1
|
Shin HW, Hong SW, Youn YC. Clinical Aspects of the Differential Diagnosis of Parkinson's Disease and Parkinsonism. J Clin Neurol 2022; 18:259-270. [PMID: 35589315 PMCID: PMC9163948 DOI: 10.3988/jcn.2022.18.3.259] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/14/2022] [Accepted: 01/14/2022] [Indexed: 11/17/2022] Open
Abstract
Parkinsonism is a clinical syndrome presenting with bradykinesia, tremor, rigidity, and postural instability. Nonmotor symptoms have recently been included in the parkinsonian syndrome, which was traditionally associated with motor symptoms only. Various pathologically distinct and unrelated diseases have the same clinical manifestations as parkinsonism or parkinsonian syndrome. The etiologies of parkinsonism are classified as neurodegenerative diseases related to the accumulation of toxic protein molecules or diseases that are not neurodegenerative. The former class includes Parkinson's disease (PD), multiple-system atrophy, progressive supranuclear palsy, and corticobasal degeneration. Over the past decade, clinical diagnostic criteria have been validated and updated to improve the accuracy of diagnosing these diseases. The latter class of disorders unrelated to neurodegenerative diseases are classified as secondary parkinsonism, and include drug-induced parkinsonism (DIP), vascular parkinsonism, and idiopathic normal-pressure hydrocephalus (iNPH). DIP and iNPH are regarded as reversible and treatable forms of parkinsonism. However, studies have suggested that the absence of protein accumulation in the nervous system as well as managing the underlying causes do not guarantee recovery. Here we review the differential diagnosis of PD and parkinsonism, mainly focusing on the clinical aspects. In addition, we describe recent updates to the clinical criteria of various disorders sharing clinical symptoms with parkinsonism.
Collapse
Affiliation(s)
- Hae-Won Shin
- Department of Neurology, Chung-Ang University College of Medicine, Seoul, Korea
| | - Sang-Wook Hong
- Department of Neurology, Chung-Ang University College of Medicine, Seoul, Korea
| | - Young Chul Youn
- Department of Neurology, Chung-Ang University College of Medicine, Seoul, Korea.
| |
Collapse
|
2
|
Vieira SRL, Toffoli M, Campbell P, Schapira AHV. Biofluid Biomarkers in Parkinson's Disease: Clarity Amid Controversy. Mov Disord 2020; 35:1128-1133. [PMID: 32220025 DOI: 10.1002/mds.28030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/21/2020] [Accepted: 03/03/2020] [Indexed: 01/15/2023] Open
Affiliation(s)
- Sophia R L Vieira
- Department of Clinical and Movement Neurosciences, University College London Queen Square Institute of Neurology, London, United Kingdom
| | - Marco Toffoli
- Department of Clinical and Movement Neurosciences, University College London Queen Square Institute of Neurology, London, United Kingdom
| | - Philip Campbell
- Department of Clinical and Movement Neurosciences, University College London Queen Square Institute of Neurology, London, United Kingdom
| | - Anthony H V Schapira
- Department of Clinical and Movement Neurosciences, University College London Queen Square Institute of Neurology, London, United Kingdom
| |
Collapse
|
3
|
Cerri S, Ghezzi C, Sampieri M, Siani F, Avenali M, Dornini G, Zangaglia R, Minafra B, Blandini F. The Exosomal/Total α-Synuclein Ratio in Plasma Is Associated With Glucocerebrosidase Activity and Correlates With Measures of Disease Severity in PD Patients. Front Cell Neurosci 2018; 12:125. [PMID: 29867358 PMCID: PMC5968118 DOI: 10.3389/fncel.2018.00125] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 04/19/2018] [Indexed: 11/24/2022] Open
Abstract
Intensive research efforts in the field of Parkinson’s disease (PD) are focusing on identifying reliable biomarkers which possibly help physicians in predicting disease onset, diagnosis, and progression as well as evaluating the response to disease-modifying treatments. Given that abnormal alpha-synuclein (α-syn) accumulation is a primary component of PD pathology, this protein has attracted considerable interest as a potential biomarker for PD. Alpha-synuclein can be detected in several body fluids, including plasma, where it can be found as free form or in association with exosomes, small membranous vesicles secreted by virtually all cell types. Together with α-syn accumulation, lysosomal dysfunctions seem to play a central