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Discovery of Park2 is our finding of a family of young onset parkinsonism, in which this family was thought to be associated with a polymorphism of the manganese superoxide gene. The gene locus of the manganese superoxide dismutase has been known. We were able to pick up a gene for this family and related families in the close approximate position at the long arm of chromosome 6. The gene for this disease has a ubiquitin-like motif in the N-terminus and two RING finger structures. It was shown that this gene had a ubiquitin-protein ligase activity. But it is not elucidated the substrate of this enzyme. Meanwhile, it has become clear that PINK1 and Parkin work together to remove the mitochondria of the lowered membrane potential in the autophagosomes (mitophagy). Now that the molecular mechanisms of mitophagy is under investigation. In addition, many hot topics are going on such as Lewy body in Park2, single heterozygotes, rare clinical manifestations, and so on.

Background and purposeWe 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.MethodsWe 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.ResultsSixty-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.ConclusionsOur 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 numberUMIN00003419.

Background In Japan, selegiline has been approved for combination therapy with levodopa for Parkinson disease (PD). We conducted a trial of selegiline monotherapy for early PD. Methods In this 12-week controlled phase III trial, a total of 292 subjects were randomized to receive placebo (n = 146) (full analysis set 140) or selegiline (n = 146) (full analysis set 139). The primary outcome measure was the change in the Unified Parkinson Disease Rating Scale part I + II + III total score from baseline to the final visit. Other secondary measures and a safety profile were evaluated. Results Selegiline monotherapy reduced the primary outcome measure by -6.26 ± 7.86 compared with the placebo -3.14 ± 6.98 (mean ± SD, P = 0.0005 by analysis of covariance). There was no significant difference in the number of adverse events between the 2 groups (P > 0.05). Conclusions Selegiline monotherapy reduced the total Unified Parkinson Disease Rating Scale part I + II + III score and was well tolerated in Japanese patients with early PD.

OBJECTIVES The aim of this open-label study was to investigate the long-term safety and efficacy of selegiline as monotherapy in Japanese patients with early Parkinson disease (PD). METHODS We conducted a 56-week prospective study in patients with early PD (N = 134) who had previously completed the randomized, double-blind, placebo-controlled phase III trial of selegiline monotherapy for 12 weeks. In the present study, dosing was titrated from 2.5 to 10 mg/d in increments of 2.5 mg/d for 2 weeks. From the seventh week, the dosage was maintained at 10 mg/d until week 56. The primary outcome was any change in the total Unified Parkinson's Disease Rating Scale (UPDRS) score (part I + II + III) from baseline. Secondary outcomes, including changes in the UPDRS subscores and safety profile, were also evaluated. RESULTS Ninety-one (67.9%) patients completed the 56-week study. Treatment with selegiline significantly reduced total UPDRS score from week 4 (mean ± SD, -2.62 ± 3.83; P < 0.0001) to week 56 (-3.39 ± 9.27; P < 0.01). The peak effect was seen at week 20 (-5.79 ± 5.57; P < 0.0001). In addition, we found similar improvements in the UPDRS parts II and III scores. The incidence rate of adverse drug reactions was 44.3% (58 patients) and did not increase during the period of 10 mg selegiline administration. CONCLUSIONS Long-term monotherapy with selegiline (10 mg/d) was effective and well tolerated in patients with early PD in this 56-week study.

