ICRBs. Punding was the most common ICRB (4.2%), followed by compulsive eating (3.4%), sexual behaviors (2.8%), buying (2.5%), and gambling (1.3%). Two or more ICRBs were present concomitantly in 34 of these 118 patients (28.8%). There were dose-response relationships between the dopamine agonist dose and the ORs for compulsive buying, gambling and sexual behaviors. On the other hand, the OR for punding was positively correlated with the dose of L-dopa. The OR for compulsive eating was not associated with the dose of dopamine agonist or L-dopa. CONCLUSIONS: The dose of dopaminergic medication is significantly associated with the development of ICRB, except compulsive eating, in PD.

Does multiple system atrophy itself affect sleep structure?

OBJECTIVES: Reports on sleep in multiple system atrophy (MSA) are rare and many confounding variables affect the results. Among them, obstructive sleep apnea and periodic limb movements during sleep are very common. We conducted this study to see the changes of sleep parameters originating from MSA itself without confounders. METHODS: We compared polysomnographic variables of 15 MSA patients and 15 age-, gender-, apnea-hypopnea index-, and periodic limb movements index-matched controls. We also applied cyclic alternating pattern scoring in 7 MSA patients and 7 controls. RESULTS: Total sleep time and sleep efficiency are decreased in MSA. Wake after sleep onset, sleep onset latency, and stage 2 latency are prolonged. There is no difference in the proportion of slow wave sleep and rapid eye movement sleep between MSA patients and the controls. Cyclic alternating pattern scoring shows no difference, either. CONCLUSIONS: MSA itself does not affect the macro- and microstructures of sleep. However, patients with MSA sleep less and it cannot be explained by obstructive sleep apnea and periodic limb movements during sleep.

The G2019S LRRK2 Mutation is Rare in Korean Patients with Parkinson's Disease and Multiple System Atrophy.

BACKGROUND AND PURPOSE: The LRRK2 (PARK8; OMIM607060) substitution was recently identified as a causative mutation for Parkinson's disease (PD). The pathologic heterogeneity of LRRK2-positive patients suggests that mutation of the LRRK2 gene is associated with the pathogenesis of PD and Parkinson-plus disorders, such as multiple system atrophy (MSA). We previously reported that the G2019S LRRK2 mutation-which is the most common LRRK2 mutation-was not found in a sample of 453 Korean PD patients. In the present study, we extended the screening for the G2019S mutation to a larger group of PD and MSA patients. METHODS: We performed a genetic analysis of the G2019S mutation in 877 patients with PD and 199 patients with MSA using a standard PCR and restriction digestion method. RESULTS: None of the subjects carried the G2019S mutation. CONCLUSIONS: The results of the present study support that the G2019S mutation is extremely rare in PD and is unlikely to be associated with MSA in the Korean population.

Reliability of semiology description.

OBJECTIVE: Seizure semiology is important for classifying patients' epilepsy. Physicians usually get most of the seizure information from observers though there have been few reports on the reliability of the observers' description. This study aims at determining the reliability of observers' description of the semiology. METHODS: We included 92 patients who had their habitual seizures recorded during video-EEG monitoring. We compared the semiology described by the observers with that recorded on the videotape, and reviewed which characteristics of the observers affected the reliability of their reported data. RESULTS: The classification of seizures and the individual components of the semiology based only on the observer-description was somewhat discordant compared with the findings from the videotape (correct classification, 85%). The descriptions of some ictal behaviors such as oroalimentary automatism, tonic/dystonic limb posturing, and head versions were relatively accurate, but those of motionless staring and hand automatism were less accurate. The specified directions by the observers were relatively correct. The accuracy of the description was related to the educational level of the observers. CONCLUSIONS: Much of the information described by well-educated observers is reliable. However, every physician should keep in mind the limitations of this information and use this information cautiously.

Association between parkinsonism and participation in agriculture in Korea.

