1
|
Simonet C, Mahlknecht P, Marini K, Seppi K, Gill A, Bestwick JP, Lees AJ, Giovannoni G, Schrag A, Noyce AJ. The Emergence and Progression of Motor Dysfunction in Individuals at Risk of Parkinson's Disease. Mov Disord 2023; 38:1636-1644. [PMID: 37317903 DOI: 10.1002/mds.29496] [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: 03/08/2023] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 06/16/2023] Open
Abstract
BACKGROUND PREDICT-PD is a United Kingdom population-based study aiming to stratify individuals for future Parkinson's disease (PD) using a risk algorithm. METHODS A randomly selected, representative sample of participants in PREDICT-PD were examined using several motor assessments, including the motor section of the Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS)-III, at baseline (2012) and after an average of 6 years of follow-up. We checked for new PD diagnoses in participants seen at baseline and examined the association between risk scores and incident sub-threshold parkinsonism, motor decline (increasing ≥5 points in MDS-UPDRS-III) and single motor domains in the MDS-UPDRS-III. We replicated analyses in two independent datasets (Bruneck and Parkinson's Progression Markers Initiative [PPMI]). RESULTS After 6 years of follow-up, the PREDICT-PD higher-risk group (n = 33) had a greater motor decline compared with the lower-risk group (n = 95) (30% vs. 12.5%, P = 0.031). Two participants (both considered higher risk at baseline) were given a diagnosis of PD during follow-up, with motor signs emerging between 2 and 5 years before diagnosis. A meta-analysis of data from PREDICT-PD, Bruneck, and PPMI showed an association between PD risk estimates and incident sub-threshold parkinsonism (odds ratio [OR], 2.01 [95% confidence interval (CI), 1.55-2.61]), as well as new onset bradykinesia (OR, 1.69 [95% CI, 1.33-2.16]) and action tremor (OR, 1.61 [95% CI, 1.30-1.98]). CONCLUSIONS Risk estimates using the PREDICT-PD algorithm were associated with the occurrence of sub-threshold parkinsonism, including bradykinesia and action tremor. The algorithm could also identify individuals whose motor examination experience a decline over time. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Cristina Simonet
- Preventive Neurology Unit, Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom
| | - Philipp Mahlknecht
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Kathrin Marini
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Klaus Seppi
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Aneet Gill
- Preventive Neurology Unit, Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom
| | - Jonathan P Bestwick
- Preventive Neurology Unit, Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom
| | - Andrew J Lees
- Reta Lila Weston Institute of Neurological Studies, University College London Queen Square Institute of Neurology, London, United Kingdom
| | - Gavin Giovannoni
- Preventive Neurology Unit, Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom
- Blizard Institute, Queen Mary University, London, United Kingdom
| | - Anette Schrag
- Reta Lila Weston Institute of Neurological Studies, University College London Queen Square Institute of Neurology, London, United Kingdom
| | - Alastair J Noyce
- Preventive Neurology Unit, Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom
| |
Collapse
|
2
|
Garcia Santa Cruz B, Husch A, Hertel F. Machine learning models for diagnosis and prognosis of Parkinson's disease using brain imaging: general overview, main challenges, and future directions. Front Aging Neurosci 2023; 15:1216163. [PMID: 37539346 PMCID: PMC10394631 DOI: 10.3389/fnagi.2023.1216163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 06/28/2023] [Indexed: 08/05/2023] Open
Abstract
Parkinson's disease (PD) is a progressive and complex neurodegenerative disorder associated with age that affects motor and cognitive functions. As there is currently no cure, early diagnosis and accurate prognosis are essential to increase the effectiveness of treatment and control its symptoms. Medical imaging, specifically magnetic resonance imaging (MRI), has emerged as a valuable tool for developing support systems to assist in diagnosis and prognosis. The current literature aims to improve understanding of the disease's structural and functional manifestations in the brain. By applying artificial intelligence to neuroimaging, such as deep learning (DL) and other machine learning (ML) techniques, previously unknown relationships and patterns can be revealed in this high-dimensional data. However, several issues must be addressed before these solutions can be safely integrated into clinical practice. This review provides a comprehensive overview of recent ML techniques analyzed for the automatic diagnosis and prognosis of PD in brain MRI. The main challenges in applying ML to medical diagnosis and its implications for PD are also addressed, including current limitations for safe translation into hospitals. These challenges are analyzed at three levels: disease-specific, task-specific, and technology-specific. Finally, potential future directions for each challenge and future perspectives are discussed.
Collapse
Affiliation(s)
| | - Andreas Husch
- Imaging AI Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Frank Hertel
- National Department of Neurosurgery, Centre Hospitalier de Luxembourg, Luxembourg, Luxembourg
| |
Collapse
|
3
|
Liman J, Wolff von Gudenberg A, Baehr M, Paulus W, Neef NE, Sommer M. Enlarged Area of Mesencephalic Iron Deposits in Adults Who Stutter. Front Hum Neurosci 2021; 15:639269. [PMID: 33643015 PMCID: PMC7904683 DOI: 10.3389/fnhum.2021.639269] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 01/20/2021] [Indexed: 12/28/2022] Open
Abstract
PURPOSE Childhood onset speech fluency disorder (stuttering) is possibly related to dopaminergic dysfunction. Mesencephalic hyperechogenicity (ME) detected by transcranial ultrasound (TCS) might be seen as an indirect marker of dopaminergic dysfunction. We here determined whether adults who stutter since childhood (AWS) show ME. METHODS We performed TCS in ten AWS and ten matched adults who never stuttered. We also assessed motor performance in finger tapping and in the 25 Foot Walking test. RESULTS Compared to controls, AWS showed enlarged ME on either side. Finger tapping was slower in AWS. Walking cadence, i.e., the ratio of number of steps by time, tended to be higher in AWS than in control participants. DISCUSSION The results demonstrate a motor deficit in AWS linked to dopaminergic dysfunction and extending beyond speech. Since iron deposits evolve in childhood and shrink thereafter, ME might serve as an easily quantifiable biomarker helping to predict the risk of persistency in children who stutter.
