Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Ami Rosen is active.

Publication


Featured researches published by Ami Rosen.


JAMA Neurology | 2008

Prevalence of vitamin d insufficiency in patients with Parkinson disease and Alzheimer disease.

Marian L. Evatt; Mahlon R. DeLong; Natasha Khazai; Ami Rosen; Shirley Triche; Vin Tangpricha

BACKGROUND A role for vitamin D deficiency in Parkinson disease (PD) has recently been proposed. OBJECTIVE To compare the prevalence of vitamin D deficiency in a research database cohort of patients with PD with the prevalence in age-matched healthy controls and patients with Alzheimer disease (AD). DESIGN Survey study and blinded comparison of plasma 25-hydroxyvitamin D (25[OH]D) concentrations of stored samples in a clinical research database at Emory University School of Medicine. SETTING Referral center (PD and AD patients), primary care clinics, and community setting (controls). PARTICIPANTS Participants were recruited into the study between May 1992 and March 2007. Every fifth consecutively enrolled PD patient was selected from the clinical research database. Unrelated AD (n = 97) and control (n = 99) participants were randomly selected from the database after matching for age, sex, race, APOE genotype, and geographic location. MAIN OUTCOME MEASURES Prevalence of suboptimal vitamin D and mean 25(OH)D concentrations. RESULTS Significantly more patients with PD (55%) had insufficient vitamin D than did controls (36%) or patients with AD (41%; P = .02, chi(2)test). The mean (SD) 25(OH)D concentration in the PD cohort was significantly lower than in the AD and control cohorts (31.9 [13.6] ng/mL vs 34.8 [15.4] ng/mL and 37.0 [14.5] ng/mL, respectively; P = .03). CONCLUSIONS This report of 25(OH)D concentrations in a predominantly white PD cohort demonstrates a significantly higher prevalence of hypovitaminosis in PD vs both healthy controls and patients with AD. These data support a possible role of vitamin D insufficiency in PD. Further studies are needed to determine the factors contributing to these differences and elucidate the potential role of vitamin D in pathogenesis and clinical course of PD.


Nature Genetics | 2009

Variant in the sequence of the LINGO1 gene confers risk of essential tremor

Hreinn Stefansson; Stacy Steinberg; Hjorvar Petursson; Omar Gustafsson; Iris H Gudjonsdottir; Gudrun A Jonsdottir; Stefan Palsson; Thorlakur Jonsson; Jona Saemundsdottir; Gyda Bjornsdottir; Yvonne Böttcher; Theodora Thorlacius; Dietrich Haubenberger; Alexander Zimprich; Eduard Auff; Christoph Hotzy; Claudia M. Testa; Lisa A Miyatake; Ami Rosen; Kristleifur Kristleifsson; David B. Rye; Friedrich Asmus; Ludger Schöls; Martin Dichgans; Finnbogi Jakobsson; John Benedikz; Unnur Thorsteinsdottir; Jeffrey R. Gulcher; Augustine Kong; Kari Stefansson

We identified a marker in LINGO1 showing genome-wide significant association (P = 1.2 x 10(-9), odds ratio = 1.55) with essential tremor. LINGO1 has potent, negative regulatory influences on neuronal survival and is also important in regulating both central-nervous-system axon regeneration and oligodendrocyte maturation. Increased axon integrity observed in Lingo1 mouse [corrected] knockout models highlights the potential role of LINGO1 in the pathophysiology of ET [corrected]We identified a marker in LINGO1 showing genome-wide significant association (P = 1.2 × 10−9, odds ratio = 1.55) with essential tremor. LINGO1 has potent, negative regulatory influences on neuronal survival and is also important in regulating both central-nervous-system axon regeneration and oligodendrocyte maturation. Increased axon integrity observed in Lingo1 mouse knockout models highlights the potential role of LINGO1 in the pathophysiology of essential tremor.


Movement Disorders | 2013

The Focal Dystonias: Current Views and Challenges for Future Research

H.A. Jinnah; Alfredo Berardelli; Cynthia L. Comella; Giovanni Defazio; Mahlon R. DeLong; Stewart A. Factor; Wendy R. Galpern; Mark Hallett; Christy L. Ludlow; Joel S. Perlmutter; Ami Rosen

The most common forms of dystonia are those that develop in adults and affect a relatively isolated region of the body. Although these adult‐onset focal dystonias are most prevalent, knowledge of their etiologies and pathogenesis has lagged behind some of the rarer generalized dystonias, in which the identification of genetic defects has facilitated both basic and clinical research. This summary provides a brief review of the clinical manifestations of the adult‐onset focal dystonias, focusing attention on less well understood clinical manifestations that need further study. It also provides a simple conceptual model for the similarities and differences among the different adult‐onset focal dystonias as a rationale for lumping them together as a class of disorders while at the same time splitting them into subtypes. The concluding section outlines some of the most important research questions for the future. Answers to these questions are critical for advancing our understanding of this group of disorders and for developing novel therapeutics.