Summary Background Identification of causative genes in mendelian forms of Parkinson's disease is valuable for understanding the cause of the disease. We did genetic studies in a Japanese family with autosomal dominant Parkinson's disease to identify novel causative genes. Methods We did a genome-wide linkage analysis on eight affected and five unaffected individuals from a family with autosomal dominant Parkinson's disease (family A). Subsequently, we did exome sequencing on three patients and whole-genome sequencing on one patient in family A. Variants were validated by Sanger sequencing in samples from patients with autosomal dominant Parkinson's disease, patients with sporadic Parkinson's disease, and controls. Participants were identified from the DNA bank of the Comprehensive Genetic Study on Parkinson's Disease and Related Disorders (Juntendo University School of Medicine, Tokyo, Japan) and were classified according to clinical information obtained by neurologists. Splicing abnormalities of CHCHD2 mutants were analysed in SH-SY5Y cells. We used the Fisher's exact test to calculate the significance of allele frequencies between patients with sporadic Parkinson's disease and unaffected controls, and we calculated odds ratios and 95% CIs of minor alleles. Findings We identified a missense mutation ( CHCHD2 , 182C>T, Thr61Ile) in family A by next-generation sequencing. We obtained samples from a further 340 index patients with autosomal dominant Parkinson's disease, 517 patients with sporadic Parkinson's disease, and 559 controls. Three CHCHD2 mutations in four of 341 index cases from independent families with autosomal dominant Parkinson's disease were detected by CHCHD2 mutation screening: 182C>T (Thr61Ile), 434G>A (Arg145Gln), and 300+5G>A. Two single nucleotide variants (−9T>G and 5C>T) in CHCHD2 were confirmed to have different frequencies between sporadic Parkinson's disease and controls, with odds ratios of 2·51 (95% CI 1·48–4·24; p=0·0004) and 4·69 (1·59–13·83, p=0·0025), respectively. One single nucleotide polymorphism (rs816411) was found in CHCHD2 from a previously reported genome-wide association study; however, there was no significant difference in its frequency between patients with Parkinson's disease and controls in a previously reported genome-wide association study (odds ratio 1·17, 95% CI 0·96–1·19; p=0·22). In SH-SY5Y cells, the 300+5G>A mutation but not the other two mutations caused exon 2 skipping. Interpretation CHCHD2 mutations are associated with, and might be a cause of, autosomal dominant Parkinson's disease. Further genetic studies in other populations are needed to confirm the pathogenicity of CHCHD2 mutations in autosomal dominant Parkinson's disease and susceptibility for sporadic Parkinson's disease, and further functional studies are needed to understand how mutant CHCHD2 might play a part in the pathophysiology of Parkinson's disease. Funding Japan Society for the Promotion of Science; Japanese Ministry of Education, Culture, Sports, Science and Technology; Japanese Ministry of Health, Labour and Welfare; Takeda Scientific Foundation; Cell Science Research Foundation; and Nakajima Foundation.

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.

Background: Clinical features, pathogenesis, and treatment of Parkinson's disease (PD) are reviewed as there has been progress in these areas. Summary: PD is a systemic disease of the nervous system as the initial symptom is related to disturbance of the autonomic nervous system, such as constipation or nocturia. Then, the disease progresses to the brain stem involving the nuclei in the pons and the substantia nigra, and inducing sleep and wakefulness disturbances, affect problems such as anxiety and depression, and motor problems when the disease process has reached the substantia nigra. Furthermore, the disease has an effect on the nucleus basalis of Meynert, the amygdaloid complex and the cerebrum manifesting cognitive impairment. The olfactory pathway is also frequently involved. Key Messages: For the treatment of PD, younger patients without dementia should be treated with a nonergot dopamine agonist first and then with levodopa if necessary. Elderly patients or those with dementia should be treated with levodopa. However, after 5 years of levodopa treatment, many patients with PD develop wearing off. Drugs for the treatment of wearing-off symptoms are reviewed. Many of the patients with wearing-off symptoms develop dyskinesia, and amantadine is so far the only drug that can ameliorate dyskinesia. Because of this situation, a new method of treatment is warranted, such as RNA interaction, according to the author's opinion. Recent progress in this field is also reviewed. i 2014 S. Karger AG, Basel

Rotigotine, a non-ergot dopamine receptor agonist, offers potential for continuous dopaminergic stimulation that could avoid the fluctuations observed with traditional treatments. We conducted a randomized, double-blind, placebo-controlled trial in Japanese patients with advanced Parkinson’s disease (PD) to investigate the efficacy and safety of rotigotine. Inclusion criteria included the presence of motor complications, such as wearing off, on–off, delayed-on/no-on, any circumstances that could interfere with levodopa dose escalation because of side effects, or declining levodopa efficacy. The enrolled patients received once-daily applications of rotigotine transdermal patches or matched placebo patches. A total of 174 patients were randomly assigned to rotigotine (87 patients) or placebo (87 patients). The full analysis set included 172 patients (86 for the rotigotine group and 86 for the placebo group). The maximum maintenance dose of rotigotine was set at 16 mg/24 h. The changes in unified PD rating scale Part III scores from baseline to the end of the trial were −10.1 ± 9.0 (mean ± standard deviation) in the rotigotine group and −4.4 ± 7.4 in the placebo group (p < 0.001). There was a significantly greater reduction in the off-time (p = 0.014) in the rotigotine group. Rotigotine was well tolerated, with serious adverse events being reported in only three patients in each group. Rotigotine at doses of up to 16 mg/24 h is efficacious and safe in Japanese patients with advanced PD.