role in the pathogenesis of PD, given the crucial role of lysosomes in the α-syn degradation. In particular, heterozygous mutations in the GBA1 gene encoding lysosomal enzyme glucocerebrosidase (GCase) are currently considered as the most important risk factor for PD. Different studies have found that GCase deficiency leads to accumulation of α-syn; whereas at the same time, increased α-syn may inhibit GCase function, thus inducing a bidirectional pathogenic loop. In this study, we investigated whether changes in plasma total and exosome-associated α-syn could correlate with disease status and clinical parameters in PD and their relationship with GCase activity. We studied 39 PD patients (mean age: 65.2 ± 8.9; men: 25), without GBA1 mutations, and 33 age-matched controls (mean age: 61.9 ± 6.2; men: 15). Our results showed that exosomes from PD patients contain a greater amount of α-syn compared to healthy subjects (25.2 vs. 12.3 pg/mL, p < 0.001) whereas no differences were found in plasma total α-syn levels (15.7 vs. 14.8 ng/mL, p = 0.53). Moreover, we highlighted a significant increase of plasma exosomal α-syn/total α-syn ratio in PD patients (1.69 vs. 0.89, p < 0.001), which negatively correlates with disease severity (p = 0.014). Intriguingly, a significant inverse correlation between GCase activity and this ratio in PD subjects was found (p = 0.006). Additional and large-scale studies comparing GCase activity and pathological protein levels will be clearly needed to corroborate these data and determine whether the association between key players in the lysosomal system and α-syn can be used as diagnostic or prognostic biomarkers for PD.
Collapse
Affiliation(s)
- Silvia Cerri
- Laboratory of Functional Neurochemistry, IRCCS Mondino Foundation Pavia, Italy
| | - Cristina Ghezzi
- Laboratory of Functional Neurochemistry, IRCCS Mondino Foundation Pavia, Italy
| | - Maria Sampieri
- Laboratory of Functional Neurochemistry, IRCCS Mondino Foundation Pavia, Italy
| | - Francesca Siani
- Laboratory of Functional Neurochemistry, IRCCS Mondino Foundation Pavia, Italy
| | - Micol Avenali
- Neurological Rehabilitation Unit, IRCCS Mondino Foundation Pavia, Italy.,Department of Brain and Behavioral Sciences, University of Pavia Pavia, Italy
| | - Gianluca Dornini
- Immunohemeatology and Transfusion Service, Fondazione IRCCS Policlinico San Matteo Pavia, Italy
| | - Roberta Zangaglia
- Parkinson's Disease and Movement Disorders Unit, IRCCS Mondino Foundation Pavia, Italy
| | - Brigida Minafra
- Parkinson's Disease and Movement Disorders Unit, IRCCS Mondino Foundation Pavia, Italy
| | - Fabio Blandini
- Laboratory of Functional Neurochemistry, IRCCS Mondino Foundation Pavia, Italy
| |
Collapse
|
4
|
Yang XL, Gao CM. c‑Jun N‑terminal kinase 3 signalling serves a potential role as a biomarker for determining the pathogenesis of Parkinson's disease. Mol Med Rep 2017; 17:3255-3259. [PMID: 29257285 DOI: 10.3892/mmr.2017.8244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 06/05/2017] [Indexed: 11/05/2022] Open
Abstract
Parkinson's disease (PD) is a movement-associated disorder that specifically affects dopamine-producing neurons. The disease causes demyelation that adversely impacts upon the motor activity of the brain. Currently there are no promising biomarkers for PD; improved understanding of the molecular mechanisms underlying the different pathological stages of PD are required to enable identification of a novel biomarker. The present study successfully established a PD mouse model via nasal injection of 1‑methyl-4‑phenyl-1,2,3,6-tetrahydropyridine. The expression of c‑Jun N‑termal kinase 3 (JNK3) and caspase‑3 in two different pathological stages of PD were analysed using immunohistochemistry and western blot analysis. The results inidcated that the initial PD pathogenesis recovers on response to rasagiline. Immunohistochemistry and western blot analysis revealed that treatment with rasagiline positively regulated early‑stage PD pathogenesis by downregulating the expression of JNK3 and upregulating caspase‑3; however, there was no positive effect on the advanced stages of PD. Overall, these results concluded that rasagiline has the ability to inhibit the expression of JNK3 and upregulate caspase‑3 in early stages of PD; however, rasagline appears to have no impact on JNK3 and caspase‑3 levels in the advanced stages of PD.