Movement Disorders | 2011

Disease-related and genetic correlates of psychotic symptoms in Parkinson's disease.

Stewart A. Factor; N. Kyle Steenland; Donald S. Higgins; Eric Molho; Denise M. Kay; Jennifer S. Montimurro; Ami Rosen; Cyrus P. Zabetian; Haydeh Payami

Our aim was to examine disease‐related and genetic correlates of the development of psychotic symptoms in a large population of patients with Parkinsons disease. We studied 500 patients with Parkinsons disease from the NeuroGenetics Research Consortium using logistic regression models. Predictors were demographic, clinical (motor/nonmotor features), and genetic, measured as continuous or dichotomous variables. Continuous measures were divided into population‐based tertiles. Results are given as odds ratios (95% confidence intervals) for dichotomous variables and by ascending tertile for continuous variables. Psychotic symptoms were associated with increasing age: 4.86 (1.62–14.30) and 6.25 (2.09–18.74) (test for trend: P = 0.01); and duration of disease: 3.81 (1.23–11.76) and 5.33 (1.68–16.89) (test for trend: P = 0.03). For nonmotor features, we demonstrated positive trends with depression: 1.31 (0.47–3.61) and 5.01 (2.04–12.33) (test for trend: P < 0.0001); cognitive dysfunction: 0.69 (0.26–1.84) and 2.51 (1.00–6.29) (test for trend: P = 0.03); and an excess for those with sleep disorders: 2.00 (1.03–3.89) (P = 0.04). Psychotic symptoms were not associated with tremor or postural instability scores, but there was an association with freezing of gait: 3.83 (1.67–8.75) (P < 0.002). Psychotic symptoms were not associated with the presence of any examined polymorphisms in the apolipoprotein, alpha‐synuclein, or microtubule associated protein tau genes. This is the largest study to examine correlates of psychotic symptoms in Parkinsons disease. We discovered a novel association with freezing of gait. We demonstrated an association with depression and duration of disease, both of which were inconsistently related in previous studies, and confirmed the association with age, cognitive dysfunction, and sleep disorders.


Neurobiology of Aging | 2012

Paraoxonase 1 polymorphisms In Alzheimer's disease, Parkinson's disease, and AD-PD spectrum diseases

Thomas S. Wingo; Ami Rosen; David J. Cutler; James J. Lah; Allan I. Levey

Paraoxonase-1 (PON1) is a serum arylsulfatase that metabolizes organophosphate pesticides and protects low-density lipoprotein from oxidation. Case-control studies of PON1 genetic variants in Alzheimers disease (AD) and Parkinsons disease (PD) have revealed some positive albeit inconsistent associations with 2 PON1 coding polymorphisms: Q192R (rs662) and L55M (rs854560). Because AD and PD exist along a spectrum of disorders with shared epidemiologic, clinical, and pathologic features, here we evaluated PON1 variants in a cohort of 746 AD, 566 PD, 132 AD-PD, and 719 cognitively normal age-matched controls. In the combined AD and Caucasian PD cohorts we had 80% power to detect a relative risk of at least 1.25 and 1.35, respectively, for each polymorphism. We found no association between 2 PON1 coding polymorphisms and AD in African Americans or Caucasians, and no association with PD or AD-PD in Caucasians. There was also no evidence of an interaction between PON1 and apolipoprotein E for any of these diseases. Our results suggest that either these functional PON1 polymorphisms are not associated with AD and PD spectrum disorders, or that the relative risk conferred is small.


JAMA Neurology | 2015

A multiancestral genome-wide exome array study of Alzheimer Disease, frontotemporal dementia, and progressive supranuclear palsy

Jason A. Chen; Qing Wang; Jeremy Davis-Turak; Yun Li; Anna Karydas; Sandy Chan Hsu; Renee Sears; Doxa Chatzopoulou; Alden Y. Huang; Kevin Wojta; Eric Klein; Jason T. Lee; Duane Beekly; Adam L. Boxer; Kelley Faber; Claudia M. Haase; Josh Miller; Wayne W. Poon; Ami Rosen; Howard J. Rosen; Anna Sapozhnikova; Jill S. Shapira; Arousiak Varpetian; Tatiana Foroud; Robert W. Levenson; Allan I. Levey; Walter A. Kukull; Mario F. Mendez; John M. Ringman; Helena C. Chui

