1
|
Zeng S, Zhou X, He R, Zhao Y, Liu Z, Xu Q, Guo J, Yan X, Li J, Tang B, Sun Q. Association Analysis of Essential Tremor-Associated Genetic Variants in Sporadic Late-Onset Parkinson's Disease. Tremor Other Hyperkinet Mov (N Y) 2024; 14:25. [PMID: 38737298 PMCID: PMC11086585 DOI: 10.5334/tohm.885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 04/25/2024] [Indexed: 05/14/2024] Open
Abstract
Background Parkinson's disease (PD) and Essential tremor (ET) are the two most common tremor diseases with recognized genetic pathogenesis. The overlapping clinical features suggest they may share genetic predispositions. Our previous study systematically investigated the association between rare coding variants in ET-associated genes and early-onset PD (EOPD), and found the suggestive association between teneurin transmembrane protein 4 (TENM4) and EOPD. In the current research, we explored the potential genetic interplay between ET-associated genetic loci/genes and sporadic late-onset PD (LOPD). Methods We performed whole-genome sequencing in the 1962 sporadic LOPD cases and 1279 controls from mainland China. We first used logistic regression analysis to test the top 16 SNPs identified by the ET genome-wide association study for the association between ET and LOPD. Then we applied the optimized sequence kernel association testing to explore the rare variant burden of 33 ET-associated genes in this cohort. Results We did not observe a significant association between the included SNPs with LOPD. We also did not discover a significant burden of rare deleterious variants of ET-associated genes in association with LOPD risk. Conclusion Our results do not support the role of ET-associated genetic loci and variants in LOPD. Highlights 1962 cases and 1279 controls were recruited to study the potential genetic interplay between ET-associated genetic loci/variants and sporadic LOPD.No significant association between the ET-associated SNPs and LOPD were observed.No significant burden of rare deleterious variants of ET-associated gene in LOPD risk were found.
Collapse
Affiliation(s)
- Sheng Zeng
- Department of Geriatrics, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
| | - Xun Zhou
- Department of Geriatric Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Runcheng He
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Yuwen Zhao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Zhenhua Liu
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Qian Xu
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Jifeng Guo
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Xinxiang Yan
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Jinchen Li
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Geriatric Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Beisha Tang
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Geriatric Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, 410008, China
| | - Qiying Sun
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, 410008, China
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, 410008, China
| |
Collapse
|
2
|
Yoo SW, Ha S, Lyoo CH, Kim Y, Yoo JY, Kim JS. Exploring the link between essential tremor and Parkinson's disease. NPJ Parkinsons Dis 2023; 9:134. [PMID: 37714868 PMCID: PMC10504235 DOI: 10.1038/s41531-023-00577-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 09/04/2023] [Indexed: 09/17/2023] Open
Abstract
Epidemiological studies have reported a link between essential tremor (ET) and Parkinson's disease (PD). Recent studies have suggested ET as a possible neurodegenerative disease whose subgroup contained Lewy bodies in the brainstem, as in PD. PD with antedated ET (PDconv) might exhibit traits different from those of the pure form of ET or PD. This study aimed to unveil the interplay between PD and premorbid ET, which might be the core pathobiology that differentiates PDconv from PD. The study included 51 ET, 32 PDconv, and 95 PD patients who underwent positron emission tomography using 18F-N-(3-fluoropropyl)-2beta-carbon ethoxy-3beta-(4-iodophenyl) nortropane and 123I-meta-iodobenzylguanidine myocardial scintigraphy to analyze central dopaminergic and peripheral noradrenergic integrity. The results show that PDconv group followed the typical striatal pathology of PD but with a delay in noradrenergic impairment as it caught up with the denervating status of PD a few years after PD diagnosis. Whereas the two PD subtypes displayed similar patterns of presynaptic dopamine transporter deficits, ET patients maintained high densities in all subregions except thalamus. Presynaptic dopaminergic availability decreased in a linear or quadratic fashion across the three groups (ET vs. PDconv vs. PD). The age at onset and duration of ET did not differ between pure ET and PDconv patients and did not influence the striatal monoamine status. The myocardium in PDconv patients was initially less denervated than in PD patients, but it degenerated more rapidly. These findings suggest that PDconv could be a distinctive subclass in which the pathobiology of PD interacts with that of ET in the early phase of the disease.
Collapse
Affiliation(s)
- Sang-Won Yoo
- Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Seunggyun Ha
- Division of Nuclear Medicine, Department of Radiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Chul Hyoung Lyoo
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Yuna Kim
- Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Ji-Yeon Yoo
- Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Joong-Seok Kim
- Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
| |
Collapse
|
3
|
Louis ED, Berry D, Ghanem A, Cosentino SA. Conversion Rate of Essential Tremor to Essential Tremor Parkinson Disease: Data From a Prospective Longitudinal Study. Neurol Clin Pract 2023; 13:e200162. [PMID: 37256209 PMCID: PMC10226077 DOI: 10.1212/cpj.0000000000200162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/02/2023] [Indexed: 06/01/2023]
Abstract
Background and Objectives There has been a long-standing dialog as to whether essential tremor (ET) increases the risk of developing Parkinson disease (PD). While there are relevant cross-sectional data, there are almost no longitudinal prospective data. We quantified the conversion rate from ET to ETPD in a prospective longitudinal cohort study of patients with ET. We compared the observed rate with that reported in the epidemiologic literature. Methods We enrolled patients with ET in a prospective, longitudinal study. A senior movement disorders neurologist evaluated standardized neurologic examinations every 18 months. Results One hundred ninety-three patients with ET (mean age = 78.1 ± 9.6 years, range = 55-96) had a mean follow-up duration of 4.1 years. Seven (3.6%) converted from ET to ETPD. The incidence of PD among patients with ET was 7/792.9 person-years (py; i.e., 882.8/100,000 py). A meta-analysis of the incidence (per 100,000 py) of PD in 14 studies from 13 countries across 4 continents reported an incidence of PD = 61.21 (men, 40 years or older) and 37.55 (women, 40 years or older). The incidence/100,000 py in men peaked in the 80- to 89-year-old age group (258.47) and in women in the 80- to 89-year-old age group (103.48 py). The abovementioned published values are 3.4-23.5 times lower than the value we observed for ET. Discussion The incidence of PD in an ET cohort is substantially higher than that reported in historical population-based control groups across numerous countries. Additional prospective longitudinal data are needed to further explore this association.
Collapse
Affiliation(s)
- Elan D Louis
- Department of Neurology (EDL, DB, AG), University of Texas Southwestern Medical Center, Dallas, TX; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain (SAC), G.H. Sergiesvky Center, and Department of Neurology, Columbia University Irving Medical Center, New York
| | - Diane Berry
- Department of Neurology (EDL, DB, AG), University of Texas Southwestern Medical Center, Dallas, TX; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain (SAC), G.H. Sergiesvky Center, and Department of Neurology, Columbia University Irving Medical Center, New York
| | - Ali Ghanem
- Department of Neurology (EDL, DB, AG), University of Texas Southwestern Medical Center, Dallas, TX; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain (SAC), G.H. Sergiesvky Center, and Department of Neurology, Columbia University Irving Medical Center, New York
| | - Stephanie A Cosentino
- Department of Neurology (EDL, DB, AG), University of Texas Southwestern Medical Center, Dallas, TX; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain (SAC), G.H. Sergiesvky Center, and Department of Neurology, Columbia University Irving Medical Center, New York
| |
Collapse
|
4
|
Louis ED, Faust PL. Prevalence of Lewy pathology in essential tremor is twice as high as expected: A plausible explanation for the enhanced risk for Parkinson disease seen in essential tremor cases. J Neuropathol Exp Neurol 2023; 82:454-455. [PMID: 36943259 PMCID: PMC10117153 DOI: 10.1093/jnen/nlad021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023] Open
Affiliation(s)
- Elan D Louis
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| |
Collapse
|
5
|
Antonazzo IC, Conti S, Rozza D, Fornari C, Eteve-Pitsaer C, Paris C, Gantzer L, Valentine D, Mantovani LG, Mazzaglia G. Time trends in the incidence of essential tremor: Evidences from UK and France primary care data. Front Neurol 2022; 13:987618. [PMID: 36203992 PMCID: PMC9531026 DOI: 10.3389/fneur.2022.987618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 08/16/2022] [Indexed: 11/30/2022] Open
Abstract
Introduction Although essential tremor (ET) is considered a common adult movement disorder, evidence on its incidence is still scant. This study aims at estimating ET incidence in two European countries, namely, the UK and France. Methods Incident cases of ET were identified within the Health Improvement Network (THIN®) database between 1st January 2014 and 31 December 2019. Yearly crude and standardized incidence rates (IR) were estimated across the study period for both countries. Poisson regression models were built to assess temporal trends in IRs and differences between sexes and age classes. Results In total, 4,970 and 4,905 incident cases of ET were identified in the UK and France, respectively. The yearly average crude IR (per 100,000 person-years) was 18.20 (95%CI: 15.09-21.32) in UK and 21.42 (17.83-25.00) in France, whereas standardized ones were 19.51 (18.97-20.01) and 19.50 (18.97-20.05). Regression analyses showed slightly increasing trends in both countries, higher incidence among males, and a significant increase with age. Yearly average IR increased from 3.96 (0.95-6.97) and 5.28 (1.12-9.44) in subjects aged <20 years to 49.27 (26.29-72.24) and 51.52 (30.19-72.86) in those aged >80 year in UK and France. Conclusions Standardized ET incidence was comparable in the UK and France, showing a slight increase in both countries, reporting a higher value among people aged 60 years and older. This study outlines the need to conduct future studies to estimate the burden of ET in terms of disease control and healthcare resource utilization.
Collapse
Affiliation(s)
| | - Sara Conti
- Research Centre on Public Health (CESP), University of Milano-Bicocca, Monza, Italy,*Correspondence: Sara Conti
| | - Davide Rozza
- Research Centre on Public Health (CESP), University of Milano-Bicocca, Monza, Italy
| | - Carla Fornari
- Research Centre on Public Health (CESP), University of Milano-Bicocca, Monza, Italy
| | | | | | | | | | | | - Giampiero Mazzaglia
- Research Centre on Public Health (CESP), University of Milano-Bicocca, Monza, Italy
| |
Collapse
|
6
|
Louis ED, Iglesias-Hernandez D, Hernandez NC, Flowers X, Kuo SH, Vonsattel JPG, Faust PL. Characterizing Lewy Pathology in 231 Essential Tremor Brains From the Essential Tremor Centralized Brain Repository. J Neuropathol Exp Neurol 2022; 81:796-806. [PMID: 35950950 PMCID: PMC9487643 DOI: 10.1093/jnen/nlac068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The Essential Tremor Centralized Brain Repository is the largest repository of prospectively collected essential tremor (ET) brains (n = 231). Hence, we are uniquely poised to address several questions: What proportion of ET cases has Lewy pathology (LP)? What is the nature of that pathology and how does it relate to other comorbidities? Each brain had a complete neuropathological assessment, including α-synuclein immunostaining. We created a 10-category classification scheme to fully encapsulate the patterns of LP observed. Four metrics of cerebellar pathology were also quantified. Mean age at death = 89.0 ± 6.4 years. Fifty-eight (25.1%) had LP and 46 (19.9%) had early to late stages of Parkinson disease (PD). LP was very heterogeneous. Of 58 cases with LP, 14 (24.1%) clinically developed possible PD or PD after a latency of 5 or more years. There was a similar degree of cerebellar pathology in ET cases both with and without LP. In summary, 1 in 4 ET cases had LP-a proportion that seems higher than expected based on studies among control populations. Heterogeneous LP likely reflects clinical associations between ET and PD, and ET with Alzheimer disease-type neuropathology. These data further our understanding of ET and its relatedness to other degenerative diseases.