The International Parkinson and Movement Disorder Society (MDS)-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) has been developed and is now available in English. Part of the overall program includes the establishment of official non-English translations of the MDS-UPDRS. We present the process for completing the official Japanese translation of the MDS-UPDRS with clinimetric testing results. In this trial, the MDS-UPDRS was translated into Japanese, underwent cognitive pretesting, and the translation was modified after taking the results into account. The final translation was approved as the Official Working Draft of the MDS-UPDRS Japanese version and tested in 365 native-Japanese–speaking patients with PD. Confirmatory analyses were used to determine whether the factor structure for the English-language MDS-UPDRS could be confirmed in data collected using the Official Working Draft of the Japanese translation. As a secondary analysis, we used exploratory factor analyses to examine the underlying factor structure without the constraint of a prespecified factor organization. Confirmatory factor analysis revealed that Comparative Fit Index for all parts of the MDS-UPDRS exceeded the minimal standard of 0.90, relative to the English version, and therefore the Japanese translation met the prespecified criterion to be designated, called an official MDS translation. Secondary analyses revealed some differences between the English-language MDS-UPDRS and the Japanese translation; however, these differences were considered to be within an acceptable range. The Japanese version of the MDS-UPDRS met the criterion as an Official MDS Translation and is now available for use (www.movementdisorders.org).

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.

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. © 2013 International Parkinson and Movement Disorder Society

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 levodopa treatment causes motor complications such as wearing-off and dyskinesias in Parkinson’s disease (PD).1 Various therapeutic approaches have been developed to overcome these difficulties while maintaining adequate therapeutic levodopa levels. However, the complications and dopaminergic side effects of long-term levodopa treatment are not yet fully resolved.2 Istradefylline, a selective adenosine A2A receptor antagonist, is considered nondopaminergic because of the lack of effects on dopamine receptors and dopamine-metabolizing enzymes. Istradefylline is a new antiparkinsonian drug that can be added as a new treatment option to current PD therapy.3,4 In experimental parkinsonian animals, istradefylline, when used in combination with levodopa, exhibits an additive effect on motor control without worsening levodopa-induced dyskinesia.6–9 All10–14 but 115 of the previous studies showed a significant decrease in OFF time. A phase 2b Japanese study showed reduction in daily OFF time16; it is the purpose of this study to confirm our previous results.

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. © 2013 Movement Disorder Society

Early-onset Parkinson’s disease (PD) denotes onset of the disease below the age of 40 years. Patients tend to have a slower disease progression, an increased rate of dystonia, an increased rate of dyskinesias in response to L-3,4-dihydroxyphenylalanine and a lower rate of dementia compared with those in late-onset PD. Early-onset PD patients may experience more social and psychosocial conflict compared with late-onset patients and these factors would contribute to greater impairment of quality of life. Unemployment due to disability or early retirement may be causes for these conflicts. We have to take these factors into account whenever we institute drug therapy in early-onset PD. There is no randomized controlled study on early-onset PD; however, we may make a reasonable decision by considering the data on PD in general and clinical characteristics of early-onset patients. The management of motor and non-motor symptoms of early-onset PD patients is reviewed here.

We report on 8 patients with Parkinson's disease (PD) who experienced suddenly episodes of speech unrelated to the topic of conversation or wrote sentences unrelated to the context. During these episodes and later, unless pointed out, patients were unaware of the behavior. We called this phenomenon Unrelated Communication Interlude (UCI). All patients were male; half of them with impulse control disorders (punding, hypersexuality, or pathological gambling). Four patients reported sleepiness when the episodes of UCI occurred. There were no significant differences in age at examination, age of onset of PD, and neuropsychological tests score (Mini-Mental State Examination, Frontal Assessment Battery, and Beck Depression Inventory) between patients with UCI and those without. To our knowledge, this is the first reported phenomena of such abnormal behavior in Parkinson's disease. UCI was considered as automatic behavior similar to that seen in narcolepsy and excessive daytime sleepiness. UCI might be occurring in relation to excessive daytime sleepiness in PD.