Collapse
Affiliation(s)
- Jan Liman
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | | | - Mathias Baehr
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Walter Paulus
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
| | - Nicole E. Neef
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
| | - Martin Sommer
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
| |
Collapse
|
4
|
De Pietro Franco Zorzenon C, Almeida Antônio Bienes GH, Duarte Alves E, Tobaru Tibana LA, Carrete Júnior H, Ballalai Ferraz H. Magnetic resonance imaging evaluation of nigrosome 1 and neuromelanin can assist Parkinson's disease diagnosis, but requires an expert neuroradiologist. Parkinsonism Relat Disord 2020; 83:8-12. [PMID: 33418131 DOI: 10.1016/j.parkreldis.2020.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 12/01/2020] [Accepted: 12/07/2020] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Parkinson's disease (PD) is the second most common neurodegenerative disease. However, the rate of misdiagnosis remains high, even at specialized movement disorder centers. PURPOSE To assess the accuracy of nigrosome 1 and midbrain neuromelanin evaluation in the diagnosis of PD, and to identify possible differences in diagnostic accuracy between neuroradiologists of different experience levels in analyzing these structures. METHODS A case-control study was conducted between April 2017 and January 2019. We prospectively evaluated 41 PD patients and 21 control individuals. Participants underwent axial, T2*-weighted, multi-echo gradient echo (GRE), and susceptibility-weighted imaging phase (SWIp) magnetic resonance imaging (MRI) sequences to evaluate nigrosome 1 and axial, T1-weighted, turbo spin-echo magnetization transfer contrast (MTC) MRI sequences to evaluate midbrain neuromelanin. All MRI sequences were acquired at 3.0 T. The images were analyzed by two experienced neuroradiologists, one with and one without expertise in nigrosome 1 and neuromelanin imaging. The sensitivity, specificity, and accuracy of the diagnoses were calculated between PD patients vs. healthy participants and between the two neuroradiologists. RESULTS The sensitivity and specificity of each imaging sequence for PD diagnosis were as follows: multi-echo, 100% and 86%; SWIp, 91% and 88%; and T1 MTC, 90% and 93%, respectively. The accuracy of clinical PD diagnosis was higher for the expert neuroradiologist compared to the neuroradiologist lacking expertise. CONCLUSION Nigrosome 1 and midbrain neuromelanin represent useful tools for PD diagnosis. However, these structures should be evaluated by experienced neuroradiologists in order to ensure high accuracy and reproducibility.
Collapse
Affiliation(s)
| | | | - Ernesto Duarte Alves
- Department of Diagnostic Imaging, Universidade Federal de São Paulo, São Paulo, Brazil.
| | | | | | | |
Collapse
|
5
|
Iranzo A, Stefani A, Niñerola-Baizan A, Stokner H, Serradell M, Vilas D, Holzknecht E, Gaig C, Pavia J, Lomeña F, Reyes D, Seppi K, Santamaria J, Högl B, Tolosa E, Poewe W. Left-hemispheric predominance of nigrostriatal deficit in isolated REM sleep behavior disorder. Neurology 2020; 94:e1605-e1613. [DOI: 10.1212/wnl.0000000000009246] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 10/17/2019] [Indexed: 01/01/2023] Open
Abstract
ObjectiveUnilateral onset of parkinsonism due to nigrostriatal damage of the contralateral hemisphere is frequent in Parkinson disease (PD). There is evidence for a left-hemispheric bias of motor asymmetry in right-handed patients with PD indicating a hemispheric dominance. Isolated REM sleep behavior disorder (IRBD) constitutes the prodromal stage of PD and other synucleinopathies. To test the hypothesis that right-handed patients with IRBD exhibit left-hemispheric predominance of subclinical nigrostriatal dysfunction, we evaluated this aspect using neuroimaging instruments.MethodsIn 167 right-handed patients with IRBD without parkinsonism, we evaluated in each hemisphere the integrity of the striatal dopaminergic terminals by dopamine transporter (DAT)-SPECT and the substantia nigra echogenicity by transcranial sonography.ResultsDAT-SPECT showed lower specific binding ratio (SBR) in the left striatum and left caudate nucleus than in the right striatum and right caudate nucleus. The percentage of patients with lower SBR was greater in the left striatum and left caudate nucleus than in the right striatum and right caudate nucleus. In those who developed a synucleinopathy in <5 years from DAT-SPECT, there was a lower SBR in the left putamen and left caudate nucleus than in the right putamen and right caudate nucleus. Substantia nigra echogenic size was greater in the left than in the right side in patients with hyperechogenicity and among individuals who phenoconverted in <5 years from transcranial sonography.ConclusionRight-handed patients with IRBD exhibit left-hemispheric predominance of subclinical nigrostriatal dysfunction. In premotor PD, the neurodegenerative process begins asymmetrically, initially impairing the nigrostriatal system of the dominant hemisphere.
Collapse
|
6
|
Mahlknecht P, Stockner H, Marini K, Gasperi A, Djamshidian A, Willeit P, Kiechl S, Willeit J, Rungger G, Poewe W, Seppi K. Midbrain hyperechogenicity, hyposmia, mild parkinsonian signs and risk for incident Parkinson's disease over 10 years: A prospective population-based study. Parkinsonism Relat Disord 2019; 70:51-54. [PMID: 31864071 DOI: 10.1016/j.parkreldis.2019.12.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 11/27/2019] [Accepted: 12/09/2019] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Associations of substantia nigra (SN) hyperechogenicity on transcranial sonography, olfactory dysfunction, and mild parkinsonian signs (MPS) with incident Parkinson's disease (PD) have only been studied over limited periods of follow-up and their long-term predictive properties are unclear. We aimed to prospectively assess the risk for incident PD over 10 years in community-dwelling elderly individuals with these risk markers. METHODS SN-hyperechogenicity, olfactory function, and MPS were assessed in the prospective population-based Bruneck Study (2005 in-person assessment; n = 574, aged 55-94 years). Cases of incident PD were identified at 5-year and 10-year follow-up visits. We estimated relative risks of baseline markers for incident cases. RESULTS After excluding 35 cases with PD or secondary parkinsonism at baseline, a total of 20 cases of incident PD were identified from the remaining 539 participants (11 at 5 years and 9 at 10 years). Relative risks for incident PD over the 10-year follow-up period were 7.43 (2.71-20.39), 3.60 (1.48-8.78), and 5.52 (2.43-12.57) for baseline SN-hyperechogenicity, hyposmia, and mild parkinsonian signs, respectively. While risk of hyposmia for incident PD was similar for the two sequential 5-year periods studied, relative risks of SN-hyperechogenicity and MPS were higher for the first five years as compared to later. CONCLUSION Our findings extend the established risk relationship of SN-hyperechogenicity, hyposmia, and MPS with incident PD beyond 5 years of follow-up.
Collapse
Affiliation(s)
- Philipp Mahlknecht
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Heike Stockner
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Kathrin Marini
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Arno Gasperi
- Department of Neurology, Hospital of Bruneck, Bruneck, Italy
| | - Atbin Djamshidian
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Peter Willeit
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria; Department of Public Health and Primary Care, University of Cambridge, United Kingdom
| | - Stefan Kiechl
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Johann Willeit
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | | | - Werner Poewe
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Klaus Seppi
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
| |
Collapse
|
7
|
Zhou HY, Huang P, Sun Q, Du JJ, Cui SS, Tan YY, Hu YY, Zhan WW, Wang Y, Xiao Q, Liu J, Chen SD. Substantia Nigra Echogenicity Associated with Clinical Subtypes of Parkinson's Disease. JOURNAL OF PARKINSONS DISEASE 2019; 8:333-340. [PMID: 29614699 DOI: 10.3233/jpd-171264] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND It is debatable whether transcranial sonography (TCS) could be a biomarker for monitoring disease progression. Various phenotypes of Parkinson's disease (PD) may be a major reason contributing to the inconsistency. OBJECTIVE We classified PD patients into different subtypes and evaluated the correlation between SN echogenicity and disease progression. METHODS A total of 411 PD patients were included in this study. TCS evaluations of the substantia nigra (SN) were performed, and motor and non-motor symptoms were assessed by a series of rating scales in all PD patients. RESULTS Three hundred and thirteen patients had appropriate temporal acoustic bone windows, and they were divided into three subgroups according to disease onset age. SN hyperechogenicity (SN+) was found to be associated with age, gender, disease duration, H-Y stage and UPDRS-II scores in 220 middle-age onset patients. Regression analysis identified both disease duration and gender as independent predictors for SN+. When this distinct group was separated into male and female subgroups, the correlation between larger SN echogenicity (SNL) and disease duration was positive in males rather than females. When these middle-age onset male patients were classified as tremor dominant (TD) and non-TD subtypes, it turned out that correlation between disease duration and SNL only existed in male non-TD PD patients. CONCLUSIONS Our study demonstrated correlation between the size of SN echogenicity and disease duration in Chinese patients with PD who were male non-TD subtypes with middle-age onset, suggesting the formation of SN echogenicity might be a dynamic process following disease progression in this distinct subtype.
