123I-MIBG myocardial scintigraphy for the diagnosis of DLB: a multicentre 3-year follow-up study.

BACKGROUND AND PURPOSE: We previously reported the usefulness of iodine-123 metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy for differentiation of dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) in a cross-sectional multicentre study. The aim of this study was, by using reassessed diagnosis after 3-year follow-up, to evaluate the diagnostic accuracy of 123I-MIBG scintigraphy in differentiation of probable DLB from probable AD. METHODS: We undertook 3-year follow-up of 133 patients with probable or possible DLB or probable AD who had undergone 123I-MIBG myocardial scintigraphy at baseline. An independent consensus panel made final diagnosis at 3-year follow-up. Based on the final diagnosis, we re-evaluated the diagnostic accuracy of 123I-MIBG scintigraphy performed at baseline. RESULTS: Sixty-five patients completed 3-year follow-up assessment. The final diagnoses were probable DLB (n=30), possible DLB (n=3) and probably AD (n=31), and depression (n=1). With a receiver operating characteristic curve analysis of heart-to-mediastinum (H/M) ratios for differentiating probable DLB from probable AD, the sensitivity/specificity were 0.77/0.94 for early images using 2.51 as the threshold of early H/M ratio, and 0.77/0.97 for delayed images using 2.20 as the threshold of delayed H/M ratio. Five of six patients who were diagnosed with possible DLB at baseline and with probable DLB at follow-up had low H/M ratio at baseline. CONCLUSIONS: Our follow-up study confirmed high correlation between abnormal cardiac sympathetic activity evaluated with 123I-MIBG myocardial scintigraphy at baseline and the clinical diagnosis of probable DLB at 3-year follow-up. Its diagnostic usefulness in early stage of DLB was suggested. TRIAL REGISTRATION NUMBER: UMIN00003419.

Long-term treatment of Parkinson's disease with levodopa and other adjunctive drugs.

We report a long-term treatment of Parkinson's disease in out-patient clinics. The patients with Parkinson's disease were evaluated at the time of clinic visit from September 1st, 2015 to February 29th, 2016. Total number of the patients was 498. The age at the evaluation was 69.9 ± 9.3 years and the age of onset was 60.2 ± 11.3. Hoehn and Yahr severity was 3.28 ± 0.94 in patients who were from 16 to 20 years (n = 53) and 3.00 ± 0.86 in patients from 21 years or more (n = 38) from the onset of the disease to the evaluation. The dose of levodopa was 741 ± 295 mg per day and the number of levodopa dosing was 5.85 ± 2.59 times in 16-20 years from the onset to the evaluation and 703 ± 251 mg/day and 6.03 ± 3.20 times a day in 21 years or more from the onset to the evaluation. Levodopa was given in most cases into an empty stomach. The incidence of wearing off was 73.6% and dyskinesia was 37.7% in the 16-20 years group and 76.3% and 55.3% in 21 years or more group, respectively. The patients who had 15 years or less from the onset to the evaluation had much milder severity of the disease. Hoehn and Yahr severity, the dose of levodopa, and the incidence of wearing off were about the same as in the literature. But the incidence of dyskinesia was much lower than those appeared in the literature. We discussed reasons why the incidence of dyskinesia was lower in our study.

I2020T mutant LRRK2 iPSC-derived neurons in the Sagamihara family exhibit increased Tau phosphorylation through the AKT/GSK-3ß signaling pathway.