Collapse
Affiliation(s)
- Elan D Louis
- From the Department of Neurology, University of Texas Southwestern, Dallas, Texas, USA
| | | | - Nora C Hernandez
- From the Department of Neurology, University of Texas Southwestern, Dallas, Texas, USA
| | - Xena Flowers
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, New York, USA
| | - Sheng-Han Kuo
- Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Jean Paul G Vonsattel
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, New York, USA
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, New York, USA
| |
Collapse
|
7
|
Cho HJ. Is essential tremor a degenerative or an electrical disorder? Electrical disorder. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:103-128. [PMID: 35750360 DOI: 10.1016/bs.irn.2022.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Essential tremor (ET) is one of the most common movement disorders, yet we do not have a complete understanding of its pathophysiology. From a phenomenology standpoint, ET is an isolated tremor syndrome of bilateral upper limb action tremor with or without tremor in other body locations. ET is a pathological tremor that arises from excessive oscillation in the central motor network. The tremor network comprises of multiple brain regions including the inferior olive, cerebellum, thalamus, and motor cortex, and there is evidence that a dynamic oscillatory disturbance within this network leads to tremor. ET is a chronic disorder, and the natural history shows a slow progression of tremor intensity with age. There are reported data suggesting that ET follows the disease model of a neurodegenerative disorder, however whether ET is a degenerative or electrical disorder has been a subject of debate. In this chapter, we will review cumulative evidence that ET as a syndrome is a fundamentally electric disorder. The etiology is likely heterogenous and may not be primarily neurodegenerative.
Collapse
Affiliation(s)
- Hyun Joo Cho
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States.
| |
Collapse
|
8
|
Louis ED, Hernandez NC, Ottman R, Clark LN. Mixed Motor Disorder: Essential Tremor Families With Heterogeneous Motor Phenomenology. Neurol Clin Pract 2022; 11:e817-e825. [PMID: 34992964 DOI: 10.1212/cpj.0000000000001100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 04/09/2021] [Indexed: 11/15/2022]
Abstract
Background and Objectives Essential tremor (ET) is one of the most prevalent movement disorders. Because ET is so common, individuals with other neurologic disorders may also have ET. There is evidence, however, that the cooccurrence of ET with Parkinson disease (PD) and/or dystonia is not merely a chance cooccurrence. We have observed combinations of these 3 movement disorders within individuals and across individuals within families containing multiple individuals with ET. This observation has a number of implications. Our objective is to present 4 ET families in whom motor phenomenology was heterogeneous and discuss the implications of this finding. Methods ET cases and their relatives were enrolled in the Family Study of Essential Tremor (2015-present). Phenotyping was performed by a senior movement disorders neurologist based on neurologic examination. Results We present 4 families, including 14 affected individuals, among whom assigned diagnoses were ET, PD, ET + PD, and ET + dystonia. In those with ET and another movement disorder, the predominant and earliest phenotype was ET. Discussion There are assortments of these 3 involuntary motor disorders, ET, dystonia, and PD, both within individuals and in different individuals within ET families. This observation has mechanistic implications. Furthermore, we believe that the concept of the mixed motor disorder should enter into and inform the clinical dialogue. In assigning diagnoses, clinicians are swayed by family history information, and they should be prepared to observe a mix of different motor disorders to manifest within particular families.
Collapse
Affiliation(s)
- Elan D Louis
- Department of Neurology (EDL, NCH), University of Texas Southwestern, Dallas; G.H. Sergievsky Center (RO), Department of Neurology (RO), College of Physicians and Surgeons, and Department of Epidemiology (RO), Mailman School of Public Health, Columbia University; Division of Translational Epidemiology (RO), New York State Psychiatric Institute; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain (LNC), College of Physicians and Surgeons, Columbia University, New York
| | - Nora C Hernandez
- Department of Neurology (EDL, NCH), University of Texas Southwestern, Dallas; G.H. Sergievsky Center (RO), Department of Neurology (RO), College of Physicians and Surgeons, and Department of Epidemiology (RO), Mailman School of Public Health, Columbia University; Division of Translational Epidemiology (RO), New York State Psychiatric Institute; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain (LNC), College of Physicians and Surgeons, Columbia University, New York
| | - Ruth Ottman
- Department of Neurology (EDL, NCH), University of Texas Southwestern, Dallas; G.H. Sergievsky Center (RO), Department of Neurology (RO), College of Physicians and Surgeons, and Department of Epidemiology (RO), Mailman School of Public Health, Columbia University; Division of Translational Epidemiology (RO), New York State Psychiatric Institute; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain (LNC), College of Physicians and Surgeons, Columbia University, New York
| | - Lorraine N Clark
- Department of Neurology (EDL, NCH), University of Texas Southwestern, Dallas; G.H. Sergievsky Center (RO), Department of Neurology (RO), College of Physicians and Surgeons, and Department of Epidemiology (RO), Mailman School of Public Health, Columbia University; Division of Translational Epidemiology (RO), New York State Psychiatric Institute; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain (LNC), College of Physicians and Surgeons, Columbia University, New York
| |
Collapse
|
9
|
Parkinsonism and tremor syndromes. J Neurol Sci 2021; 433:120018. [PMID: 34686357 DOI: 10.1016/j.jns.2021.120018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 06/06/2021] [Accepted: 09/29/2021] [Indexed: 01/22/2023]
Abstract
Tremor, the most common movement disorder, may occur in isolation or may co-exist with a variety of other neurologic and movement disorders including parkinsonism, dystonia, and ataxia. When associated with Parkinson's disease, tremor may be present at rest or as an action tremor overlapping in phenomenology with essential tremor. Essential tremor may be associated not only with parkinsonism but other neurological disorders, suggesting the possibility of essential tremor subtypes. Besides Parkinson's disease, tremor can be an important feature of other parkinsonian disorders, such as atypical parkinsonism and drug-induced parkinsonism. In addition, tremor can be a prominent feature in patients with other movement disorders such as fragile X-associated tremor/ataxia syndrome, and Wilson's disease in which parkinsonian features may be present. This article is part of the Special Issue "Parkinsonism across the spectrum of movement disorders and beyond" edited by Joseph Jankovic, Daniel D. Truong and Matteo Bologna.
Collapse
|
10
|
Phenotypic Features of Isolated Essential Tremor, Essential Tremor Plus, and Essential Tremor-Parkinson's Disease in a Movement Disorders Clinic. Tremor Other Hyperkinet Mov (N Y) 2021; 11:12. [PMID: 33828900 PMCID: PMC8015706 DOI: 10.5334/tohm.581] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Background: Patients with essential tremor were initially considered to have isolated tremor, but additional motor and non-motor features have been increasingly recognized. The term “essential tremor plus” was adopted by the Task Force on Tremor of the International Parkinson and Movement Disorder Society to describe essential tremor patients with additional neurologic signs. Objectives: To characterize essential tremor patients and their phenotypes in a movement disorders clinic population in the context of the new tremor classification. Methods: Demographic, clinical, historical, treatment, and diagnostic data were retrospectively collected on 300 patients diagnosed by movement disorder experts with essential tremor. Patients were classified as having essential tremor, essential tremor plus, or essential tremor-Parkinson’s disease combination, and features between these groups were compared. Results: Of the 300 patients, 20.7% were classified as isolated essential tremor, 53.3% as essential tremor plus, and 26.0% as essential tremor-Parkinson’s disease. There was no significant difference in the duration of tremor symptoms. Essential tremor plus patients were more likely to have dystonia, tandem gait abnormalities, head tremor and greater tremor severity. Essential tremor-Parkinson’s disease patients were more likely to have RBD symptoms. There was no significant difference in cognitive impairment between essential tremor plus and essential tremor-Parkinson’s disease patients. Conclusions: Additional motor and non-motor features, including parkinsonism, are common in patients with essential tremor. Further studies are needed to clarify essential tremor phenotypes and to provide insights into possible subtypes. Highlights: 300 patients with essential tremor from a movement disorders clinic were re-classified based on the Movement Disorder Society Consensus Statement on the Classification of Tremors. Additional motor and non-motor features, including parkinsonism, were common, and only 20.7% of patients remained classified as isolated essential tremor.
Collapse
|
11
|
Elhassanien MEM, Bahnasy WS, El-Heneedy YAE, Kishk AM, Tomoum MO, Ramadan KM, Allah Ragab OA. Olfactory dysfunction in essential tremor versus tremor dominant Parkinson disease. Clin Neurol Neurosurg 2020; 200:106352. [PMID: 33168334 DOI: 10.1016/j.clineuro.2020.106352] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 10/01/2020] [Accepted: 10/28/2020] [Indexed: 01/03/2023]
Abstract
BACKGROUND Essential tremor (ET) and tremor dominant Parkinson disease (TDPD) variant constitute the main causes of geriatric tremor which differentiation is not always an easy mission. The objective of this work was to study the olfactory performance in ET and PD patients for possible consideration as a differentiating biomarker. METHODS This study was performed on 36ET, 22 TDPD variant and 24 healthy controls subjects (HCS) submitted to extended n-butanol Sniffin' Sticks test (SST) and olfactory bulbs volumetry (OBV). RESULTS There were significant decreases in SST threshold, discrimination, identification and TDI variables in TDPD patients compared to ET and HCS. ET patients showed significant decrease in the same variables compared to HCS. Regarding OBV, there were significant decreases in TDPD patients compared to ET and HCS with nonsignificant difference between the 2-latter groups. Our results showed that TDI score of 25 can differentiate between TDPD and ET patients with sensitivity and specificity (94 %, 91 %) respectively. CONCLUSION Olfactory assessment is a rapid, safe, and easily applicable biomarker that could differentiate TDPD from ET in doubtful cases.
