Publications by authors named "Marie Vidailhet"

275 Publications

Acoustic, perceptual and clinical correlates of speech and voice in isolated dystonia: Preliminary findings.

Int J Lang Commun Disord 2021 Aug 12. Epub 2021 Aug 12.

Aix Marseille Univ, CNRS, LPL, Marseille, France.

Background: Hyperkinetic dysarthria is often present in isolated dystonia (ID) and is still understudied. Four main clusters of deviant speech dimensions in dystonia hyperkinetic dysarthria were initially provided: articulatory inaccuracy, phonatory stenosis, prosodic excess and prosodic insufficiency.

Aim: The aim of our exploratory study was to provide preliminary data on both perceptual and acoustic analyses in relation to three out of these four main clusters.

Methods & Procedures: Eleven patients with ID and 11 healthy controls (HC) participated in this study. Clinical/perceptual assessments and acoustic analyses of speech recordings were performed, the latter allowing for the analysis of parameters referring to aerophonatory control, voice quality, prosodic features and speech intelligibility estimated by nine listeners. Between-group statistical comparisons were performed (Wilcoxon tests, p < 0.05). Single-case differences between each patient and the control group were also carried out (effect size index and t < 0.05).

Outcomes & Results: Between-group comparisons confirmed the presence of a 'phonatory stenosis'; in addition, deficit in aerophonatory control and hypophonia was also displayed. 'Prosodic insufficiency' was confirmed, but not at the individual level. 'Prosodic excess' manifested only in patients with marked and severe dysarthria. Correlations between altered maximum phonation time, loudness variation, speech and articulatory rates on the one hand, and several clinical speech assessments on the other hand, were also found.

Conclusions & Implications: From these findings, altogether, perceptual characteristics of hyperkinetic dysarthria, as suggested by Darley et al., were quantified by the acoustic parameters we measured. As regards to our data obtained in a small participant sample, we would suggest that Darley et al.'s clusters of excess and insufficiency prosody should be questioned in future studies involving larger numbers of dystonic patients. Our study provides novel and preliminary results that demonstrate the relevance of using quantitative measures to further characterise speech/voice deficits in patients with ID.
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http://dx.doi.org/10.1111/1460-6984.12661DOI Listing
August 2021

A Multi-center Genome-wide Association Study of Cervical Dystonia.

Mov Disord 2021 Jul 28. Epub 2021 Jul 28.

Department of Neurology, University of Lübeck, Lübeck, Germany.

Background: Several monogenic causes for isolated dystonia have been identified, but they collectively account for only a small proportion of cases. Two genome-wide association studies have reported a few potential dystonia risk loci; but conclusions have been limited by small sample sizes, partial coverage of genetic variants, or poor reproducibility.

Objective: To identify robust genetic variants and loci in a large multicenter cervical dystonia cohort using a genome-wide approach.

Methods: We performed a genome-wide association study using cervical dystonia samples from the Dystonia Coalition. Logistic and linear regressions, including age, sex, and population structure as covariates, were employed to assess variant- and gene-based genetic associations with disease status and age at onset. We also performed a replication study for an identified genome-wide significant signal.

Results: After quality control, 919 cervical dystonia patients compared with 1491 controls of European ancestry were included in the analyses. We identified one genome-wide significant variant (rs2219975, chromosome 3, upstream of COL8A1, P-value 3.04 × 10 ). The association was not replicated in a newly genotyped sample of 473 cervical dystonia cases and 481 controls. Gene-based analysis identified DENND1A to be significantly associated with cervical dystonia (P-value 1.23 × 10 ). One low-frequency variant was associated with lower age-at-onset (16.4 ± 2.9 years, P-value = 3.07 × 10 , minor allele frequency = 0.01), located within the GABBR2 gene on chromosome 9 (rs147331823).

Conclusion: The genetic underpinnings of cervical dystonia are complex and likely consist of multiple distinct variants of small effect sizes. Larger sample sizes may be needed to provide sufficient statistical power to address the presumably multi-genic etiology of cervical dystonia. © 2021 International Parkinson and Movement Disorder Society.
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http://dx.doi.org/10.1002/mds.28732DOI Listing
July 2021

Predictive modeling of spread in adult-onset isolated dystonia: Key properties and effect of tremor inclusion.

Eur J Neurol 2021 Jul 22. Epub 2021 Jul 22.

Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.

Background And Purpose: Several clinical and demographic factors relate to anatomic spread of adult-onset isolated dystonia, but a predictive model is still lacking. The aims of this study were: (i) to develop and validate a predictive model of anatomic spread of adult-onset isolated dystonia; and (ii) to evaluate whether presence of tremor associated with dystonia influences model predictions of spread.

Methods: Adult-onset isolated dystonia participants with focal onset from the Dystonia Coalition Natural History Project database were included. We developed two prediction models, one with dystonia as sole disease manifestation ("dystonia-only") and one accepting dystonia OR tremor in any body part as disease manifestations ("dystonia OR tremor"). Demographic and clinical predictors were selected based on previous evidence, clinical plausibility of association with spread, or both. We used logistic regressions and evaluated model discrimination and calibration. Internal validation was carried out based on bootstrapping.

Results: Both predictive models showed an area under the curve of 0.65 (95% confidence intervals 0.62-0.70 and 0.62-0.69, respectively) and good calibration after internal validation. In both models, onset of dystonia in body regions other than the neck, older age, depression and history of neck trauma were predictors of spread.

Conclusions: This predictive modeling of spread in adult-onset isolated dystonia based on accessible predictors (demographic and clinical) can be easily implemented to inform individuals' risk of spread. Because tremor did not influence prediction of spread, our results support the argument that tremor is a part of the dystonia syndrome, and not an independent or coincidental disorder.
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http://dx.doi.org/10.1111/ene.15031DOI Listing
July 2021

Sweet or Bland Dreams? Taste Loss in Isolated REM-Sleep Behavior Disorder and Parkinson's Disease.

Mov Disord 2021 Jun 12. Epub 2021 Jun 12.

Sleep Disorders Unit, University Hospital Pitié-Salpêtrière, APHP-Sorbonne, Paris, France.

Background: Hyposmia and isolated REM sleep behavior disorder are well-established features of prodromal Parkinson's disease (PD).

Objectives: The objective of the present study was to evaluate whether taste loss (reported in PD and possibly suggesting brain stem involvement) is present at the isolated REM sleep behavior disorder stage.

Methods: We assessed taste function using the Taste Strip Test (evaluating 4 concentrations of bitter, sweet, sour, and salty) in 44 participants with isolated REM sleep behavior disorder, 19 with PD, and 29 controls. All participants underwent video-polysomnography, standardized questionnaires, and clinical examination, including olfactory assessment.