IMPORTANCE Previous studies have indicated a heritable component of the etiology of neurodegenerative diseases such as Alzheimer disease (AD), frontotemporal dementia (FTD), and progressive supranuclear palsy (PSP). However, few have examined the contribution of low-frequency coding variants on a genome-wide level. OBJECTIVE To identify low-frequency coding variants that affect susceptibility to AD, FTD, and PSP. DESIGN, SETTING, AND PARTICIPANTS We used the Illumina HumanExome BeadChip array to genotype a large number of variants (most of which are low-frequency coding variants) in a cohort of patients with neurodegenerative disease (224 with AD, 168 with FTD, and 48 with PSP) and in 224 control individuals without dementia enrolled between 2005-2012 from multiple centers participating in the Genetic Investigation in Frontotemporal Dementia and Alzheimers Disease (GIFT) Study. An additional multiancestral replication cohort of 240 patients with AD and 240 controls without dementia was used to validate suggestive findings. Variant-level association testing and gene-based testing were performed. MAIN OUTCOMES AND MEASURES Statistical association of genetic variants with clinical diagnosis of AD, FTD, and PSP. RESULTS Genetic variants typed by the exome array explained 44%, 53%, and 57% of the total phenotypic variance of AD, FTD, and PSP, respectively. An association with the known AD gene ABCA7 was replicated in several ancestries (discovery P=.0049, European P=.041, African American P=.043, and Asian P=.027), suggesting that exonic variants within this gene modify AD susceptibility. In addition, 2 suggestive candidate genes, DYSF (P=5.53×10(-5)) and PAXIP1 (P=2.26×10(-4)), were highlighted in patients with AD and differentially expressed in AD brain. Corroborating evidence from other exome array studies and gene expression data points toward potential involvement of these genes in the pathogenesis of AD. CONCLUSIONS AND RELEVANCE Low-frequency coding variants with intermediate effect size may account for a significant fraction of the genetic susceptibility to AD and FTD. Furthermore, we found evidence that coding variants in the known susceptibility gene ABCA7, as well as candidate genes DYSF and PAXIP1, confer risk for AD.


Neurogenetics | 2007

Evidence of shared risk for Alzheimer’s disease and Parkinson’s disease using family history

Ami Rosen; N. Kyle Steenland; John J. Hanfelt; Stewart A. Factor; James J. Lah; Allan I. Levey

This case-control study examined the potential for a common etiology of Parkinson’s disease (PD) and Alzheimer’s disease (AD) using reported family history. Structured interviews were used to collect AD and PD family history from subjects (n = 1531) with AD, PD, AD/PD, or controls. Intergroup analysis compared reported AD and PD family histories in the three case groups to the histories reported in the control group. Intragroup analysis stratified each diagnostic group based on positive family history of AD, then compared the subgroups for a family history of PD. Subjects with AD had a higher risk of having a family history of AD [odds ratio (OR) 2.3; 1.5–3.4] and subjects with PD had a higher risk of having a family history of PD (OR 2.2; 1.2–4.0) as compared to control subjects. Intergroup analyses revealed no significant crossed risk, increased risk of subjects with AD having a family history of PD vs controls and vice versa. Intragroup analysis found that subjects with PD and a family history of AD were more likely to have a family history of PD (OR 1.7; 1.1–2.6) when compared to subjects with PD and no family history of AD. A similar trend was found for subjects with AD (OR 1.7; 0.9–3.1). AD and PD cases each have an increased familial risk of their respective disease. Probands with AD or PD and a family history of either disease have a higher crossed risk of a family history of the other disease. These findings suggest the existence of common genetic and/or environmental factors that predispose to both AD and PD in the subset of cases with positive family history of both neurodegenerative diseases.


Movement Disorders Clinical Practice | 2015

Development of the Comprehensive Cervical Dystonia Rating Scale: Methodology

Cynthia L. Comella; Susan H. Fox; Kailash P. Bhatia; Joel S. Perlmutter; H.A. Jinnah; Mateusz Zurowski; William M. McDonald; Laura Marsh; Ami Rosen; Tracy Waliczek; Laura J. Wright; Wendy R. Galpern; Glenn T. Stebbins

We present the methodology utilized for development and clinimetric testing of the Comprehensive Cervical Dystonia (CD) Rating scale, or CCDRS. The CCDRS includes a revision of the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS‐2), a newly developed psychiatric screening tool (TWSTRS‐PSYCH), and the previously validated Cervical Dystonia Impact Profile (CDIP‐58). For the revision of the TWSTRS, the original TWSTRS was examined by a committee of dystonia experts at a dystonia rating scales workshop organized by the Dystonia Medical Research Foundation. During this workshop, deficiencies in the standard TWSTRS were identified and recommendations for revision of the severity and pain subscales were incorporated into the TWSTRS‐2. Given that no scale currently evaluates the psychiatric features of cervical dystonia (CD), we used a modified Delphi methodology and a reiterative process of item selection to develop the TWSTRS‐PSYCH. We also included the CDIP‐58 to capture the impact of CD on quality of life. The three scales (TWSTRS2, TWSTRS‐PSYCH, and CDIP‐58) were combined to construct the CCDRS. Clinimetric testing of reliability and validity of the CCDRS are described. The CCDRS was designed to be used in a modular fashion that can measure the full spectrum of CD. This scale will provide rigorous assessment for studies of natural history as well as novel symptom‐based or disease‐modifying therapies.