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.

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.

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.

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.

Perhaps the most important unmet need in Parkinson's disease (PD) is the ability to slow or prevent progression of the neurodegeneration that underlies the motor and nonmotor features of this disorder. Pramipexole, a dopamine agonist used for the symptomatic treatment of PD, has demonstrated neuroprotective properties in laboratory studies. The PRamipexole On Underlying Disease (PROUD) study is a randomized, double-blind clinical trial evaluating the ability of pramipexole to modify disease progression using a delayed-start design. PD patients (n = 535) with mean age 62.5 years, mean duration since diagnosis of 4.4 months, and mean total Unified Parkinson's disease Rating Scale (UPDRS) score of 24.5 were recruited. In Phase I, patients were randomly assigned to be titrated to 1.5 mg pramipexole or placebo and maintained on study drug for 6-9 months. In Phase II, all patients were titrated to 1.5 mg pramipexole and maintained on study drug until the end of the study at 15 months. No rescue medication was allowed in the protocol. The primary endpoint is the change in total UPDRS score (parts I-III) from baseline to 15 months. A range of secondary endpoints separately assess UPDRS subscales, quality of life, depression, and impulse control disorders. A sub-study examined dopamine transporter uptake scans at baseline and 15 months. The results of PROUD will provide insight into the potential for early versus delayed treatment with pramipexole to modify motor outcome at 15 months in recently diagnosed PD patients.

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.

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.

To evaluate the clinical outcome of Parkinson disease (PD) patients treated with selegiline (with L-Dopa/decarboxylase inhibitor) in the early stage of the disease in comparison with that of late-stage use of selegiline.The study and the reference groups were extracted from a large database of the registry of all selegiline users (4692) between year 1998 and 2003 according to the defined criteria. The study group consisted of 106 PD patients who received selegiline within 5 years from the onset of the disease and were followed up for 7 years in average. The reference group consisted of 585 PD patients with comparable disease duration who received selegiline for 16 weeks from 9 to 11 years (mean [SD], 9.9 [0.7]) after the onset of the disease, and the evaluation was made before and after the treatment with selegiline.The sum of the Unified Parkinson's Disease Rating Scale (UPDRS) scores of 6 major motor symptoms of the study group was significantly lower than that of the reference group (mean [SD], 7.78 [4.30] vs 11.41 [3.88]; P0.0001) when compared at a point with the same disease duration (9.8 [1.7] vs 9.9 [0.7] years). The mean UPDRS score of the reference group after 4 months' treatment with selegiline did not reach that of the study group (mean [SD], 9.40 [3.76] vs 7.78 [4.30]; P = 0.0002).The clinical outcome as evaluated by the selected UPDRS motor scores was better for L-Dopa-treated patients who received selegiline within 5 years from the onset compared with those who received selegiline approximately 10 years from the onset.

SNCA duplication is a recognized cause of familial Parkinson's disease (PD). We aimed to explore the genetic and clinical variability in the disease manifestation. Molecular characterization was performed using real-time PCR, SNP arrays, and haplotype analysis. We further studied those patients who were found to harbor SNCA duplication with olfactory function tests, polysomnography, and PET. We identified four new families and one sporadic patient with SNCA duplication. Eleven symptomatic patients from these four families presented with parkinsonism, of which three subsequently developed dementia. The lifetime estimate of overall penetrance was 43.8%. FDG-PET study of symptomatic patients showed hypometabolism in the occipital lobe, whereas asymptomatic carriers of SNCA duplication demonstrated normal glucose metabolism. Symptomatic patients showed abnormal olfactory function and polysomnography and asymptomatic carriers showed normal results. The clinical features of SNCA duplication include parkinsonism with or without dementia. Asymptomatic carriers displayed normal test results with the eldest individual aged 79 years; thus, even a carrier of SNCA duplication may escape the development of PD. This difference in age-associated penetrance may be due to the genetic background or environmental exposures. Further studies of SNCA duplication carriers will help identify disease-modifiers and may open novel avenues for future treatment.