Collapse
Affiliation(s)
- Xiu-Li Yang
- The Department of Blood Transfusion, The First People's Hospital of Shangqiu, Shangqiu, Henan 476100, P.R. China
| | - Chun-Mei Gao
- The Department of Blood Transfusion, The First People's Hospital of Shangqiu, Shangqiu, Henan 476100, P.R. China
| |
Collapse
|
5
|
|
6
|
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease and pathologically is characterised by a progressive loss of dopaminergic cells of the nigrostriatal pathway. Clinically, PD is mainly defined by the presence of the motor symptoms of bradykinesia, rigidity, rest tremor and postural instability, but non-motor symptoms such as depression, dementia and autonomic disturbances are recognised as integral parts of the disease. Although pharmacotherapy for PD was introduced almost 50 years ago, and has improved significantly over the intervening period, the timing of initiation of treatment in newly diagnosed PD remains controversial. While some physicians favour an early start of pharmacotherapy at or soon after diagnosis, others prefer to delay pharmacological treatment until a certain degree of disability has developed. This article aims to discuss the advantages and disadvantages of both strategies by exploring their effects on symptoms, disease progression and quality of life. Although the data on putative disease-modifying effects of early pharmacological intervention in PD are still inconclusive, we believe that the most important indication for an early initiation of anti-parkinsonian treatment should be to maintain the quality of life of PD patients and to secure their socioeconomic status as long as possible.
Collapse
|
7
|
Prakash KM, Nadkarni NV, Lye WK, Yong MH, Chew LM, Tan EK. A longitudinal study of non-motor symptom burden in Parkinson's disease after a transition to expert care. Parkinsonism Relat Disord 2015; 21:843-7. [PMID: 25997863 DOI: 10.1016/j.parkreldis.2015.04.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 04/12/2015] [Accepted: 04/17/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Non-motor symptoms (NMS) are common among patients with Parkinson's disease (PD) however little is known about their progression in terms of severity or burden after referral to expert care. OBJECTIVE This study was aimed to establish the progression of NMS burden in PD patients after referral to tertiary healthcare centre and factors affecting it. METHODS Newly referred PD patients were prospectively enrolled and follow-up for up to 18 months. Non-motor symptoms scale (NMSS) was used to evaluate the burden of non-motor symptoms. RESULTS There was a significant median reduction of total NMS burden over the follow-up period. Similarly all NMS domains except domains 2 (sleep/fatigue), 3 (mood/cognition), 6 (gastrointestinal) and 7 (urinary) showed significant median reduction of scores. In the univariate regression analysis, Hoehn & Yahr staging, disease duration, visit, Schwab & England Activities of Daily Living score and UPDRS motor scores were individually predictive of change in total NMS burden. However, in the multivariable regression analysis only the latter three were significantly predictive of change in the total NMS burden. CONCLUSION There was a significant reduction of total NMS burden over the study period. The severity of motor and activity of daily living impairments as well as subsequent visit were the best predictors of NMS change.
Collapse
Affiliation(s)
- Kumar M Prakash
- Department of Neurology, Singapore; Singapore General Hospital, Singapore; National Neuroscience Institute, Singapore; Duke-NUS Graduate Medical School, Singapore.
