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author:("litman, Irene")
1.  Behavioral abnormalities in progressive supranuclear palsy 
Psychiatry research  2013;210(3):10.1016/j.psychres.2013.08.045.
Progressive supranuclear palsy (PSP) is a rare neurodegenerative disorder in which, classically, patients present with postural instability and falls, parkinsonism, and slowing of vertical saccades. PSP patients typically have deficits in cognitive functioning, difficulties with most daily activities, and present with notable behavioral disturbances—particularly apathy, impulsivity, and irritability. Using data from 154 patients meeting criteria for clinically probable PSP, domain and total scores of the Neuropsychiatric Inventory were examined and compared to demographics, disease severity, cognition, and motor features. Behavioral abnormalities were common in this cohort of PSP patients, with more than half experiencing apathy, depression, and sleeping problems, and approximately one third displaying agitation, irritability, disinhibition, and eating problems. Few clinical correlates of neuropsychiatric symptoms were observed in this cohort. Given the prevalence of neuropsychiatric symptoms in PSP, these patients are expected to be frequently seen by psychiatrists and other mental health professionals for symptom management and increased quality of life. Clinical trials are clearly needed to address the neuropsychiatric morbidity in these patients.
doi:10.1016/j.psychres.2013.08.045
PMCID: PMC3840159  PMID: 24035530
Parkinsonism; Parkinsonian; Neuropsychiatric inventory; Neuropsychiatric functioning; Apathy; depression
2.  Time to Redefine PD? Introductory Statement of the MDS Task Force on the Definition of Parkinson’s Disease 
With advances in knowledge disease, boundaries may change. Occasionally, these changes are of such a magnitude that they require redefinition of the disease. In recognition of the profound changes in our understanding of Parkinson’s disease (PD), the International Parkinson and Movement Disorders Society (MDS) commissioned a task force to consider a redefinition of PD. This review is a discussion article, intended as the introductory statement of the task force. Several critical issues were identified that challenge current PD definitions. First, new findings challenge the central role of the classical pathologic criteria as the arbiter of diagnosis, notably genetic cases without synuclein deposition, the high prevalence of incidental Lewy body (LB) deposition, and the nonmotor prodrome of PD. It remains unclear, however, whether these challenges merit a change in the pathologic gold standard, especially considering the limitations of alternate gold standards. Second, the increasing recognition of dementia in PD challenges the distinction between diffuse LB disease and PD. Consideration might be given to removing dementia as an exclusion criterion for PD diagnosis. Third, there is increasing recognition of disease heterogeneity, suggesting that PD subtypes should be formally identified; however, current subtype classifications may not be sufficiently robust to warrant formal delineation. Fourth, the recognition of a nonmotor prodrome of PD requires that new diagnostic criteria for early-stage and prodromal PD should be created; here, essential features of these criteria are proposed. Finally, there is a need to create new MDS diagnostic criteria that take these changes in disease definition into consideration.
doi:10.1002/mds.25844
PMCID: PMC4204150  PMID: 24619848
redefinition of PD; gold standard; subtypes; disease heterogeneity; nonmotor prodrome; MDS diagnostic criteria
3.  Parkinsonian Syndromes 
Continuum : Lifelong Learning in Neurology  2013;19(5 Movement Disorders):1189-1212.
Supplemental Digital Content is available in the text.
Purpose of Review
The different parkinsonian conditions can be challenging to separate clinically. This review highlights the important clinical features that guide the diagnosis of Parkinson disease (PD), progressive supranuclear palsy (PSP), multiple system atrophy (MSA), and corticobasal degeneration (CBD). Strategies for treatment and disease management are also discussed.
Recent Findings
Over the past decade there has been an increasing recognition of the broad clinical presentations of the neurodegenerative forms of parkinsonism. Nonmotor symptoms in these diseases, including psychiatric, cognitive, autonomic, and gastrointestinal dysfunction, appear to have a major impact on quality of life and disability. PSP and CBD are now considered pathologic diagnoses, with several different and varied clinical phenotypes, that overlap and share features with PDand frontotemporal dementia syndromes. PD is distinguished by its excellent response to dopaminergic medications that is maintained over many years, in contrast to the response seen in patients with MSA and PSP. New diagnostic criteria have been proposed for CBD. No new therapeutic interventions have emerged for PSP, MSA, or CBD. Infusional therapies and deep brain stimulation surgery are established therapies for advanced PD.
Summary
The “parkinsonian syndromes” encompass a number of nosologic entities that are grouped together on the basis of their shared clinical features but are separated on the basis of their different pathologies. Overall, the consideration of clinical signs, mode of disease onset, and nature of disease progression are all important to make a timely and definitive diagnosis.
doi:10.1212/01.CON.0000436152.24038.e0
PMCID: PMC4234134  PMID: 24092286
4.  Executive Dysfunction Is the Primary Cognitive Impairment in Progressive Supranuclear Palsy 
Cognitive difficulties appear to be a more prevalent clinical feature in progressive supranuclear palsy (PSP) than previously thought, and significant cognitive impairment is prevalent in a majority of patients PSP patients not considered clinically demented. The neurocognitive performance of 200 patients with PSP across multiple sites was examined with a variety of commonly used neuropsychological tests. Results indicate primary executive dysfunction (e.g., 74% impaired on the Frontal Assessment Battery, 55% impaired on Initiation/Perseveration subscale of the Dementia Rating Scale), with milder difficulties in memory, construction, and naming. These results have important clinical implications for providers following patients with PSP.
doi:10.1093/arclin/acs098
PMCID: PMC3569947  PMID: 23127882
Progressive supranuclear palsy; Frontal-executive; Parkinsonism; Dementia; Memory
5.  Criteria for the diagnosis of corticobasal degeneration 
Neurology  2013;80(5):496-503.
Current criteria for the clinical diagnosis of pathologically confirmed corticobasal degeneration (CBD) no longer reflect the expanding understanding of this disease and its clinicopathologic correlations. An international consortium of behavioral neurology, neuropsychology, and movement disorders specialists developed new criteria based on consensus and a systematic literature review. Clinical diagnoses (early or late) were identified for 267 nonoverlapping pathologically confirmed CBD cases from published reports and brain banks. Combined with consensus, 4 CBD phenotypes emerged: corticobasal syndrome (CBS), frontal behavioral-spatial syndrome (FBS), nonfluent/agrammatic variant of primary progressive aphasia (naPPA), and progressive supranuclear palsy syndrome (PSPS). Clinical features of CBD cases were extracted from descriptions of 209 brain bank and published patients, providing a comprehensive description of CBD and correcting common misconceptions. Clinical CBD phenotypes and features were combined to create 2 sets of criteria: more specific clinical research criteria for probable CBD and broader criteria for possible CBD that are more inclusive but have a higher chance to detect other tau-based pathologies. Probable CBD criteria require insidious onset and gradual progression for at least 1 year, age at onset ≥50 years, no similar family history or known tau mutations, and a clinical phenotype of probable CBS or either FBS or naPPA with at least 1 CBS feature. The possible CBD category uses similar criteria but has no restrictions on age or family history, allows tau mutations, permits less rigorous phenotype fulfillment, and includes a PSPS phenotype. Future validation and refinement of the proposed criteria are needed.
doi:10.1212/WNL.0b013e31827f0fd1
PMCID: PMC3590050  PMID: 23359374
6.  Functional impairment in progressive supranuclear palsy 
Neurology  2013;80(4):380-384.
Objective:
The current study sought to describe the functional profiles of patients with early-stage progressive supranuclear palsy (PSP) in a large prospective, multisite study.
Methods:
Using data from 202 individuals meeting criteria for clinically definite or probable PSP, 3 functional scales were examined. Functional scores were then compared to measures of motor, cognition, and psychiatric symptoms.
Results:
Functional disability was high in early-stage PSP, with 100% of patients having less than perfect scores on all functional scales. Whereas functional scores tended not to be related to cognition or psychiatric symptoms, they were strongly related to motoric ratings.
Conclusions:
Both clinically and in research settings, the definition of functional intactness/impairment has important implications. Future studies should examine if functional impairment is this high in PSP or if new scales of functional abilities need to be developed for this condition.
doi:10.1212/WNL.0b013e31827f0859
PMCID: PMC3589239  PMID: 23303854
7.  Long-duration Parkinson’s disease: Role of lateralization of motor features 
Background
A mean of 10 years elapse before patients with Parkinson’s disease (PD) reach Hoehn & Yahr (H&Y) stage 4, and 14 years for stage 5. A small proportion of PD patients survive and are ambulatory for ≥20 years. We sought to identify features associated with long-duration PD (dPD).