Leucine-rich repeat kinase 2 (LRRK2) is the causative molecule of the autosomal dominant hereditary form of Parkinson's disease (PD), PARK8, which was originally defined in a study of a Japanese family (the Sagamihara family) harboring the I2020T mutation in the kinase domain. Although a number of reported studies have focused on cell death mediated by mutant LRRK2, details of the pathogenetic effect of LRRK2 still remain to be elucidated. In the present study, to elucidate the mechanism of neurodegeneration in PD caused by LRRK2, we generated induced pluripotent stem cells (iPSC) derived from fibroblasts of PD patients with I2020T LRRK2 in the Sagamihara family. We found that I2020T mutant LRRK2 iPSC-derived neurons released less dopamine than control-iPSC-derived neurons. Furthermore, we demonstrated that patient iPSC-derived neurons had a lower phospho-AKT level than control-iPSC-derived neurons, and that the former showed an increased incidence of apoptosis relative to the controls. Interestingly, patient iPSC-derived neurons exhibited activation of glycogen synthase kinase-3ß (GSK-3ß) and high Tau phosphorylation. In addition, the postmortem brain of the patient from whom the iPSC had been established exhibited deposition of neurofibrillary tangles as well as increased Tau phosphorylation in neurons. These results suggest that I2020T LRRK2-iPSC could be a promising new tool for reproducing the pathology of PD in the brain caused by the I2020T mutation, and applicable as a model in studies of targeted therapeutics.

Twenty years since the discovery of the parkin gene.

Nearly 20 years have passed since we identified the causative gene for a familial Parkinson's disease, parkin (now known as PARK2), in 1998. PARK2 is the most common gene responsible for young-onset Parkinson's disease. It codes for the protein Parkin RBR E3 ubiquitin-protein ligase (PARK2), which directly links to the ubiquitin-proteasome as a ubiquitin ligase. PARK2 is involved in mitophagy, which is a type of autophagy, in collaboration with PTEN-induced putative kinase 1 (PINK1). The PINK1 gene (previously known as PARK6) is also a causative gene for young-onset Parkinson's disease. Both gene products may be involved in regulating quality control within the mitochondria. The discovery of PARK2 as a cause of young-onset Parkinson's disease has had a major impact on other neurodegenerative diseases. The involvement of protein degradation systems has been implicated as a common mechanism for neurodegenerative diseases in which inclusion body formation is observed. The discovery of the involvement of PARK2 in Parkinson's disease focused attention on the involvement of protein degradation systems in neurodegenerative diseases. In this review, we focus on the history of the discovery of PARK2, the clinical phenotypes of patients with PARK2 mutations, and its functional roles.

Effects of donepezil dose escalation in Parkinson's patients with dementia receiving long-term donepezil treatment: an exploratory study.

BACKGROUND: The benefits of escalating the dose of donepezil in patients who are already receiving long-term treatment with it have not been well evaluated. Therefore, an exploratory study to assess the effects of donepezil dose escalation in patients with Parkinson's disease with dementia, and specifically on patients receiving long-term treatment with donepezil, was performed. METHODS: Patients treated with 5-mg/day donepezil for at least 3 months and having a Mini-Mental State Examination (MMSE) score between 10 and 26 were included in this study. Donepezil dosage was then increased to 10 mg/day for 12 weeks. The outcome measures were a modified form of the Neuropsychiatric Inventory (NPI) with an extra domain for additional evaluation of fluctuation in cognitive functions (NPI-11) and the MMSE. RESULTS: Of the nine patients enrolled, two withdrew because of nausea and inability to be assessed on the predetermined date; this left seven participants (four men and three women) with a mean age of 74.6 ± 6.9 years, a mean period of Parkinson's disease of 11.7 ± 7.5 years, and median donepezil use of 7 months (range: 3-56 months). At baseline, the mean total NPI-11 and mean MMSE scores were 18.3 ± 5.6 points and 21.3 ± 5.3 points, respectively. At week 12, they improved by 8.3 points (P < 0.01) and 3.0 points (P = 0.08), respectively, from the baseline. The NPI symptom domains that improved by 1 or more points were hallucination (1.3 points), depression (1.0 points), anxiety (1.6 points), and aberrant motor behaviour (1.7 points). None of the patients withdrew because of worsening of parkinsonism. CONCLUSIONS: The present results suggest that treatment with dose escalation of donepezil from 5 mg/day to 10 mg/day may be therapeutically useful for patients with Parkinson's disease with dementia who have taken donepezil 5 mg/day in the long term.