| | - Nivedita V Nadkarni
- Centre for Quantitative Medicine, Singapore; Duke-NUS Graduate Medical School, Singapore
| | - Weng-Kit Lye
- Centre for Quantitative Medicine, Singapore; Duke-NUS Graduate Medical School, Singapore
| | - Ming-Hui Yong
- Department of Neurology, Singapore; Singapore General Hospital, Singapore
| | - Lai-Mun Chew
- Department of Neurology, Singapore; Singapore General Hospital, Singapore; National Neuroscience Institute, Singapore
| | - Eng-King Tan
- Department of Neurology, Singapore; Singapore General Hospital, Singapore; National Neuroscience Institute, Singapore; Duke-NUS Graduate Medical School, Singapore
| |
Collapse
|
8
|
Deep brain stimulation of the subthalamic nucleus: All that glitters isn't gold? Mov Disord 2015; 30:632-7. [DOI: 10.1002/mds.26149] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 12/08/2014] [Accepted: 12/14/2014] [Indexed: 12/27/2022] Open
|
9
|
Mestre TA, Espay AJ, Marras C, Eckman MH, Pollak P, Lang AE. Subthalamic nucleus-deep brain stimulation for early motor complications in Parkinson's disease-the EARLYSTIM trial: Early is not always better. Mov Disord 2014; 29:1751-6. [DOI: 10.1002/mds.26024] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 07/02/2014] [Accepted: 07/06/2014] [Indexed: 11/10/2022] Open
Affiliation(s)
- Tiago A. Mestre
- Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, University Health Network, Division of Neurology, University of Toronto; Toronto Ontario Canada
- Parkinson's Disease and Movement Disorders Clinic; Division of Neurology; University of Ottawa, The Ottawa Hospital; Ottawa Ontario Canada
| | - Alberto J. Espay
- James J. and Joan A. Gardner Family Center for Parkinson's Disease and, Movement Disorders, Department of Neurology, UC Neuroscience, Institute University of Cincinnati; Cincinnati Ohio USA
| | - Connie Marras
- Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, University Health Network, Division of Neurology, University of Toronto; Toronto Ontario Canada
| | - Mark H. Eckman
- James J. and Joan A. Gardner Family Center for Parkinson's Disease and, Movement Disorders, Department of Neurology, UC Neuroscience, Institute University of Cincinnati; Cincinnati Ohio USA
| | - Pierre Pollak
- Service de Neurologie; Département de Neurosciences Cliniques; Hôpitaux Universitaires de Genève; Genève Switzerland
| | - Anthony E. Lang
- Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, University Health Network, Division of Neurology, University of Toronto; Toronto Ontario Canada
| |
Collapse
|
10
|
Reinoso G, Allen JC, Au WL, Seah SH, Tay KY, Tan LCS. Clinical evolution of Parkinson's disease and prognostic factors affecting motor progression: 9-year follow-up study. Eur J Neurol 2014; 22:457-63. [PMID: 24888502 DOI: 10.1111/ene.12476] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 04/07/2014] [Indexed: 11/26/2022]
Abstract
BACKGROUND AND PURPOSE There have been few long-term studies that have characterized and charted the clinical progression of Parkinson's disease (PD). This study was therefore undertaken to understand the natural clinical evolution of treated PD patients and to identify the variables that predict greater progression in these patients. METHODS A longitudinal linear mixed model analysis of motor score progression was performed on 576 PD patients derived from the National Neuroscience Institute Movement Disorders Database. Clinical and demographic variables were taken at baseline and formed the subgroups for comparison (gender, age at diagnosis, subtype, Mini-Mental State Examination score and baseline motor score). Motor score progression was calculated at each patient follow-up time point as the difference between Unified Parkinson's Disease Rating Scale (UPDRS) motor score at baseline and follow-up scores. RESULTS The overall annual motor score progression as measured by the change of UPDRS motor scores from baseline ranged from 0.62% to 3.67%. There are three distinct phases: improvement, stability, and steady progression. Patients returned to baseline score 2-2.5 years after diagnosis, with stability lasting to 7 years, followed by a period of steady progression. When analyzed longitudinally, male gender (P < 0.03), older age at diagnosis (P < 0.05), akinetic-rigid subtype (P < 0.04), cognitive impairment (P < 0.005) and lower baseline motor score (P < 0.04) were associated with greater progression of motor scores. CONCLUSIONS Our results show that, when measured clinically, motor progression was non-linear and that it occurred in distinct phases, all of which were affected by baseline demographic and clinical variables such as gender, age at diagnosis, disease subtype, cognitive status and baseline motor score.