Results: Participants with isolated REM sleep behavior disorder and PD had lower taste scores than controls. There was no difference between isolated REM sleep behavior disorder and PD cohorts, nor was there any correlation between taste and olfaction, age, disease duration, cognition, or autonomic function.

Conclusion: This study demonstrates for the first time the presence of taste impairment in isolated REM sleep behavior disorder that is independent of olfactory dysfunction and comparable to participants with PD. © 2021 International Parkinson and Movement Disorder Society.
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http://dx.doi.org/10.1002/mds.28692DOI Listing
June 2021

Long-term effect of apomorphine infusion in advanced Parkinson's disease: a real-life study.

NPJ Parkinsons Dis 2021 Jun 11;7(1):50. Epub 2021 Jun 11.

Neurology Department, Pitié-Salpêtrière Hospital, AP-HP, Paris, France.

Long-term effects of continuous subcutaneous apomorphine infusion (CSAI) on health-related quality of life (HRQoL) and predictors of CSAI discontinuation are poorly known. Data from consecutive advanced Parkinson's disease patients treated in routine care were retrospectively collected over 24 months after CSAI initiation, with a focus on the 39-item Parkinson's disease questionnaire (PDQ-39). We determined predictors of CSAI discontinuation and HRQoL improvement using multiple regression analysis. Of the 110 subjects evaluated over a 2-year period, 35% discontinued CSAI. Of those who continued treatment, HRQoL remained stable with a sustained reduction in motor fluctuations. The observed effect on dyskinesias was mild and transient. Of note, patients with preexisting impulse control disorders showed an overall good tolerability. PDQ-39 was the only baseline predictor of HRQoL improvement after 2 years of treatment. The presence of dyskinesias, poorer psychological status, shorter disease duration, male sex, and worse OFF state were predictors of discontinuation. Best candidates for CSAI are patients with: (i) poor baseline HRQoL and (ii) marked motor fluctuations.
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http://dx.doi.org/10.1038/s41531-021-00194-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8196159PMC
June 2021

The spatiotemporal changes in dopamine, neuromelanin and iron characterizing Parkinson's disease.

Brain 2021 May 12. Epub 2021 May 12.

Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, INSERM, CNRS, 75013 Paris, France.

In Parkinson's disease, there is a progressive reduction in striatal dopaminergic function, and loss of neuromelanin-containing dopaminergic neurons and increased iron deposition in the substantia nigra. We tested the hypothesis of a relationship between impairment of the dopaminergic system and changes in the iron metabolism. Based on imaging data of patients with prodromal and early clinical Parkinson's disease, we assessed the spatiotemporal ordering of such changes and relationships in the sensorimotor, associative and limbic territories of the nigrostriatal system. Patients with Parkinson's disease (disease duration < 4 years) or idiopathic REM sleep behaviour disorder (a prodromal form of Parkinson's disease) and healthy controls underwent longitudinal examination (baseline and 2-year follow-up). Neuromelanin and iron sensitive MRI and dopamine transporter single-photon emission tomography were performed to assess nigrostriatal levels of neuromelanin, iron, and dopamine. For all three functional territories of the nigrostriatal system, in the clinically most and least affected hemispheres separately, the following was performed: cross-sectional and longitudinal inter-group difference analysis of striatal dopamine and iron, and nigral neuromelanin and iron; in Parkinson's disease patients, exponential fitting analysis to assess the duration of the prodromal phase and the temporal ordering of changes in dopamine, neuromelanin or iron relative to controls; voxel-wise correlation analysis to investigate concomitant spatial changes in dopamine-iron, dopamine-neuromelanin and neuromelanin-iron in the substantia nigra pars compacta. The temporal ordering of dopaminergic changes followed the known spatial pattern of progression involving first the sensorimotor, then the associative and limbic striatal and nigral regions. Striatal dopaminergic denervation occurred first followed by abnormal iron metabolism and finally neuromelanin changes in the substantia nigra pars compacta, which followed the same spatial and temporal gradient observed in the striatum but shifted in time. In conclusion, dopaminergic striatal dysfunction and cell loss in the substantia nigra pars compacta are interrelated with increased nigral iron content.
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http://dx.doi.org/10.1093/brain/awab191DOI Listing
May 2021

Grumpy face during adult sleep: A clue to negative emotion during sleep?

J Sleep Res 2021 Apr 29:e13369. Epub 2021 Apr 29.

Sleep Disorder Unit, APHP, Pitie-Salpetriere University Hospital, Paris, France.

Negative facial expressions and frowns have been studied (albeit more rarely than smiles) in fetus' and neonate' sleep, but they have not been investigated during adult sleep. Video polysomnography (including corrugator muscle electromyography and face-focussed video) was used to study negative facial expressions in sleeping adults, including healthy subjects and patients with/out parasomnia. Frowns were observed during sleep in 89/91 (97.8%) adults during normal (29 healthy subjects) and abnormal sleep (29 patients without parasomnia, 15 patients with disorders of arousal and 18 patients with rapid eye movement [REM] sleep behaviour disorder [RBD]). In healthy subjects, the following events occurred in decreasing frequency: isometric corrugator activations, brief frowns, and then prolonged frowns and raised eyebrows (both similarly rare). Frowns predominated in REM sleep, and had a lower frequency in non-REM sleep. In healthy subjects, frowns were elementary and not associated with other face movements to the point of composing negative expressions. In contrast, frowns were occasionally associated with overt negative facial expressions in REM sleep in patients with RBD and a young patient with night terrors. They included mostly painful expressions and rarely sadness and anger in connection with apparently negative behaviours (shouts, painful moaning, and speeches). Frowns persist during normal sleep (mostly in REM sleep) in adults, but overt negative facial expressions are restricted to patients with parasomnia. Whether elementary frowns translate a negative dream emotion should be determined, but overt negative facial expressions during RBD could be used as a direct access to dream emotions.
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http://dx.doi.org/10.1111/jsr.13369DOI Listing
April 2021

Social cognitive impairment in early Parkinson's disease: A novel "mild impairment"?

Parkinsonism Relat Disord 2021 04 4;85:117-121. Epub 2021 Mar 4.

Sorbonne Université, Inserm, CNRS, Institut du Cerveau - Paris Brain Institute - ICM, Paris, France; Department of Neurology, Pitié-Salpêtrière Hospital, Assistance Publique Hôpitaux de Paris (APHP), Paris, France; Institute of Memory and Alzheimer's Disease (IM2A), Pitié-Salpêtrière Hospital, Assistance Publique Hôpitaux de Paris (APHP), Paris, France.

Introduction: Social cognition (SC) deficit has recently been described in the early stages of Parkinson's disease (PD), but findings remain unclear. Our objective was to determine the frequency of SC impairment in newly-diagnosed PD patients and whether it is independent of Mild Cognitive Impairment (MCI).

Methods: We enrolled 109 patients with idiopathic PD diagnosed within the previous four years (ICEBERG cohort) and 39 healthy participants. SC was evaluated using the Mini-Social Cognition and Emotional Assessment (Mini-SEA) that allows a multi-domain assessment of SC. Relationships between SC and clinical characteristics, global cognitive efficiency, mood, anxiety, apathy and impulse control disorders, were also evaluated.

Results: 30% of patients had significant socio-emotional impairment. Moreover, SC deficit in isolation was 3.5 times more frequent than MCI in isolation (20.2% vs 5.5% respectively). Both emotion identification and Theory of Mind were impaired compared to healthy participants. No effect of age, level of education, disease severity, dopamine replacement therapy, or global cognitive efficiency were found. Only scores on the Frontal Assessment Battery were correlated with SC abilities.

Conclusion: SC impairment is frequent in early PD and should be given more consideration. It often occurs in the absence of any other cognitive disorder and may represent the most common neuropsychological deficit in early-stage PD. In line with the definition of PD-MCI criteria, we consider the addition of a sixth MCI sub-type termed "Mild Social Cognition Impairment (MSCI)". Further studies are required to validate the addition of this new MCI domain.
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http://dx.doi.org/10.1016/j.parkreldis.2021.02.023DOI Listing
April 2021

Trans-Spinal Direct Current Stimulation for Managing Primary Orthostatic Tremor.

Mov Disord 2021 08 27;36(8):1835-1842. Epub 2021 Mar 27.

Institut du Cerveau / Paris Brain Institute, ICM, Hôpital de la Pitié-Salpêtrière, CNRS UMR 7225, Inserm U 1127, Sorbonne Université UM75, Paris, France.

Background: Primary orthostatic tremor (POT) is a rare disorder, characterized by 13 to 18 Hz tremor in the legs when standing and is often refractory to medical treatment. Epidural spinal cord stimulation has been proposed as an alternative treatment. However, this approach is invasive, which limits its application.

Objective: Trans-spinal direct current stimulation (tsDCS) is a non-invasive method to modulate spinal cord circuits. The aim of this proof-of-concept study was to investigate the potential beneficial effect of tsDCS in POT.

Methods: We conducted a double-blind, sham-controlled study in 16 patients with POT. In two separate visits, patients received sham tsDCS first followed by active (either cathodal or anodal) tsDCS. The primary outcome was the change in time in standing position. Secondary outcomes comprised quantitative assessment of tremor, measurement of corticospinal excitability including short-latency afferent inhibition, and clinical global impression-improvement (CGI-I). Measurements were made at baseline, after sham tsDCS, 0-30 min, and 30-60 min after active conditions.

Results: Cathodal-tsDCS reduced tremor amplitude and frequency and lowered corticospinal excitability whereas anodal-tsDCS reduced tremor frequency only. CGI-I scores positively correlated with the time in standing position after both active tsDCS conditions.

Conclusion: A single session of tsDCS can improve instability in POT. This opens a new vista for experimental treatment options using multiple sessions of spinal DC stimulation. © 2021 International Parkinson and Movement Disorder Society.
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http://dx.doi.org/10.1002/mds.28581DOI Listing
August 2021

Longitudinal Changes in Neuromelanin MRI Signal in Parkinson's Disease: A Progression Marker.

Mov Disord 2021 07 10;36(7):1592-1602. Epub 2021 Mar 10.

Paris Brain Institute- ICM, Center for NeuroImaging Research - CENIR, Paris, France.

Background: Development of reliable and accurate imaging biomarkers of dopaminergic cell neurodegeneration is necessary to facilitate therapeutic drug trials in Parkinson's disease (PD). Neuromelanin-sensitive MRI techniques have been effective in detecting neurodegeneration in the substantia nigra pars compacta (SNpc). The objective of the current study was to investigate longitudinal neuromelanin signal changes in the SNpc in PD patients.

Methods: In this prospective, longitudinal, observational case-control study, we included 140 PD patients and 64 healthy volunteers divided into 2 cohorts. Cohort I included 99 early PD patients (disease duration, 1.5 ± 1.0 years) and 41 healthy volunteers analyzed at baseline (V1), where 79 PD patients and 32 healthy volunteers were rescanned after 2.0 ± 0.2 years of follow-up (V2). Cohort II included 41 progressing PD patients (disease duration, 9.3 ± 3.7 years) and 23 healthy volunteers at V1, where 30 PD patients were rescanned after 2.4 ± 0.5 years of follow-up. Subjects were scanned at 3 T MRI using 3-dimensional T1-weighted and neuromelanin-sensitive imaging. Regions of interest were delineated manually to calculate SN volumes, volumes corrected by total intracranial volume, signal-to-noise ratio, and contrast-to-noise ratio.

Results: Results showed (1) significant reduction in volume and volume corrected by total intracranial volume between visits, greater in progressing PD than nonsignificant changes in healthy volunteers; (2) no significant effects of visit for signal intensity (signal-to-noise ratio); (3) significant interaction in volume between group and visit; (4) greater volume corrected by total intracranial volume at baseline in female patients and greater decrease in volume and increase in the contrast-to-noise ratio in progressing female PD patients compared with male patients; and (5) correlations between neuromelanin SN changes and disease severity and duration.

Conclusions: We observed a progressive and measurable decrease in neuromelanin-based SN signal and volume in PD, which might allow a direct noninvasive assessment of progression of SN loss and could represent a target biomarker for disease-modifying treatments. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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http://dx.doi.org/10.1002/mds.28531DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8359265PMC
July 2021

X-Vectors: New Quantitative Biomarkers for Early Parkinson's Disease Detection From Speech.

Front Neuroinform 2021 19;15:578369. Epub 2021 Feb 19.

Department of Electrical & Computer Engineering, PERFORM Center, Concordia University, Montreal, QC, Canada.

Many articles have used voice analysis to detect Parkinson's disease (PD), but few have focused on the early stages of the disease and the gender effect. In this article, we have adapted the latest speaker recognition system, called x-vectors, in order to detect PD at an early stage using voice analysis. X-vectors are embeddings extracted from Deep Neural Networks (DNNs), which provide robust speaker representations and improve speaker recognition when large amounts of training data are used. Our goal was to assess whether, in the context of early PD detection, this technique would outperform the more standard classifier MFCC-GMM (Mel-Frequency Cepstral Coefficients-Gaussian Mixture Model) and, if so, under which conditions. We recorded 221 French speakers (recently diagnosed PD subjects and healthy controls) with a high-quality microphone and via the telephone network. Men and women were analyzed separately in order to have more precise models and to assess a possible gender effect. Several experimental and methodological aspects were tested in order to analyze their impacts on classification performance. We assessed the impact of the audio segment durations, data augmentation, type of dataset used for the neural network training, kind of speech tasks, and back-end analyses. X-vectors technique provided better classification performances than MFCC-GMM for the text-independent tasks, and seemed to be particularly suited for the early detection of PD in women (7-15% improvement). This result was observed for both recording types (high-quality microphone and telephone).
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http://dx.doi.org/10.3389/fninf.2021.578369DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7935511PMC
February 2021

Striatal and cerebellar vesicular acetylcholine transporter expression is disrupted in human DYT1 dystonia.

Brain 2021 04;144(3):909-923

Institut des Maladies Neurodégénératives (IMN, CNRS U5393), Université de Bordeaux, 33076, Bordeaux, France.

Early-onset torsion dystonia (TOR1A/DYT1) is a devastating hereditary motor disorder whose pathophysiology remains unclear. Studies in transgenic mice suggested abnormal cholinergic transmission in the putamen, but this has not yet been demonstrated in humans. The role of the cerebellum in the pathophysiology of the disease has also been highlighted but the involvement of the intrinsic cerebellar cholinergic system is unknown. In this study, cholinergic neurons were imaged using PET with 18F-fluoroethoxybenzovesamicol, a radioligand of the vesicular acetylcholine transporter (VAChT). Here, we found an age-related decrease in VAChT expression in the posterior putamen and caudate nucleus of DYT1 patients versus matched controls, with low expression in young but not in older patients. In the cerebellar vermis, VAChT expression was also significantly decreased in patients versus controls, but independently of age. Functional connectivity within the motor network studied in MRI and the interregional correlation of VAChT expression studied in PET were also altered in patients. These results show that the cholinergic system is disrupted in the brain of DYT1 patients and is modulated over time through plasticity or compensatory mechanisms.
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http://dx.doi.org/10.1093/brain/awaa465DOI Listing
April 2021

Quality of life in isolated dystonia: non-motor manifestations matter.

J Neurol Neurosurg Psychiatry 2021 Feb 9. Epub 2021 Feb 9.

Department of Neurology, University of Luebeck, Luebeck, Germany

Objective: To evaluate the relationship between health-related quality of life (HR-QoL) and both physical and psychiatric factors in a large, international, multicentre cohort of patients with isolated dystonia, the Dystonia Coalition.

Methods: Natural history data from 603 patients with isolated dystonia (median age 57 years (IQR: 48 to 64 years), 67.0% women) were prospectively acquired and analysed. HR-QoL (RAND 36-Item Health Survey), severity of depressive symptoms, generalised anxiety (Hospital Anxiety and Depression Scale) and social anxiety (Liebowitz Social Anxiety Scale) were assessed. Dystonia severity (Burke-Fahn-Marsden Dystonia Rating Scale) and dystonic tremor were examined. Statistical predictors of HR-QoL were calculated using saturated path analysis.

Results: Reduced HR-QoL was strongly associated with the degree of depressive symptoms and generalised and social anxiety (8/8 RAND 36 subscales, p≤0.001). Increased dystonia severity was associated with worse physical functioning, physical and emotional role functioning and social functioning (all p≤0.001). The presence of tremor correlated with worse physical functioning and pain (all p≤0.006). Younger age was associated with reduced emotional well-being and vitality (all p≤0.006). There were no HR-QoL differences between sexes.

Conclusion: HR-QoL in isolated dystonia is strongly associated with psychiatric and physical features. While current standard of care focus on motor aspects of dystonia, comprehensive care should address both physical and mental aspects of health.
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http://dx.doi.org/10.1136/jnnp-2020-325193DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8356023PMC
February 2021

Loss of floor plate Netrin-1 impairs midline crossing of corticospinal axons and leads to mirror movements.

Cell Rep 2021 01;34(3):108654

Sorbonne Université, CNRS, INSERM, Institut de Biologie Paris-Seine (IBPS), Neuroscience Paris-Seine (NPS), 75005 Paris, France. Electronic address:

In humans, execution of unimanual movements requires lateralized activation of the primary motor cortex, which then transmits the motor command to the contralateral hand through the crossed corticospinal tract (CST). Mutations in NTN1 alter motor control lateralization, leading to congenital mirror movements. To address the role of midline Netrin-1 on CST development and subsequent motor control, we analyze the morphological and functional consequences of floor plate Netrin-1 depletion in conditional knockout mice. We show that depletion of floor plate Netrin-1 in the brainstem critically disrupts CST midline crossing, whereas the other commissural systems are preserved. The only associated defect is an abnormal entry of CST axons within the inferior olive. Alteration of CST midline crossing results in functional ipsilateral projections and is associated with abnormal symmetric movements. Our study reveals the role of Netrin-1 in CST development and describes a mouse model recapitulating the characteristics of human congenital mirror movements.
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http://dx.doi.org/10.1016/j.celrep.2020.108654DOI Listing
January 2021

Antisaccade, a predictive marker for freezing of gait in Parkinson's disease and gait/gaze network connectivity.

Brain 2021 03;144(2):504-514

Sorbonne Université, UMR S 1127, Inserm U 1127, and CNRS UMR 7225, and Institut du Cerveau et de la Moelle épinière, F-75013, Paris, France.

Freezing of gait is a challenging sign of Parkinson's disease associated with disease severity and progression and involving the mesencephalic locomotor region. No predictive factor of freezing has been reported so far. The primary objective of this study was to identify predictors of freezing occurrence at 5 years. In addition, we tested whether functional connectivity of the mesencephalic locomotor region could explain the oculomotor factors at baseline that were predictive of freezing onset. We performed a prospective study investigating markers (parkinsonian signs, cognitive status and oculomotor recordings, with a particular focus on the antisaccade latencies) of disease progression at baseline and at 5 years. We identified two groups of patients defined by the onset of freezing at 5 years of follow-up; the 'Freezer' group was defined by the onset of freezing in the ON medication condition during follow-up (n = 17), while the 'non-Freezer' group did not (n = 8). Whole brain resting-state functional MRI was recorded at baseline to determine how antisaccade latencies were associated with connectivity of the mesencephalic locomotor region networks in patients compared to 25 age-matched healthy volunteers. Results showed that, at baseline and compared to the non-Freezer group, the Freezer group had equivalent motor or cognitive signs, but increased antisaccade latencies (P = 0.008). The 5-year course of freezing of gait was correlated with worsening antisaccade latencies (P = 0.0007). Baseline antisaccade latencies was also predictive of the freezing onset (χ2 = 0.008). Resting state connectivity of mesencephalic locomotor region networks correlated with (i) antisaccade latency differently in patients and healthy volunteers at baseline; and (ii) the further increase of antisaccade latency at 5 years. We concluded that antisaccade latency is a predictive marker of the 5-year onset of freezing of gait. Our study suggests that functional networks associated with gait and gaze control are concurrently altered during the course of the disease.
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http://dx.doi.org/10.1093/brain/awaa407DOI Listing
March 2021

Parkinson Disease Propagation Using MRI Biomarkers and Partial Least Squares Path Modeling.

Neurology 2021 01 4;96(3):e460-e471. Epub 2020 Dec 4.

From the Institut Cerveau Moelle (N.P., L.Y.-C., R.V., R.G., S.F.-V., S.L.), Centre de NeuroImagerie de Recherche; Sorbonne Université (N.P., L.Y.-C,, R.G., F.G., C.E., C.G., S.F.-V., I.A., M.V., S.L.), Paris 06, UMR S 1127, CNRS UMR 7225, Institut Cerveau Moelle, F-75013; Institut Cerveau Moelle Team Movement Investigation and Therapeutics (N.P., R.G., F.G., C.E., C.G., I.A., M.V., S.L.); Service de neuroradiologie (N.P., M.V., S.L.), APHP, Pitié-Salpêtrière; and Clinique des Mouvements Anormaux (C.E.), Département des Maladies du Système Nerveux, and Service des Pathologies du Sommeil (I.A.), Hôpital Pitié-Salpêtrière, APHP, Paris, France.

Objectives: The classic Braak neuropathologic staging model in Parkinson disease (PD) suggests that brain lesions progress from the medulla oblongata to the cortex. An alternative model in which neurodegeneration first occurs in the cortex has also been proposed. These 2 models may correspond to different patient phenotypes. To test these 2 models and to investigate whether they were influenced by the presence of REM sleep behavior disorder (RBD), we used multimodal MRI and partial least squares path modeling (PLS-PM) assuming that patients with RBD followed distinct neurodegeneration pattern.

Methods: Fifty-four patients with PD (34 with RBD) and 25 healthy volunteers were scanned with T1-weighted, diffusion tensor, and neuromelanin-sensitive imaging. Volume, signal, and mean, axial, and radial diffusivities were calculated in brainstem, basal forebrain, and cortical regions. PLS-PM, estimating a network of causal relationships between blocks of variables, was used to build and test an analytical model based on Braak staging. The overall quality of the model was assessed with goodness of fit coefficient (Gof).

Results: PLS-PM was run on patients with PD with RBD and without RBD separately. In PD with RBD, a brainstem-to-cortex model had significant Gof (0.71, = 0.01), whereas a cortex-to-brainstem model did not. In contrast, in patients with PD without RBD, the brainstem-to-cortex model was not significant (Gof = 0.64, = 0.27), and the cortex-to-brainstem model was highly significant (Gof = 0.72, = 0.008).

Conclusions: With the PLS-PM imaging-based model, the neurodegeneration pattern of patients with PD with RBD was consistent with the Braak brainstem-to-cortex model, whereas that of patients without RBD followed the cortex-to-brainstem model.
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http://dx.doi.org/10.1212/WNL.0000000000011155DOI Listing
January 2021

Automated Categorization of Parkinsonian Syndromes Using Magnetic Resonance Imaging in a Clinical Setting.

Mov Disord 2021 02 2;36(2):460-470. Epub 2020 Nov 2.

Paris Brain Institute-ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, UMR S 1127, CNRS UMR 7225, Paris, France.

Background: Machine learning algorithms using magnetic resonance imaging (MRI) data can accurately discriminate parkinsonian syndromes. Validation in patients recruited in routine clinical practice is missing.

Objective: The aim of this study was to assess the accuracy of a machine learning algorithm trained on a research cohort and tested on an independent clinical replication cohort for the categorization of parkinsonian syndromes.

Methods: Three hundred twenty-two subjects, including 94 healthy control subjects, 119 patients with Parkinson's disease (PD), 51 patients with progressive supranuclear palsy (PSP) with Richardson's syndrome, 35 with multiple system atrophy (MSA) of the parkinsonian variant (MSA-P), and 23 with MSA of the cerebellar variant (MSA-C), were recruited. They were divided into a training cohort (n = 179) scanned in a research environment and a replication cohort (n = 143) examined in clinical practice on different MRI systems. Volumes and diffusion tensor imaging (DTI) metrics in 13 brain regions were used as input for a supervised machine learning algorithm. To harmonize data across scanners and reduce scanner-dependent effects, we tested two types of normalizations using patient data or healthy control data.

Results: In the replication cohort, high accuracies were achieved using volumetry in the classification of PD-PSP, PD-MSA-C, PSP-MSA-C, and PD-atypical parkinsonism (balanced accuracies: 0.840-0.983, area under the receiver operating characteristic curves: 0.907-0.995). Performances were lower for the classification of PD-MSA-P, MSA-C-MSA-P (balanced accuracies: 0.765-0.784, area under the receiver operating characteristic curve: 0.839-0.871) and PD-PSP-MSA (balanced accuracies: 0.773). Performance using DTI was improved when normalizing by controls, but remained lower than that using volumetry alone or combined with DTI.

Conclusions: A machine learning approach based on volumetry enabled accurate classification of subjects with early-stage parkinsonism, examined on different MRI systems, as part of their clinical assessment. © 2020 International Parkinson and Movement Disorder Society.
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http://dx.doi.org/10.1002/mds.28348DOI Listing
February 2021

Dystonia: genetics, phenomenology, and pathophysiology.

Lancet Neurol 2020 11;19(11):881-882

Department of Neurology, Sorbonne Université, Paris, France; Institut du Cerveau et de la Moëlle épinière-Inserm U1127, Groupe Hospitalier Pitié-Salpêtrière, France; Department of Neurology, Groupe Hospitalier Pitié-Salpêtrière, France.

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http://dx.doi.org/10.1016/S1474-4422(20)30366-5DOI Listing
November 2020

Whispering dysphonia in TUBB4A-related disorders responsive to bipallidal deep brain stimulation.

Eur J Neurol 2021 03;28(3):1082-1083

Département de Neurologie, Hôpital Pitié-Salpêtrière, AP-HP, Paris, France.

Background: Mutations in TUBB4A are associated with a wide phenotypic spectrum including generalized dystonia with whispering dysphonia (DYT-TUBB4A).

Methods: We report the case of a 44-year-old patient with DYT-TUBB4A with a clinical presentation of disabling progressive dystonia, with a prominent laryngeal, cervical and facial involvement.

Results: Bipallidal deep brain stimulation (DBS) resulted in a 55% reduction of dystonia severity assessed by the Burke-Fahn-Marsden scale score 6 months after surgery. The effect was obvious on the cervical and facial components of dystonia.

Conclusion: We suggest that bipallidal DBS should be considered in patients with disabling dystonia related to TUBB4A variants.
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http://dx.doi.org/10.1111/ene.14602DOI Listing
March 2021

Dystonia and Tremor: A Cross-Sectional Study of the Dystonia Coalition Cohort.

Neurology 2021 01 12;96(4):e563-e574. Epub 2020 Oct 12.

From the Departments of Biomedical Engineering (A.G.S., S.B.B.) and Neurology (A.G.S.), Case Western University School of Medicine; Neurological Institute (A.G.S.), University Hospitals Cleveland; Neurology Service (A.G.S.), Louis Stokes Cleveland VA Medical Center, OH; Department of Neurology (L.S., G.K.-B., A.F., S. Factor, H.A.J.), Human Genetics (H.A.J.), and Pediatrics (H.A.J.), Emory University School of Medicine, Atlanta, GA; Institute of Neurogenetics (C.K., J.J., S.L., N.B., A.M., T.B.), University of Lübeck, Germany; Department of Neurology (M.V., E.R., C.B.), Pitié-Salpêtrière Hospital, Paris, France; Department of Neurology (J.J.), Baylor College of Medicine, Houston, TX; Neurology and Neurosurgery (J.J.-S.), Icahn School of Medicine at Mount Sinai, New York, NY; Department of Neurology (N.P.), Henry Ford Health System, West Bloomfield, MI; Department of Psychiatry and Neurology (L.M.), Baylor College of Medicine, Houston, TX; Department of Neurological Sciences (C.C.), Rush University Medical Center, Chicago, IL; Department of Neurology (R.L.B.), University of Rochester, NY; Department of Neurology (B.D.B.), University of Colorado School of Medicine, Aurora; Department of Neurology (I.M., A.W.S.), Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville; Department of Neurology (S.G.R.), University of Maryland School of Medicine, Baltimore; University of Tennessee Health Science Center (M.S.L.), Memphis; Department of Neurosciences (A.B.), Mental Health and Sensory Organs, Suicide Prevention Center, Sant'Andrea Hospital, Sapienza University of Rome; IRCCS Neuromed (G.F.), Pozzilli, Italy; The University of Alabama at Birmingham (N.S.); Methodist Neurological Institute (W.O.), Houston, TX; Department of Neurology (S.P.R.), University of New Mexico Health Sciences Center, Albuquerque; Department of Neurology (R.S.-P.), Mount Sinai Beth Israel, New York, NY; Lou Ruvo Center for Brain Health (Z.M.), Cleveland Clinic, Las Vegas, NV; Booth Gardner Parkinson's Care Center (P.A.), Kirkland, WA; Mayo Clinic (C.A.), Scottsdale, AZ; Andre Barbeau Movement Disorders Unit (S.C.), Montreal University Hospital Center (CHUM); Movement Disorder Clinic (S.H.F.), Toronto Western Hospital, Division of Neurology University of Toronto, Canada; UC Davis School of Medicine (A.B.), Sacramento; The Parkinson's and Movement Disorder Institute (D.T.), Orange Coast Memorial Medical Center, Fountain Valley, CA; Department of Medicine (O.S.), Medical Genetics, and Pediatrics, University of Alberta, Canada; Department of Neurology (S. Frank), Beth Israel Deaconess Medical Center, Boston, MA; and Neurology, Radiology, Neuroscience, Physical Therapy and Occupational Therapy (J.P.), Washington University School of Medicine, St Louis, MO.

Objective: To assess the clinical manifestations and predictors of different types of tremors in individuals with different types of isolated dystonia.

Methods: Clinical manifestations of tremor were assessed in a multicenter, international cross-sectional, cohort study of 2,362 individuals with all types of isolated dystonia (focal, segmental, multifocal, and generalized) recruited through the Dystonia Coalition.

Results: Methodical and standardized assessments of all participants in this cohort revealed the overall prevalence of any type of tremor was 53.3%. The prevalence of dystonic tremor varied from 36.9% to 48.4%, depending on criteria used to define it. To identify the factors associated with tremors in dystonia, the data were analyzed by generalized linear modeling and cluster analyses. Generalized linear modeling indicated 2 of the strongest factors associated with tremor included body region affected by dystonia and recruitment center. Tremor was also associated with severity of dystonia and duration of dystonia, but not with sex or race. The cluster analysis distinguished 8 subgroups within the whole cohort; defined largely by body region with dystonia, and secondarily by other clinical characteristics.

Conclusion: The large number of cases evaluated by an international team of movement disorder experts facilitated the dissection of several important factors that influence the apparent prevalence and phenomenology of tremor in dystonia. These results are valuable for understanding the many differences reported in prior studies, and for guiding future studies of the nosology of tremor and dystonia.
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http://dx.doi.org/10.1212/WNL.0000000000011049DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7905789PMC
January 2021

Characterization of Recessive Parkinson Disease in a Large Multicenter Study.

Ann Neurol 2020 10 28;88(4):843-850. Epub 2020 Jul 28.

Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.

Studies of the phenotype and population distribution of rare genetic forms of parkinsonism are required, now that gene-targeting approaches for Parkinson disease have reached the clinical trial stage. We evaluated the frequencies of PRKN, PINK1, and DJ-1 mutations in a cohort of 1,587 cases. Mutations were found in 14.1% of patients; 27.6% were familial and 8% were isolated. PRKN was the gene most frequently mutated in Caucasians, whereas PINK1 mutations predominated in Arab-Berber individuals. Patients with PRKN mutations had an earlier age at onset, and less asymmetry, levodopa-induced motor complications, dysautonomia, and dementia than those without mutations. ANN NEUROL 2020;88:843-850.
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http://dx.doi.org/10.1002/ana.25787DOI Listing
October 2020

Longitudinal association between dopamine agonists and weight in Parkinson's disease.

Parkinsonism Relat Disord 2020 11 24;80:158-164. Epub 2020 Sep 24.

Université Paris-Saclay, UVSQ, Univ. Paris-Sud, Inserm, Équipe « Exposome, Hérédité, Cancer et Santé », CESP, 94807, Villejuif, France.