Accumulation of α-synuclein triggered by presynaptic dysfunction.

Pathological examination of dementia with Lewy bodies patients identified the presence of abnormal α-synuclein (αSyn) aggregates in the presynaptic terminals. αSyn is involved in the regulation of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex. Importantly, αSyn-transgenic mouse and postmortem examination of patients with Parkinson's disease have demonstrated the abnormal distribution of SNARE protein in presynaptic terminals. In this study, we investigated the effects of SNARE dysfunction on endogenous αSyn using Snap25(S187A/S187A) mutant mice. These mice have homozygous knock-in gene encoding unphosphorylatable S187A-substituted synaptosomal-associated protein of 25 kDa (SNAP-25). The mice displayed a significant age-dependent change in the distribution of αSyn and its Ser(129)-phosphorylated form in abnormally hypertrophied glutamatergic nerve terminals in the striatum. Electron-microscopic analysis revealed the abnormally condensed synaptic vesicles with concomitant mislocalization of αSyn protein to the periactive zone in the glutamatergic nerve terminals. However, the Snap25(S187A/S187A) mutant mouse harbored no abnormalities in the nigrostriatal dopaminergic neurons. Our present results suggest that SNARE dysfunction is the initial trigger of mislocalization and accumulation of αSyn, and probably is an important pathomechanism of α-synucleinopathies.

Adenosine A2A receptor antagonist istradefylline reduces daily OFF time in Parkinson's disease.

BACKGROUND: We evaluated the efficacy and safety of istradefylline, a selective adenosine A2A receptor antagonist administered as adjunctive treatment to levodopa for 12 weeks in a double-blind manner in Parkinson's disease patients with motor complications in Japan. METHODS: A total of 373 subjects were randomized to receive placebo (n=126), istradefylline 20 mg/day (n=123), or istradefylline 40 mg/day (n=124). The primary efficacy variable was the change in daily OFF time. Other secondary variables were also evaluated. RESULTS: The change in daily OFF time was significantly reduced in the istradefylline 20 mg/day (-0.99 hours, P=.003) and istradefylline 40 mg/day (-0.96 hours, P=.003) groups compared with the placebo group (-0.23 hours). The most common adverse event was dyskinesia (placebo, 4.0%; istradefylline 20 mg/day, 13.0%; istradefylline 40 mg/day, 12.1%). CONCLUSIONS: Istradefylline reduced daily OFF time and was well tolerated in Japanese PD patients with motor complications on levodopa treatment.

Transdermal rotigotine in early stage Parkinson's disease: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: We conducted a randomized, double-blind, placebo-controlled trial to determine the safety and efficacy of transdermal rotigotine at doses up to 16 mg/24 hours in patients with early stage Parkinson's disease (PD) in Japan. METHODS: Patients received once-daily rotigotine 2 to 16 mg/24 hours (mean dose, 12.8 mg/24 hours; n = 82) or placebo (n = 90) for 12 weeks. The primary endpoint was the change in Unified Parkinson's Disease Rating Scale (UPDRS) part II (activities of daily living) and part III (motor function) scores from baseline to the end of treatment. RESULTS: The mean (± standard deviation) changes in UPDRS part II and III scores were -8.4 ± 9.7 in the rotigotine group and -4.1 ± 8.2 in the placebo group and were significantly different (P = 0.002). More patients in the rotigotine group than in the placebo group had a ≥ 20% score reduction. No serious drug-related adverse events were reported. CONCLUSIONS: Rotigotine at doses up to 16 mg/24 hours was well tolerated and improved function in patients with early stage PD.

Lewy body pathology in a patient with a homozygous parkin deletion.