Collapse
Affiliation(s)
- Hai-Yan Zhou
- Department of Neurology and Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Pei Huang
- Department of Neurology and Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qian Sun
- Department of Neurology and Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Juan-Juan Du
- Department of Neurology and Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shi-Shuang Cui
- Department of Neurology and Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yu-Yan Tan
- Department of Neurology and Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yun-Yun Hu
- Department of Ultrasonography, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wei-Wei Zhan
- Department of Ultrasonography, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ying Wang
- Department of Neurology and Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qin Xiao
- Department of Neurology and Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jun Liu
- Department of Neurology and Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Sheng-Di Chen
- Department of Neurology and Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| |
Collapse
|
8
|
Tao A, Chen G, Deng Y, Xu R. Accuracy of Transcranial Sonography of the Substantia Nigra for Detection of Parkinson's Disease: A Systematic Review and Meta-analysis. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:628-641. [PMID: 30612821 DOI: 10.1016/j.ultrasmedbio.2018.11.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/31/2018] [Accepted: 11/26/2018] [Indexed: 06/09/2023]
Abstract
A systematic review and meta-analysis were conducted to evaluate the diagnostic accuracy of substantia nigra hyper-echogenicity by transcranial sonography (TCS) for the diagnosis of Parkinson's disease (PD). PubMed, Embase and the Cochrane Library were electronically searched from inception to June 2018 for all relevant studies. The methodological quality of each study was evaluated by two independent reviewers, who used the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Articles reporting information sufficient to calculate the sensitivity and specificity of TCS to diagnose PD were included. Statistical analysis included data pooling, heterogeneity testing, sensitivity analyses and forest meta-regression. Thirty-nine studies (3123 participants with PD) were analyzed. The pooled sensitivity and specificity of TCS were 0.84 (95% confidence interval: 0.81-0.87) and 0.85 (0.80-0.88), respectively, for differentiating PD from normal controls or participants with other parkinsonian syndromes. In the secondary outcome, PD participants exhibited a significant increase in substantia nigra areas than either normal controls (0.14 [0.12-0.16], p < 0.0001) or participants with other parkinsonian syndromes (0.11 [0.08-0.13], p < 0.0001). This meta-analysis revealed the high diagnostic performance of TCS in differentiating patients with PD from both normal controls and participants with other parkinsonian syndromes.
Collapse
Affiliation(s)
- Anyu Tao
- Department of Medical Ultrasound, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Guangzhi Chen
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Youbin Deng
- Department of Medical Ultrasound, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Renfan Xu
- Department of Medical Ultrasound, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| |
Collapse
|
9
|
Toomsoo T, Liepelt-Scarfone I, Berg D, Kerner R, Pool AH, Kadastik-Eerme L, Rubanovits I, Asser T, Taba P. Effect of Age on Substantia Nigra Hyper-echogenicity in Parkinson's Disease Patients and Healthy Controls. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:122-128. [PMID: 30482710 DOI: 10.1016/j.ultrasmedbio.2018.09.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/13/2018] [Accepted: 09/18/2018] [Indexed: 06/09/2023]
Abstract
Substantia nigra (SN) hyper-echogenicity (SN+) describes an enlargement (>90th percentile) of the area of echogenicity at the anatomic site of the SN in the midbrain detected by transcranial sonography. This ultrasound sign has proven to be a valuable marker supporting the clinical diagnosis of Parkinson's disease (PD). Although there is considerable variation in the extent of echogenic signals at the anatomic site of the SN among PD patients, previous work suggests that SN+ is a stable marker throughout the course of the disease. The present study focused on two aspects: (i) determining whether SN+ values differ between the sides, mirroring the asymmetric character of the disease; and (ii) determining whether age has an influence on SN echogenicity. This cross-sectional study included 300 PD patients and 200 healthy controls. SN+ was measured planimetrically by transcranial sonography. Echogenicity was analyzed separately for onset and non-onset sides, with onset side defined as the SN contralateral to the side of the body that first manifested PD-related motor impairment. Age of the patients and healthy controls at study time was used for correlation. We found that the onset SN+ contralateral to the side of initial motor symptoms was on average 17.6% larger than its counterpart. However, we also found that contrary to the control group, where an increase in age was associated with an increase in size of SN+, age of PD patients was associated with a decline in size of the onset SN+. Furthermore, SN measured at the onset side of PD patients correlated significantly with patient age and Hoehn and Yahr stage, a scale that grades PD severity, although this was not the case for the non-onset side. The present study indicates that changes in SN echogenicity have a different dynamic depending on the onset side of the disease. The age at study time had a significantly negative effect on the size of onset SN+, the effect on the non-onset side was non-significant. We conclude that for appropriate PD analysis, onset SN+ is a more important marker than the average of both sides of SN. Furthermore, we found that among healthy controls, the size of SN+ increases with age.
Collapse
Affiliation(s)
- Toomas Toomsoo
- Center of Neurology, East Tallinn Central Hospital, Tallinn, Estonia.