Objective: To examine the longitudinal relation of dopamine agonists (DA) use with body mass index (BMI) change and weight gain in Parkinson's disease (PD).

Methods: In a cohort of 356 patients with PD annually followed up to 6 years, BMI, antiparkinsonian drugs use, and impulse control disorders (ICDs) were assessed at each visit. DA dose trajectories were estimated using latent class mixed models. The association of DA use with BMI change and weight gain was examined using latent-process mixed models and time-dependent Cox models respectively, while adjusting for disease severity and levodopa (LD) use.

Results: In the mixed model, BMI (kg/m) increased over the follow-up in DA users (beta = 0.13, 95% CI = 0.02, 0.24) compared to non-users, while it decreased in LD users (beta = -0.26, 95% CI = -0.38, -0.13). We identified three trajectories of average daily DA dose over the follow-up. Patients in the high trajectory gained more weight than patients who never used DA (P = .001) and in the low (P = .02) or moderate (P = .04) trajectories. The incidence of weight gain of ≥6 kg was 2.10-fold (95% CI = 1.03, 4.28) higher in DA users compared to non-users, while LD users were less likely to gain weight (HR = 0.60, 95% CI = 0.33, 1.11). Associations decreased in analyses adjusted for compulsive eating or ICDs.

Conclusion: Weight increased in DA users over 6 years, and DA use was associated with increased incidence of weight gain. These associations were partially explained by compulsive eating. Alternatively, weight decreased in LD users. These findings warrant careful monitoring of compulsive eating and weight in PD patients.
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http://dx.doi.org/10.1016/j.parkreldis.2020.09.037DOI Listing
November 2020

Isolated parkinsonism is an atypical presentation of GRN and C9orf72 gene mutations.

Parkinsonism Relat Disord 2020 11 15;80:73-81. Epub 2020 Sep 15.

Sorbonne Université, Paris Brain Institute - Institut du Cerveau - ICM, Inserm U1127, CNRS UMR 7225, AP-HP - Hôpital Pitié-Salpêtrière, Paris, France; Centre de Référence des Démences Rares ou Précoces, IM2A, Département de Neurologie, AP-HP - Hôpital Pitié-Salpêtrière, Paris, France; Département de Neurologie, AP-HP - Hôpital Pitié-Salpêtrière, Paris, France; Paris Brain Institute - Institut du Cerveau - ICM, FrontLab, Paris, France. Electronic address:

Introduction: A phenotype of isolated parkinsonism mimicking Idiopathic Parkinson's Disease (IPD) is a rare clinical presentation of GRN and C9orf72 mutations, the major genetic causes of frontotemporal dementia (FTD). It still remains controversial if this association is fortuitous or not, and which clinical clues could reliably suggest a genetic FTD etiology in IPD patients. This study aims to describe the clinical characteristics of FTD mutation carriers presenting with IPD phenotype, provide neuropathological evidence of the mutation's causality, and specifically address their "red flags" according to current IPD criteria.

Methods: Seven GRN and C9orf72 carriers with isolated parkinsonism at onset, and three patients from the literature were included in this study. To allow better delineation of their phenotype, the presence of supportive, exclusion and "red flag" features from MDS criteria were analyzed for each case.

Results: Amongst the ten patients (5 GRN, 5 C9orf72), seven fulfilled probable IPD criteria during all the disease course, while behavioral/language or motoneuron dysfunctions occurred later in three. Disease duration was longer and dopa-responsiveness was more sustained in C9orf72 than in GRN carriers. Subtle motor features, cognitive/behavioral changes, family history of dementia/ALS were suggestive clues for a genetic diagnosis. Importantly, neuropathological examination in one patient revealed typical TDP-43-inclusions without alpha-synucleinopathy, thus demonstrating the causal link between FTD mutations, TDP-43-pathology and PD phenotype.

Conclusion: We showed that, altogether, family history of early-onset dementia/ALS, the presence of cognitive/behavioral dysfunction and subtle motor characteristics are atypical features frequently present in the parkinsonian presentations of GRN and C9orf72 mutations.
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http://dx.doi.org/10.1016/j.parkreldis.2020.09.019DOI Listing
November 2020

Spatiotemporal changes in substantia nigra neuromelanin content in Parkinson's disease.

Brain 2020 09;143(9):2757-2770

Institut du Cerveau - ICM,  INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France.

This study aimed to investigate the spatiotemporal changes in neuromelanin-sensitive MRI signal in the substantia nigra and their relation to clinical scores of disease severity in patients with early or progressing Parkinson's disease and patients with idiopathic rapid eye movement sleep behaviour disorder (iRBD) exempt of Parkinsonian signs compared to healthy control subjects. Longitudinal T1-weighted anatomical and neuromelanin-sensitive MRI was performed in two cohorts, including patients with iRBD, patients with early or progressing Parkinson's disease, and control subjects. Based on the aligned substantia nigra segmentations using a study-specific brain anatomical template, parametric maps of the probability of a voxel belonging to the substantia nigra were calculated for patients with various degrees of disease severity and controls. For each voxel in the substantia nigra, probability map of controls, correlations between signal-to-noise ratios on neuromelanin-sensitive MRI in patients with iRBD and Parkinson's disease and clinical scores of motor disability, cognition and mood/behaviour were calculated. Our results showed that in patients, compared to the healthy control subjects, the volume of the substantia nigra was progressively reduced for increasing disease severity. The neuromelanin signal changes appeared to start in the posterolateral motor areas of the substantia nigra and then progressed to more medial areas of this region. The ratio between the volume of the substantia nigra in patients with Parkinson's disease relative to the controls was best fitted by a mono-exponential decay. Based on this model, the pre-symptomatic phase of the disease started at 5.3 years before disease diagnosis, and 23.1% of the substantia nigra volume was lost at the time of diagnosis, which was in line with previous findings using post-mortem histology of the human substantia nigra and radiotracer studies of the human striatum. Voxel-wise patterns of correlation between neuromelanin-sensitive MRI signal-to-noise ratio and motor, cognitive and mood/behavioural clinical scores were localized in distinct regions of the substantia nigra. This localization reflected the functional organization of the nigrostriatal system observed in histological and electrophysiological studies in non-human primates (motor, cognitive and mood/behavioural domains). In conclusion, neuromelanin-sensitive MRI enabled us to assess voxel-wise modifications of substantia nigra's morphology in vivo in humans, including healthy controls, patients with iRBD and patients with Parkinson's disease, and identify their correlation with nigral function across all motor, cognitive and behavioural domains. This insight could help assess disease progression in drug trials of disease modification.
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http://dx.doi.org/10.1093/brain/awaa216DOI Listing
September 2020

Genetic and Phenotypic Basis of Autosomal Dominant Parkinson's Disease in a Large Multi-Center Cohort.

Front Neurol 2020 28;11:682. Epub 2020 Jul 28.

Sorbonne Université, Unité Mixte de Recherche (UMR) 1127, Paris, France.

, and are unequivocally associated with autosomal dominant Parkinson's disease (PD). We evaluated the prevalence of , and mutations and associated clinical features in a large French multi-center cohort of PD patients. Demographic and clinical data were collected for 1,805 index cases (592 with autosomal dominant inheritance and 1,213 isolated cases) since 1990. All probands were screened with TaqMan assays for Gly2019Ser. In the absence of this mutation, the coding sequences of the three genes were analyzed by Sanger sequencing and/or next-generation sequencing. The data for the three genes were analyzed according to age at onset, family history, ethnic origin and clinical features. We identified 160 index cases (8.9%) with known pathogenic variants: 138 with pathogenic variants (7.6%), including 136 with the Gly2019Ser mutation, 19 with point mutations or genomic rearrangements (1.1%), and three with the Asp620Asn mutation (0.16%). Mutation frequencies were higher in familial than isolated cases, consistent with autosomal dominant inheritance (12.0 vs. 7.3%; OR 1.7, 95% CI [1.2-2.4], = 0.001). PD patients with variants were more likely to have higher rates of late-onset PD (>50 years; OR 1.5, 95% CI [1.0-2.1], = 0.03), whereas those with mutations tended to have earlier age at onset disease (≤ 50 years, = 0.06). The clinical features of carriers and those without any pathogenic variants in known PD-associated genes were similar. The likelihood of detecting disease-causing mutations was higher in cases compatible with autosomal dominant inheritance.
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http://dx.doi.org/10.3389/fneur.2020.00682DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7399219PMC
July 2020

Clinical and Demographic Characteristics of Upper Limb Dystonia.

Mov Disord 2020 11 26;35(11):2086-2090. Epub 2020 Aug 26.

Departments of Neurology and Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.

Background: Knowledge of characteristics in upper limb dystonia remains limited, derived primarily from small, single-site studies.

Objective: The objective of this study was to characterize demographic and clinical characteristics of upper limb dystonia from the Dystonia Coalition data set, a large, international, multicenter resource.

Methods: We evaluated clinical and demographic characteristics of 367 participants with upper limb dystonia from onset, comparing across subcategories of focal (with and without dystonia spread) versus nonfocal onset.

Results: Focal onset occurred in 80%; 67% remained focal without spread. Task specificity was most frequent in this subgroup, most often writer's cramp and affecting the dominant limb (83%). Focal onset with spread was more frequent in young onset (<21 years). Focal onset occurred equally in women and men; nonfocal onset affected women disproportionately.

Conclusions: Upper limb dystonia distribution, focality, and task specificity relate to onset age and likelihood of regional spread. Observations may inform clinical counseling and design, execution, and interpretation of future studies. © 2020 International Parkinson and Movement Disorder Society.
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http://dx.doi.org/10.1002/mds.28223DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8350751PMC
November 2020

Interpretation of health-related quality of life outcomes in Parkinson's disease from the EARLYSTIM Study.

PLoS One 2020 21;15(8):e0237498. Epub 2020 Aug 21.

Department of Neurology, University Hospital Bern, University of Bern, Bern, Switzerland.

The EARLYSTIM Study compared deep brain stimulation (DBS) with best medical treatment (BMT) over 2-years, showing a between-group difference of 8.0 from baseline in favor of DBS in health-related quality of life (HRQoL), measured with the PDQ-39 SI (summary index). This study obtained complementary information about the importance of the change in HRQoL as measured by the PDQ-39, using anchor-based (Patient Global Impression of Change, PGIC) and distribution-based techniques (magnitude of change, effect size, thresholds, distribution of benefit) applied to the EARLYSTIM study data. Anchor-based techniques showed a difference follow-up-baseline for patients who reported "minimal improvement" of -5.8 [-9.9, -1.6] (mean [95%CI]) in the DBS group vs -2.9 [-9.0, 3.1] in the BMT group. As the vast majority (80.8%) of DBS patients reported "much or very much improvement", this difference was explored for the latter group and amounted to -8.7 for the DBS group and -6.5 in the BMT group. Distribution-based techniques that analyzed the relative change and treatment effect size showed a moderate benefit of the DBS on the HRQoL, whereas a slight worsening was observed in the BMT group. The change in the DBS group (-7.8) was higher than the MIC (Minimally Important Change) estimated value (-5.8 by the anchor; -6.3 by triangulation of thresholds), but not in the BMT (0.2 vs. -3.0 to -5.4, respectively). Almost 90% of the patients in the DBS group declared some improvement (58.3% and 56.7% beyond the estimated MIC), which was significantly different from the BMT group whose proportions were 32.0% and 30.3%, respectively. The number needed to treat to improve ≥1 MIC by DBS vs BMT was 3.8. Change in depression, disability and pain influenced the improvement of the DBS group. DBS improved HRQoL in a high proportion of patients to a significant and moderate degree, at 2 years follow-up.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237498PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7442251PMC
October 2020

Dissociation in reactive and proactive inhibitory control in Myoclonus dystonia.

Sci Rep 2020 08 18;10(1):13933. Epub 2020 Aug 18.

Sorbonne University, 75005, Paris, France.

Myoclonus-dystonia (MD) is a syndrome characterized by myoclonus of subcortical origin and dystonia, frequently associated with psychiatric comorbidities. The motor and psychiatric phenotypes of this syndrome likely result from cortico-striato-thamalo-cerebellar-cortical pathway dysfunction. We hypothesized that reactive and proactive inhibitory control may be altered in these patients. Using the Stop Signal Task, we assessed reactive and proactive inhibitory control in MD patients with (n = 12) and without (n = 21) deep brain stimulation of the globus pallidus interna and compared their performance to matched healthy controls (n = 24). Reactive inhibition was considered as the ability to stop an already initiated action and measured using the stop signal reaction time. Proactive inhibition was assessed through the influence of several consecutive GO or STOP trials on decreased response time or inhibitory process facilitation. The proactive inhibition was solely impaired in unoperated MD patients. Patients with deep brain stimulation showed impairment in reactive inhibition, independent of presence of obsessive-compulsive disorders. This impairment in reactive inhibitory control correlated with intrinsic severity of myoclonus (i.e. pre-operative score). The results point to a dissociation in reactive and proactive inhibitory control in MD patients with and without deep brain stimulation of the globus pallidus interna.
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http://dx.doi.org/10.1038/s41598-020-70926-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7434767PMC
August 2020
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