BACKGROUND: We report neuropathologic findings in a patient with homozygous deletions of exons 2 to 4 of parkin. RESULTS: Although the absence of Lewy bodies has been considered a neuropathologic characteristic of parkin mutation, here we report a pathologic finding with the presence of Lewy bodies. METHODS: The patient was a 72-year-old woman with onset of the disease at age 61. Her autopsy revealed marked decrease in melanized neurons in the substantia nigra and the locus coeruleus. Lewy bodies were found in the substantia nigra, the locus coeruleus, the dorsal motor nucleus of the vagus, the basal nucleus of Meynert, the amygdaloid nucleus, and the sympathetic nerve bundles in the myocardium. CONCLUSIONS: Only 3 previous case reports described Lewy body formation in patients carrying parkin mutations. The distribution of Lewy bodies in our patient appeared to be reminiscent of sporadic Parkinson's disease.

Loss of DARPP-32 and calbindin in multiple system atrophy.

We evaluated the immunohistochemical intensities of α-synuclein, phosphorylated α-synuclein (p-syn), dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32), calbindin-D 28k, calpain-cleaved carboxy-terminal 150-kDa spectrin fragment, and tyrosine hydroxylase in multiple system atrophy (MSA). The caudate head, anterior putamen, posterior putamen, substantia nigra, pontine nucleus, and cerebellar cortex from six MSA brains, six age-matched disease control brains (amyotrophic lateral sclerosis), and five control brains were processed for immunostaining by standard methods. Immunostaining for α-synuclein, p-syn, or both was increased in all areas examined in oligodendrocytes in MSA. Immunostaining for DARPP-32 and calbindin-D 28k was most prominently decreased in the posterior putamen, where neuronal loss was most prominent. Immunostaining for DARPP-32 and calbindin-D 28k was also diminished in the anterior putamen and caudate head, where neuronal loss was less prominent or absent. Calbindin immunostaining was also decreased in the dorsal tier of the substantia nigra and cerebellar cortex. Loss of immunostaining for DARPP-32 and calbindin-D 28k compared with that of neurons indicates calcium toxicity and disturbance of the phosphorylated state of proteins as relatively early events in the pathogenesis of MSA.

Long-term oral lithium treatment attenuates motor disturbance in tauopathy model mice: implications of autophagy promotion.

Lithium, a drug used to treat bipolar disorders, has a variety of neuroprotective mechanisms including inhibition of glycogen synthase kinase-3 (GSK-3), a major tau kinase. Recently, it has been shown that, in various neurodegenerative proteinopathies, lithium could induce autophagy. To analyze how lithium is therapeutically beneficial in tauopathies, transgenic mice overexpressing human mutant tau (P301L) were treated with oral lithium chloride (LiCl) for 4 months starting at the age of 5 months. At first, we examined the effects of treatment on behavior (using a battery of behavioral tests), tau phosphorylation (by biochemical assays), and number of neurofibrillary tangles (NFTs) (by immunohistopathology). In comparison with control mice, LiCl-treated mice showed a significantly better score in the sensory motor tasks, as well as decreases in tau phosphorylation, soluble tau level, and number of NFTs. Next, we examined lithium effects on autophagy using an antibody against microtubule-associated protein 1 light chain 3 (LC3) as an autophagosome marker. The number of LC3-positive autophagosome-like puncta was increased in neurons of LiCl-treated mice. Neurons containing NFTs were completely LC3-negative, whereas LC3-positive autophagosome-like puncta contained phosphorylated-tau (p-tau). The protein level of p62 was decreased in LiCl-treated mice. These data suggested that oral long-term lithium treatment could attenuate p-tau-induced motor disturbance not only by inhibiting GSK-3 but also by enhancing autophagy in tauopathy model mice.

Differential regional distribution of phosphorylated tau and synapse loss in the nucleus accumbens in tauopathy model mice.