Collapse
Affiliation(s)
- G Reinoso
- Duke - NUS Graduate Medical School, Singapore
| | | | | | | | | | | |
Collapse
|
11
|
Small intestinal bacterial overgrowth in Parkinson's disease. Parkinsonism Relat Disord 2014; 20:535-40. [PMID: 24637123 DOI: 10.1016/j.parkreldis.2014.02.019] [Citation(s) in RCA: 187] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 02/10/2014] [Accepted: 02/19/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND Recent studies reported a high prevalence of small intestinal bacterial overgrowth (SIBO) in Parkinson's disease (PD), and a possible association with gastrointestinal symptoms and worse motor function. We aimed to study the prevalence and the potential impact of SIBO on gastrointestinal symptoms, motor function, and quality of life in a large cohort of PD patients. METHODS 103 Consecutive PD patients were assessed using the lactulose-hydrogen breath test; questionnaires of gastrointestinal symptoms and quality of life (PDQ-39); the Unified PD Rating Scale (UPDRS) including "on"-medication Part III (motor severity) score; and objective and quantitative measures of bradykinesia (Purdue Pegboard and timed test of gait). Patients and evaluating investigators were blind to SIBO status. RESULTS 25.3% of PD patients were SIBO-positive. SIBO-positive patients had a shorter mean duration of PD (5.2 ± 4.1 vs. 8.1 ± 5.5 years, P = 0.007). After adjusting for disease duration, SIBO was significantly associated with lower constipation and tenesmus severity scores, but worse scores across a range of "on"-medication motor assessments (accounting for 4.2-9.0% of the variance in motor scores). There was no association between SIBO and motor fluctuations or PDQ-39 Summary Index scores. CONCLUSIONS This is the largest study to date on SIBO in PD. SIBO was detected in one quarter of patients, including patients recently diagnosed with the disease. SIBO was not associated with worse gastrointestinal symptoms, but independently predicted worse motor function. Properly designed treatment trials are needed to confirm a causal link between SIBO and worse motor function in PD.
Collapse
|
12
|
Abstract
PURPOSE OF REVIEW Parkinson disease is the second most common neurodegenerative disease after Alzheimer disease, and current demographic trends indicate a life-time risk approaching 4% and predict a doubling of prevalence by 2030. Strategies are being developed to apply recent advances in our understanding of the cause of Parkinson disease to the development of biomarkers that will enable the identification of at-risk individuals, enable early diagnosis and reflect the progression of disease. The latter will be particularly important for the testing of disease-modifying therapies. This review summarizes recent advances in Parkinson disease biomarker development. RECENT FINDINGS Recent reports continue to reflect the application of a variety of clinical, imaging or biochemical measurements, alone or in combination, to general Parkinson disease populations. Probably the most promising is the assay of alpha-synuclein in the diagnosis and evolution of Parkinson disease. At present, detection techniques are still being refined, but once accurate and reproducible assays are available, it will be important to define the relationship of these to early diagnosis and progression. Alpha-synuclein concentrations may also be modulated by certain disease-modifying agents in development and so may represent a measure of their efficacy. It has to be accepted that no single measure currently fulfils all the necessary criteria for a biomarker in Parkinson disease, but combinations of measures are more likely to deliver benefit. SUMMARY The Parkinson disease biomarker field is approaching a stage when certain combinations of clinical, imaging and biochemical measures may identify a proportion of individuals at risk for developing the disease. However, their general applicability may be limited. Attention is now turning to stratification of Parkinson disease into certain at-risk groups defined by genotype. The application of multimodal screening to these populations may be more rewarding in the short term.
Collapse
|
13
|
Ray Chaudhuri K, Rojo JM, Schapira AHV, Brooks DJ, Stocchi F, Odin P, Antonini A, Brown RJ, Martinez-Martin P. A proposal for a comprehensive grading of Parkinson's disease severity combining motor and non-motor assessments: meeting an unmet need. PLoS One 2013; 8:e57221. [PMID: 23468940 PMCID: PMC3584126 DOI: 10.1371/journal.pone.0057221] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 01/18/2013] [Indexed: 01/25/2023] Open
Abstract
Background Non-motor symptoms are present in Parkinson's disease (PD) and a key determinant of quality of life. The Non-motor Symptoms Scale (NMSS) is a validated scale that allows quantifying frequency and severity (burden) of NMS. We report a proposal for using NMSS scores to determine levels of NMS burden (NMSB) and to complete PD patient classification. Methods This was an observational, cross-sectional international study of 935 consecutive patients. Using a distribution of NMSS scores by quartiles, a classification based on levels from 0 (no NMSB at all) to 4 (very severe NMSB) was obtained and its relation with Hoehn and Yahr (HY) staging, motor and health-related quality of life scales was analyzed. Concordance between NMSB levels and grouping based on clinician's global impression of severity, using categorical regression, was determined. Disability and HRQoL predictors were identified by multiple regression models. Results The distribution of motor and QoL scales scores by HY and NMSB levels was significantly discriminative. The difference in the classification of cases for both methods, HY and NMSB, was significant (gamma = 0.45; ASE = 0.032). Concordance between NMSB and global severity-based levels from categorical regression was 91.8%, (kappaw = 0.97). NMS score was predictor of disability and QoL. Conclusions Current clinical practice does not address a need for inclusion of non-motor scores in routine assessment of PD in spite of the overwhelming influence of NMS on disability and quality of life. Our data overcome the problems of “pure motor assessment” and we propose a combined approach with addition of NMSB levels to standard motor assessments.