Methods
This five-center, case–control study compared 136 PD patients with ≥20 years of duration and H&Y stage ≤4 (dPD) to 134 H&Y-, age- and gender-matched PD patients between 10 and 15 years of disease (cPD).
Results
By study design, there were no between-group differences in age, gender and H&Y. dPD subjects were younger at onset (p < 0.0001), had more psychosis (p: 0.038), were receiving higher levodopa equivalent daily doses (p: 0.02), were predominantly left-handed (p: 0.048), and had greater frequency of left-sided onset (p: 0.015) compared to cPD subjects. Both groups had similar rates of resting tremor, dementia and REM sleep behavior disorder.
Conclusions
Early disease onset, left-handedness and left-sided onset are associated with long disease and ambulatory PD survival. The neurobiological basis of the prognostic value of lateralization deserves further investigation.
doi:10.1016/j.parkreldis.2012.07.008
PMCID: PMC3635808  PMID: 22858180
Parkinson’s disease; Longevity; Handedness
8.  White-Matter Changes Correlate with Cognitive Functioning in Parkinson’s Disease 
Diffusion tensor imaging (DTI) findings from emerging studies of cortical white-matter integrity in Parkinson’s disease (PD) without dementia are inconclusive. When white-matter changes have been found, their relationship to cognitive functioning in PD has not been carefully investigated. To better characterize changes in tissue diffusivity and to understand their functional significance, the present study conducted DTI in 25 PD patients without dementia and 26 controls of similar ages. An automated tract-based DTI method was used. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were analyzed. Neuropsychological measures of executive functioning (working memory, verbal fluency, cognitive flexibility, inhibitory control) and visuospatial ability were then correlated with regions of interest that showed abnormal diffusivity in the PD group. We found widespread reductions in FA and increases in MD in the PD group relative to controls. These changes were predominantly related to an increase in RD. Increased AD in the PD group was limited to specific frontal tracks of the right hemisphere, possibly signifying more significant tissue changes. Motor symptom severity did not correlate with FA. However, different measures of executive functioning and visuospatial ability correlated with FA in different segments of tracts, which contain fiber pathways to cortical regions that are thought to support specific cognitive processes. The findings suggest that abnormal tissue diffusivity may be sensitive to subtle cognitive changes in PD, some of which may be prognostic of future cognitive decline.
doi:10.3389/fneur.2013.00037
PMCID: PMC3624087  PMID: 23630517
Parkinson’s disease; cognition; diffusion tensor imaging; white-matter; cerebral cortex
9.  Assessment of cognition in early dementia 
Better tools for assessing cognitive impairment in the early stages of Alzheimer’s disease (AD) are required to enable diagnosis of the disease before substantial neurodegeneration has taken place and to allow detection of subtle changes in the early stages of progression of the disease. The National Institute on Aging and the Alzheimer’s Association convened a meeting to discuss state of the art methods for cognitive assessment, including computerized batteries, as well as new approaches in the pipeline. Speakers described research using novel tests of object recognition, spatial navigation, attentional control, semantic memory, semantic interference, prospective memory, false memory and executive function as among the tools that could provide earlier identification of individuals with AD. In addition to early detection, there is a need for assessments that reflect real-world situations in order to better assess functional disability. It is especially important to develop assessment tools that are useful in ethnically, culturally and linguistically diverse populations as well as in individuals with neurodegenerative disease other than AD.
doi:10.1016/j.jalz.2011.05.001
PMCID: PMC3613863  PMID: 23559893
10.  CYTOKINE EXPRESSION AND MICROGLIAL ACTIVATION IN PROGRESSIVE SUPRANUCLEAR PALSY 
Parkinsonism & related disorders  2011;17(9):683-688.
Although little is known about the etiology of progressive supranuclear palsy (PSP), genetic and epigenetic factors, oxidative injury and inflammation are thought to contribute to its development and/or progression. Evidence for activated glia involvement in PSP has raised the possibility that neuroinflammation may contribute to its pathogenesis. To investigate the correlation between neuroinflammation and PSP, a comparative study was conducted on the patterns of cytokine expression in different regions of the brains of PSP, Alzheimer’s disease (AD) patients and normal controls. Our results show different patterns of cytokine expression in each disease, with the expression of IL-1β transcripts being significantly higher in the substantia nigra of PSP than in AD and controls, while AD brains had significantly higher IL-1β expression in the parietal cortex compared to PSP and controls. In addition, expression of TGFβ was significantly higher in the cortical areas (particularly frontal and parietal lobes) of AD compared to PSP and controls. These results show a disease-specific topographical relationship among the expression of certain cytokines (IL-1β and TGFβ), microglial activation and neurodegenerative changes, suggesting that these cytokines may contribute to the pathologic process. If so, the use of cytokine-inhibitors and/or other anti-inflammatory agents may be able to slow disease progression in PSP.
doi:10.1016/j.parkreldis.2011.06.007
PMCID: PMC3196843  PMID: 21741294
Alzheimer’s disease; brain; cytokines; inflammation; microglia; progressive supranuclear palsy
11.  Neuropathological features of corticobasal degeneration presenting as corticobasal syndrome or Richardson syndrome 
Brain  2011;134(11):3264-3275.
Patients with corticobasal degeneration can present with several different clinical syndromes, making ante-mortem diagnosis a challenge. Corticobasal syndrome is the clinical phenotype originally described for corticobasal degeneration, characterized by asymmetric rigidity and apraxia, cortical sensory deficits, dystonia and myoclonus. Some patients do not develop these features, but instead have clinical features consistent with the Richardson syndrome presentation of progressive supranuclear palsy, characterized by postural instability, early unexplained falls, vertical supranuclear gaze palsy, symmetric motor disability and dysphagia. The aim of this study was to identify differences in corticobasal degeneration presenting with corticobasal syndrome (n = 11) or Richardson syndrome (n = 15) with respect to demographic, clinical and neuropathological features. Corticobasal degeneration cases were also compared with patients with pathologically proven progressive supranuclear palsy with Richardson syndrome (n = 15). Cases with corticobasal degeneration, regardless of presentation, shared histopathological and tau biochemical characteristics, but they had differing densities of tau pathology in neuroanatomical regions that correlated with their clinical presentation. In particular, those with corticobasal syndrome had greater tau pathology in the primary motor and somatosensory cortices and putamen, while those with Richardson syndrome had greater tau pathology in limbic and hindbrain structures. Compared with progressive supranuclear palsy, patients with corticobasal degeneration and Richardson syndrome had less neuronal loss in the subthalamic nucleus, but more severe neuronal loss in the medial substantia nigra and greater atrophy of the anterior corpus callosum. Clinically, they had more cognitive impairment and frontal behavioural dysfunction. The results suggest that Richardson syndrome can be a clinicopathological presentation of corticobasal degeneration. Atrophy of anterior corpus callosum may be a potential neuroimaging marker to differentiate corticobasal degeneration from progressive supranuclear palsy in patients with Richardson syndrome.
doi:10.1093/brain/awr234
PMCID: PMC3212714  PMID: 21933807
pathology; immunocytochemistry; progressive supranuclear palsy; tau protein; corticobasal degeneration
12.  Phosphorylated α-Synuclein in Parkinson’s Disease 
Science Translational Medicine  2012;4(121):121ra20.
Phosphorylated α-synuclein (PS-129), a protein implicated in the pathogenesis of Parkinson’s disease (PD), was identified by mass spectrometry in human cerebrospinal fluid (CSF). A highly sensitive and specific assay was established and used to measure PS-129, along withtotal α-synuclein, in the CSF of patients with PD, other parkinsonian disorders such as multiple system atrophy (MSA) and progressive supranuclear palsy (PSP), and healthy individuals (a total of ~600 samples). PS-129 CSF concentrations correlated weakly with PD severity and, when combined with total α-synuclein CSF concentrations, contributed to distinguishing PD from MSA and PSP. Further rigorous validation in independent cohorts of patients, especially those where samples have been collected longitudinally, will determine whether PS-129 CSF concentrations will be useful for diagnosing PD and for monitoring PD severity and progression.
doi:10.1126/scitranslmed.3002566
PMCID: PMC3302662  PMID: 22344688
13.  Examining the Motor Phenotype of Patients with Both Essential Tremor and Parkinson’s Disease 
Background
The subset of patients with essential tremor (ET) that develops Parkinson’s disease (PD) has not been fully clinically characterized.
Methods
Motor features were retrospectively reviewed in 18 ET patients who developed PD (ET→PD), 20 ET and 30 PD patients with similar ages and disease durations.
Results
Fewer ET→PD than ET patients had widespread postural and/or action tremor (2/17 [11.8%] vs. 11/17 [64.7%]; p = 0.001) and marginally fewer had cerebellar signs (1/15 [6.7%] vs. 6/18 [33.3%], p = 0.06). ET→PD patients required fewer ET medications than did their counterparts with ET (p = 0.001). ET→PD patients and PD patients did not differ in UPDRS, Hoehn and Yahr, or Schwab and England scores (each p≥0.14).
Discussion
ET patients who develop PD may have distinct pre-PD motor features compared to their counterparts with ET who do not develop co-existing PD. Prospective studies are needed to evaluate the predictive value of these clinical features for the emergence of PD.
PMCID: PMC3379814  PMID: 23439850
Essential tremor; Parkinson’s disease; tremor severity
14.  Examining the Motor Phenotype of Patients with Both Essential Tremor and Parkinson's Disease 
Tremor and Other Hyperkinetic Movements  2012;2:tre-02-47-149-3.
Background
The subset of patients with essential tremor (ET) that develops Parkinson's disease (PD) has not been fully clinically characterized.
Methods
Motor features were retrospectively reviewed in 18 ET patients who developed PD (ET→PD), 20 ET and 30 PD patients with similar ages and disease durations.
Results
Fewer ET→PD than ET patients had widespread postural and/or action tremor (2/17 [11.8%] vs. 11/17 [64.7%]; p = 0.001) and marginally fewer had cerebellar signs (1/15 [6.7%] vs. 6/18 [33.3%], p = 0.06). ET→PD patients required fewer ET medications than did their counterparts with ET (p = 0.001). ET→PD patients and PD patients did not differ in UPDRS, Hoehn and Yahr, or Schwab and England scores (each p≥0.14).
Discussion
ET patients who develop PD may have distinct pre-PD motor features compared to their counterparts with ET who do not develop co-existing PD. Prospective studies are needed to evaluate the predictive value of these clinical features for the emergence of PD.
PMCID: PMC3379814  PMID: 23439850
Essential tremor; Parkinson's disease; tremor severity
15.  Parkinsonism and Frontotemporal Dementia: The Clinical Overlap 
Journal of Molecular Neuroscience  2011;45(3):343-349.
Frontotemporal dementia is commonly associated with parkinsonism in several sporadic (i.e., progressive supranuclear palsy, corticobasal degeneration) and familial neurodegenerative disorders (i.e., frontotemporal dementia associated with parkinsonism and MAPT or progranulin mutations in chromosome 17). The clinical diagnosis of these disorders may be challenging in view of overlapping clinical features, particularly in speech, language, and behavior. The motor and cognitive phenotypes can be viewed within a spectrum of clinical, pathologic, and genetic disorders with no discrete clinicopathologic correlations but rather lying within a dementia–parkinsonism continuum. Neuroimaging and cerebrospinal fluid analysis can be helpful, but the poor specificity of clinical and imaging features has enormously challenged the development of biological markers that could differentiate these disorders premortem. This gap is critical to bridge in order to allow testing of novel biological therapies that may slow the progression of these proteinopathies.
doi:10.1007/s12031-011-9632-1
PMCID: PMC3324113  PMID: 21892619
Frontotemporal dementia; Frontotemporal lobar degeneration; Parkinsonism; Corticobasal syndrome; Progressive supranuclear palsy; Corticobasal degeneration
16.  Polymorphic genes of detoxification and mitochondrial enzymes and risk for progressive supranuclear palsy: a case control study 
BMC Medical Genetics  2012;13:16.
Background
There are no known causes for progressive supranuclear palsy (PSP). The microtubule associated protein tau (MAPT) H1 haplotype is the major genetic factor associated with risk of PSP, with both oxidative stress and mitochondrial dysfunction also implicated. We investigated whether specific single nucleotide polymorphisms (SNPs) in genes encoding enzymes of xenobiotic detoxification, mitochondrial functioning, or oxidative stress response, including debrisoquine 4-hydroxylase, paraoxonase 1 and 2, N-acetyltransferase 1 and 2 (NAT2), superoxide dismutase 1 and 2, and PTEN-induced putative kinase are associated with PSP.
Methods
DNA from 553 autopsy-confirmed Caucasian PSP cases (266 females, 279 males; age at onset 68 ± 8 years; age at death 75 ± 8) from the Society for PSP Brain Bank and 425 clinical control samples (197 females, 226 males; age at draw 72 ± 11 years) from healthy volunteers were genotyped using Taqman PCR and the SequenomiPLEX Gold assay.
Results
The proportion of NAT2 rapid acetylators compared to intermediate and slow acetylators was larger in cases than in controls (OR = 1.82, p < 0.05). There were no allelic or genotypic associations with PSP for any other SNPs tested with the exception of MAPT (p < 0.001).
Conclusions
Our results show that NAT2 rapid acetylator phenotype is associated with PSP, suggesting that NAT2 may be responsible for activation of a xenobiotic whose metabolite is neurotoxic. Although our results need to be further confirmed in an independent sample, NAT2 acetylation status should be considered in future genetic and epidemiological studies of PSP.
doi:10.1186/1471-2350-13-16
PMCID: PMC3344705  PMID: 22424094
Progressive supranuclear palsy (PSP); N-acetyltransferase 2 (NAT2); Tauopathy; Single nucleotide polymorphisms (SNPs); Parkinson's disease (PD)
17.  Identification of common variants influencing risk of the tauopathy Progressive Supranuclear Palsy 
Nature genetics  2011;43(7):699-705.
Progressive supranuclear palsy (PSP) is a movement disorder with prominent tau neuropathology. Brain diseases with abnormal tau deposits are called tauopathies, the most common being Alzheimer’s disease. Environmental causes of tauopathies include repetitive head trauma associated with some sports. To identify common genetic variation contributing to risk for tauopathies, we carried out a genome-wide association study of 1,114 PSP cases and 3,247 controls (Stage 1) followed up by a second stage where 1,051 cases and 3,560 controls were genotyped for Stage 1 SNPs that yielded P ≤ 10−3. We found significant novel signals (P < 5 × 10−8) associated with PSP risk at STX6, EIF2AK3, and MOBP. We confirmed two independent variants in MAPT affecting risk for PSP, one of which influences MAPT brain expression. The genes implicated encode proteins for vesicle-membrane fusion at the Golgi-endosomal interface, for the endoplasmic reticulum unfolded protein response, and for a myelin structural component.
doi:10.1038/ng.859
PMCID: PMC3125476  PMID: 21685912
18.  A Recommended Scale for Cognitive Screening in Clinical Trials of Parkinson’s Disease 
Background
Cognitive impairment is common in Parkinson’s disease (PD). There is a critical need for a brief, standard cognitive screening measure for use in PD trials whose primary focus is not on cognition.
Methods
The Parkinson Study Group (PSG) Cognitive/Psychiatric Working Group formed a Task Force to make recommendations for a cognitive scale that could screen for dementia and mild cognitive impairment in clinical trials of PD where cognition is not the primary outcome. This Task Force conducted a systematic literature search for cognitive assessments previously used in a PD population. Scales were then evaluated for their appropriateness to screen for cognitive deficits in clinical trials, including brief administration time (<15 minutes), assessment of the major cognitive domains, and potential to detect subtle cognitive impairment in PD.
Results
Five scales of global cognition met the predetermined screening criteria and were considered for review. Based on the Task Force’s evaluation criteria the Montreal Cognitive Assessment (MoCA), appeared to be the most suitable measure.