Tauopathies differ in terms of the brain regions that are affected. In Alzheimer's disease, basal forebrain and hippocampus are mainly involved, while frontotemporal lobar degeneration affects the frontal and temporal lobes and subcortical nuclei including striatum. Over 90% of human cases of tauopathies are sporadic, although the majority of established tau-transgenic mice have had mutations. This prompted us to establish transgenic mice expressing wild-type human tau (Tg601). Old (>14 months old) Tg601 mice displayed decreased anxiety in the elevated plus maze test and impaired place learning in the Morris water maze test. Immunoblotting of brain tissue identified that soluble tau multimer was increased with aging even though insoluble tau was not observed. In the striatum of old Tg601, the level of AT8- or AT180-positive tau was decreased compared with that of other regions, while PHF-1-positive tau levels remained equal. Phosphorylated tau-positive axonal dilations were present mainly in layers V and VI of the prefrontal cortex. Loss of synaptic dendritic spine and decreased immunohistochemical level of synaptic markers were observed in the nucleus accumbens. In vivo 2-[(18)F]fluoro-2-deoxy-d-glucose positron emission tomography analysis also showed decreased activity exclusively in the nucleus accumbens of living Tg601 mice. In Tg601 mice, the axonal transport defect in the prefrontal cortex-nucleus accumbens pathway may lead to decreased anxiety behavior. Differential distribution of hyperphosphorylated tau may cause region-specific neurodegeneration.

Comprehensive mutational analysis of LRRK2 reveals variants supporting association with autosomal dominant Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by neurodegeneration, most notably of dopaminergic neurons in the substantia nigra. To date, six causative genes have been identified including LRRK2, whose mutations are the most frequent in autosomal dominant PD (Ad-PD). We conducted a comprehensive mutational analysis of LRRK2 in 30 Ad-PD (11 Japanese and 19 Caucasian) families employing a DNA microarray-based resequencing system and direct nucleotide sequence analysis, and identified 23 variants including two known mutations, p.G2019S and p.I1371V, in three Caucasian families and one Caucasian family, respectively, a novel putative pathogenic mutation, p.N1221K, in one Japanese family, and a known nonsynonymous variant, p.G2385R, in two Japanese families. Detailed analysis of the frequency of p.G2385R among 100 Japanese Ad-PD, 73 sporadic PD (sPD) and 238 controls revealed that the frequency of the p.G2385R variant was significantly higher in Ad-PD than in controls (allele frequency, 9.0 vs 2.1%) (χ(2)=16.32, P=5.34 × 10(-5)). The p.G2385R variant, however, did not show complete cosegregation with PD. In addition, the frequency of p.G2385R was also higher in sPD than in controls, although not significant (allele frequency, 3.4 vs 2.1%) (χ(2)=0.76, P=0.38). These observations support the possibility that p.G2385R is associated with an increased risk of PD.

Milestones in PD genetics.

Over the last 25 years, genetic findings have profoundly changed our views on the etiology of Parkinson's disease. Linkage studies and positional cloning strategies have identified mutations in a number of genes that cause several monogenic autosomal-dominant or autosomal-recessive forms of the disorder. Although most of these Mendelian forms of Parkinson's disease are rare, whole-genome association studies have more recently provided convincing evidence that low-penetrance variants in at least some of these, but also in several other genes, play a direct role in the etiology of the common sporadic disease as well. In addition, rare variants with intermediate-effect strengths in genes such as Gaucher's disease-associated glucocerebrosidase A have been discovered as important risk factors. "Next-generation" sequencing technologies are expected by some to identify many more of these variants. Thus, an increasingly complex network of genes contributing in different ways to disease risk and progression is emerging. These findings may provide the "genetic entry points" to identify molecular targets and readouts necessary to design rational disease-modifying treatments.

Posterior hypoperfusion in Parkinson's disease with and without dementia measured with arterial spin labeling MRI.