Phosphorylated tau (p-tau) is the principal component of neurofibrillary tangles, a pathological hallmark, and likely plays a neurotoxic role in tauopathies including Alzheimer’s disease (AD), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). We subjected brains from autopsy cases of AD, PSP, and CBD to a variety of immunohistochemical, immunoblotting, and pull-down assays. In this study, we show that excitatory amino acid transporter 2 (EAAT2) preferentially interacted with phosphorylated tau and was localized in neurofibrillary tangles in the brains of such patients. These results strongly indicate that EAAT2 acts in tauopathy-related neurodegeneration, and abnormalities in glutamate transport play an important role in the pathogenesis of tauopathies.Structured summaryMINT-7148349, MINT-7148361:TAU (uniprotkb:P10636) physically interacts (MI:0914) with EAAT2 (uniprotkb:P43004) by pull-down (MI:0096)MINT-7148372, MINT-7148384:TAU (uniprotkb:P10636) physically interacts (MI:0914) with EAAT2 (uniprotkb:P43004) by anti bait coimmunoprecipitation (MI:0006)

Dropped head syndrome (DHS) associated with parkinsonism is not frequent, but it markedly reduces the activities of daily living and is refractory. To elucidate the mechanism and treatment of DHS associated with parkinsonism, we assessed 28 parkinsonian patients with DHS (2 men and 26 women) by examining their clinical features and cervical-muscle-needle and surface electromyographic (EMG) recordings. We also evaluated the effects of lidocaine, muscle afferent block (MAB; 1% lidocaine mixed with ethanol), and botulinum toxin injected into the bilateral sternocleidomastoid muscles (SCMs), which were considered to be the affected muscles. In some patients, DHS occurred after the initiation or loading of dopamine agonists (less common after pergolide than cabergoline and pramipexole). Improvement was noted after a reduction in the dopamine agonist dose in some patients, and loading of l-dopa in others. Needle EMG revealed no evidence for weakness of the dorsal neck muscles. Surface EMG showed a gradual increase in SCMs activity upon passive head lifting. Lidocaine injection into SCMs markedly improved DHS, but the effect was temporary. The effect of botulinum toxin and MAB was not satisfactory. Whereas DHS could have a heterogeneous etiology, dopamine receptor sensitivity may play a role in its pathogenesis. For the treatment of DHS in parkinsonian patients, an increase in the dosage of l-dopa and a decrease in that of the dopamine agonist should be considered. Lidocaine injection (lidocaine test) could be useful for determining the most affected muscle before using botulinum toxin or MAB. Further studies are needed to examine the outcome of such treatments that include GPi-DBS.

The rare inherited form of Parkinson's disease (PD), PARK5, is caused by a missense mutation in ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1) gene, resulting in Ile93Met substitution in its gene product (UCH-L1(Ile93Met)). PARK5 is inherited in an autosomal-dominant mode, but whether the Ile93Met mutation gives rise to a gain-of-toxic-function or loss-of-function of UCH-L1 protein remains controversial. Here, we investigated the selective vulnerabilities of dopaminergic (DA) neurons in UCH-L1-transgenic (Tg) and spontaneous UCH-L1-null gracile axonal dystrophy mice to an important PD-causing insult, abnormal accumulation of alpha-synuclein (alphaSyn). Immunohistochemistry of midbrain sections of a patient with sporadic PD showed alphaSyn- and UCH-L1-double-positive Lewy bodies in nigral DA neurons, suggesting physical and/or functional interaction between the two proteins in human PD brain. Recombinant adeno-associated viral vector-mediated over-expression of alphaSyn for 4 weeks significantly enhanced the loss of nigral DA cell bodies in UCH-L1(Ile93Met)-Tg mice, but had weak effects in age-matched UCH-L1(wild-type)-Tg mice and non-Tg littermates. In contrast, the extent of alphaSyn-induced DA cell loss in gracile axonal dystrophy mice was not significantly different from wild-type littermates at 13-weeks post-injection. Our results support the hypothesis that PARK5 is caused by a gain-of-toxic-function of UCH-L1(Ile93Met) mutant, and suggest that regulation of UCH-L1 in nigral DA cells could be a future target for treatment of PD.