| | - Inga Liepelt-Scarfone
- Department of Neurodegeneration, Center of Neurology, Hertie Institute of Clinical Brain Research and German Center of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany
| | - Daniela Berg
- Department of Neurodegeneration, Center of Neurology, Hertie Institute of Clinical Brain Research and German Center of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany; Department of Neurology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | | | | | - Liis Kadastik-Eerme
- Department of Neurology and Neurosurgery, University of Tartu, Tartu, Estonia
| | - Inna Rubanovits
- Center of Neurology, East Tallinn Central Hospital, Tallinn, Estonia
| | - Toomas Asser
- Department of Neurology and Neurosurgery, University of Tartu, Tartu, Estonia
| | - Pille Taba
- Department of Neurology and Neurosurgery, University of Tartu, Tartu, Estonia
| |
Collapse
|
10
|
The measuring of substantia nigra hyperechogenicity in an Italian cohort of Parkinson disease patients: a case/control study (NOBIS Study). J Neural Transm (Vienna) 2017; 124:869-879. [DOI: 10.1007/s00702-017-1724-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 04/11/2017] [Indexed: 10/19/2022]
|
11
|
Deistung A, Schweser F, Reichenbach JR. Overview of quantitative susceptibility mapping. NMR IN BIOMEDICINE 2017; 30:e3569. [PMID: 27434134 DOI: 10.1002/nbm.3569] [Citation(s) in RCA: 167] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 05/03/2016] [Accepted: 05/09/2016] [Indexed: 06/06/2023]
Abstract
Magnetic susceptibility describes the magnetizability of a material to an applied magnetic field and represents an important parameter in the field of MRI. With the recently introduced method of quantitative susceptibility mapping (QSM) and its conceptual extension to susceptibility tensor imaging (STI), the non-invasive assessment of this important physical quantity has become possible with MRI. Both methods solve the ill-posed inverse problem to determine the magnetic susceptibility from local magnetic fields. Whilst QSM allows the extraction of the spatial distribution of the bulk magnetic susceptibility from a single measurement, STI enables the quantification of magnetic susceptibility anisotropy, but requires multiple measurements with different orientations of the object relative to the main static magnetic field. In this review, we briefly recapitulate the fundamental theoretical foundation of QSM and STI, as well as computational strategies for the characterization of magnetic susceptibility with MRI phase data. In the second part, we provide an overview of current methodological and clinical applications of QSM with a focus on brain imaging. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Andreas Deistung
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Ferdinand Schweser
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, NY, USA
- MRI Clinical and Translational Research Center, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, NY, USA
| | - Jürgen R Reichenbach
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
- Michael Stifel Center for Data-driven and Simulation Science Jena, Friedrich Schiller University Jena, Jena, Germany
| |
Collapse
|
12
|
Mahlknecht P, Seppi K, Poewe W. The Concept of Prodromal Parkinson's Disease. JOURNAL OF PARKINSONS DISEASE 2016; 5:681-97. [PMID: 26485429 PMCID: PMC4927924 DOI: 10.3233/jpd-150685] [Citation(s) in RCA: 162] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Parkinson’s disease (PD) is currently clinically defined by a set of cardinal motor features centred on the presence of bradykinesia and at least one additional motor symptom out of tremor, rigidity or postural instability. However, converging evidence from clinical, neuropathological, and imaging research suggests initiation of PD-specific pathology prior to appearance of these classical motor signs. This latent phase of neurodegeneration in PD is of particular relevance in relation to the development of disease-modifying or neuroprotective therapies which would require intervention at the earliest stages of disease. A key challenge in PD research, therefore, is to identify and validate markers for the preclinical and prodromal stages of the illness. Currently, several nonmotor symptoms have been associated with an increased risk to develop PD in otherwise healthy individuals and ongoing research is aimed at validating a variety of candidate PD biomarkers based on imaging, genetic, proteomic, or metabolomic signatures, supplemented by work on tissue markers accessible to minimally invasive biopsies. In fact, the recently defined MDS research criteria for prodromal PD have included combinations of risk and prodromal markers allowing to define target populations of future disease modification trials.
Collapse
Affiliation(s)
- Philipp Mahlknecht
- Department of Neurology, Medical University Innsbruck, Austria.,Sobell Department of Motor Neuroscience, UCL Institute of Neurology, London, UK
| | - Klaus Seppi
- Department of Neurology, Medical University Innsbruck, Austria
| | - Werner Poewe
- Department of Neurology, Medical University Innsbruck, Austria
| |
Collapse
|
13
|
Mašková J, Školoudík D, Burgetová A, Fiala O, Brůha R, Záhoráková D, Serranová T, Slovák M, Ulmanová O, Růžička E, Dušek P. Comparison of transcranial sonography-magnetic resonance fusion imaging in Wilson's and early-onset Parkinson's diseases. Parkinsonism Relat Disord 2016; 28:87-93. [DOI: 10.1016/j.parkreldis.2016.04.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 04/20/2016] [Accepted: 04/26/2016] [Indexed: 11/16/2022]
|
14
|
Mahlknecht P, Gasperi A, Willeit P, Kiechl S, Stockner H, Willeit J, Rungger G, Sawires M, Nocker M, Rastner V, Mair KJ, Hotter A, Poewe W, Seppi K. Prodromal Parkinson's disease as defined per MDS research criteria in the general elderly community. Mov Disord 2016; 31:1405-8. [PMID: 27273736 DOI: 10.1002/mds.26674] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 04/08/2016] [Accepted: 04/13/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recently, the International Parkinson and Movement Disorder Society has defined research criteria for prodromal Parkinson's disease (PD), but to date their predictive value has not yet been tested in population-based cohorts. METHODS We retrospectively applied these criteria to the longitudinal Bruneck Study cohort aged 55-94 years using recorded data on all included risk and prodromal markers that are quick and easily assessable. RESULTS After excluding participants with idiopathic PD or secondary parkinsonism, prevalence of probable prodromal PD in the remaining 539 participants was 2.2% (95% confidence interval, 1.2%-3.9%). Of 488 participants followed up over 5 years, 11 developed incident PD. Sensitivity of "probable prodromal PD" status for incident PD was 54.6% (95% confidence interval, 28.0%-78.8%), specificity was 99.2% (97.8%-99.8%), positive predictive value was 60.0% (31.2%-83.3%), and negative predictive value was 99.0% (97.5%-99.6%). CONCLUSIONS Our findings suggest that the new research criteria for prodromal PD are a promising tool to identify cases of incident PD over 5 years, arguing for their usefulness in defining target populations for disease-prevention trials. © 2016 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Philipp Mahlknecht
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.,Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, United Kingdom
| | - Arno Gasperi
- Department of Neurology, Hospital of Bruneck, Bruneck, Italy
| | - Peter Willeit
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.,King's British Heart Foundation Centre, King's College London, London, United Kingdom.,Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom
| | - Stefan Kiechl
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Heike Stockner
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Johann Willeit
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | | | - Martin Sawires
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Michael Nocker
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Verena Rastner
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Katherina J Mair
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Anna Hotter
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Werner Poewe
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
| | - Klaus Seppi
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
| |
Collapse
|
15
|
Mahlknecht P, Pechlaner R, Boesveldt S, Volc D, Pinter B, Reiter E, Müller C, Krismer F, Berendse HW, van Hilten JJ, Wuschitz A, Schimetta W, Högl B, Djamshidian A, Nocker M, Göbel G, Gasperi A, Kiechl S, Willeit J, Poewe W, Seppi K. Optimizing odor identification testing as quick and accurate diagnostic tool for Parkinson's disease. Mov Disord 2016; 31:1408-13. [PMID: 27159493 PMCID: PMC5026160 DOI: 10.1002/mds.26637] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 02/10/2016] [Accepted: 02/29/2016] [Indexed: 12/05/2022] Open
Abstract