BACKGROUND AND PURPOSE: Environmental factors might influence the pathogenesis of Parkinson's disease (PD) or multiple-system atrophy (MSA), and previous examinations of pesticide exposure, well-water drinking, and farming have produced inconclusive results. Because agriculture has been of considerable importance to Korean society, and hence the risk of exposure to pesticides was high in Korea, this study investigated whether such exposure is associated with elevated risks of developing PD and MSA. METHODS: Two hundred and thirty-five PD patients, 133 MSA patients, and 77 normal control subjects were examined. Data concerning environmental factors were collected by face-to-face interviews using a structured questionnaire. Odds ratios (ORs) were calculated by binary logistic regression. RESULTS: ORs for environmental risk factors for developing PD were 1.06 [95% confidence interval (CI) = 1.02-1.10] for age and 2.37 (95% CI = 1.32-4.27) for rural well-water drinking for >10 years. Smoking >10 pack-years (OR = 0.31; 95% CI = 0.11-0.64) was a preventable factor for developing PD in this study. However, no significant risk factors were identified for MSA. CONCLUSIONS: These results suggest that exposure to certain environmental risk factors plays a role in the development of PD. However, the development of MSA appears to be independent of environmental risk factors in Korean patients.

The G2019S LRRK2 mutation is rare in Korean patients with Parkinson's disease.

BACKGROUND: A number of causative mutations such as alpha-synuclein, parkin, UCHL1, Pink-1, DJ-1 have been identified in Parkinson's disease (PD). They are usually found in the familial cases. One mutation of great interest is the G2019S mutation in the LRRK2 gene, which has been reported in both familial and sporadic PD. Its prevalence has been reported to vary markedly among different races. We examined the prevalence of the G2019S mutation in the Korean PD population for genetic study planning. METHODS: We conducted a genetic analysis of the G2019S mutation by standard PCR and restriction digestion method. 453 PD patients were studied, 34% of whom had an age at onset of < 50 years and 3.8% had a positive family history. RESULTS: None of the 453 study subjects carried the G2019S mutation. CONCLUSIONS: Our result confirms previous reports that the G2019S mutation is rare among PD patients in the Asian population. This result supports the notion that the prevalence of this LRRK2 mutation is population specific, and that there may be a founder effect within western populations.

Handedness and Asymmetry of Motor Skill Learning in Right-handers.

BACKGROUND AND PURPOSE: The most remarkable behavioral asymmetry is handedness. The preferred hand often has better performance, motor strength, nonpreferred hand. However, whether these components are associated with skill learning is not clear. METHODS: We evaluated healthy right-handers by setting a series of motor-performance tasks including skill learning, grip strength, and speed. RESULTS: The preferred hand showed better skill performance and learning rate. However, the degree of the right-left difference in grip strength or speed difference did not correlate with the asymmetry in skill-learning rate. Therefore, although the preferred hand exhibits a better skill-learning capacity than the nonpreferred hand, asymmetry in skill learning cannot be explained by motor strength or speed. CONCLUSIONS: Our findings suggest that better skill performance of the right hand in right-handers cannot be attributed to the degree of hand preference score, strength, or motor speed.

Anatomical basis of glial cell line-derived neurotrophic factor expression in the striatum and related basal ganglia during postnatal development of the rat.

There is increasing evidence that glial cell line-derived neurotrophic factor (GDNF) plays a role as a limiting, striatal target-derived neurotrophic factor for dopamine neurons of the substantia nigra pars compacta (SNpc) by regulating the magnitude of the first phase of postnatal natural cell death which occurs in these neurons. While it has been shown that GDNF mRNA is relatively abundant in postnatal striatum, the cellular basis of its expression has been unknown. We therefore used nonradioactive in situ hybridization and immunohistochemistry to examine the cellular basis of GDNF mRNA and protein expression, respectively, in postnatal striatum and related structures. We found that GDNF mRNA is expressed within medium-sized striatal neurons. Expression in glia was not observed. At the protein level, regionally, GDNF expression in striatum was observed in striosomal patches, as previously described. At a cellular level a few neurons were observed, but they do not account for the striosomal pattern. This pattern is predominantly due to GDNF-positive neuropil. Some of this neuropil arises from tyrosine hydroxylase-positive nigro-striatal dopaminergic afferents. Astrocytic processes do not appear to contribute to the striosomal pattern. GDNF-positive fibers are identified not only within intrinsic striatal neuropil, but also in fibers within the major striatal efferent targets: the globus pallidus, the entopeduncular nucleus, and the SN pars reticulata. We conclude that during normal postnatal development, medium-sized neurons are the principal source of GDNF within the striatum.