Recent progresses in the pathogenesis of sporadic Parkinson's disease (PD) and genetics of familial PD are reviewed. There are common molecular events between sporadic and familial PD, particularly between sporadic PD and PARK1 -linked PD due to α - synuclein ( SNCA ) mutations. In sporadic form, interaction of genetic predisposition and environmental factors is probably a primary event inducing mitochondrial dysfunction and oxidative damage resulting in oligomer and aggregate formations of α-synuclein. In PARK1 -linked PD, mutant α-synuclein proteins initiate the disease process as they have increased tendency for self-aggregation. As highly phosphorylated aggregated proteins are deposited in nigral neurons in PD, dysfunctions of proteolytic systems, i.e. the ubiquitin–proteasome system and autophagy–lysosomal pathway, seem to be contributing to the final neurodegenerative process. Studies on the molecular mechanisms of nigral neuronal death in familial forms of PD will contribute further on the understanding of the pathogenesis of sporadic PD.

To investigate the frequency of cardiac valve regurgitation related with low dose dopamine agonists in patients with Parkinson's disease (PD), echocardiograms were analyzed in 527 consecutive PD patients (448 patients treated with dopamine agonists, 79 patients never treated with dopamine agonists as age-matched controls). The frequency of mild or above mild regurgitation of the aortic valve (AR) was significantly higher in the cabergoline group (13.7%, P < 0.05) compared with the controls (2.5%). Odds ratio adjusted by age and sex for AR was significantly higher in the cabergoline group (OR, 6.45; 95% CI, 1.46-28.60; P = 0.01): odds ratio was significantly higher in patients treated with higher daily doses (OR, 14.41; 95% CI, 3.08-67.38; P = 0.0007) and higher cumulative doses (OR, 15.29; 95% CI, 3.19-73.18; P = 0.0006). No statistical difference was identified in the frequency of the tricuspid and mitral regurgitation. None of the other dopamine agonist groups including pergolide gave higher frequency or higher odds ratio compared with the controls. None of our patients showed severe regurgitation or was operated for valvular heart disease. The question as to whether or not longer duration of low dose dopamine agonist treatment would yield the same results needs further studies.

There is evidence that α-synuclein gene ( SNCA ) point mutations and gene multiplications play a pivotal role in the development of Lewy bodies (LBs) and Lewy neuritic (LN) pathology. Dysregulation of the production/degradation of the α-synuclein protein, a major component of LBs and LNs, is speculated to result in its accumulation and produce the neuropathological features of SNCA -related neurodegeneration.1 The identification of SNCA multiplications in families with parkinsonism suggests that SNCA gene dosage may play a role in the onset of Parkinson disease (PD).2 Most patients with SNCA triplication develop cognitive and autonomic dysfunction in early stage of the disease.3,4 However, three families with SNCA duplication have been reported with symptoms more reminiscent of typical PD.5,6 Interestingly, a recent study reported that one triplication (a Swedish-American pedigree) and one duplication pedigree have a common ancestor.7 As a common mechanism of multiplications, the area including the SNCA-MMRN1 locus could play a role in multiple copy numbers. Another multiplication family has been reported also to have the rearrangement change in the same region indicating the SNCA-MMRN1 locus may be fragile.2,5–7 With regard to clinical aspects, patients with SNCA duplication tend to have milder symptoms compared to those with triplication.5–7 The onset of disease in SNCA duplication patients occurs approximately 15 years later (50 years of age) than that of SNCA triplication families (35 years of age). These features suggest that differences in genetic copy numbers could influence the clinical features of PD. Recently, we identified two families of Japanese origin with SNCA duplications.8 One patient from Family B (named as B-1) developed severe parkinsonism and dementia. These findings indicate that SNCA duplication also causes PD with dementia (PDD). Three copies of the locus SNCA-MMRN1 were identified in the two duplication families. The length of …

Enhancement of neurogenesis could be a suitable treatment approach to up-regulate dopaminergic neurons in Parkinson's disease (PD). In the present study, we focused on the kinetics of the subventricular zone (SVZ) in a mouse model of PD induced by MPTP injection. We showed recently the proliferation potential of neuronal stem cells (NSCs) prepared from the olfactory bulb of an animal model of PD [Hayakawa, H., Hayashita-Kinoh, H., Nihira, T., Seki, T., Mizuno, Y., Mochizuki, H., 2007. The isolation of neural stem cells from the OB of Parkinson's disease model. Neurosci. Res.]. In this study, we examined the relationship between proliferation and differentiation of NSCs in SVZ of both acute and chronic PD models. Only acute MPTP treatment significantly increased the areas of glial fibrillary acidic protein (GFAP)-expressing cells and decreased the areas of polysialylated neural cell adhesion molecule (PSA-NCAM)-expressing cells in the SVZ. In the case of caspase-11 knockout mice, MPTP did not induce alteration in the areas of GFAP-expressing cells and PSA-NCAM-expressing cells. Our results suggest that neuroinflammation related to the caspase-11 cascade in the striatum regulates differentiation of neural stem cells in the SVZ of our mouse model of PD.

We report the results of a randomized, double-blind, placebo-controlled, 16-week study to evaluate the efficacy and safety of ropinirole, 0.75 to 15.0 mg/day, as an adjunct to levodopa. A total of 243 patients were randomly assigned into placebo or ropinirole groups. The mean (standard deviation) dose of ropinirole at endpoint was 7.12 (2.88) mg/day. The primary endpoint-the mean reduction in the Unified Parkinson's Disease Rating Scale (UPDRS) total motor score-was significantly greater for the ropinirole group than the placebo group (-9.5 vs. -4.5, P = 0.00001). The mean reduction in the UPDRS total activities of daily living (ADL) score was also significantly greater for ropinirole than for placebo (-2.7 vs. -1.0, P = 0.0002). The percentage of patients showing at least a 20% reduction in the percentage of time spent "off" was significantly greater for the ropinirole group than for the placebo group (58.7% vs. 38.6%, P = 0.030). A total of 84.3 and 65.6% of the patients experienced adverse events while receiving ropinirole or placebo, respectively. The results showed that ropinirole was more effective than placebo in improving motor function and ADL when used as an adjunct to levodopa in patients with advanced Parkinson's disease.

This article reviews the current situation regarding the treatment of Parkinson's disease (PD). How to apply the various therapeutic options to treat PD appears to be internationally agreed, but the currently available treatment methods are said to be all symptomatic ones. However, some of these may have marginal disease modifying effects. In addition, there are many investigational interventions aiming at modification of the disease processes; some of these interesting strategies are reviewed here. Regarding the currently available drugs, dopamine agonists may delay the loss of dopamine transporters in the striatum and even L-dopa may have some neuroprotective effects. Monoamine oxidase B inhibitors and coenzyme Q10 may also be disease modifying. Recently, a more systemic approach to finding disease modifying drugs has been initiated in the United States which has revealed that creatine and minocycline might have a small disease modifying effect. Although the disease modifying effect of each drug is small, eventually it may be possible to find more potent drugs for PD using this approach. Another important issue is to exchange specialists' “know-how” on the management of various problems arising from long-term L-dopa treatment such as disabling dyskinesia. Although it has not been proven by controlled clinical trials, giving small amounts of liquid L-dopa in frequent doses may be helpful in reducing the severity of dyskinesia and wearing off phenomenon.

Leucine-Rich Repeat Kinase 2 (LRRK2) is a causative gene for the autosomal dominant form of Parkinson's disease (PD). The gene encodes the approximately 280 kDa LRRK2 protein composed of domains such as leucine-rich repeats, Ras in complex proteins (Roc) followed by C-terminal of Roc (COR), mitogen-activated protein kinase kinase kinase (MAPKKK) and WD40. However, the normal function of the protein as well as its contribution to the pathogenesis of PD remains largely unknown. Here we describe the localization of LRRK2 in Golgi apparatus, plasma membrane and synaptic vesicles in cultured cells including mouse primary neurons. The membrane association of LRRK2 resists solubilization by ice-cold 1% Triton X-100, indicating its association through lipid rafts. To investigate whether mutations found in PD patients affect the localization of LRRK2, we transfected various LRRK2 mutants into cultured cells and performed fractionation experiments. Unexpectedly, the mutants are collected in both membrane and soluble fractions in a manner similar to wild type (WT). I2020T mutant LRRK2 associates with lipid rafts, similar to the WT. The lipid raft association of LRRK2 mutants as well as WT LRRK2 suggests that alteration of LRRK2 function on lipid rafts contributes to the pathogenesis of PD.