Neurology Genetics | 2016

Clinical and genetic features of cervical dystonia in a large multicenter cohort

Mark S. LeDoux; Satya R. Vemula; Jianfeng Xiao; Misty M. Thompson; Joel S. Perlmutter; Laura J. Wright; H.A. Jinnah; Ami Rosen; Peter Hedera; Cynthia L. Comella; Anne Weissbach; Johanna Junker; Joseph Jankovic; Richard L. Barbano; Stephen G. Reich; Ramon L. Rodriguez; Brian D. Berman; Sylvain Chouinard; Lawrence Severt; Pinky Agarwal; Natividad P. Stover

Objective: To characterize the clinical and genetic features of cervical dystonia (CD). Methods: Participants enrolled in the Dystonia Coalition biorepository (NCT01373424) with initial manifestation as CD were included in this study (n = 1,000). Data intake included demographics, family history, and the Global Dystonia Rating Scale. Participants were screened for sequence variants (SVs) in GNAL, THAP1, and Exon 5 of TOR1A. Results: The majority of participants were Caucasian (95%) and female (75%). The mean age at onset and disease duration were 45.5 ± 13.6 and 14.6 ± 11.8 years, respectively. At the time of assessment, 68.5% had involvement limited to the neck, shoulder(s), and proximal arm(s), whereas 47.4% had dystonia limited to the neck. The remaining 31.5% of the individuals exhibited more extensive anatomical spread. A head tremor was noted in 62% of the patients. Head tremor and laryngeal dystonia were more common in females. Psychiatric comorbidities, mainly depression and anxiety, were reported by 32% of the participants and were more common in females. Family histories of dystonia, parkinsonian disorder, and tremor were present in 14%, 11%, and 29% of the patients, respectively. Pathogenic or likely pathogenic SVs in THAP1, TOR1A, and GNAL were identified in 8 participants (0.8%). Two individuals harbored novel missense SVs in Exon 5 of TOR1A. Synonymous and noncoding SVs in THAP1 and GNAL were identified in 4% of the cohort. Conclusions: Head tremor, laryngeal dystonia, and psychiatric comorbidities are more common in female participants with CD. Coding and noncoding variants in GNAL, THAP1, and TOR1A make small contributions to the pathogenesis of CD.


Journal of the Neurological Sciences | 2013

How long does it take to diagnose cervical dystonia

Evan Tiderington; Emily M. Goodman; Ami Rosen; Edie R. Hapner; Michael M. Johns; Marian L. Evatt; Alan Freeman; Stewart A. Factor; H.A. Jinnah

BACKGROUND Dystonia is a neurological disorder characterized by involuntary twisting movements and postures. The neck is among the most commonly affected regions, and diagnosis can be made readily through a simple clinical evaluation. The goal of this study was to explore how long it took patients to receive a diagnosis of cervical dystonia after symptom onset. METHODS A structured questionnaire was administered at outpatient clinics of a tertiary care academic medical center to 146 consecutively evaluated patients. The questionnaire addressed the length of time from symptom onset to diagnosis, the numbers and types of providers seen before reaching a diagnosis, and treatments attempted prior to receiving botulinum toxin. RESULTS A total of 108 patients saw a mean of 3.5 providers over a mean period of 44 months from symptom onset to diagnosis. For patients with symptom onset in the last decade only, patients saw a mean of 3.0 providers over a mean of 14 months. CONCLUSIONS Although cervical dystonia is the most common form of dystonia with clinical features readily identifiable by a simple history and examination, patients typically see multiple providers over more than a year before reaching a diagnosis and receiving optimal therapy. Improved awareness of the clinical features will enable patients to obtain appropriate therapy more rapidly.

Collaboration


Dive into the Ami Rosen's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Joel S. Perlmutter

Washington University in St. Louis

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Cynthia L. Comella

Rush University Medical Center

View shared research outputs
Top Co-Authors

Avatar

Wendy R. Galpern

National Institutes of Health

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Susan H. Fox

University Health Network

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge