Prevalence and Associated Factors of Sarcopenia and Frailty in Parkinson's Disease: A Cross-Sectional Study.

BACKGROUND: Sarcopenia and frailty are found in up to one-third of the general elderly population. Both are associated with major adverse health outcomes such as nursing home placement, disability, decreased quality of life, and death. Data on the frequency of both syndromes in Parkinson's disease (PD), however, are very limited. OBJECTIVE: We aimed to screen for sarcopenia and frailty in PD patients and to assess potential associations of both geriatric syndromes with demographic and clinical parameters as well as quality of life. METHODS: In this observational, cross-sectional study, we included 104 PD patients from a tertiary center and 330 non-PD controls from a population-based cohort aged > 65 years. All groups were screened for sarcopenia using the SARC-F score and for frailty using the Clinical Frailty Scale of the Canadian Study of Health and Aging (CSHA CFS). Prevalence rates of sarcopenia and frailty were also assessed in 18 PD patients from a population-based cohort aged > 65 years. Moreover, PD patients from the tertiary center were evaluated for motor and non-motor symptoms, quality of life, and dependency. RESULTS: The prevalence of sarcopenia was 55.8% (95% CI: 46.2-64.9%) in PD patients from the tertiary center and 8.2% (5.7-11.7%; p < 0.001) in non-PD controls. Frailty was detected in 35.6% (27.0-45.2%) and 5.2% (3.2-8.1%; p < 0.001). Prevalence rates for sarcopenia and frailty were 33.3% (16.1-56.4%; p = 0.004) and 22.2% (8.5-45.8%; p = 0.017) in the community-based PD sample. Both sarcopenia and frailty were significantly associated with longer disease duration, higher motor impairment, higher Hoehn and Yahr stages, decreased quality of life, higher frequency of falls, a higher non-motor symptom burden, institutionalization, and higher care levels in PD patients from a tertiary center compared to not affected PD patients (all p < 0.05). CONCLUSIONS: Both frailty and sarcopenia are more common in PD patients than in the general community and are associated with a more adverse course of the disease. Future studies should look into underlying risk factors for the occurrence of sarcopenia and frailty in PD patients and into adequate management to prevent and mitigate them.

Molecular diversity of combined and complex dystonia: insights from diagnostic exome sequencing.

Combined and complex dystonias are heterogeneous movement disorders combining dystonia with other motor and/or systemic signs. Although we are beginning to understand the diverse molecular causes of these disease entities, clinical pattern recognition and conventional genetic workup achieve an etiological diagnosis only in a minority of cases. Our goal was to provide a window into the variable genetic origins and distinct clinical patterns of combined/complex dystonia more broadly. Between August 2016 and January 2017, we applied whole-exome sequencing to a cohort of nine patients with varied combined and/or complex dystonic presentations, being on a diagnostic odyssey. Bioinformatics analyses, co-segregation studies, and sequence-interpretation algorithms were employed to detect causative mutations. Comprehensive clinical review was undertaken to define the phenotypic spectra and optimal management strategies. On average, we observed a delay in diagnosis of 23 years before whole-exome analysis enabled determination of each patient's genetic defect. Whereas mutations in ACTB, ATP1A3, ADCY5, and SGCE were associated with particular phenotypic clues, trait manifestations arising from mutations in PINK1, MRE11A, KMT2B, ATM, and SLC6A1 were different from those previously reported in association with these genes. Apart from improving counseling for our entire cohort, genetic findings had actionable consequences on preventative measures and therapeutic interventions for five patients. Our investigation confirms unique genetic diagnoses, highlights key clinical features and phenotypic expansions, and suggests whole-exome sequencing as a first-tier diagnostic for combined/complex dystonia. These results might stimulate independent teams to extend the scope of agnostic genetic screening to this particular phenotypic group that remains poorly characterized through existing studies.

Prodromal Parkinson's disease as defined per MDS research criteria in the general elderly community.

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.

Optimizing odor identification testing as quick and accurate diagnostic tool for Parkinson's disease.

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.

Nonmotor symptoms in subjects without evidence of dopaminergic deficits.

BACKGROUND: A subgroup of patients initially diagnosed with Parkinson's disease (PD) turn out to have normal dopamine transporter single-photon emission computed tomography imaging and have been labeled as subjects without evidence of dopaminergic deficit (SWEDDs). In this study, we sought to further characterize these patients and have analyzed the frequency of nonmotor symptoms (NMS) in SWEDDs, PD patients, and healthy controls. METHODS: We analyzed the baseline clinical data of 412 PD patients, 184 controls, and 62 SWEDDs included in the Parkinson's Progression Marker Initiative study on a variety of different NMS questionnaires. RESULTS: Both PD patients and SWEDDs had greater frequency of NMS than healthy controls. Furthermore, some NMS, such as orthostatic hypotension as well as cardiovascular and thermoregulatory dysfunction were even more commonly reported in SWEDDs than in PD patients, whereas hyposmia was more common in PD, compared to SWEDDs. CONCLUSION: NMS are more frequent in SWEDDs than in controls, and autonomic dysfunction and orthostatic hypotension were even more common than in PD patients. These findings support the notion that SWEDDS represent a group of patients with still poorly understood pathophysiology. © 2015 International Parkinson and Movement Disorder Society.

Probable RBD and association with neurodegenerative disease markers: A population-based study.

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.

Correlation of dopaminergic terminal dysfunction and microstructural abnormalities of the basal ganglia and the olfactory tract in Parkinson's disease.

Signal abnormalities of the substantia nigra and the olfactory tract detected either by diffusion tensor imaging, including measurements of mean diffusivity, a parameter of brain tissue integrity, and fractional anisotropy, a parameter of neuronal fibre integrity, or transcranial sonography, were recently reported in the early stages of Parkinson's disease. In this study, changes in the nigral and olfactory diffusion tensor signal, as well as nigral echogenicity, were correlated with clinical scales of motor disability, odour function and putaminal dopamine storage capacity measured with 6-[(18)F] fluorolevodopa positron emission tomography in early and advanced stages of Parkinson's disease. Diffusion tensor imaging, transcranial sonography and positron emission tomography were performed on 16 patients with Parkinson's disease (mean disease duration 3.7 ± 3.7 years, Hoehn and Yahr stage 1 to 4) and 14 age-matched healthy control subjects. Odour function was measured by the standardized Sniffin' Sticks Test. Mean putaminal 6-[(18)F] fluorolevodopa influx constant, mean nigral echogenicity, mean diffusivity and fractional anisotropy values of the substantia nigra and the olfactory tract were identified by region of interest analysis. When compared with the healthy control group, the Parkinson's disease group showed significant signal changes in the caudate and putamen by 6-[(18)F] fluorolevodopa positron emission tomography, in the substantia nigra by transcranial sonography, mean diffusivity and fractional anisotropy (P < 0.001, P < 0.01, P < 0.05, respectively) and in the olfactory tract by mean diffusivity (P < 0.05). Regional mean diffusivity values of the substantia nigra and the olfactory tract correlated significantly with putaminal 6-[(18)F] fluorolevodopa uptake (r = -0.52, P < 0.05 and r = -0.71, P < 0.01). Significant correlations were also found between nigral mean diffusivity values and the Unified Parkinson's Disease Rating Scale motor score (r = -0.48, P < 0.01) and between mean putaminal 6-[(18)F] fluorolevodopa uptake and the total odour score (r = 0.58; P < 0.05) as well as the Unified Parkinson's Disease Rating Scale motor score (r = -0.53, P < 0.05). This study reports a significant association between increased mean diffusivity signal and decreased 6-[(18)F] fluorolevodopa uptake, indicating that microstructural degradation of the substantia nigra and the olfactory tract parallels progression of putaminal dopaminergic dysfunction in Parkinson's disease. Since increases in nigral mean diffusivity signal also correlated with motor dysfunction, diffusion tensor imaging may serve as a surrogate marker for disease progression in future studies of putative disease modifying therapies.

Substantia nigra hyperechogenicity as a marker for Parkinson's disease: a population-based study.

BACKGROUND: The clinical diagnosis of Parkinson's disease (PD) is currently anchored in its cardinal motor symptoms. According to hospital-based studies, an enlarged echogenicity in the area of the substantia nigra (SN) assessed with transcranial sonography (TCS) may represent a useful biomarker in the diagnosis of PD. OBJECTIVE: To evaluate SN hyperechogenicity as a marker for PD in the Bruneck Study cohort, which is representative of the general elderly community. METHODS: The diagnostic accuracy of TCS in distinguishing clinically diagnosed PD from nonparkinsonian subjects was assessed in 574 subjects from this cohort. RESULTS: There was a good diagnostic accuracy of TCS in distinguishing PD subjects from nonparkinsonian subjects with an area under the curve value of 0.82. At a receiver-operating characteristic curve analysis-based cutoff value for SN hyperechogenicity of 0.18 cm(2), TCS had a sensitivity of 88.2% (95% confidence interval, CI, 64.4-98.0), a specificity of 77.0% (95% CI 72.8-80.6), a positive predictive value of 12.7% (95% CI 7.8-20.0) and a negative predictive value of 99.4% (95% CI 97.8-100.0) for subjects with clinically definite PD at baseline. When analyzing the same population after 5 years with regard to the presence of known and newly diagnosed PD cases, baseline TCS yielded very similar diagnostic accuracy values. CONCLUSION: SN hyperechogenicity may represent a useful biomarker for PD not only in a hospital-based setting but also in the general community.

Progression of dopamine transporter decline in patients with the Parkinson variant of multiple system atrophy: a voxel-based analysis of [123I]ß-CIT SPECT.

PURPOSE: We characterized the progression of dopamine transporter (DAT) decline in the striatum and extrastriatal regions including the midbrain and pons of patients with the Parkinson variant of multiple system atrophy (MSA-P) and compared longitudinally collected SPECT results with those in a cohort of patients with Parkinson's disease (PD). METHODS: Eight patients with MSA-P (age 60.4 ± 7.7 years, disease duration 2.4 ± 1 years, UPDRS-III motor score 39.7 ± 4.7), and 11 patients with PD (age 61.2 ± 6.4 years, disease duration 2.4 ± 1.1 years, UPDRS-III motor score 18.9 ± 7.6) underwent a baseline and follow-up [(123)I]ß-CIT SPECT investigation within a time period of 1.3 years. Statistical parametric mapping (SPM) and a repetitive ANOVA design were used to objectively localize the decline in DAT availability without having to make an a priori hypothesis as to its location. RESULTS: SPM localized significant reductions in [(123)I]ß-CIT uptake in the dorsal brainstem of MSA-P patients compared to PD patients (p < 0.001) at baseline. Additional reductions in the DAT signal were localized in the caudate and anterior putamen of patients with MSA-P patients compared to PD patients at the follow-up examination (p < 0.001). Relative decline in tracer binding was evident in the caudate and anterior putamen of MSA-P patients compared to PD patients in the longitudinal analysis (p < 0.05), whereas no significant relative signal alteration was observed in the brainstem. CONCLUSION: In contrast to PD, the relatively higher rate of signal reduction in the caudate and anterior putamen is consistent with the faster disease progression reported in MSA-P. At baseline, the tracer uptake in the brainstem was already at very low levels in the MSA-P patients compared to that in healthy control subjects and did not progress any further, suggesting that the degeneration of monoaminergic neurons is almost complete early in the disease course.

Prognostic value at 5 years of microvascular obstruction after acute myocardial infarction assessed by cardiovascular magnetic resonance.

BACKGROUND: Early and late microvascular obstruction (MVO) assessed by cardiovascular magnetic resonance (CMR) are prognostic markers for short-term clinical endpoints after acute ST-elevation myocardial infarction (STEMI). However, there is a lack of studies with long-term follow-up periods (>24 months). METHODS: STEMI patients reperfused by primary angioplasty (n = 129) underwent MRI at a median of 2 days after the index event. Early MVO was determined on dynamic Gd first-pass images directly after the administration of 0.1 mmol/kg bodyweight Gd-based contrast agent. Furthermore, ejection fraction (EF, %), left ventricular myocardial mass (LVMM) and total infarct size (% of LVMM) were determined with CMR. Clinical follow-up was conducted after a median of 52 months. The primary endpoint was defined as a composite of death, myocardial re-infarction, stroke, repeat revascularization, recurrence of ischemic symptoms, atrial fibrillation, congestive heart failure and hospitalization. RESULTS: Follow-up was completed by 107 patients. 63 pre-defined events occurred during follow-up. Initially, 74 patients showed early MVO. Patients with early MVO had larger infarcts (mean: 24.9 g vs. 15.5 g, p = 0.002) and a lower EF (mean: 39% vs. 46%, p = 0.006). The primary endpoint occurred in 66.2% of patients with MVO and in 42.4% of patients without MVO (p < 0.05). The presence of early MVO was associated with a reduced event-free survival (log-rank p < 0.05). Early MVO was identified as the strongest independent predictor for the occurrence of the primary endpoint in the multivariable Cox regression analysis adjusting for age, ejection fraction and infarct size (hazard ratio: 2.79, 95%-CI 1.25-6.25, p = 0.012). CONCLUSION: Early MVO, as assessed by first-pass CMR, is an independent long-term prognosticator for morbidity after AMI.

Has Deep Brain Stimulation Changed the Very Long-Term Outcome of Parkinson's Disease? A Controlled Longitudinal Study.

BACKGROUND: The long-term impact of deep brain stimulation (DBS) on Parkinson's disease (PD) is difficult to assess and has not yet been rigorously evaluated in comparison to its natural history. OBJECTIVE: Comparison of key disability milestones (recurrent falls, psychosis, dementia, and institutionalization) and death in patients with PD with versus without DBS. METHODS: We collected retrospective information from clinical notes of patients with PD at our center that were implanted with subthalamic DBS >8 years ago (1999-2010) and a control group of PD patients without DBS similar in age at onset, age at baseline, sex distribution, and number of comorbidities at baseline (extracted from a registry study performed in 2004). Cox regression models were used to calculate hazard ratios, adjusted for potential baseline confounding variables (age, sex, disease duration, disease severity, and number of comorbidities). RESULTS: A total of 74 DBS-treated and 61 control patients with PD were included. For a median observational period of 14 years, patients treated with DBS were at lower risk of experiencing recurrent falls (hazard ratio = 0.57; 95% confidence interval, 0.37-0.90; P = 0.015) and psychosis (hazard ratio = 0.26; 95% confidence interval, 0.12-0.59; P = 0.001) compared with control patients. There was no significant difference in risk for dementia, institutionalization, or death. Disease progression as assessed by Hoehn and Yahr scores was not slower in DBS-treated patients. CONCLUSIONS: Treatment with chronic subthalamic DBS was associated with lower risk for recurrent falls and psychotic symptoms, effects that may be mediated through improved motor symptom control and reduction in dopaminergic therapies, respectively. There was no evidence for DBS effects on underlying disease progression.

Paroxysmal and non-paroxysmal dystonia in 3 patients with biallelic ECHS1 variants: Expanding the neurological spectrum and therapeutic approaches.

BACKGROUND: ECHS1 encodes the mitochondrial short chain enoyl CoA hydratase 1 (SCEH). Biallelic ECHS1 variants have been associated with Leigh-like presentations and milder phenotypes with paroxysmal exercise-induced dystonia. PATIENTS/METHODS: We used exome sequencing to investigate molecular bases of paroxysmal and non-paroxysmal dystonia in three patients and performed functional studies in fibroblasts. Disease presentation and response upon dietary interventions were documented. RESULTS: We identified compound heterozygous ECHS1 missense variants in all individuals; all of them harbouring an c.518C > T (p.Ala173Val) variant. SCEH activity was impaired in patients' fibroblasts, respiratory chain-, and pyruvate-dehydrogenase-complex activities were normal in one individual. Patient 1 presented from the age of 2.5 years on with paroxysmal opisthotonic posturing. Patient 2 had a first metabolic crisis at the age 20 months developing recurrent exercise-induced dystonic episodes. Disease history of patient 3 was unremarkable for neurological findings until he first presented at the age of 20 years with persistent dystonia. Ketogenic diet had beneficial effects in patient 1. Neither ketogenic nor low protein diets led to milder symptoms in patient 2. Patient 3 benefits from low protein diet with improvement of his torticollis. CONCLUSIONS: In line with literature, our findings corroborate that the pathogenic ECHS1 variant c.518C > T (p.Ala173Val) is associated with milder phenotypes characterized by paroxysmal and non-paroxysmal dystonia. Because of the potentially treatable defect, especially in milder affected patients, it is important to consider SCEH deficiency not only in patients with Leigh-like syndrome but also in patients with paroxysmal dystonia and normal neurological findings between episodes.

Dopamine transporter SPECT: how to remove subjectivity?

Clinical criteria enable accurate and reliable diagnosis of parkinsonian syndromes when cardinal clinical features are fully developed. Single photon emission computed tomography (SPECT) investigating the striatal dopamine transporter (DAT) status have been suggested to increase the diagnostic accuracy in uncertain parkinsonian syndromes such as isolated tremor symptoms not fulfilling essential tremor criteria, as well as drug-induced, vascular and psychogenetic parkinsonism. Several approaches for the analysis of the striatal DAT distribution have been tested for their ability to analyze and quantify SPECT images. Visual assessment of DAT binding and semiquantitative analysis using region of interests have been recommended by Nuclear Medicine Associations to be incorporated in the routine work-up of DAT-SPECT. Besides these observer dependent approaches, fully automated image-analysis techniques have been validated in the clinical setting. Their potential as tools to improve the diagnostic accuracy in patients presenting with parkinsonian features is reviewed here.

Diagnostic Potential of Multimodal MRI Markers in Atypical Parkinsonian Disorders.

BACKGROUND: The diagnostic potential of multimodal MRI approaches to discriminate among progressive supranuclear palsy (PSP), Parkinson variant of multiple system atrophy (MSA-P) and Parkinson's disease (PD) has not been well investigated. OBJECTIVE: To identify disease-specific neurodegenerative patterns and evaluate the diagnostic accuracy of dedicated MRI, iron concentration (R2*), microstructural integrity (mean diffusivity; MD and fractional anisotropy; FA) as well as volumes were analyzed in patients with PSP, MSA-P and PD. METHODS: 3T MRI of 18 PSP and 16 MSA-P patients were compared with 16 PD patients matched for age and disease duration as well as 21 healthy controls. Statistical parametric mapping (SPM) was applied to objectively identify focal MRI changes throughout the whole-brain. Following dimensionality reduction of significant and multiple comparison-corrected SPM clusters through principal component analysis (PCA), stepwise receiver-operating characteristic curve analysis (ROC) was applied to determine the diagnostic potential of multimodal MRI parameters. RESULTS: PCA revealed two components involving multiple regions identified from SPM analysis. The first component was primarily composed of the mean MD value of the thalamus and the mean MD and FA values of the dentatorubrothalamic tract and the corpus callosum. The second component mainly consisted of mean MD and FA values of the middle cerebellar peduncle. ROC analysis showed 92% of PSP patients were differentiated correctly from MSA-P and PD and 80% of MSA-P patients could be distinguished from PD. CONCLUSION: Multimodal MRI improved the detection of disease-specific neurodegenerative patterns in PSP and MSA-P and highlights its potential to improve the diagnostic accuracy of atypical parkinsonian disorders.

The diagnostic accuracy of the hummingbird and morning glory sign in patients with neurodegenerative parkinsonism.