We and other workers found markedly increased levels of proinflammatory cytokines and apoptosis-related proteins in parkinsonian brain. Although the pathogenesis of Parkinson's disease (PD) remains enigmatic, apoptosis might be involved in the degeneration of dopaminergic neurons in PD. To investigate the possible presence of other inflammatory cytokines and/or apoptosis-related protein, the levels of p53 protein, interferon-gamma, and NF-kappaB were measured for the first time in the brain (substantia nigra, caudate nucleus, putamen, cerebellum, and frontal cortex) from control and parkinsonian patients by a highly sensitive sandwich enzyme-linked immunosorbent assay. The p53 protein level in the caudate nucleus was significantly higher in parkinsonian patients than in controls (P

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-3β (GSK-3β) 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.

Objectives Istradefylline is a selective adenosine A2A receptor antagonist. We evaluated the safety and efficacy of istradefylline administered once daily for 52 weeks in Parkinson disease (PD) patients experiencing wearing-off symptoms on levodopa therapy. Methods This was a phase 3, multicenter, open-label, long-term study in PD patients experiencing wearing-off who had previously completed a double-blind placebo-controlled clinical study of istradefylline in Japan. Istradefylline was administered for 52 weeks at a starting dosage of 20 mg/d, with or without dosage adjustment up to 40 mg/d. Safety was assessed using the incidence of treatment-emergent adverse events, and efficacy was assessed as the change in the daily off time. Results A total of 308 patients were included in this study. The most frequently reported treatment-emergent adverse events were nasopharyngitis (24.4%) and dyskinesia (21.4%). The mean change in the daily off time from day 1 was -0.65 hour in week 2, fluctuating between -0.71 and -0.04 hour until week 52 in patients who had previously taken placebo in the preceding double-blind study. The off time reduction from baseline of the double-blind study remained at similar levels between weeks 2 and 52 in patients who had previously taken istradefylline 20 and 40 mg/d in the preceding double-blind study. Conclusions This study showed that istradefylline treatment was well tolerated and produced a sustained reduction in off time in levodopa-treated PD patients over a 52-week period.

We report on a male patient with Pick disease who had shown severe white matter atrophy and dilatation of the lateral ventricle in the frontal lobe from an early stage. Upon admission to our hospital 2 years after disease onset, the patient showed apathy, and MRI revealed severe atrophy of the cortex and white matter of the frontal lobe. He died at age 74, 11 years after disease onset. Autopsy revealed severe atrophy of the frontal and temporal lobes, severe loss of white matter in the frontal lobe, dilatation of the lateral ventricles, and cortical thinning. Histopathological examination showed severe loss of myelinated fibers in the frontal white matter and severe neuronal loss with gliosis in the frontal and temporal cortices. Many Pick bodies were seen. Our patient had a rare case of Pick disease predominantly affecting the frontal lobe with severe involvement of the white matter from an early stage. This case suggests that myelinated fibers in the white matter as well as cerebral neurons are primarily affected in Pick disease.

Oxidative stress is involved in the degeneration of the nigrostriatal dopaminergic system in Parkinson's disease (PD). Vitamin E (alpha-tocopherol) is a potent antioxidant in the cell membrane that can trap free radicals and prohibit lipid peroxidation. The retention and secretion of vitamin E are regulated by alpha-tocopherol transfer protein (TTP) in the brain and liver. Dysfunction of TTP results in systemic deficiency of vitamin E in humans and mice, and increased oxidative stress in mouse brain. In this study, we investigated the effect of vitamin E deficiency in PD development by generating an 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD using TTP knockout (TTP-/-) mice. Vitamin E concentration in the brains of TTP+/- mice was half that in TTP+/+ mice, and in TTP-/- mice, was undetectable. MPTP treatment tended to decrease striatal dopamine, but the effect was comparable and not significant in any of the three genotypes. Furthermore, the extent of loss of dopaminergic cell bodies in the substantia nigra did not differ among the groups. One the other hand, oral administration of vitamin E resulted in the partial protection of striatal dopaminergic terminals against MPTP toxicity. Our results suggest that vitamin E does not play a major protective role in MPTP-induced nigrostriatal dopaminergic neurodegeneration in the brain.