Conclusions
This Task Force recommends consideration of the MoCA as a minimum cognitive screening measure in clinical trials of PD where cognitive performance is not the primary outcome measure. The MoCA still requires further study of its diagnostic utility in PD populations but appears to be the most appropriate measure among the currently available brief cognitive assessments. Widespread adoption of a single instrument such as the MoCA in clinical trials can improve comparability between research studies on PD.
doi:10.1002/mds.23362
PMCID: PMC2978783  PMID: 20878991
19.  Huntington CAG repeat size does not modify onset age in familial Parkinson’s disease: The GenePD Study 
The ATP/ADP ratio reflects mitochondrial function and has been reported to be influenced by the size of the Huntington disease gene (HD) repeat. Impaired mitochondrial function has long been implicated in the pathogenesis of Parkinson’s disease (PD) and therefore, we evaluated the relationship of the HD CAG repeat size to PD onset age in a large sample of familial PD cases. PD affected siblings (n=495) with known onset ages from 248 families, were genotyped for the HD CAG repeat. Genotyping failed in 11 cases leaving 484 for analysis, including 35 LRRK2 carriers. All cases had HD CAG repeats (range 15 to 34) below the clinical range for HD, although 5.2 percent of the sample (n=25) had repeats in the intermediate range (the intermediate range lower limit=27; upper limit=35 repeats), suggesting that the prevalence of intermediate allele carriers in the general population is significant. No relation between the HD CAG repeat size and the age at onset for PD was found in this sample of familial PD.
doi:10.1002/mds.22186
PMCID: PMC2655323  PMID: 18649400
Parkinson’s disease; Huntington’s disease; CAG repeat; onset age; genetics; mitochondria
20.  Replication of association between ELAVL4 and Parkinson disease: the GenePD study 
Human genetics  2008;124(1):95-99.
Genetic variants in embryonic lethal, abnormal vision, Drosophila-like 4 (ELAVL4) have been reported to be associated with onset age of Parkinson disease (PD) or risk for PD affection in Caucasian populations. In the current study we genotyped three single nucleotide polymorphisms in ELAVL4 in a Caucasian study sample consisting of 712 PD patients and 312 unrelated controls from the GenePD study. The minor allele of rs967582 was associated with increased risk of PD (odds ratio = 1.46, nominal P value = 0.011) in the GenePD population. The minor allele of rs967582 was also the risk allele for PD affection or earlier onset age in the previously studied populations. This replication of association with rs967582 in a third cohort further implicates ELAVL4 as a PD susceptibility gene.
doi:10.1007/s00439-008-0526-4
PMCID: PMC2716559  PMID: 18587682
21.  The Gly2019Ser mutation in LRRK2 is not fully penetrant in familial Parkinson's disease: the GenePD study 
BMC Medicine  2008;6:32.
Background
We report age-dependent penetrance estimates for leucine-rich repeat kinase 2 (LRRK2)-related Parkinson's disease (PD) in a large sample of familial PD. The most frequently seen LRRK2 mutation, Gly2019Ser (G2019S), is associated with approximately 5 to 6% of familial PD cases and 1 to 2% of idiopathic cases, making it the most common known genetic cause of PD. Studies of the penetrance of LRRK2 mutations have produced a wide range of estimates, possibly due to differences in study design and recruitment, including in particular differences between samples of familial PD versus sporadic PD.
Methods
A sample, including 903 affected and 58 unaffected members from 509 families ascertained for having two or more PD-affected members, 126 randomly ascertained PD patients and 197 controls, was screened for five different LRRK2 mutations. Penetrance was estimated in families of LRRK2 carriers with consideration of the inherent bias towards increased penetrance in a familial sample.
Results
Thirty-one out of 509 families with multiple cases of PD (6.1%) were found to have 58 LRRK2 mutation carriers (6.4%). Twenty-nine of the 31 families had G2019S mutations while two had R1441C mutations. No mutations were identified among controls or unaffected relatives of PD cases. Nine PD-affected relatives of G2019S carriers did not carry the LRRK2 mutation themselves. At the maximum observed age range of 90 to 94 years, the unbiased estimated penetrance was 67% for G2019S families, compared with a baseline PD risk of 17% seen in the non-LRRK2-related PD families.