Collapse
|
12
|
Kudrevatykh A, Senkevich K, Miliukhina I. Postural instability and neuropsychiatric disturbance in the overlapping phenotype of essential tremor and Parkinson's Disease. Neurophysiol Clin 2020; 50:489-494. [PMID: 32873435 DOI: 10.1016/j.neucli.2020.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 07/15/2020] [Accepted: 07/15/2020] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVES The aim of this study was to perform a comparative analysis of postural and neuropsychiatric features in patients with essential tremor (ET), various Parkinson's disease (PD) phenotypes, and the phenotype of combined ET and PD (ET-PD). METHODS 169 PD patients with early (1.0-2.0) and 111 PD patients with advanced (2.5-3.0) stages based on the Hoehn and Yahr scale, 55 patients with ET and 26 patients with ET-PD were enrolled in the study. Motor and non-motor symptoms of patients with PD, ET and ET-PD were studied using standardized scales and stabilometry. RESULTS Patients with ETPD had milder manifestations of parkinsonism compared to PD patients at the same stages of the disease. Patients in the advanced PD group showed more pronounced posture and balance impairment compared to all other groups assessed by standardized walking and balance scales. No difference using scales for postural assessment was found between ETPD, ET and early stage PD. Using stabilometry, we discovered that indexes of stabilometric parameters were lower in ETPD patients compared to ET and advanced PD, although no difference between ETPD and early PD was found. PD patients in early stages had lower results in most of the indexes compared to ET. CONCLUSION Here, we conducted for the first time a stabilometric examination of ET-PD patients, which could be helpful in differential diagnosis. This analysis helps expand understanding of the clinical manifestations of PD, ET and ET-PD.
Collapse
Affiliation(s)
- Anastasia Kudrevatykh
- Institute of Experimental Medicine, St. Petersburg, Russia; First Pavlov State Medical University of St. Petersburg, St. Petersburg, Russia
| | - Konstantin Senkevich
- First Pavlov State Medical University of St. Petersburg, St. Petersburg, Russia; Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of National Research Centre "Kurchatov Institute", Gatchina, Russia.
| | - Irina Miliukhina
- Institute of Experimental Medicine, St. Petersburg, Russia; First Pavlov State Medical University of St. Petersburg, St. Petersburg, Russia; Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of National Research Centre "Kurchatov Institute", Gatchina, Russia
| |
Collapse
|
13
|
Hossein‐Tehrani MR, Ghaedian T, Hooshmandi E, Kalhor L, Foroughi AA, Ostovan VR. Brain TRODAT‐SPECT Versus MRI Morphometry in Distinguishing Early Mild Parkinson's Disease from Other Extrapyramidal Syndromes. J Neuroimaging 2020; 30:683-689. [DOI: 10.1111/jon.12740] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/18/2020] [Accepted: 05/21/2020] [Indexed: 01/26/2023] Open
Affiliation(s)
| | - Tahereh Ghaedian
- Nuclear Medicine and Molecular Imaging Research Center, Namazi Teaching Hospital Shiraz University of Medical Sciences Shiraz Iran
| | - Etrat Hooshmandi
- Clinical Neurology Research Center Shiraz University of Medical Sciences Shiraz Iran
| | - Leila Kalhor
- Nuclear Medicine and Molecular Imaging Research Center, Namazi Teaching Hospital Shiraz University of Medical Sciences Shiraz Iran
| | - Amin Abolhasani Foroughi
- Medical Imaging Research Center Shiraz University of Medical Sciences Shiraz Iran
- Epilepsy Research Center Shiraz University of Medical Sciences Shiraz Iran
| | - Vahid Reza Ostovan
- Clinical Neurology Research Center Shiraz University of Medical Sciences Shiraz Iran
| |
Collapse
|
14
|
Abstract
Essential tremor is one of the most common movement disorders in adults and can affect both children and adults. An updated consensus statement in 2018 redefined essential tremor as an isolated action tremor present in bilateral upper extremities for at least three years. Tremor may also be present in other locations, commonly the neck or the vocal cords. Patients with additional neurologic symptoms are now categorized as "essential tremor plus." Additional clinical features associated with the condition include but are not limited to cognitive impairment, psychiatric disorders, and hearing loss. When treatment is needed, propranolol and primidone are considered first line treatments. Patients who are severely affected are often offered deep brain stimulation. Although the ventral intermediate nucleus of the thalamus is the traditional surgical target, the caudal zona incerta is also being studied as a possible superior alternative. Magnetic resonance imaging guided high intensity focused ultrasound is a newer surgical alternative that may be ideal for patients with substantial medical comorbidities. Current research explores novel oral treatments, chemodenervation, and noninvasive neuromodulation for treatment of essential tremor.
Collapse
Affiliation(s)
- Vicki Shanker
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| |
Collapse
|
15
|
Cardaioli G, Ripandelli F, Paolini Paoletti F, Nigro P, Simoni S, Brahimi E, Romoli M, Filidei M, Eusebi P, Calabresi P, Tambasco N. Substantia nigra hyperechogenicity in essential tremor and Parkinson's disease: a longitudinal study. Eur J Neurol 2019; 26:1370-1376. [PMID: 31094036 DOI: 10.1111/ene.13988] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 04/23/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE Essential tremor (ET) and Parkinson's disease (PD) sometimes overlap in their clinical expression with ET preceding PD onset, often leading to misdiagnosis. Transcranial sonography (TCS) has been shown to be a valid and non-invasive diagnostic tool to identify early idiopathic PD and to differentiate it from ET. The purpose of this study was to investigate the relevance of substantia nigra hyperechogenicity in patients with ET. METHODS A total of 138 patients (79 with PD, 59 with ET) and 50 matched controls underwent TCS examination at baseline. All patients were followed in a 3-year longitudinal assessment. RESULTS A total of 10 subjects were excluded from the analysis due to the bilateral absence of a temporal acoustic window. During the follow-up period, 11 of the patients with ET developed new-onset parkinsonian features, without fulfilling criteria for PD diagnosis (ET+). Nine patients developed clinical features meeting diagnostic criteria for probable PD (ET-PD). Patients with ET- did not develop parkinsonian features. For each group, the maximum size of the substantia nigra hyperechogenicity was as follows: 5.62 ± 5.40 mm2 in the control group, 19.02 ± 14.27 mm2 in patients with PD, 9.15 ± 11.26 mm2 in patients with ET-, 20.05 ± 13.78 mm2 in patients with ET+ and 20.13 ± 13.51 mm2 in patients with ET-PD. ET-PD maximum values were significantly different from controls. Maximum values in patients with ET+ were different from both controls and patients with ET-. CONCLUSION Substantia nigra hyperechogenicity in ET seems to represent a risk marker for developing early parkinsonian symptoms or signs in the 3 years following TCS assessment.
Collapse
Affiliation(s)
- G Cardaioli
- Neurology Clinic, University of Perugia, Perugia, Italy
| | - F Ripandelli
- Neurology Clinic, University of Perugia, Perugia, Italy
| | | | - P Nigro
- Neurology Clinic, University of Perugia, Perugia, Italy
| | - S Simoni
- Neurology Clinic, University of Perugia, Perugia, Italy
| | - E Brahimi
- Neurology Clinic, University of Perugia, Perugia, Italy
| | - M Romoli
- Neurology Clinic, University of Perugia, Perugia, Italy
| | - M Filidei
- Neurology Clinic, University of Perugia, Perugia, Italy
| | - P Eusebi
- Neurology Clinic, University of Perugia, Perugia, Italy
| | - P Calabresi
- Neurology Clinic, University of Perugia, Perugia, Italy.,IRCCS, Fondazione Santa Lucia, Rome, Italy
| | - N Tambasco
- Neurology Clinic, University of Perugia, Perugia, Italy
| |
Collapse
|
16
|
Tarakad A, Jankovic J. Essential Tremor and Parkinson's Disease: Exploring the Relationship. Tremor Other Hyperkinet Mov (N Y) 2019; 8:589. [PMID: 30643667 PMCID: PMC6329774 DOI: 10.7916/d8md0gvr] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/04/2018] [Indexed: 12/31/2022] Open
Abstract
Background There is longstanding controversy surrounding the possible link between essential tremor (ET) and Parkinson's disease (PD). Inconsistent and unreliable diagnostic criteria may in part account for some of the difficulties in defining the relationship between these two common movement disorders. Methods References for this systematic review were identified using PubMed with the search terms "essential tremor" AND "Parkinson's disease" with articles published in English between 1960 and September 2018 included. Results In this review we provide evidence that some patients diagnosed with ET have an increased risk of developing PD years or decades after onset of action tremor. There are several still unresolved questions about the link between the two disorders including lack of verifiable diagnostic criteria for the two disorders and marked overlap in phenomenology. Here we review clinical, epidemiologic, imaging, pathologic, and genetic studies that address the ET-PD relationship. Several lines of evidence support the association between ET and PD, including overlapping motor and non-motor features, relatively high prevalence of rapid eye movement sleep behavior disorder (26-43%) in ET patients, increased prevalence of PD in patients with longstanding antecedent ET, increased prevalence of ET in family members of patients with PD, and the presence of Lewy bodies in the brains of some ET patients (15-24%). Discussion There is a substantial body of evidence supporting the association between ET and PD within at least a subset of patients, although the nature and possible pathogenic mechanisms of the relationship are not well understood.
Collapse
Affiliation(s)
- Arjun Tarakad
- Parkinson’s Disease Center and Movement Disorders Clinic, Baylor College of Medicine Houston, TX, USA
| | - Joseph Jankovic
- Parkinson’s Disease Center and Movement Disorders Clinic, Baylor College of Medicine Houston, TX, USA
| |
Collapse
|
17
|
Yuan L, Deng X, Song Z, Deng S, Zheng W, Mao P, Deng H. Systematic analysis of genetic variants in patients with essential tremor. Brain Behav 2018; 8:e01100. [PMID: 30252209 PMCID: PMC6192404 DOI: 10.1002/brb3.1100] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 07/21/2018] [Accepted: 07/28/2018] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Essential tremor (ET), a prevalent neurological disorder, is featured by postural and kinetic tremors in upper limbs. Studies of twins and families indicate an important role for genetic factors in ET development. There are substantial overlaps between ET and Parkinson's disease (PD). The aim of this study was to examine the possible roles of genetic variants in ET development. METHODS A total of 200 Han Chinese ET patients and 432 ethnically matched normal controls were enrolled, and genetic analysis of 23 variants in 15 genes was performed. RESULTS Genotypic and allelic frequencies of the melanocortin 1 receptor gene (MC1R) variant rs34090186 showed statistically significant differences in ET patients and controls (p = 0.027 and 0.028, odds ratio = 2.789 and 2.744, 95% confidence interval: 1.084-7.179 and 1.075-7.005). No statistically significant difference was revealed in either genotypic or allelic distributions of other variants or haplotypes (all p > 0.05). CONCLUSIONS The discrepancies found in this study indicate the variant rs34090186 in the MC1R gene, some variants of which were reported to be related to increased risk of PD and melanoma, may play a risk role in ET, confirming a potential association between ET and PD. Evidence supporting ET-PD link will continue to accumulate and improve our understanding of any underlying mechanisms for both disorders.
Collapse
Affiliation(s)
- Lamei Yuan
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiong Deng
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zhi Song
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Sheng Deng
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha, China
| | - Wen Zheng
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Ping Mao
- Department of Nursing Education, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Hao Deng
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| |
Collapse
|
18
|
Arabia G, Lupo A, Manfredini LI, Vescio B, Nisticò R, Barbagallo G, Salsone M, Morelli M, Novellino F, Nicoletti G, Quattrone A, Cascini GL, Louis ED, Quattrone A. Clinical, electrophysiological, and imaging study in essential tremor-Parkinson's disease syndrome. Parkinsonism Relat Disord 2018; 56:20-26. [PMID: 29885986 DOI: 10.1016/j.parkreldis.2018.06.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 05/17/2018] [Accepted: 06/03/2018] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Essential tremor-Parkinson's disease (ET-PD) syndrome is a clinical condition in which individuals with a long-lasting history of Essential tremor (ET) eventually develop Parkinson's disease (PD). The aim of the study was to investigate the accuracy performances of clinical, neurophysiological, and imaging biomarkers in differentiating patients affected by ET-PD syndrome from patients with ET or PD. METHODS Nineteen patients affected by ET-PD syndrome, 48 ET patients, and 37 tremor-dominant PD (t-PD) patients were included. Electrophysiological studies, including blink-reflex recovery cycle and tremor parameters analyses, were performed in all groups. Nigro-striatal and cardiac sympathetic denervation were also investigated. Sensitivity, specificity and accuracy of clinical, electrophysiological, and radiological features in differentiating ET-PD syndrome from ET and PD were calculated. RESULTS ET-PD patients had significantly lower rigidity (p = 0.007) and higher postural/kinetic tremor (p = 0.007) scores, in comparison to t-PD patients. ET-PD patients, differently from PD patients, had a synchronous pattern of resting tremor and, differently from ET patients, had abnormal blink-reflex recovery cycle. ET-PD patients also showed reduced nigro-striatal and cardiac sympathetic uptakes, albeit to a lesser extent than in PD patients. The highest accuracy values were found for the synchronous pattern of resting tremor (97.1%) in distinguishing ET-PD from PD, and for presence of abnormal blink-recovery cycle (100%) in distinguishing ET-PD syndrome from ET. CONCLUSION Our study demonstrates that some electrophysiological parameters, such as a synchronous resting tremor pattern and the abnormal blink-recovery cycle were the most accurate biomarkers in distinguishing patient with ET-PD syndrome from those with ET or those with PD.
Collapse
Affiliation(s)
- Gennarina Arabia
- Institute of Neurology, Department of Medical Sciences, University "Magna Graecia" of Catanzaro, Italy
| | - Angela Lupo
- Institute of Neurology, Department of Medical Sciences, University "Magna Graecia" of Catanzaro, Italy
| | - Lucia Ilaria Manfredini
- Institute of Neurology, Department of Medical Sciences, University "Magna Graecia" of Catanzaro, Italy
| | | | - Rita Nisticò
- Neuroimaging Research Unit, IBFM, National Research Council, Catanzaro, Italy
| | - Gaetano Barbagallo
- Institute of Neurology, Department of Medical Sciences, University "Magna Graecia" of Catanzaro, Italy
| | - Maria Salsone
- Neuroimaging Research Unit, IBFM, National Research Council, Catanzaro, Italy
| | - Maurizio Morelli
- Institute of Neurology, Department of Medical Sciences, University "Magna Graecia" of Catanzaro, Italy
| | - Fabiana Novellino
- Neuroimaging Research Unit, IBFM, National Research Council, Catanzaro, Italy
| | - Giuseppe Nicoletti
- Neuroimaging Research Unit, IBFM, National Research Council, Catanzaro, Italy
| | - Andrea Quattrone
- Institute of Neurology, Department of Medical Sciences, University "Magna Graecia" of Catanzaro, Italy
| | | | - Elan D Louis
- Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, USA; Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT, USA; Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Aldo Quattrone
- Neuroimaging Research Unit, IBFM, National Research Council, Catanzaro, Italy; Neuroscience Center, University "Magna Graecia" of Catanzaro, Italy.
| |
Collapse
|
19
|
Ng ASL, Ng EYL, Tan YJ, Prakash KM, Au WL, Tan LCS, Tan EK. Case-control analysis of LRRK2 protective variants in Essential Tremor. Sci Rep 2018; 8:5346. [PMID: 29593234 PMCID: PMC5871891 DOI: 10.1038/s41598-018-23711-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 03/19/2018] [Indexed: 01/16/2023] Open
Abstract
Co-existence of Parkinson’s disease (PD) and essential tremor (ET) may reflect overlapping pathophysiology underlying both conditions. Furthermore, PD patients with leucine-rich repeat kinase-2 (LRRK2) mutations may present with ET-like features, suggesting the possibility of common genetic underpinnings. Two common LRRK2 variants, R1398H and N551K, have been shown to be protective in multiple PD cohorts. We hypothesized that R1398H and N551K may show a similar effect in ET. In a case-control study involving 3198 subjects (2680 controls and 518 ET cases), R1398H was detected in 16.6% of ET cases compared to 18.0% in controls (OR = 0.91, 95% CI = 0.71–1.17, p = 0.46); while N551K was detected in 16.5% of ET cases compared to 18.0% of controls (OR = 0.89, 95% CI = 0.69–1.15, p = 0.37). While these results suggest that LRRK2 R1398H or N551K do not appear to modulate the risk of ET, it remains possible that a protective trend for both variants may be present in ET and a much larger sample size is required to identify this.
Collapse
Affiliation(s)
- Adeline S L Ng
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore.
| | - Ebonne Y L Ng
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, 20 College Road, Singapore, 169856, Singapore
| | - Yi Jayne Tan
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
| | - Kumar M Prakash
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, 20 College Road, Singapore, 169856, Singapore.,Neuroscience and Behavioural Disorders Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Wing Lok Au
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
| | - Louis C S Tan
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
| | - Eng-King Tan
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, 20 College Road, Singapore, 169856, Singapore. .,Neuroscience and Behavioural Disorders Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore.
| |
Collapse
|
20
|
Abstract
Essential tremor (ET) is one of the most common neurologic disorders, and genetic factors are thought to contribute significantly to disease etiology. There has been a relative lack of progress in understanding the genetic etiology of ET. This could reflect a number of factors, including the presence of substantial phenotypic and genotypic heterogeneity. Thus, a meticulous approach to phenotyping is important for genetic research. A lack of standardized phenotyping across studies and patient centers likely has contributed to the relative lack of success of genomewide association studies in ET. To dissect the genetic architecture of ET, whole-genome sequencing will likely be of value. This will allow specific hypotheses about the mode of inheritance and genetic architecture to be tested. A number of approaches still remain unexplored in ET genetics, including the contribution of copy number variants, uncommon moderate-effect alleles, rare variant large-effect alleles (including Mendelian and complex/polygenic modes of inheritance), de novo and gonadal mosaicism, epigenetic changes, and noncoding variation.
Collapse
Affiliation(s)
- Lorraine N Clark
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, and Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, United States
| | - Elan D Louis
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York; and Departments of Neurology and of Chronic Disease Epidemiology and Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, New Haven, CT, United States.
| |
Collapse
|
21
|
Abstract
Essential tremor (ET) is a progressive and highly prevalent neurologic disease. Along with the tremors, mild to moderate gait ataxia and other signs of cerebellar dysfunction may occur (i.e., subtle saccadic eye movement abnormalities and abnormalities of motor timing) as well as cognitive features, some of which may be due to cerebellar dysfunction. Numerous neuroimaging studies indicate the presence of functional, metabolic, and structural abnormalities in the cerebellum of a patient with ET. In tandem with these clinical and imaging studies, which were gathering increasing support for the notion that the cerebellum and/or cerebellar systems seemed to be at the root of ET, a growing postmortem literature is for the first time beginning to identify microscopic abnormalities in the ET brain, most of which are centered on the Purkinje cells and connected neuronal populations, and are likely to be degenerative. In terms of treatment, most of these pharmacotherapeutic agents serve to enhance GABAergic neurotransmission, further bolstering the notion that ET may very well be a disorder with a primary Purkinje cell dysfunction resulting in reduced cerebellar cortical inhibition. Similarly, the interruption of presumably abnormal cerebellar outflow pathways to the thalamus is the mechanism of deep-brain stimulation surgery, which is highly effective in treating ET.
Collapse
Affiliation(s)
- Elan D Louis
- Department of Neurology and Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, New Haven, CT, United States; Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT, United States.
| |
Collapse
|
22
|
Bouwmans AEP, Weber WEJ, Leentjens AFG, Mess WH. Transcranial sonography findings related to depression in parkinsonian disorders: cross-sectional study in 126 patients. PeerJ 2016; 4:e2037. [PMID: 27231659 PMCID: PMC4878362 DOI: 10.7717/peerj.2037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/23/2016] [Indexed: 12/02/2022] Open
Abstract
Background. Transcranial sonography (TCS) has emerged as a potential diagnostic tool for Parkinson’s disease. Recent research has suggested that abnormal echogenicity of substantia nigra, raphe nuclei and third ventricle is associated with increased risk of depression among these patients. We sought to reproduce these findings in an ongoing larger study of patients with parkinsonian syndromes. Methods. A total of 126 patients with parkinsonian symptoms underwent the Hamilton Depression Scale, and TCS of the substantia nigra (SN) (n = 126), the raphe nuclei (RN) (n = 80) and the third ventricle (n = 57). We then calculated the correlation between depression and hyper-echogenic SN, hypo-echogenic RN and a wider third ventricle. Results. In patients with PD we found no significant difference of the SN between non-depressed and depressed patients (46% vs. 22%; p = 0.18). Non-depressed patients with other parkinsonisms more often had hyperechogenicity of the SN than depressed patients (51% vs. 0%; p = 0.01). We found no relation between depression and the echogenicity of the RN or the width of the third ventricle. Conclusions. In patients with parkinsonian syndromes, we found no association between depression and hyper-echogenic SN, hypo-echogenic RN or a wider third ventricle, as determined by transcranial sonography.
Collapse
Affiliation(s)
| | - Wim E J Weber
- Department of Neurology, Maastricht University Medical Centre , Maastricht , Netherlands
| | - Albert F G Leentjens
- Department of Psychiatry, Maastricht University Medical Centre , Maastricht , Netherlands
| | - Werner H Mess
- Department of Clinical Neurophysiology, Maastricht University Medical Centre , Maastricht , Netherlands
| |
Collapse
|
23
|
Hamed SA, Abdellah MM. The relationship between valproate induced tremors and circulating neurotransmitters: a preliminary study. Int J Neurosci 2016; 127:236-242. [PMID: 27161592 DOI: 10.1080/00207454.2016.1181631] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
24
|
Martino R, Candundo H, Lieshout PV, Shin S, Crispo JAG, Barakat-Haddad C. Onset and progression factors in Parkinson's disease: A systematic review. Neurotoxicology 2016; 61:132-141. [PMID: 27058967 DOI: 10.1016/j.neuro.2016.04.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 04/04/2016] [Indexed: 12/18/2022]
Abstract
Current research has identified several factors thought to be associated with the onset and progression of Parkinson's Disease (PD); however, whether certain factors contribute to or are protective against PD remains unclear. As such, a systematic search of the literature was performed using variations of MeSH and keyword search terms to identify and summarize systematic reviews and primary studies pertaining to factors associated with the onset and progression of PD. Factors referred to both traditional risk factors and prodromal markers. The following databases were searched: MEDLINE, MEDLINE In-Process, EMBASE, PsycINFO, Scopus, Web of Science, Cochrane Database of Systematic Reviews, Cumulative Index to Nursing and Allied Health Literature (CINAHL), ProQuest Dissertations & Theses, AARP AgeLine, and PDGene. A quality assessment of included systematic reviews was completed using the validated Assessment of the Methodological Quality of Systematic Reviews (AMSTAR) tool. Data extraction targeted reported factors, risk estimates, and 95% confidence intervals (CI). Findings identified 11 systematic reviews of sufficient quality reporting factors for PD onset, and no systematic reviews reporting factors for PD progression. In addition, 93 primary articles were identified, of which, 89 articles addressed factors related to PD onset and 4 articles addressed factors related to the PD progression. Pesticide exposure, rural living, well-water drinking, and farming occupation were consistently found to be positively associated with the onset of PD. Moreover, family history and polymorphisms to key genes were also found to be positively associated with the onset of PD. Conversely, coffee consumption, cigarette smoking, and some polymorphisms were consistently found to be negatively associated with the onset of PD. Urate was the only identified factor linked to the progression of PD; it was mostly found to be negatively associated with PD. In sum, the evidence was systematically found and summarized in the literature pertaining to factors related to the onset and progression of PD.
Collapse
Affiliation(s)
- Rosemary Martino
- Department of Speech-Language Pathology, University of Toronto, Toronto, Canada; Rehabilitation Sciences Institute, University of Toronto, Toronto, Canada; Health Care and Outcomes Research, Krembil Research Institute, University Health Network, Toronto, Canada.
| | - Hamilton Candundo
- Faculty of Health Sciences, University of Ontario Institute of Technology, Toronto, Canada
| | - Pascal van Lieshout
- Department of Speech-Language Pathology, University of Toronto, Toronto, Canada; Rehabilitation Sciences Institute, University of Toronto, Toronto, Canada; Department of Psychology, University of Toronto, Toronto, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada; Toronto Rehabilitation Institute, University Health Network, Toronto, Canada
| | - Sabina Shin
- Faculty of Health Sciences, University of Ontario Institute of Technology, Toronto, Canada
| | - James A G Crispo
- McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada
| | | |
Collapse
|
25
|
The relationship between essential tremor and Parkinson's disease. Parkinsonism Relat Disord 2016; 22 Suppl 1:S162-5. [DOI: 10.1016/j.parkreldis.2015.09.032] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 09/13/2015] [Accepted: 09/15/2015] [Indexed: 11/18/2022]
|
26
|
Lafo JA, Jones JD, Okun MS, Bauer RM, Price CC, Bowers D. Memory Similarities Between Essential Tremor and Parkinson's Disease: A Final Common Pathway? Clin Neuropsychol 2015; 29:985-1001. [PMID: 26689342 DOI: 10.1080/13854046.2015.1118553] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
OBJECTIVE A growing body of literature supports the view that essential tremor (ET) involves alteration of cerebellar-thalamo-cortical networks which can result in working memory and executive deficits. In this study, we tested the hypothesis that individuals with ET would exhibit worse performance on memory tasks requiring more intrinsic organization and structuring (i.e., word lists) relative to those with fewer 'executive' demands (i.e., stories), similar to that previously observed in individuals with Parkinson's disease (PD). METHOD Participants included a convenience sample of 68 ET patients and 68 idiopathic PD patients, retrospectively matched based on age, education, and sex. All patients underwent routine neuropsychological evaluation assessing recent memory, auditory attention/working memory, language, and executive function. Memory measures included the Hopkins Verbal Learning Test-R and WMS-III Logical Memory. RESULTS Both ET and PD patients performed significantly worse on word list than story memory recall tasks. The magnitude of the difference between these two memory tasks was similar for ET and PD patients. In both patient groups, performance on measures of executive function and auditory attention/working memory was not distinctly correlated with word list vs. story recall. CONCLUSIONS These findings suggest that frontal-executive dysfunction in both ET and PD may negatively influence performance on memory tests that are not inherently organized. Although the pathophysiology of these two 'movement disorders' are quite distinct, both have downstream effects on thalamo-frontal circuitry which may provide a common pathway for a similar memory phenotype. Findings are discussed in terms of neuroimaging evidence, conceptual models, and best practice.
Collapse
Affiliation(s)
- Jacob A Lafo
- a Department of Clinical and Health Psychology, College of Public Health & Health Professions , University of Florida , Gainesville , FL , USA.,c Center for Movement Disorders and Neurorestoration , University of Florida College of Medicine, University of Florida , Gainesville , FL , USA
| | - Jacob D Jones
- a Department of Clinical and Health Psychology, College of Public Health & Health Professions , University of Florida , Gainesville , FL , USA.,c Center for Movement Disorders and Neurorestoration , University of Florida College of Medicine, University of Florida , Gainesville , FL , USA
| | - Michael S Okun
- b Department of Neurology , University of Florida College of Medicine, University of Florida , Gainesville , FL , USA.,c Center for Movement Disorders and Neurorestoration , University of Florida College of Medicine, University of Florida , Gainesville , FL , USA
| | - Russell M Bauer
- a Department of Clinical and Health Psychology, College of Public Health & Health Professions , University of Florida , Gainesville , FL , USA.,c Center for Movement Disorders and Neurorestoration , University of Florida College of Medicine, University of Florida , Gainesville , FL , USA
| | - Catherine C Price
- a Department of Clinical and Health Psychology, College of Public Health & Health Professions , University of Florida , Gainesville , FL , USA.,c Center for Movement Disorders and Neurorestoration , University of Florida College of Medicine, University of Florida , Gainesville , FL , USA
| | - Dawn Bowers
- b Department of Neurology , University of Florida College of Medicine, University of Florida , Gainesville , FL , USA.,c Center for Movement Disorders and Neurorestoration , University of Florida College of Medicine, University of Florida , Gainesville , FL , USA
| |
Collapse
|
27
|
Louis ED, Clark L, Ottman R. Familial Aggregation and Co-Aggregation of Essential Tremor and Parkinson's Disease. Neuroepidemiology 2015; 46:31-6. [PMID: 26606512 DOI: 10.1159/000442021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 10/25/2015] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Current data suggest that the 2 common tremor disorders, essential tremor (ET) and Parkinson's disease (PD), may be associated with one another. Familial aggregation studies allow one to further explore their relatedness. METHODS Probands with ET (n = 110), PD (n = 130) or both ET and PD (n = 27) and control probands (n = 177) reported whether they had relatives with these diseases or with non-specific tremor. RESULTS A greater proportion of ET probands than control probands reported relatives with ET (30.0 vs. 2.8%, p < 0.001), non-specific tremor (38.2 vs. 13.6%, p < 0.001) and both ET and PD in different relatives (6.4 vs. 0.6%, p = 0.004). A greater proportion of PD probands than control probands reported relatives with PD (20.0 vs. 8.5%, p = 0.003), ET (11.5 vs. 2.8%, p = 0.002) and both ET and PD in different relatives (6.9 vs. 0.6%, p = 0.002). CONCLUSIONS This study provides evidence for the aggregation of ET in ET families and PD in PD families, and the familial co-aggregation of ET and PD.
Collapse
Affiliation(s)
- Elan D Louis
- Department of Neurology, Yale School of Medicine, Yale University, New Haven, Conn., USA
| | | | | |
Collapse
|
28
|
Béliveau E, Tremblay C, Aubry-Lafontaine É, Paris-Robidas S, Delay C, Robinson C, Ferguson L, Rajput AH, Rajput A, Calon F. Accumulation of amyloid-β in the cerebellar cortex of essential tremor patients. Neurobiol Dis 2015; 82:397-408. [PMID: 26253607 DOI: 10.1016/j.nbd.2015.07.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 07/24/2015] [Accepted: 07/31/2015] [Indexed: 12/31/2022] Open
Abstract
The accumulation of insoluble amyloid-beta (Aβ) peptides is associated with neurodegenerative disorders, such as Alzheimer's disease (AD). As essential tremor (ET) could involve neurodegenerative processes in the cerebellum, we quantified soluble and insoluble Aβ in cerebellar cortices from patients diagnosed with ET (n=9), compared to Controls (n=16) or individuals with Parkinson's disease (n=10). Although ante-mortem cognitive performance was not documented, all individuals included had the diagnosis of AD ruled out by a neuropathologist. ELISA-determined concentrations of insoluble Aβ42 in ET patients displayed a bimodal distribution, with a median 246-fold higher than in Controls (P<0.01, Kruskal-Wallis). Higher Aβ42 concentrations were measured in the parietal cortex of the same ET patients, compared to Controls (107-fold median increase, P<0.01, Kruskal-Wallis), but similar phosphorylated tau levels were detected. The rise in cerebellar insoluble Aβ42 concentrations is not associated to APP expression and processing or the ApoE4 status. However, Aβ42 levels in ET individuals were correlated with cerebellar insoluble phosphorylated tau (r(2)=0.71, P=0.005), unphosphorylated neurofilament heavy chain (NF-H; r(2)=0.50, P=0.030) and Lingo-1 (r(2)=0.73, P=0.007), indicative of a generalized neurodegenerative process involving the cerebellum. Our results suggest prevalent accumulations of insoluble Aβ42 in the cerebellum of ET, but not in age-matched PD. Whether this anomaly plays a role in ET symptoms warrants further investigations.
Collapse
Affiliation(s)
- Eric Béliveau
- Faculty of Pharmacy, Université Laval, Québec, QC, Canada; Neurosciences Axis, Centre de recherche du CHU de Québec, Québec, QC, Canada
| | - Cyntia Tremblay
- Faculty of Pharmacy, Université Laval, Québec, QC, Canada; Neurosciences Axis, Centre de recherche du CHU de Québec, Québec, QC, Canada
| | - Émilie Aubry-Lafontaine
- Faculty of Pharmacy, Université Laval, Québec, QC, Canada; Neurosciences Axis, Centre de recherche du CHU de Québec, Québec, QC, Canada
| | - Sarah Paris-Robidas
- Faculty of Pharmacy, Université Laval, Québec, QC, Canada; Neurosciences Axis, Centre de recherche du CHU de Québec, Québec, QC, Canada
| | | | - Chris Robinson
- Division of Neurology, Royal University Hospital, University of Saskatchewan, Saskatoon, SK, Canada
| | - Les Ferguson
- Division of Neurology, Royal University Hospital, University of Saskatchewan, Saskatoon, SK, Canada
| | - Ali H Rajput
- Division of Neurology, Royal University Hospital, University of Saskatchewan, Saskatoon, SK, Canada
| | - Alex Rajput
- Division of Neurology, Royal University Hospital, University of Saskatchewan, Saskatoon, SK, Canada
| | - Frédéric Calon
- Faculty of Pharmacy, Université Laval, Québec, QC, Canada; Neurosciences Axis, Centre de recherche du CHU de Québec, Québec, QC, Canada.
| |
Collapse
|
29
|
Agúndez JA, Jiménez-Jimenez FJ, Alonso-Navarro H, García-Martín E. The potential of LINGO-1 as a therapeutic target for essential tremor. Expert Opin Ther Targets 2015; 19:1139-48. [PMID: 25862159 DOI: 10.1517/14728222.2015.1028360] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
INTRODUCTION LINGO-1 is a negative regulator of neuronal survival, oligodendrocyte differentiation and axonal outgrowth and regeneration, because it interacts with diverse growth factor receptors blocking or inhibiting their action. Consistent findings obtained in vitro and in animal models suggest that anti-LINGO-1 therapy may be useful in neurodegenerative disorders such as multiple sclerosis (MS), Parkinson's disease or essential tremor (ET). Moreover, genetic and pathological evidence provide a robust link between LINGO-1 and ET. AREAS COVERED In this review, we present an overview of current knowledge on findings linking LINGO-1 and ET, with a special focus on genetic linkage, we include an overview of LINGO1 gene variations according to the 1000 genomes catalog, and we identify potential gene areas where common changes occur because, as well as the risk developing ET, LINGO1 genetic changes may influence the response to anti-LINGO-1 therapy. EXPERT OPINION The goal of anti-LINGO-1 therapy in neurodegenerative diseases is to ease the brakes of neuronal growth and recovery. An anti-LINGO-1 antibody is under clinical trials for MS patients. Before planning trials with ET patients, refinement on the genetic link between LINGO1 and ET, and a detailed genetic and phenotypic assessment of ET patients to be enrolled, should be carried out.