PURPOSE: To determine whether quantitative arterial spin labeling (ASL) can be used to evaluate regional cerebral blood flow in Parkinson's disease with dementia (PDD) and without dementia (PD). MATERIALS AND METHODS: Thirty-five PD patients, 11 PDD patients, and 35 normal controls were scanned by using a quantitative ASL method with a 3 Tesla MRI unit. Regional cerebral blood flow was compared in the posterior cortex using region-of-interest analysis. RESULTS: PD and PDD patients showed lower regional cerebral blood flow in the posterior cortex than normal controls (P = 0.002 and P = 0.001, respectively, analysis of variance with a Bonferroni post hoc test). CONCLUSION: This is the first study to detect hypoperfusion in the posterior cortex in PD and PDD patients using ASL perfusion MRI. Because ASL perfusion MRI is completely noninvasive and can, therefore, safely be used for repeated assessments, this method can be used to monitor treatment effects or disease progression in PD.

Ectopic expression of α-synuclein affects the migration of neural stem cells in mouse subventricular zone.

α-Synuclein (α-syn) is a key protein in Parkinson's disease (PD), and its abnormal accumulation is implicated only not in the loss of dopaminergic neurons in the substantia nigra but also in impairment of olfactory bulb (OB) in PD. Olfactory dysfunction could arise from these OB changes as an early symptom in PD. We reported previously the impairment of neuronal stem cell (NSC) proliferation in the subventricular zone, which is upstream of OB in PD models. Reduction of NSC generation could potentially lead to olfactory dysfunction, which is commonly associated with and precedes the motor symptoms by several years in PD. Here, we investigated neurosphere formation in vitro and migration of NSCs in vivo after transduction of α-syn-encoding retroviral vector to characterize the function of α-syn in NSC. Over-expression of α-syn caused less effective formation of neurospheres and induced morphological changes. Fluorescence-activated cell sorting showed diminished NSC cell cycle progression induced by over-expression of α-syn. Intriguingly, suppression of NSC migration along the rostral migratory stream was observed when the α-syn-encoding vector was directly injected into the subventricular zone of mice in vivo. These results indicate that α-syn affects the generation of NSC and suggest that this protein could serve as a tool for the design of potentially useful therapy for PD patients.

Clinical efficacy of istradefylline (KW-6002) in Parkinson's disease: a randomized, controlled study.

The objectives of this study were to evaluate the efficacy of istradefylline at an oral dose of 20 mg or 40 mg once daily for 12 weeks in Parkinson's disease (PD) patients with motor complications on levodopa therapy based on the change in the daily OFF time compared with placebo and to assess the safety at these doses. A total of 363 subjects were randomly assigned to receive 20 mg/day istradefylline (n = 119), 40 mg/day istradefylline (n = 125), or placebo (n = 119). The primary outcome variable was the change from baseline at endpoint in daily OFF time based on patients' ON/OFF diaries. At endpoint, the daily OFF time reduced from baseline by 1.31 hours for 20 mg/day istradefylline (P = 0.013 as compared to the placebo), 1.58 hours for 40 mg/day istradefylline (P < 0.001), and 0.66 hours for placebo; istradefylline significantly reduced the daily OFF time compared with placebo. The UPDRS Part III subscale score (ON state) reduced by 5.7 at endpoint in both istradefylline groups and 3.7 in the placebo group (P = 0.006 for 20 mg/day and P = 0.006 for 40 mg/day group as compared with placebo). The most commonly reported drug-related treatment emergent adverse event (TEAE) was dyskinesia, which occurred in 2.5% (3/119) of subjects receiving placebo, 8.5% (10/118) receiving 20 mg/day istradefylline, and 6.4% (8/125) receiving 40 mg/day istradefylline. We conclude that istradefylline at 20 mg and 40 mg once daily is effective in relieving wearing-off fluctuations of PD patients. In addition, istradefylline was well tolerated at both doses.

Efficacy, safety, and tolerability of overnight switching from immediate- to once daily extended-release pramipexole in early Parkinson's disease.