Introduction The aim of this study was to evaluate odor identification testing as a quick, cheap, and reliable tool to identify PD. Methods Odor identification with the 16‐item Sniffin' Sticks test (SS‐16) was assessed in a total of 646 PD patients and 606 controls from three European centers (A, B, and C), as well as 75 patients with atypical parkinsonism or essential tremor and in a prospective cohort of 24 patients with idiopathic rapid eye movement sleep behavior disorder (center A). Reduced odor sets most discriminative for PD were determined in a discovery cohort derived from a random split of PD patients and controls from center A using L1‐regularized logistic regression. Diagnostic accuracy was assessed in the rest of the patients/controls as validation cohorts. Results Olfactory performance was lower in PD patients compared with controls and non‐PD patients in all cohorts (each P < 0.001). Both the full SS‐16 and a subscore of the top eight discriminating odors (SS‐8) were associated with an excellent discrimination of PD from controls (areas under the curve ≥0.90; sensitivities ≥83.3%; specificities ≥82.0%) and from non‐PD patients (areas under the curve ≥0.91; sensitivities ≥84.1%; specificities ≥84.0%) in all cohorts. This remained unchanged when patients with >3 years of disease duration were excluded from analysis. All 8 incident PD cases among patients with idiopathic rapid eye movement sleep behavior disorder were predicted with the SS‐16 and the SS‐8 (sensitivity, 100%; positive predictive value, 61.5%). Conclusions Odor identification testing provides excellent diagnostic accuracy in the distinction of PD patients from controls and diagnostic mimics. A reduced set of eight odors could be used as a quick tool in the workup of patients presenting with parkinsonism and for PD risk indication. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society
Collapse
Affiliation(s)
- Philipp Mahlknecht
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria.,Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, United Kingdom
| | - Raimund Pechlaner
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Sanne Boesveldt
- Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Centre, Amsterdam, The Netherlands.,Divisions of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Dieter Volc
- Study Center Confraternitaet-PKJ Vienna, Vienna, Austria
| | - Bernardette Pinter
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Eva Reiter
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Christoph Müller
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Florian Krismer
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Henk W Berendse
- Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Centre, Amsterdam, The Netherlands
| | - Jacobus J van Hilten
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | | | - Wolfgang Schimetta
- Department of Applied Systems Research and Statistics, Johannes Kepler University Linz, Linz, Austria
| | - Birgit Högl
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Atbin Djamshidian
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Michael Nocker
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Georg Göbel
- Department of Medical Statistics, Informatics and Health Economics, Medical University Innsbruck, Innsbruck, Austria
| | - Arno Gasperi
- Department of Neurology, Hospital of Bruneck, Bruneck, Italy
| | - Stefan Kiechl
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Johann Willeit
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Werner Poewe
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Klaus Seppi
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria.
| |
Collapse
|
16
|
Sprenger FS, Wurster I, Seppi K, Stockner H, Scherfler C, Sojer M, Schmidauer C, Berg D, Poewe W. Substantia nigra hyperechogenicity and Parkinson's disease risk in patients with essential tremor. Mov Disord 2016; 31:579-83. [PMID: 26893155 DOI: 10.1002/mds.26515] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 11/02/2015] [Accepted: 11/08/2015] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Several studies have reported an increased risk for patients with essential tremor to develop Parkinson's disease. In addition, hyperechogenicity in the area of the substantia nigra has been associated with a markedly increased risk for Parkinson's disease. The objective of this study was to evaluate the validity of substantia nigra hyperechogenicity in patients with essential tremor as a risk marker for Parkinson's disease. METHODS Transcranial sonography was performed in 70 patients suffering from essential tremor. Fifty-four of these patients were available for follow-up after a mean of 6.16 ± 2.05 years and were assessed for the incidence of new-onset Parkinson's disease. RESULTS The relative risk for developing Parkinson's disease in patients with essential tremor who had hyperechogenicity at baseline versus those without this hyperechogenicity was 7.00 (95% confidence interval, 1.62-30.34; sensitivity, 77.8%; specificity, 75.6%). CONCLUSIONS Substantia nigra hyperechogenicity is also associated with an increased risk for Parkinson's disease in patients with essential tremor. These findings further support the potential role of this echofeature as a risk marker for Parkinson's disease.
Collapse
Affiliation(s)
| | - Isabel Wurster
- Neurology Center, Hertie Institute for Clinical Brain Research, Department of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany
| | - Klaus Seppi
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | - Heike Stockner
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | | | - Martin Sojer
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| | | | - Daniela Berg
- Neurology Center, Hertie Institute for Clinical Brain Research, Department of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany
| | - Werner Poewe
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria
| |
Collapse
|
17
|
Li DH, He YC, Liu J, Chen SD. Diagnostic Accuracy of Transcranial Sonography of the Substantia Nigra in Parkinson's disease: A Systematic Review and Meta-analysis. Sci Rep 2016; 6:20863. [PMID: 26878893 PMCID: PMC4754637 DOI: 10.1038/srep20863] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 01/08/2016] [Indexed: 11/20/2022] Open
Abstract
A large number of articles have reported substantia nigra hyperechogenicity in Parkinson’s disease (PD) and have assessed the diagnostic accuracy of transcranial sonography (TCS); however, the conclusions are discrepant. Consequently, this systematic review and meta-analysis aims to consolidate the available observational studies and provide a comprehensive evaluation of the clinical utility of TCS in PD. Totally, 31 studies containing 4,386 participants from 13 countries were included. A random effects model was utilized to pool the effect sizes. Meta-regression and sensitivity analysis were performed to explore potential heterogeneity. Overall diagnostic accuracy of TCS in differentiating PD from normal controls was quite high, with a pooled sensitivity of 0.83 (95% CI: 0.81–0.85) and a pooled specificity of 0.87 (95% CI: 0.85–0.88). The positive likelihood ratio, the negative likelihood ratio and diagnostic odds ratio were calculated 6.94 (95% CI: 5.09–9.48), 0.19 (95% CI: 0.16–0.23), and 42.89 (95% CI: 30.03–61.25) respectively. Our systematic review of the literature and meta-analysis suggest that TCS has high diagnostic accuracy in the diagnosis of PD when compared to healthy control.
Collapse
Affiliation(s)
- Dun-Hui Li
- Department of Neurology &Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Ya-Chao He
- Department of Neurology &Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Jun Liu
- Department of Neurology &Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Sheng-Di Chen
- Department of Neurology &Institute of Neurology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| |
Collapse
|
18
|
Zhou HY, Sun Q, Tan YY, Hu YY, Zhan WW, Li DH, Wang Y, Xiao Q, Liu J, Chen SD. Substantia nigra echogenicity correlated with clinical features of Parkinson's disease. Parkinsonism Relat Disord 2016; 24:28-33. [PMID: 26842545 DOI: 10.1016/j.parkreldis.2016.01.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Revised: 01/21/2016] [Accepted: 01/21/2016] [Indexed: 11/28/2022]
Abstract
BACKGROUND Transcranial sonography can display structural alterations in the substantia nigra (SN) of patients with Parkinson's disease (PD), and is considered to be a potential useful tool for the diagnosis of PD. The aim of this study was to assess the correlation between SN echogenicity and clinical features in Chinese patients with PD. METHODS A total of 420 subjects including 290 patients with PD and 130 controls were recruited from the neurological clinic or the community. Transcranial sonographic evaluations of the SN were performed in all subjects, and motor and non-motor symptoms were thoroughly assessed by a series of rating scales in PD patients. RESULTS Two hundred and one patients were successfully assessed by transcranial sonography. SN hyperechogenicity was found to be associated with male sex (p = 0.004), higher scores on the Unified Parkinson's Disease Rating Scale (UPDRS) part II (p = 0.001) and autonomic symptoms scores (p = 0.003). Moreover, regression analysis revealed that UPDRS part II scores (odds ratio = 1.141, p < 0.001) and gender (odds ratio = 2.409, p = 0.007) could be the independent predictors for SN hyperechogenicity; in addition, among all items of UPDRS part II, speech, dressing, hygiene, and turning in bed and adjusting bed clothes significantly correlated with SN hyperechogenicity. CONCLUSIONS This is the first report suggesting the correlation between SN echogenicity and UPDRS part II, and we conclude that increased SN echogenicity might reflect more severe disease disability or poorer medical response.