Collapse
Affiliation(s)
- Kallol Ray Chaudhuri
- National Parkinson Foundation Centre of Excellence, Kings College Hospital and Kings College, and University Hospital Lewisham, London, United Kingdom
| | - Jose Manuel Rojo
- Department of Statistics, Centre of Human and Social Sciences, Spanish Council for Scientific Research, Madrid, Spain
| | | | - David J. Brooks
- Department of Medicine, Imperial College London, London, United Kingdom
| | | | - Per Odin
- Department of Neurology, Lund University Hospital, Lund, Sweden
| | - Angelo Antonini
- Department for Parkinson's Disease, IRCCS San Camillo, Venice, Italy
| | - Richard J. Brown
- Department of Psychology, Institute of Psychiatry, Kings College London, London, United Kingdom
| | - Pablo Martinez-Martin
- Alzheimer Disease Research Unit and CIBERNED, CIEN Foundation, Carlos III Institute of Health, Alzheimer Centre Reina Sofia Foundation, Madrid, Spain
- * E-mail:
| |
Collapse
|
14
|
Abstract
SIGNIFICANCE Several genetic causes of familial Parkinson's disease (PD) have now been identified and include mutations of genes encoding mitochondrial proteins. Mitochondrial complex I toxins can induce dopaminergic cell death and produce a parkinsonian state. Importantly, defects of mitochondrial function have been identified in postmortem substantia nigra from pathologically proven cases of PD. RECENT ADVANCES These observations provide compelling evidence to support the notion that mitochondria play an important role in the pathogenesis of PD. Thus, targeting mitochondrial function to delay or prevent neuronal cell death would represent a logical means to modify the course of this disease. Several attempts have already been made in this respect, and have been tested in clinical trial. CRITICAL ISSUES To date, there is no unequivocal evidence for an effective intervention to slow the disease. However, several novel mitochondrial targets are now emerging, including the potential to manipulate the mitochondrial pool to maintain function via biogenesis and mitophagy. FUTURE DIRECTIONS This development in drug targets needs to be supported by a parallel improvement in clinical trial design to be able to detect a neuroprotective or disease-modifying effect over a reasonable time scale.
Collapse
|
15
|
Schapira AHV. Monoamine oxidase B inhibitors for the treatment of Parkinson's disease: a review of symptomatic and potential disease-modifying effects. CNS Drugs 2011; 25:1061-71. [PMID: 22133327 DOI: 10.2165/11596310-000000000-00000] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Parkinson's disease is a disorder characterized pathologically by progressive neurodegeneration of the dopaminergic cells of the nigrostriatal pathway. Although the resulting dopamine deficiency is the cause of the typical motor features of Parkinson's disease (bradykinesia, rigidity, tremor), additional non-motor symptoms appear at various timepoints and are the result of non-dopamine nerve degeneration. Monoamine oxidase B (MAO-B) inhibitors are used in the symptomatic treatment of Parkinson's disease as they increase synaptic dopamine by blocking its degradation. Two MAO-B inhibitors, selegiline and rasagiline, are currently licensed in Europe and North America for the symptomatic improvement of early Parkinson's disease and to reduce off-time in patients with more advanced Parkinson's disease and motor fluctuations related to levodopa. A third MAO-B inhibitor (safinamide), which also combines additional non-dopaminergic properties of potential benefit to Parkinson's disease, is currently under development in phase III clinical trials as adjuvant therapy to either a dopamine agonist or levodopa. MAO-B inhibitors have also been studied extensively for possible neuroprotective or disease-modifying actions. There is considerable laboratory evidence that MAO-B inhibitors do exert some neuroprotective properties, at least in the Parkinson's disease models currently available. However, these models have significant limitations and caution is required in assuming that such results may easily be extrapolated to clinical trials. Rasagiline 1 mg/day has been shown to provide improved motor control in terms of Unified Parkinson's Disease Rating Scale (UPDRS) score at 18 months in those patients with early disease who began the drug 9 months before a second group. There are a number of possible explanations for this effect that may include a disease-modifying action; however, the US FDA recently declined an application for the licence of rasagiline to be extended to cover disease modification.
Collapse
|