Collapse
Affiliation(s)
- José Ag Agúndez
- University of Extremadura, Department of Pharmacology , Avda. de la Universidad s/n, E-10071, Cáceres , Spain +34927257000 Ext 86897 ; +34924289676 ;
| | | | | | | |
Collapse
|
30
|
Mitochondrial serine protease HTRA2 gene mutation in Asians with coexistent essential tremor and Parkinson disease. Neurogenetics 2015; 16:241-2. [PMID: 25791756 DOI: 10.1007/s10048-015-0443-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 03/05/2015] [Indexed: 11/27/2022]
|
31
|
Štenc Bradvica I, Mihaljević I, Butković-Soldo S, Kadojić D, Titlić M, Bradvica M, Kralik K. Transcranial sonography and the pocket smell test in the differential diagnosis between parkinson's disease and essential tremor. Neurol Sci 2015; 36:1403-10. [PMID: 25787809 DOI: 10.1007/s10072-015-2152-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 03/05/2015] [Indexed: 11/29/2022]
Abstract
The aim of this study was to determine the specificity and sensitivity of transcranial sonography (TCS) and the Pocket Smell Test (PST) in differing Parkinson's disease from essential tremor. The results were compared with the dopamin transporter scan (DaTSCAN) findings. Based on the DaTSCAN finding we formed a group of patients with essential tremor (51 patients) and a group with the Parkinson's disease (59 patients). The control group consisted of 26 healthy one. To evaluate the olfactory dysfunction the PST was used, whereas by TCS the substantia nigra hyperechogenicity was marked. The sensitivity and specificity of each diagnostic method was statistically calculated. In confirming Parkinson's disease the specificity of TCS was 88.2 % and the sensitivity 94.9 %. The specificity of PST was 80.4 % whereas the sensitivity was 74.6 %. TCS and PST should be performed to evaluate which patients need to be examined by DaTSCAN.
Collapse
Affiliation(s)
- Ivanka Štenc Bradvica
- Department of Neurology, Faculty of Medicine, Osijek University Hospital, "Josip Juraj Strossmayer" University of Osijek, Osijek, Croatia,
| | | | | | | | | | | | | |
Collapse
|
32
|
Chao YX, Ng EY, Tan L, Prakash KM, Au WL, Zhao Y, Tan EK. Lrrk2 R1628P variant is a risk factor for essential tremor. Sci Rep 2015; 5:9029. [PMID: 25761573 PMCID: PMC4356963 DOI: 10.1038/srep09029] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 02/16/2015] [Indexed: 12/30/2022] Open
Abstract
Essential tremor (ET) and Parkinson's disease (PD) are two of the most common adult onset movement disorders with overlapping clinical features. PD patients with leucine-rich repeat kinase-2 (LRRK2) mutations may present initially with an ET phenotype. To address the possibility of a common genetic link between ET and PD, we examined the association between a common LRRK2 R1628P gene variant and ET. The LRRK2 R1628P was genotyped in ET cases and matched healthy controls. A total of 1277 subjects comprising of 450 ET cases and 827 controls were included. There were 40 heterozygote (GG to CG) variant out of 450 ET cases (genotypic frequency 8.9%) and 36 heterozygote variant (GG to CG, genotypic frequency 4.3%) and one homozygote variant (GG to CC) out of 827 controls. Subjects carrying the R1628P variant had a twofold increased risk of ET (p = 0.0035, OR = 2.20 and 95% confidence interval is 1.30–3.73). Using a case control methodology, we demonstrated an association between a known PD risk variant, LRRK2 R1628P, with ET. Subjects carrying the R1628P variant had twice the risk of developing ET. The sharing of a similar gene risk variant suggests a possible pathophysiologic link between PD and ET.
Collapse
Affiliation(s)
- Yin Xia Chao
- 1] Departments of Neurology, Singapore General Hospital [2] National Neuroscience Institute
| | - Ebonne Yulin Ng
- 1] Departments of Neurology, Singapore General Hospital [2] National Neuroscience Institute
| | | | | | | | - Yi Zhao
- Clinical Research, Singapore General Hospital
| | - Eng-King Tan
- 1] Departments of Neurology, Singapore General Hospital [2] Clinical Research, Singapore General Hospital [3] National Neuroscience Institute [4] Duke-NUS Graduate Medical School
| |
Collapse
|
33
|
Zou YM, Tan JP, Li N, Yang JS, Yu BC, Yu JM, Zhao YM, Wang LN. Do physical exercise and reading reduce the risk of Parkinson's disease? a cross-sectional study on factors associated with Parkinson's disease in elderly Chinese veterans. Neuropsychiatr Dis Treat 2015; 11:695-700. [PMID: 25834444 PMCID: PMC4370918 DOI: 10.2147/ndt.s79707] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND The purpose of this study was to investigate risk factors for and factors protecting against Parkinson's disease (PD) in elderly Chinese veterans. METHODS Using a database containing detailed information on the health status of the nervous system in elderly Chinese veterans, univariate and multivariate analyses of factors that may be associated with PD were performed. Univariate analysis of qualitative data was done using the Pearson Chi-square and Fisher's exact tests, and the Mann-Whitney U nonparametric test was used for univariate analysis of quantitative data. Multivariate logistic regression analysis was used to identify independent risk factors for and factors protecting against PD in elderly Chinese veterans. RESULTS A total of 9,676 elderly Chinese veterans were enrolled, including 228 cases with PD and 183 cases with Parkinson's syndrome, with 9,265 non-PD subjects serving as controls. Age (odds ratio [OR] 1.343, 95% confidence interval [CI] 1.028-1.755) and medical history of essential tremor (OR 1.228, 95% CI 1.081-1.396) were identified as independent risk factors for PD, with age being the most important risk factor. Physical exercise (OR 0.478, 95% CI 0.355-0.643) and reading (OR 0.513, 95% CI 0.357-0.735) were identified as independent factors protecting against PD, and physical exercise showed better protection against PD relative to reading. Smoking, alcohol use, anemia, cerebral trauma, education level, and electromagnetic field exposure showed no association with PD. CONCLUSION Physical exercise and reading may be independent factors that protect against PD among elderly Chinese veterans, while advancing age and medical history of essential tremor may be independent risk factors for PD. This study was cross-sectional, so further research is needed to confirm its results.
Collapse
Affiliation(s)
- Y M Zou
- Department of Neurology, Huanhu Hospital, Tianjin, People's Republic of China
| | - J P Tan
- Department of Geriatric Neurology, Chinese PLA General Hospital, Peking University Third Hospital, Beijing, People's Republic of China
| | - N Li
- Research Center of Clinical Epidemiology, Peking University Third Hospital, Beijing, People's Republic of China
| | - J S Yang
- Department of Neurology, General Hospital of Lanzhou Military Command, Lanzhou, People's Republic of China
| | - B C Yu
- Department of Gerontology, Bethune International Peace Hospital, Shijiazhuang, People's Republic of China
| | - J M Yu
- Department of Neurology, Chinese PLA 107 Hospital, Yantai, People's Republic of China
| | - Y M Zhao
- Research Center of Clinical Epidemiology, Peking University Third Hospital, Beijing, People's Republic of China
| | - L N Wang
- Department of Geriatric Neurology, Chinese PLA General Hospital, Peking University Third Hospital, Beijing, People's Republic of China
| |
Collapse
|
34
|
Wurster I, Abaza A, Brockmann K, Liepelt-Scarfone I, Berg D. Parkinson's disease with and without preceding essential tremor-similar phenotypes: a pilot study. J Neurol 2014; 261:884-8. [PMID: 24590404 DOI: 10.1007/s00415-014-7285-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 01/27/2014] [Accepted: 02/12/2014] [Indexed: 01/12/2023]
Abstract
The aim of this pilot study was to compare clinical aspects of tremor-dominant Parkinson's disease (PD) patients with and without preceding essential tremor to identify characteristics of these two subgroups. Nineteen patients with diagnoses of both essential tremor (ET) and Parkinson's disease in comparison to 18 patients with tremor-dominant Parkinson's disease without preceding tremor were investigated. The profile of several motor and non-motor symptoms, including cognitive dysfunction, depression, sleep alterations, olfaction changes and some autonomic symptoms, as well as imaging aspects obtained by transcranial sonography were compared between groups. Parkinson's patients with essential tremor scored higher in kinetic and postural tremor items (p < 0.05) and displayed an enlarged third ventricle on transcranial sonography (p = 0.010), which was not found in tremor-dominant Parkinson's disease patients. All other motor and non-motor symptoms could not distinguish between either study group. Neither group showed a distinct clinical profile related to non-motor symptoms or symptoms other than tremor-specific motor aspects. The fact that non-motor symptoms were similar in ET-PD gives rise to the hypothesis that also the prodromal phase of PD is similar in ET patients later developing classical PD compared to individuals developing PD without preceding ET. This hypothesis needs to be followed in prospective studies to verify whether the establishment of an ET subgroup with prodromal markers for PD is feasible.
Collapse
Affiliation(s)
- Isabel Wurster
- Department of Neurodegeneration and Hertie Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany,
| | | | | | | | | |
Collapse
|
35
|
Louis ED. 'Essential tremor' or 'the essential tremors': is this one disease or a family of diseases? Neuroepidemiology 2013; 42:81-9. [PMID: 24335621 DOI: 10.1159/000356351] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 10/10/2013] [Indexed: 12/14/2022] Open
Abstract
There is accumulating evidence that the entity referred to as 'essential tremor' (ET) is not a single disease. It may be a family of diseases better referred to as 'the ETs'. This review will summarize the following evidence: (1) the presence of etiological heterogeneity; (2) the heterogeneity of findings in postmortem studies, thus suggesting several diseases; (3) the recent discussion that age of onset may be an important marker of disease heterogeneity; (4) the clinical expansion of the concept of ET in recent years to include a broader range of tremor phenomenology, other motor features (gait ataxia), other involuntary movements (dystonia), and nonmotor features (cognitive problems, psychiatric problems), some of which could be primary; (5) the heterogeneity of pharmacological response profiles and clinical progression, and (6) the association of ET with Parkinson's disease, Alzheimer's disease, and possibly progressive supranuclear palsy, with the possibility that some ET patients are more predisposed to develop one of these. © 2013 S. Karger AG, Basel.