Collapse
Affiliation(s)
- Hai-Yan Zhou
- Department of Neurology & Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qian Sun
- Department of Neurology & Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yu-Yan Tan
- Department of Neurology & Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yun-Yun Hu
- Department of Ultrasonography, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wei-Wei Zhan
- Department of Ultrasonography, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Dun-Hui Li
- Department of Neurology & Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ying Wang
- Department of Neurology & Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qin Xiao
- Department of Neurology & Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jun Liu
- Department of Neurology & Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Sheng-Di Chen
- Department of Neurology & Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| |
Collapse
|
19
|
Toomsoo T, Liepelt-Scarfone I, Kerner R, Kadastik-Eerme L, Asser T, Rubanovits I, Berg D, Taba P. Substantia Nigra Hyperechogenicity: Validation of Transcranial Sonography for Parkinson Disease Diagnosis in a Large Estonian Cohort. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2016; 35:17-23. [PMID: 26589647 DOI: 10.7863/ultra.14.12069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 04/07/2015] [Indexed: 06/05/2023]
Abstract
OBJECTIVES Substantia nigra hyperechogenicity is a promising biomarker for Parkinson disease (PD). Substantia nigra hyperechogenicity has previously been established as a useful diagnostic criterion in several European and Asian patient cohorts. However, diagnostic cutoff values for substantia nigra hyperechogenicity remain unknown for most patient populations. This study validated the diagnostic accuracy of substantia nigra hyperechogenicity in a large cohort of patients with PD in Estonia. METHODS The study included 300 patients with PD from Estonia, representing 10% of the national PD patient population, and 200 healthy control participants. To define the optimal cutoff value in the PD cohort, data from a single assessment versus repetitive assessments by transcranial sonography were compared. With the use of 3 repetitive assessments, the diagnostic accuracy of the data was measured. In addition, calculations for percentile values were used to define substantia nigra hyperechogenicity among controls. RESULTS Our data showed that the multiassessment approach yielded higher diagnostic accuracy than a single assessment (P = .021). The highest diagnostic accuracy was achieved by using the measurement mean to define substantia nigra hyperechogenicity, which was 0.23 cm(2) (sensitivity, 88.7%; specificity, 92.2%), whereas single measurements detected PD with higher sensitivity (sensitivity, 93.2%; specificity, 85.1%). No significant difference was found between mean and median measurements (P= .18). CONCLUSIONS This study indicates the diagnostic merit of transcranial sonography in PD diagnosis in an additional population and demonstrates that transcranial sonography of the substantia nigra is a relevant and useful diagnostic tool for patients with PD.
Collapse
Affiliation(s)
- Toomas Toomsoo
- Center of Neurology, East Tallinn Central Hospital, Tallinn, Estonia (T.T., I.R.); Department of Neurodegeneration, Center of Neurology, Hertie Institute of Clinical Brain Research and German Center of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany (I.L.-S., D.B.); Statistics Estonia, Tallinn, Estonia (R.K.); and Department of Neurology and Neurosurgery, University of Tartu, Tartu, Estonia (L.K.-E., T.A., P.T.)
| | - Inga Liepelt-Scarfone
- Center of Neurology, East Tallinn Central Hospital, Tallinn, Estonia (T.T., I.R.); Department of Neurodegeneration, Center of Neurology, Hertie Institute of Clinical Brain Research and German Center of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany (I.L.-S., D.B.); Statistics Estonia, Tallinn, Estonia (R.K.); and Department of Neurology and Neurosurgery, University of Tartu, Tartu, Estonia (L.K.-E., T.A., P.T.)
| | - Riina Kerner
- Center of Neurology, East Tallinn Central Hospital, Tallinn, Estonia (T.T., I.R.); Department of Neurodegeneration, Center of Neurology, Hertie Institute of Clinical Brain Research and German Center of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany (I.L.-S., D.B.); Statistics Estonia, Tallinn, Estonia (R.K.); and Department of Neurology and Neurosurgery, University of Tartu, Tartu, Estonia (L.K.-E., T.A., P.T.)
| | - Liis Kadastik-Eerme
- Center of Neurology, East Tallinn Central Hospital, Tallinn, Estonia (T.T., I.R.); Department of Neurodegeneration, Center of Neurology, Hertie Institute of Clinical Brain Research and German Center of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany (I.L.-S., D.B.); Statistics Estonia, Tallinn, Estonia (R.K.); and Department of Neurology and Neurosurgery, University of Tartu, Tartu, Estonia (L.K.-E., T.A., P.T.)
| | - Toomas Asser
- Center of Neurology, East Tallinn Central Hospital, Tallinn, Estonia (T.T., I.R.); Department of Neurodegeneration, Center of Neurology, Hertie Institute of Clinical Brain Research and German Center of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany (I.L.-S., D.B.); Statistics Estonia, Tallinn, Estonia (R.K.); and Department of Neurology and Neurosurgery, University of Tartu, Tartu, Estonia (L.K.-E., T.A., P.T.).
| | - Inna Rubanovits
- Center of Neurology, East Tallinn Central Hospital, Tallinn, Estonia (T.T., I.R.); Department of Neurodegeneration, Center of Neurology, Hertie Institute of Clinical Brain Research and German Center of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany (I.L.-S., D.B.); Statistics Estonia, Tallinn, Estonia (R.K.); and Department of Neurology and Neurosurgery, University of Tartu, Tartu, Estonia (L.K.-E., T.A., P.T.)
| | - Daniela Berg
- Center of Neurology, East Tallinn Central Hospital, Tallinn, Estonia (T.T., I.R.); Department of Neurodegeneration, Center of Neurology, Hertie Institute of Clinical Brain Research and German Center of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany (I.L.-S., D.B.); Statistics Estonia, Tallinn, Estonia (R.K.); and Department of Neurology and Neurosurgery, University of Tartu, Tartu, Estonia (L.K.-E., T.A., P.T.)
| | - Pille Taba
- Center of Neurology, East Tallinn Central Hospital, Tallinn, Estonia (T.T., I.R.); Department of Neurodegeneration, Center of Neurology, Hertie Institute of Clinical Brain Research and German Center of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany (I.L.-S., D.B.); Statistics Estonia, Tallinn, Estonia (R.K.); and Department of Neurology and Neurosurgery, University of Tartu, Tartu, Estonia (L.K.-E., T.A., P.T.)