Conclusion
Lifetime penetrance of LRRK2 estimated in the unascertained relatives of multiplex PD families is greater than that reported in studies of sporadically ascertained LRRK2 cases, suggesting that inherited susceptibility factors may modify the penetrance of LRRK2 mutations. In addition, the presence of nine PD phenocopies in the LRRK2 families suggests that these susceptibility factors may also increase the risk of non-LRRK2-related PD. No differences in penetrance were found between men and women, suggesting that the factors that influence penetrance for LRRK2 carriers are independent of the factors which increase PD prevalence in men.
doi:10.1186/1741-7015-6-32
PMCID: PMC2596771  PMID: 18986508
22.  Traumatic brain injury as a risk factor for Alzheimer disease. Comparison of two retrospective autopsy cohorts with evaluation of ApoE genotype 
BMC Neurology  2001;1:3.
Background and Purpose
The impact of traumatic brain injury (TBI) on the pathogenesis of Alzheimer disease (AD) is still controversial. The aim of our retrospective autopsy study was to assess the impact of TBE and ApoE allele frequency on the development of AD.
Material and Methods
We examined 1. the incidence of AD pathology (Braak stageing, CERAD, NIA-Reagan Institute criteria) in 58 consecutive patients (mean age ± SD 77.0 ± 6.8 years) with residual closed TBI lesions, and 2. the frequency of TBI residuals in 57 age-matched autopsy proven AD cases. In both series, ApoE was evaluated from archival paraffin-embedded brain material.
Results
1. TBE series: 12.1 % showed definite and 10.3% probable AD (mean age 77.6 and 75.2 years), only 2/13 with ApoEε3/4. From 45 (77.6%) non-AD cases (mean age 78.2 years), 3 had ApoEε3/4. The prevalence of 22.4% AD in this small autopsy cohort was significantly higher than 3.3% in a recent large clinical series and 14% in the general population over age 70. 2. In the AD cohort with ApoEε4 allele frequency of 30% similar to other AD series, residuals of closed TBI were seen in 4 brains (7%) (mean age ± SD 78.2 ± 6.4), all lacking the ApoEε4 allele. TBI incidence was slightly lower than 8.5% in the clinical MIRAGE study.
Conclusions
The results of this first retrospective autopsy study of TBI, ApoEε allele frequency, and AD confirm clinical studies suggesting severe TBI to be a risk factor for the development AD higher in subjects lacking ApoEε4 alleles. Further studies in larger autopsy series are needed to elucidate the relationship between TBI, genetic predisposition, and AD.
doi:10.1186/1471-2377-1-3
PMCID: PMC37390  PMID: 11504565
23.  Time to Redefine PD? Introductory Statement of the MDS Task Force on the Definition of Parkinson's Disease 
Movement Disorders  2014;29(4):454-462.
With advances in knowledge disease, boundaries may change. Occasionally, these changes are of such a magnitude that they require redefinition of the disease. In recognition of the profound changes in our understanding of Parkinson's disease (PD), the International Parkinson and Movement Disorders Society (MDS) commissioned a task force to consider a redefinition of PD. This review is a discussion article, intended as the introductory statement of the task force. Several critical issues were identified that challenge current PD definitions. First, new findings challenge the central role of the classical pathologic criteria as the arbiter of diagnosis, notably genetic cases without synuclein deposition, the high prevalence of incidental Lewy body (LB) deposition, and the nonmotor prodrome of PD. It remains unclear, however, whether these challenges merit a change in the pathologic gold standard, especially considering the limitations of alternate gold standards. Second, the increasing recognition of dementia in PD challenges the distinction between diffuse LB disease and PD. Consideration might be given to removing dementia as an exclusion criterion for PD diagnosis. Third, there is increasing recognition of disease heterogeneity, suggesting that PD subtypes should be formally identified; however, current subtype classifications may not be sufficiently robust to warrant formal delineation. Fourth, the recognition of a nonmotor prodrome of PD requires that new diagnostic criteria for early-stage and prodromal PD should be created; here, essential features of these criteria are proposed. Finally, there is a need to create new MDS diagnostic criteria that take these changes in disease definition into consideration. © 2014 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
doi:10.1002/mds.25844
PMCID: PMC4204150  PMID: 24619848
redefinition of PD; gold standard; subtypes; disease heterogeneity; nonmotor prodrome; MDS diagnostic criteria

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