Collapse
Affiliation(s)
- Elan D Louis
- GH Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, N.Y., USA
| |
Collapse
|
36
|
Louis ED, Ottman R. Is there a one-way street from essential tremor to Parkinson's disease? Possible biological ramifications. Eur J Neurol 2013; 20:1440-4. [PMID: 24033795 DOI: 10.1111/ene.12256] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 07/26/2013] [Indexed: 11/28/2022]
Abstract
There is considerable evidence for an association between essential tremor (ET) and Parkinson's disease (PD), although the topic remains somewhat controversial. An important issue, not previously addressed, is what seems to be the unidirectional nature of the relationship (ET→ET + PD and not PD→PD + ET). The aims of this review are (i) to discuss the evidence for and against a unidirectional relationship and (ii) to discuss the implications of such a unidirectional relationship, if it exists, for disease mechanisms. Evidence 'for' a unidirectional relationship includes (i) abundant clinical anecdotal observation and (ii) clinical and epidemiological studies. Evidence 'against' is theoretical rather than empirical. Overall, the evidence 'for' is stronger, although additional studies are needed in order to be certain; for the time being, it might be best to leave this as an open question. The biological ramifications/extensions of such a unidirectional relationship include (i) that the association is causal (i.e., some aspect of ET pathophysiology predisposes an individual to develop PD) and (ii) that some ET cases may have a circumscribed form of Lewy body disease, and the secondary development of PD may represent a spread of those Lewy bodies in the brainstem. The presence and nature of the links between ET and PD are controversial. Further primary data (epidemiological and pathological) are needed to improve understanding of the relationship and its implications for the pathogenesis of both disorders.
Collapse
Affiliation(s)
- E D Louis
- GH Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA
| | | |
Collapse
|
37
|
Wu Y, Ding J, Gao Y, Chen S, Li L, Li R. Mini Review: linkages between essential tremor and Parkinson's disease? Front Cell Neurosci 2013; 7:118. [PMID: 23914155 PMCID: PMC3728484 DOI: 10.3389/fncel.2013.00118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 07/07/2013] [Indexed: 11/17/2022] Open
Abstract
Essential tremor (ET) and Parkinson’s disease (PD) are two of the most common movement disorders. Tremors are the primary symptoms of ET and of some PD patients, the two are often mistaken for each other. Especially since there are no available differentiate tests for the tremor of ET or PD, the early diagnoses mainly based on clinical assessments of medical symptoms, family and medication history, and examination by physicians. There is increasing evidence suggesting an association between ET and PD, such as a similar tremor frequency, overlapping resting tremors (a typical PD tremor), postural tremors (mainly in ET patients) in both ET and PD patients, and many ET patients develop PD later in life. Although it is difficult to make a differential diagnosis of ET and tremor-dominant PD based on clinical assessment, recent developments of objective measurements, such as brain imaging, neuropathology, and genetic analysis, has opened a helpful window for distinguishing ET from PD. In this mini review, we included literatures of ET and PD studies and discussed various advanced methods for differential diagnosis between ET and PD such as neuroimaging, genetic markers, tremor intensity and frequency, and drug-responses.
Collapse
Affiliation(s)
- Yiwen Wu
- 1 Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | | | | | | | | | | |
Collapse
|
38
|
Essential tremor followed by progressive supranuclear palsy: postmortem reports of 11 patients. J Neuropathol Exp Neurol 2013; 72:8-17. [PMID: 23242279 DOI: 10.1097/nen.0b013e31827ae56e] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
For many years, clinicians have commented on the development of signs of parkinsonism among their essential tremor (ET) patients, but the links between ET and parkinsonism are not well understood. We report 11 (12.4%) of 89 ET patients who were prospectively collected at the Essential Tremor Centralized Brain Repository during the course of its first 9 years. All patients had long-standing ET (median duration, 38 years); there was a 5- to 49-year latency from the onset of ET to the development of either parkinsonism or dementia.Despite the presence of parkinsonism or dementia during life, none had been diagnosed clinically with progressive supranuclear palsy(PSP). All 11 received the postmortem diagnosis of PSP. The prevalence of PSP in this ET sample (12.4%) is clearly larger than the population prevalence of PSP (0.001%-0.0065%). It is also 2 to 5 times the proportion of normal cases with incidental PSP in 2 previous autopsy series. This case series raises the questions of an association between ET and PSP, whether ET patients are at an increased risk of developing PSP, and what the proportion of ET patients who develop presumed Parkinson disease or Alzheimer disease in life actually have PSP (i.e. ET + PSP).
Collapse
|
39
|
Jiménez-Jiménez FJ, Alonso-Navarro H, García-Martín E, Agúndez JAG. The relationship between Parkinson's disease and essential tremor: review of clinical, epidemiologic, genetic, neuroimaging and neuropathological data, and data on the presence of cardinal signs of parkinsonism in essential tremor. TREMOR AND OTHER HYPERKINETIC MOVEMENTS (NEW YORK, N.Y.) 2012; 2. [PMID: 23439992 PMCID: PMC3572635 DOI: 10.7916/d8fn14z6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 01/18/2012] [Indexed: 12/01/2022]
Abstract
BACKGROUND The possible relationship between essential tremor (ET) and Parkinson's disease (PD) has been controversial since the first description of PD. However, there is increasing evidence suggesting an overlap between these two disorders. The aim of this review is to examine the relationship between PD and ET, focusing on clinical, epidemiologic, genetic, neuroimaging, and neuropathological data, and the presence of cardinal parkinsonism symptoms in ET. METHODS We conducted a PubMed search for articles published between 1966 and November 2011 regarding the relationship between ET and PD and the presence of postural tremor in PD patients; the presence of rest tremor, rigidity, and slowed movements in ET patients is reviewed. RESULTS Clinical series, follow-up studies of ET patients, and case-control and genetic epidemiological studies indicate that ET is associated with increased risk for PD. Some neuroimaging studies and neuropathological reports suggest an association between the two diseases. ET patients show high prevalence of rest tremor, and at least seven studies described slowed movements (possibly related to cerebellar dysfunction and/or bradykinesia) in patients with ET. DISCUSSION There is reasonable epidemiological and clinical evidence to support a link between ET and PD, although it is not clear what factors predict ET patient risk for developing PD or, more rarely, of PD patients developing ET. Future multicentric and multidisciplinary studies including epidemiological, clinical, neuroimaging, genetic, and neuropathological assessments are required to understand these associations.
Collapse
|
40
|
Essential tremor: is it a neurodegenerative disease? No. J Neural Transm (Vienna) 2012; 119:1375-81; discussion 1373. [DOI: 10.1007/s00702-012-0875-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 07/25/2012] [Indexed: 12/23/2022]
|
41
|
Simões RM, Constantino A, Gibadullina E, Houghton D, Louis ED, Litvan I. Examining the motor phenotype of patients with both essential tremor and Parkinson's disease. TREMOR AND OTHER HYPERKINETIC MOVEMENTS (NEW YORK, N.Y.) 2012; 2. [PMID: 23439850 PMCID: PMC3379814 DOI: 10.7916/d8cn72n0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Accepted: 09/09/2011] [Indexed: 12/01/2022]
Abstract
Background The subset of patients with essential tremor (ET) that develops Parkinson's disease (PD) has not been fully clinically characterized. Methods Motor features were retrospectively reviewed in 18 ET patients who developed PD (ET→PD), 20 ET and 30 PD patients with similar ages and disease durations. Results Fewer ET→PD than ET patients had widespread postural and/or action tremor (2/17 [11.8%] vs. 11/17 [64.7%]; p = 0.001) and marginally fewer had cerebellar signs (1/15 [6.7%] vs. 6/18 [33.3%], p = 0.06). ET→PD patients required fewer ET medications than did their counterparts with ET (p = 0.001). ET→PD patients and PD patients did not differ in UPDRS, Hoehn and Yahr, or Schwab and England scores (each p≥0.14). Discussion ET patients who develop PD may have distinct pre-PD motor features compared to their counterparts with ET who do not develop co-existing PD. Prospective studies are needed to evaluate the predictive value of these clinical features for the emergence of PD.
Collapse
Affiliation(s)
- Rita M Simões
- Hospital Professor Dr. Fernando Fonseca - EPE, Amadora, Portugal
| | | | | | | | | | | |
Collapse
|
42
|
Cox BC, Cincotta M, Espay AJ. Mirror movements in movement disorders: a review. Tremor Other Hyperkinet Mov (N Y) 2012; 2:tre-02-59-398-1. [PMID: 23440079 PMCID: PMC3569961 DOI: 10.7916/d8vq31dz] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 12/30/2011] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Mirror movements (MM) are involuntary movements of homologous muscles during voluntary movements of contralateral body regions. While subtle mirroring can be present in otherwise healthy adults, overt MM may be common in many movement disorders. Examining these collective findings may further our understanding of MM and help define their usefulness as a clinical sign. METHODS We sought to review English language research articles examining the presence, clinical significance, and/or pathophysiology of MM in Parkinson's disease (PD), corticobasal syndrome (CBS), essential tremor (ET), focal hand dystonia, Creutzfeldt-Jakob's disease (CJD), and Huntington's disease. When available, MM in these disorders were compared with those of healthy age-matched controls and congenital disorders such as Klippel-Feil syndrome and X-linked Kallman's syndrome. RESULTS Clinical presentation of MM is common in asymmetric parkinsonian disorders (early PD, CBS) and manifests differently depending on the side affected (less affected hand in PD, more affected hand in CBS, either hand in ET, and both hands in healthy adults and congenital disorders), stage of disease (early, asymmetric PD and CJD), and presence of concomitant mirror-like overflow phenomena (focal dystonia and CBS-associated alien hand). In general, uncrossed descending corticospinal projections (congenital MM) and/or abnormal activation of the motor cortex ipsilateral to the voluntary task (most acquired MM), i.e., activation of the normal crossed corticospinal pathway, are required for the generation of MM. DISCUSSION MM are common motor phenomena and present differently in several acquired (mostly neurodegenerative) and congenital movement disorders. Future studies on MM will enhance the clinical diagnosis of selected movement disorders and contribute to our understanding of the normal physiology of bimanual coordination.