| |
Collapse
|
20
|
Stefani A, Gabelia D, Högl B, Mitterling T, Mahlknecht P, Stockner H, Poewe W, Frauscher B. Long-Term Follow-up Investigation of Isolated Rapid Eye Movement Sleep Without Atonia Without Rapid Eye Movement Sleep Behavior Disorder: A Pilot Study. J Clin Sleep Med 2015; 11:1273-9. [PMID: 26156949 DOI: 10.5664/jcsm.5184] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 06/02/2015] [Indexed: 11/13/2022]
Abstract
STUDY OBJECTIVES Idiopathic rapid eye movement (REM) sleep behavior disorder (RBD) is a harbinger of synuclein-mediated neurodegenerative diseases. It is unknown if this also applies to isolated REM sleep without atonia (RWA). We performed a long-term follow-up investigation of subjects with isolated RWA. METHODS Participants were recruited from 50 subjects with isolated RWA who were identified at the sleep laboratory of the Department of Neurology at the Medical University of Innsbruck between 2003 and 2005. Eligible subjects underwent follow-up clinical examination, polysomnography, and assessment of neurodegenerative biomarkers (cognitive impairment, finger speed deficit, impaired color vision, olfactory dysfunction, orthostatic hypotension, and substantia nigra hyperechogenicity). RESULTS After a mean of 8.6 ± 0.9 y, 1 of 14 participating subjects (7.3%) progressed to RBD. Ten of 14 RWA subjects (71.4%) were positive for at least one neurodegenerative biomarker. Substantia nigra hyperechogenicity and presence of mild cognitive impairment were both present in 4 of 14 subjects with isolated RWA. Electromyographic activity measures increased significantly from baseline to follow-up polysomnography ("any" mentalis and both anterior tibialis muscles: 32.5 ± 9.4 versus 52.2 ± 16.6%; p = 0.004). CONCLUSION This study provides first evidence that isolated RWA is an early biomarker of synuclein-mediated neurodegeneration. These results will have to be replicated in larger studies with longer observational periods. If confirmed, these disease findings have implications for defining at-risk cohorts for Parkinson disease.
Collapse
Affiliation(s)
- Ambra Stefani
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - David Gabelia
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Birgit Högl
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas Mitterling
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Philipp Mahlknecht
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Heike Stockner
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Werner Poewe
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Birgit Frauscher
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
21
|
Autonomic dysfunction in subjects at high risk for Parkinson's disease. J Neurol 2015; 262:2643-52. [PMID: 26530505 DOI: 10.1007/s00415-015-7888-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/21/2015] [Accepted: 08/22/2015] [Indexed: 12/15/2022]
Abstract
Aim of this project was to evaluate autonomic dysfunction in subjects proposed to be at high risk to develop Parkinson's disease (PD) compared to control subjects and PD patients at different disease stages. Combinations of substantia nigra hyperechogenicity (SN+) assessed by transcranial ultrasound (TCS), hyposmia, lifetime prevalence of depression and mild PD-specific motor signs were used to identify subjects at high risk for motor Parkinson's disease (HR-PD). Supine and standing blood pressure (BP), hearth rate (HR), orthostatic, urinary, sexual and bowel symptoms were evaluated in HR-PD, healthy control subjects and PD patients, divided into mild and advanced stages. The study group consisted of 113 PD patients (mild PD n = 71, advanced PD, n = 42), 40 HR-PD individuals and 50 controls. Compared to controls, HR-PD subjects complained more often about urinary (p = 0.002) and bowel dysfunction (p = 0.001) and had a higher diastolic BP drop after standing (p = 0.01). The cumulative number of autonomic symptoms differentiated PD as well as HR-PD significantly from controls (p < 0.001). Advanced PD patients presented often and severe orthostatic symptoms, not significantly different from mild PD after concomitant medication correction. Our results support the presence of urinary and bowel dysfunction in subjects at high risk for motor PD. Presence and severity of orthostatic symptoms was higher during stages and increase in advanced stages, at least partly due to increase in dopaminergic and conflicting medication. Understanding the progression of non-motor aspects in PD might offer the possibility to use them as targets for disease-modifying therapies.
Collapse
|
22
|
Mahlknecht P, Seppi K, Frauscher B, Kiechl S, Willeit J, Stockner H, Djamshidian A, Nocker M, Rastner V, Defrancesco M, Rungger G, Gasperi A, Poewe W, Högl B. Probable RBD and association with neurodegenerative disease markers: A population-based study. Mov Disord 2015. [PMID: 26208108 DOI: 10.1002/mds.26350] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND The prevalence of rapid eye movement sleep behavior disorder (RBD) and its association with markers of neurodegeneration in the general population are poorly defined. METHODS We assessed the prevalence of probable RBD defined by two validated questionnaires, the RBD Screening Questionnaire (RBDSQ) and the Innsbruck RBD-Inventory (RBD-I), and studied its associations with clinical and imaging markers for neurodegeneration in the Bruneck Study cohort aged 60 y or older. RESULTS Of the 456 participants without Parkinson's disease, 4.6% (RBDSQ; 95%CI, 3.0%-7.0%) and 7.7% (RBD-I; 95%CI, 5.6%-10.5%) had probable RBD. Probable RBD diagnosed with either of the questionnaires was associated with hyposmia (trend; P < 0.1), anxiety (P < 0.05), depression (P < 0.05), antidepressant use (P < 0.05), and self-reported non-motor symptoms (P < 0.01), specifically, dribbling saliva, memory problems, apathy, concentration problems, and anxiety. CONCLUSIONS Our findings may provide a basis for future studies intending to identify cohorts at risk for Lewy body diseases through screening of the general elderly population for RBD.
Collapse
Affiliation(s)
- Philipp Mahlknecht
- Department of Neurology, Medical University of Innsbruck, Austria.,Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK
| | - Klaus Seppi
- Department of Neurology, Medical University of Innsbruck, Austria
| | - Birgit Frauscher
- Department of Neurology, Medical University of Innsbruck, Austria
| | - Stefan Kiechl
- Department of Neurology, Medical University of Innsbruck, Austria
| | - Johann Willeit
- Department of Neurology, Medical University of Innsbruck, Austria
| | - Heike Stockner
- Department of Neurology, Medical University of Innsbruck, Austria
| | - Atbin Djamshidian
- Department of Neurology, Medical University of Innsbruck, Austria.,Department of Molecular Neuroscience and Reta Lila Weston Institute for Neurological Studies, University of London, London, UK
| | - Michael Nocker
- Department of Neurology, Medical University of Innsbruck, Austria
| | - Verena Rastner
- Department of Neurology, Medical University of Innsbruck, Austria
| | | | | | - Arno Gasperi
- Department of Neurology, Hospital of Bruneck, Italy
| | - Werner Poewe
- Department of Neurology, Medical University of Innsbruck, Austria
| | - Birgit Högl
- Department of Neurology, Medical University of Innsbruck, Austria
| |
Collapse
|
23
|
Jellinger KA. Neuropathobiology of non-motor symptoms in Parkinson disease. J Neural Transm (Vienna) 2015; 122:1429-40. [PMID: 25976432 DOI: 10.1007/s00702-015-1405-5] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 04/30/2015] [Indexed: 01/23/2023]
Abstract
Parkinson disease (PD) is a multisystem disorder associated with α-synuclein aggregates throughout the central, autonomic, and peripheral nervous system, clinically characterized by motor and non-motor (NM) symptoms. The NMS in PD, many of which antedating motor dysfunction and representing a preclinical phase spanning 20 or more years, are linked to widespread distribution of α-synuclein pathology not restricted to the dopaminergic nigrostriatal system that is responsible for core motor features of PD. The pathologic substrate of NM manifestations such as olfactory, autonomic (gastrointestinal, urogenital, cardia, respiratory), sensory, skin, sleep, visual, neuropsychiatric dysfunctions (cognitive, mood, dementia), and others are critically reviewed. In addition to non-nigral brainstem nuclei, α-synuclein pathology involves sympathetic and parasympathetic, enteric, cardiac and pelvic plexuses, and many other organs indicating a topographical and chronological spread, particularly in the prodromal stages of the disease. Few animal models recapitulate NMS in PD. The relationship between regional α-synuclein/Lewy pathology, neurodegeneration and the corresponding clinical deficits awaits further elucidation. Controlled clinicopathologic studies will refine the correlations between presymptomatic and late-developing NM features of PD and neuropathology, and new premotor biomarkers will facilitate early diagnosis of PD as a basis for more effective preventive and therapeutic options of this devastating disease.