The aim of this article is to test the feasibility, in early Parkinson's disease (PD), of an overnight switch from immediate-release (IR) pramipexole to a new once-daily extended-release (ER) formulation. Nonfluctuating patients on pramipexole IR three-times daily, alone or with levodopa, for early PD were randomly switched overnight to double-blind IR three-times daily (N = 52) or ER once-daily (N = 104) at initially unchanged daily dosage. Successful switching (defined as no worsening >15% of baseline UPDRS II+III score and no drug-related adverse event withdrawal) was assessed at 9 weeks, after optional dosage adjustments (primary endpoint), and at 4 weeks, before adjustment. Other secondary endpoints included adjusted mean changes from baseline in UPDRS scores and proportion of responders based on Clinical or Patient Global Impression (CGI/PGI). Absolute difference between percentage of successful switch to ER versus IR was tested for ER noninferiority, defined as a 95% confidence-interval lower bound not exceeding -15%. At 9 weeks, 84.5% of the ER group had been successfully switched, versus 94.2% for IR. Noninferiority was not demonstrated, with a difference of -9.76% (95% CI: [-18.81%, +1.66%]). At 4 weeks, 81.6% of the ER group had been successfully switched, versus 92.3% for IR, a difference of -10.75% (95% CI: [-20.51%, +1.48%]). UPDRS changes and CGI/PGI analyses showed no differences between the groups. Both formulations were safe and well tolerated. Pramipexole ER was not equivalent to IR, but the difference was marginal. The fact that >80% of the patients successfully switched overnight at unchanged dosage shows that this practice was feasible in most patients.

Randomized, double-blind, multicenter evaluation of pramipexole extended release once daily in early Parkinson's disease.

The objective of this study was to evaluate the efficacy and safety of pramipexole extended release (ER) administered once daily in early Parkinson's disease (PD). Pramipexole immediate release (IR) administered three times daily (TID) is an efficacious and generally well-tolerated treatment for PD. A pramipexole ER formulation is now available. We performed a randomized, double-blind, placebo and active comparator-controlled trial in subjects with early PD. The primary efficacy and safety evaluation of pramipexole ER compared with placebo took place at week 18. Two hundred fifty-nine subjects were randomized 2:2:1 to treatment with pramipexole ER once daily, pramipexole IR TID, or placebo. Levodopa rescue was required by 7 subjects in the placebo group (14%), 3 subjects in the pramipexole ER group (2.9%, P = 0.0160), and 1 subject in the pramipexole IR group (1.0%, P = 0.0017). Adjusted mean [standard error (SE)] change in Unified Parkinson Disease Rating Scale (UPDRS) II [activities of daily living (ADL)] + III (motor) scores from baseline to week 18, including post-levodopa rescue evaluations, was -5.1 (1.3) in the placebo group, -8.1 (1.1) in the pramipexole ER group (P = 0.0282), and -8.4 (1.1) in the pramipexole IR group (P = 0.0153). Adjusted mean (SE) change in UPDRS ADL + motor scores, censoring post-levodopa rescue data, was -2.7 (1.3) in the placebo group, -7.4 (1.1) in the pramipexole ER group (P = 0.0010), and -7.5 (1.1) in the pramipexole IR group (P = 0.0006). Adverse events more common with pramipexole ER than placebo included somnolence, nausea, constipation, and fatigue. Pramipexole ER administered once daily was demonstrated to be efficacious compared with placebo and provided similar efficacy and tolerability as pramipexole IR administered TID.

Rapid screening of ATP13A2 variant with high-resolution melting analysis.

Several genetic and environmental factors are involved in the pathogenesis of Parkinson's disease (PD). Recently, a novel variant of ATP13A2 (p.A746T) responsible for PARK9 was reported as a risk factor for PD in the Han-Chinese population. To investigate the role of this variant in Japanese PD patients, we examined 917 Japanese PD patients (871 index cases) and 190 controls by high-resolution melting curve analysis. We detected heterozygous p.A746T variant in a single patient with sporadic PD and a single control subject. These results suggest that ATP13A2 p.A746T variant is unlikely to play a role as a common risk factor or a pathogenic mutation for PD at least in Japanese. Our data on Japanese differ from those reported recently on Han-Chinese. Further studies are needed to confirm conclusions on roles of ATP13A2 variant in Asians or other populations.