Collapse
Affiliation(s)
- Benjamin C. Cox
- University of Cincinnati Neuroscience Institute, Department of Neurology, Gardner Family Center for Parkinson's Disease and Movement Disorders, University of Cincinnati, Cincinnati, Ohio, United States of America
| | | | - Alberto J. Espay
- University of Cincinnati Neuroscience Institute, Department of Neurology, Gardner Family Center for Parkinson's Disease and Movement Disorders, University of Cincinnati, Cincinnati, Ohio, United States of America
| |
Collapse
|
43
|
Louis ED, Gerbin M, Viner AS. Color vision: a study of essential tremor cases versus normal controls. Eur J Neurol 2012; 19:1136-9. [PMID: 22417326 DOI: 10.1111/j.1468-1331.2012.03688.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND PURPOSE Patients with essential tremor (ET) and Parkinson's disease (PD) may exhibit overlapping clinical features. Also, a growing number of non-motor features are being documented in ET. Color vision abnormalities, although well known to occur in PD, have not been studied extensively in ET. We assessed color vision in ET cases and controls. We furthermore assessed subgroups of ET cases with clinical features that might link them to PD (i.e., ET cases with a family history of PD, and ET cases with rest tremor) to determine whether these cases had greater color vision abnormalities than ET cases without those features. METHODS Participants were enrolled in a case-control study at Columbia University Medical Center. Color discrimination testing was performed using the Farnsworth-Munsell 100 Hue test. The total error score (TES) for the hue test was determined. RESULTS The TES was similar in 55 ET cases and 55 controls (144.6 ± 91.8 vs. 145.6 ± 96.6, P = 0.96). ET cases with rest tremor (n = 8) were similar to ET cases without rest tremor (n = 47) with respect to the TES (117.0 ± 73.4 vs. 149.3 ± 94.4, P = 0.36), as were ET cases with a family history of PD (n = 9) versus without (n = 46) (144.4 ± 57.0 vs. 144.6 ± 97.6, P = 0.996). CONCLUSIONS Although a number of links exist between ET and PD, and non-motor features have been described in both, a color vision abnormality does not seem to be a feature of ET.
Collapse
Affiliation(s)
- E D Louis
- G.H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
| | | | | |
Collapse
|
44
|
Gerasimou G, Costa DC, Papanastasiou E, Bostanjiopoulou S, Arnaoutoglou M, Moralidis E, Aggelopoulou T, Gotzamani-Psarrakou A. SPECT study with I-123-Ioflupane (DaTSCAN) in patients with essential tremor. Is there any correlation with Parkinson’s disease? Ann Nucl Med 2012; 26:337-44. [DOI: 10.1007/s12149-012-0577-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 01/24/2012] [Indexed: 11/30/2022]
|
45
|
Louis ED. Treatment of Essential Tremor: Are there Issues We are Overlooking? Front Neurol 2012; 2:91. [PMID: 22275907 PMCID: PMC3257846 DOI: 10.3389/fneur.2011.00091] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 12/28/2011] [Indexed: 12/19/2022] Open
Abstract
Background: Essential tremor (ET) is one of the most common neurological diseases. Although a large number of medications have been tested, there are only two first-line medications, primidone and propranolol, which is a situation that has not changed in approximately 30 years. Several recent reviews have summarized the current pharmacotherapeutic options for ET and the approach to the management of ET patients. Yet there remain a number of important issues, both scientific and clinical, that have not been broached in the literature and that have therapeutic implications. Objectives: To introduce several clinical and scientific issues that have not formally entered the published literature on the treatment of ET. Methods: In September 2011, materials for this article were gathered during a literature search of PubMed using the following terms: ET, clinical, clinical trial, treatment, medications, therapeutics. English-language articles were selected for further review. Results: The paper focuses on several topics that have received scant or no discussion in the published literature on ET therapeutics. These topics are as follows: the nature of the underlying disease pathophysiology, the presence of pathological heterogeneity, the complexity of cellular and neurochemical changes which may be underlying this disorder, the presence of clinical heterogeneity, the selection of treatment endpoints, the effects of diagnostic uncertainty, the presence of cognitive and psychiatric features in ET, the identification of possible modifiable risk factors, and the absence of any neuroprotective therapies. Conclusion: The author has identified several topics that have received scant or no discussion in the published literature on ET therapeutics. Further discussion of the issues raised here may lead to improvements in clinical trial methodologies as well as facilitate the development of fresh approaches to pharmacotherapy.
Collapse
Affiliation(s)
- Elan D Louis
- Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University New York, NY, USA
| |
Collapse
|
46
|
Ross OA, Conneely KN, Wang T, Vilarino-Guell C, Soto-Ortolaza AI, Rajput A, Wszolek ZK, Uitti RJ, Louis ED, Clark LN, Farrer MJ, Testa CM. Genetic variants of α-synuclein are not associated with essential tremor. Mov Disord 2011; 26:2552-6. [PMID: 22025277 DOI: 10.1002/mds.23909] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 05/25/2011] [Accepted: 07/18/2011] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Given the overlap between Parkinson's disease and essential tremor, we examined genetic variants in α-synuclein (SNCA) as risk determinants for essential tremor. METHODS Samples from 661 essential tremor subjects and 1316 control subjects from 4 participating North American sites were included in this study. Parkinson's disease samples (n = 427) were compared against controls. Twenty variants were selected for association analysis within the SNCA locus. Individual logistic regression analyses against essential tremor diagnosis were run for each variant and then combined using meta-analysis. RESULTS Our results do not show a significant association between variants in the SNCA locus and risk of essential tremor, whereas the established association of SNCA variants with Parkinson's disease risk was observed. CONCLUSIONS Whereas genetic factors are likely to play a large role in essential tremor pathogenesis, our results do not support a role for common SNCA genetic variants in risk for essential tremor.
Collapse
Affiliation(s)
- Owen A Ross
- Department of Neuroscience, Mayo Clinic College of Medicine, Jacksonville, Florida, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Fekete R, Jankovic J. Revisiting the relationship between essential tremor and Parkinson's disease. Mov Disord 2011; 26:391-8. [PMID: 21462256 DOI: 10.1002/mds.23512] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND The relationship between essential tremor and Parkinson's disease has been a subject of reviews and debates for long time, but there is now growing evidence that the two common movement disorders are pathogenically related, at least in some patient populations. METHODS PubMed as well as authors' own files were searched for relevant keywords regarding overlap between the disorders in clinical features as well as on epidemiologic, genetic, imaging, and pathological studies. RESULTS New findings in each of these categories are critically reviewed and placed in the context of previously published data. DISCUSSION Although we believe that there is compelling evidence for the notion that some patients with "pure" ET evolve into PD, the biologic nature of the association is not well understood. Furthermore, it is not clear what factors predict which ET patients later develop PD and whether patients with PD are more likely to develop ET. Further epidemiologic, clinical, genetic, imaging, and pathological studies are needed to better understand this mixed, ET-PD phenotype.
Collapse
Affiliation(s)
- R Fekete
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, Texas 77030, USA
| | | |
Collapse
|
48
|
LaRoia H, Louis ED. Association between essential tremor and other neurodegenerative diseases: what is the epidemiological evidence? Neuroepidemiology 2011; 37:1-10. [PMID: 21757958 DOI: 10.1159/000328866] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 04/27/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The possible links between essential tremor (ET) and Parkinson's disease (PD) and, more recently, between ET and Alzheimer's disease (AD) have been of great interest, particularly with the emergence of postmortem data suggesting that ET itself may be a neurodegenerative disease. Given the very high population prevalence of ET, its possible role as a risk factor for PD and AD is of special significance. At the center of this debate is the burgeoning evidence from epidemiological studies, examining whether there is an increased co-occurrence of these conditions within the same individuals or within families. METHODS We conducted a PubMed search from 1966 to March 2011 and reviewed the epidemiological evidence, restricting our analyses to studies that generated quantifiable measures of association (odds ratios or relative risks), thereby being able to assess the role of chance. RESULTS The most robust evidence, from case-control, prospective and familial aggregation studies, indicates that ET is associated with increased odds and increased risks of both PD and AD. CONCLUSIONS There is reasonable epidemiological evidence to support a link between ET and these neurodegenerative diseases. Further studies are needed to corroborate the current results, provide additional estimates of effect and begin to explore the mechanistic underpinnings for these intriguing associations.
Collapse
Affiliation(s)
- Hiral LaRoia
- Department of Neurology, Columbia University, New York, NY, USA
| | | |
Collapse
|
49
|
Puschmann A, Pfeiffer RF, Stoessl AJ, Kuriakose R, Lash JL, Searcy JA, Strongosky AJ, Vilariño-Güell C, Farrer MJ, Ross OA, Dickson DW, Wszolek ZK. A family with Parkinsonism, essential tremor, restless legs syndrome, and depression. Neurology 2011; 76:1623-30. [PMID: 21555728 DOI: 10.1212/wnl.0b013e318219fb42] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Previous epidemiologic and genetic studies have suggested a link between Parkinson disease (PD), essential tremor (ET), and restless legs syndrome (RLS). METHODS We describe the clinical, PET, and pathologic characteristics of an extensive kindred from Arkansas with hereditary PD, ET, and RLS. The pedigree contains 138 individuals. Sixty-five family members were examined neurologically up to 3 times from 2004 to 2010. Clinical data were collected from medical records and questionnaires. Genetic studies were performed. Five family members underwent multitracer PET. Two individuals with PD were examined postmortem. RESULTS Eleven family members had PD with generally mild and slowly progressive symptoms. Age at onset was between 39 and 74 years (mean 59.1, SD 13.4). All individuals treated with l-dopa responded positively. Postural or action tremor was present in 6 individuals with PD, and in 19 additional family members. Fifteen persons reported symptoms of RLS. PET showed reduced presynaptic dopamine function typical of sporadic PD in a patient with PD and ET, but not in persons with ET or RLS. The inheritance pattern was autosomal dominant for PD and RLS. No known pathogenic mutation in PD-related genes was found. Fourteen of the family members with PD, ET, or RLS had depression. Neuropathologic examination revealed pallidonigral pigment spheroid degeneration with ubiquitin-positive axonal spheroids, TDP43-positive pathology in the basal ganglia, hippocampus, and brainstem, and only sparse Lewy bodies. CONCLUSION Familial forms of PD, ET, RLS, and depression occur in this family. The genetic cause remains to be elucidated.
Collapse
Affiliation(s)
- A Puschmann
- Department of Neurology, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Paus S, Gadow F, Kaut O, Knapp M, Klein C, Klockgether T, Wüllner U. Tremor in Parkinson's disease is not associated with the DRD3 Ser9Gly polymorphism. Parkinsonism Relat Disord 2011; 16:381-3. [PMID: 20434388 DOI: 10.1016/j.parkreldis.2010.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 03/26/2010] [Accepted: 03/29/2010] [Indexed: 11/16/2022]
Abstract
A common subset of genetic risk factors for Parkinson's disease (PD) and essential tremor (ET) has been postulated. Recently, an association between the dopamine D(3) receptor (DRD3) Ser9Gly polymorphism and ET has been reported. We studied whether PD tremor is influenced by Ser9Gly in a genetic association study based on the gene bank of the German Competence Network on Parkinson's disease. The study included analyses of motor predominance (mixed, hypokinetic, and tremor), and tremor type (resting, postural, and action). We did not identify any effect of DRD3 Ser9Gly on tremor in PD, even when regarding various symptom combinations to avoid missing a weak effect on the phenotype. Additional studies incorporating symptoms at disease onset, and grading of tremor response to dopaminergic therapy, are warranted.
Collapse
Affiliation(s)
- S Paus
- Department of Neurology, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany.
| | | | | | | | | | | | | |
Collapse
|