Collapse
Affiliation(s)
- Kurt A Jellinger
- Institute of Clinical Neurobiology, Kenyongasse 18, 1070, Vienna, Austria.
| |
Collapse
|
24
|
Stanković I, Stefanova E, Žiropadja L, Mijajlović M, Pavlović A, Kostić VS. Transcranial midbrain sonography and depressive symptoms in patients with Parkinson’s disease. J Neurol 2015; 262:689-95. [DOI: 10.1007/s00415-014-7624-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 12/19/2014] [Accepted: 12/22/2014] [Indexed: 12/31/2022]
|
25
|
Mahlknecht P, Kiechl S, Stockner H, Willeit J, Gasperi A, Poewe W, Seppi K. Predictors for mild parkinsonian signs: a prospective population-based study. Parkinsonism Relat Disord 2014; 21:321-4. [PMID: 25585991 DOI: 10.1016/j.parkreldis.2014.12.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 12/09/2014] [Accepted: 12/16/2014] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Mild parkinsonian signs (MPS) are common in the elderly population and are associated with a wide range of adverse health outcomes, including incident Parkinson's disease (PD). We aimed to prospectively evaluate potential risk factors for incident MPS. METHODS Participants of the population-based Bruneck Study representative for the general elderly community underwent a baseline assessment of substantia nigra (SN)-echogenicity with transcranial sonography, olfactory function with the Sniffin' Sticks identification test and vascular risk according to the Framingham risk score as well as a baseline and 5-year follow-up neurological examination. MPS were defined according to established criteria based on the entire motor section of the Unified PD Rating Scale. Participants with PD at baseline or follow-up and subjects with MPS at baseline were excluded. A logistic regression analysis adjusted for age and sex was used to detect risk factors for incident MPS in the remaining 393 participants. RESULTS SN-hyperechogenicity and hyposmia were related to the development of MPS with odds ratios of 2.0 (95%CI, 1.1-3.7) and 1.6 (95%CI, 1.0-2.7), respectively, while increased vascular risk was not. Having both, SN-hyperechogenicity and hyposmia, was associated with an odds ratio of 3.0 (95%CI, 1.2-7.7) for incident MPS. Among the various motor domains, increased SN-echogenicity predicted the development of bradykinesia and rigidity, whereas diminished olfactory function predicted the development of impaired axial motor function. CONCLUSIONS In addition to their established roles as risk factors for PD, SN-hyperechogenicity and hyposmia are associated with an increased risk for MPS in the general elderly community.
Collapse
Affiliation(s)
- Philipp Mahlknecht
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria; Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK.
| | - Stefan Kiechl
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
| | - Heike Stockner
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
| | - Johann Willeit
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
| | - Arno Gasperi
- Department of Neurology, Hospital of Bruneck, Bruneck, Italy.
| | - Werner Poewe
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
| | - Klaus Seppi
- Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
| |
Collapse
|
26
|
Mijajlovic MD, Tsivgoulis G, Sternic N. Transcranial brain parenchymal sonography in neurodegenerative and psychiatric diseases. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2014; 33:2061-2068. [PMID: 25425361 DOI: 10.7863/ultra.33.12.2061] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Transcranial sonography is a highly sensitive noninvasive sonographic method for detection of early and specific echogenic changes in basal ganglia of patients with some neurodegenerative diseases. Transcranial sonography showed substantia nigra hyperechogenicity as a typical echo feature in idiopathic Parkinson disease and lenticular nucleus hyperechogenicity as a characteristic finding in atypical parkinsonian syndromes. Brain stem raphe hypoechogenicity or interruption has been shown to be highly prevalent in patients with unipolar depression as well as depression associated with certain neurodegenerative diseases. Transcranial sonography also revealed basal ganglia hyperechoic changes in movement disorders with trace metal accumulation such as Wilson disease, some entities of neurodegeneration with brain iron accumulation, as well as several forms of spinocerebellar ataxia. Transcranial sonography is a valuable neuro imaging method for early and differential diagnosis and follow-up of patients with neurodegenerative and psychiatric diseases.
Collapse
Affiliation(s)
- Milija D Mijajlovic
- Neurology Clinic, Clinical Center of Serbia, School of Medicine, University of Belgrade, Belgrade, Serbia (M.D.M., N.S.); Second Department of Neurology, University of Athens, School of Medicine, Attikon University Hospital, Athens, Greece (G.T.); and International Clinical Research Center, St Anne's University Hospital, Brno, Czech Republic (G.T.).
| | - Georgios Tsivgoulis
- Neurology Clinic, Clinical Center of Serbia, School of Medicine, University of Belgrade, Belgrade, Serbia (M.D.M., N.S.); Second Department of Neurology, University of Athens, School of Medicine, Attikon University Hospital, Athens, Greece (G.T.); and International Clinical Research Center, St Anne's University Hospital, Brno, Czech Republic (G.T.)
| | - Nadezda Sternic
- Neurology Clinic, Clinical Center of Serbia, School of Medicine, University of Belgrade, Belgrade, Serbia (M.D.M., N.S.); Second Department of Neurology, University of Athens, School of Medicine, Attikon University Hospital, Athens, Greece (G.T.); and International Clinical Research Center, St Anne's University Hospital, Brno, Czech Republic (G.T.)
| |
Collapse
|
27
|
Bor-Seng-Shu E, Pedroso JL, Felicio AC, Ciampi de Andrade D, Teixeira MJ, Braga-Neto P, Batista IR, Barsottini OGP, Borges V, Ferraz HB, Shih MC, Bressan RA, de Andrade LAF, Walter U. Substantia nigra echogenicity and imaging of striatal dopamine transporters in Parkinson's disease: A cross-sectional study. Parkinsonism Relat Disord 2014; 20:477-81. [DOI: 10.1016/j.parkreldis.2014.01.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 01/03/2014] [Accepted: 01/11/2014] [Indexed: 10/25/2022]
|