INTRODUCTION: The hummingbird sign and the morning glory flower sign, reflecting midbrain pathology on MRI, have previously been shown to separate patients with progressive supranuclear palsy (PSP) from those with Parkinson's disease (PD) and multiple system atrophy (MSA). The aim of the present study was to determine the diagnostic accuracy and reproducibility of visual assessment of midbrain atrophy patterns in a large cohort of patients with neurodegenerative parkinsonism. METHODS: Retrospective analysis of midbrain atrophy patterns on T1-weighted MRI in a large cohort of patients with neurodegenerative parkinsonism and healthy controls who underwent MR imaging during their diagnostic work-up. RESULTS: 481 patients with neurodegenerative parkinsonism and 79 healthy controls were included in the present study. The presence of the hummingbird sign had a specificity of 99.5% and a positive predictive value of 96.1% for a diagnosis of PSP while sensitivity was suboptimal with 51.6%. Similarly, the presence of the morning glory flower sign yielded a specificity of 97.7% for a diagnosis of PSP, but sensitivity was only 36.8%. Sensitivity of both signs was 35.3% in early, clinically unclassifiable parkinsonism. Visual assessment of these midbrain alterations showed excellent inter-rater agreement. CONCLUSION: Midbrain atrophy patterns are useful in the differential diagnosis of neurodegenerative parkinsonism but both the hummingbird sign and more so the morning glory flower sign suffer from low sensitivity, especially in early disease stages.

Diagnostic potential of dentatorubrothalamic tract analysis in progressive supranuclear palsy.

BACKGROUND: The differentiation of progressive supranuclear palsy-parkinsonism (PSP-P) from Parkinson's disease (PD) remains a major clinical challenge. OBJECTIVES: To evaluate the diagnostic potential of observer-independent assessments of microstructural integrity within infratentorial brain regions to differentiate PSP-Richardson's syndrome (PSP-RS), PSP-P and PD. METHODS: 3T MRI parameters of mean diffusivity, fractional anisotropy, grey and white matter volumes from patients with PSP-RS (n = 12), PSP-P (n = 12) and mean disease duration of 2.4 ±â€¯1.7 years were compared with PD patients (n = 20) and healthy controls (n = 23) by using statistical parametric mapping and the spatially unbiased infratentorial template. Subsequently MRI measurements of the dentatorubrothalamic tract were determined observer-independently by a validated probabilistic infratentorial atlas. The impairment of gait and postural stability was evaluated by a sum-score derived from the Unified Parkinson Disease Rating Scale. RESULTS: Significant mean diffusivity increases, fractional anisotropy decreases and corresponding volume loss were localized in mesencephalic tegmentum, superior cerebellar peduncle, decussation of superior cerebellar peduncle and dentate nucleus in PSP-RS and PSP-P compared to PD and healthy controls. Altered microstructural integrity of the dentatorubrothalamic tract in PSP-RS was significantly more pronounced compared to PSP-P and correlated significantly with the gait and postural stability sum-score. Linear discriminant analysis identified diffusion tensor imaging measures of the dentatorubrothalamic tract and the gait and postural stability sum-score to classify correctly 95.5% of PRP-RS, PSP-P and PD patients. CONCLUSIONS: Observer-independent analysis of microstructural integrity within the dentatorubrothalamic tract in combination with assessments of gait and postural stability differentiate PSP-P from PSP-RS and PD in early to moderately advanced stages.

The reorganization of functional architecture in the early-stages of Parkinson's disease.