Glial cell line-derived neurotrophic factor receptor GFRalpha1 is expressed in the rat striatum during postnatal development.

Dopamine neurons of the substantia nigra (SN) undergo a natural cell death event which is biphasic, with peaks at postnatal days (PNDs) 2 and 14. There is growing evidence that GDNF functions as a striatal target-derived neurotrophic factor to regulate the first phase. It has been unknown whether the GDNF receptor, GFRalpha1, may play a role in regulating either phase. To evaluate a possible role for GFRalpha1 we have examined its expression throughout postnatal development in the SN and particularly in the striatum, where its expression has been uncertain. GFRalpha1 mRNA is highly expressed in SN, as previously shown, with highest levels at PND14-28. We find that it is also expressed in striatum with a similar time course, but with a more discrete period of maximal expression between PND10 and PND14. The cellular basis of this maximum of expression is an increased number of GFRalpha1 mRNA-positive medium-sized neurons evenly distributed within the striatum. Immunostaining reveals GFRalpha1 protein-positive neurons with a similar morphology and distribution. We conclude that GFRalpha1 is expressed in striatum maximally late in postnatal development. In this location it may act in trans to influence the viability and development of nigral dopamine neurons.

Patterns of developmental mRNA expression of neurturin and GFRalpha2 in the rat striatum and substantia nigra do not suggest a role in the regulation of natural cell death in dopamine neurons.

We examined the mRNA expression of neurturin (NTN) and its receptor GFRalpha2 in rat substantia nigra (SN) and striatum by northern analysis at ages ranging from postnatal day (PND) 2 to adult. NTN mRNA expression is developmentally regulated in striatum with a peak at PND10, but its expression in striatum is low, and less than that of SN. In SN, there is no developmental regulation. GFRalpha2 was expressed most highly during the first two postnatal weeks. Like NTN, GFRalpha2 mRNA was also more abundant in SN, at both PND2 and 14. Our results show that NTN expression is relatively low in the striatum, the target of dopamine (DA) neurons, and there is no apparent pattern of developmental regulation in SN. Thus these studies are not strongly supportive of a role for NTN in regulating natural cell death (NCD) in DA neurons, either as a target-derived or as a local paracrine factor.

A patient with proximal myotonic myopathy and parkinsonism.

INTRODUCTION: There are two case reports of patients who had proximal myotonic myopathy (PROMM)/myotonic dystrophy (DM) Type 1 and parkinsonism. The combination of myotonic myopathy and parkinsonism is so rare that it may appear to be just a coincidence. However, previous neuropathological examinations of patients who had myotonic dystrophy showed that there were intracytoplasmic inclusion bodies in the nigra and striatum, which raises the possibility that myotonic myopathy may be associated with parkinsonism. In this report we describe a patient with PROMM and a clinically definite parkinsonism to highlight this possibility. CASE REPORT: A 65-year-old man developed proximal muscle weakness, myotonia and atrophy around the age of 55 and was diagnosed as having PROMM at the age of 62. Needle electromyography and muscle biopsy supported the diagnosis. A gene study of the DM Type 1 showed a normal CTG repeat length. At age 63, he developed rest tremor, bradykinesia, hypomimia, stooped posture, and gait disturbance. The postural instability worsened rapidly. The tremor and rigidity were much worse in his right side, where myotonia was more severe. Levodopa therapy was only partially effective. CONCLUSION: This is a case report of a patient with PROMM that shows an association with a rapidly progressive form of parkinsonism. We suggest that this may be a novel form of a neurodegenerative disorder, which we name 'Parkinsonism-Myotonic Myopathy-Complex'.