INTRODUCTION: The study aim was to identify longitudinal abnormalities of functional connectivity and its relation with motor disability in early to moderately advanced stages of Parkinson's disease patients. METHODS: 3.0T structural and resting-state functional MRI was performed in healthy subjects (n = 16) and Parkinson's disease patients (n = 16) with mean disease duration of 2.2 ±â€¯1.2 years at baseline with a clinical follow-up of 1.5 ±â€¯0.3 years. Resting-state fMRI analysis included region-to-region connectivity in correlation with UPDRS-III scores and computation of Global Efficiency and Degree Centrality. RESULTS: At baseline, patients' connectivity increased between the cerebellum and somatomotor network, and decreased between motor regions (Rolandic operculum, precentral gyrus, supplementary motor area, postcentral gyrus) and cingulate connectivity. At 1.5 years follow-up, connectivity remained altered in the same regions identified at baseline. The cerebellum showed additional hyperconnectivity within itself and to the caudate nucleus, thalamus and amygdala compared to controls. These differences correlated with UPDRS-III scores. Seed-based connectivity revealed increased involvement of the default mode network with precentral gyrus in patients at follow-up investigation. CONCLUSION: Resting-state fMRI identified marked disturbances of the overall architecture of connectivity in Parkinson's disease. The noted alterations in cortical motor areas were associated with cerebellar hyperconnectivity in early to moderately advanced stages of Parkinson's disease suggesting ongoing attempts of recovery and compensatory mechanism for affected functions. The potential to identify connectivity alterations in regions related to both motor and attentional functions requires further evaluation as an objective marker to monitor disease progression, and medical, as well as surgical interventions.

Topography of Dopamine Transporter Availability in the Cerebellar Variant of Multiple System Atrophy.

BACKGROUND: Voxel-wise comparison of [123I]-2ß-carbomethoxy-3beta-(4-iodophenyl)tropane ([123I]ß-CIT) radioligand distribution measured by single-photon emission computed tomography (SPECT) revealed distinct patterns of reduced dopamine transporter (DAT) availability in the Parkinson's variant of MSA (MSA-P). The aim of this study was to identify the monoamine transporter distribution pattern in patients with the cerebellar variant of MSA (MSA-C). Additionally, monoamine transporter availability was investigated in a small cohort of patients with sporadic adult-onset ataxia (SAOA). METHODS: [123I]ß-CIT SPECT was performed in patients with MSA-C (n = 12), MSA-P (n = 14), SAOA (n = 5), and controls (n = 15) matched for age. Parametric images of [123I]ß-CIT binding potential (BPND) were generated and analyzed by statistical parametric mapping (SPM) and region of interest (ROI) analysis. RESULTS: SPM localized significant reductions of [123I]ß-CIT BPND in the striatum, midbrain, and pons in MSA-C compared to controls. When compared with MSA-P, the striatal DAT decline was significantly less affected in MSA-C. ROI analysis revealed reductions of striatal and midbrain [123I]ß-CIT binding in MSA-C compared to SAOA, whereas no significant difference was apparent between the SAOA and control groups. CONCLUSIONS: Midbrain and pontine monoaminergic transporter binding was severely impaired in MSA-C, matching the underlying pathological features. Striatal DAT availability was relatively less affected in MSA-C compared to MSA-P, reflecting measureable, but less-profound, degeneration of the nigrostriatal dopaminergic projections. Preliminary results of reduced striatal and midbrain [123I]ß-CIT binding in MSA-C, compared to SAOA, suggest that the potential of DAT-SPECT as a surrogate marker in the diagnostic workup of patients with adult-onset cerebellar ataxia should be further investigated.

Consistency of "Probable RBD" Diagnosis with the RBD Screening Questionnaire: A Follow-up Study.

INTRODUCTION: The aim of this study was to evaluate the consistency of "probable RBD" diagnosis with the RBD screening questionnaire (RBDSQ) assessed 2 years apart in a population-based study. METHODS: Probable RBD was assessed by RBDSQ in 2008 and in 2010 in the Bruneck Study Cohort, with participants aged ≥60 years. RESULTS: A total of 437 participants completed the RBDSQ in 2008 and 2010. There were 29 (6.6%) and 23 (5.3%) participants with probable RBD in 2008 and in 2010, respectively. Only eight (1.8%) screened positive on both occasions. RBDSQ values 2 years apart showed low correlation with each other (Spearman rank coefficient r = 0.348, P < 0.001) and low agreement (intraclass correlation coefficient 0.388, P < 0.001). CONCLUSIONS: We found low agreement between the two assessments. Possible explanations are the fluctuation of untreated RBD expression and the poor utility of the RBDSQ to detect RBD in the general population. Until further PSG validation of the RBDSQ in population-based studies, investigators must be aware of the inherent uncertainty of questionnaire-based RBD diagnosis.