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1.
Hum Brain Mapp ; 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33410575

RESUMO

Several diffusion tensor imaging studies reveal that white matter (WM) lesions are common in children suffering from benign cerebellar tumours who are treated with surgery only. The clinical implications of WM alterations that occur as a direct consequence of cerebellar disease have not been thoroughly studied. Here, we analysed structural and diffusion imaging data from cerebellar patients with chronic surgical lesions after resection for benign cerebellar tumours. We aimed to elucidate the impact of focal lesions of the cerebellum on WM integrity across the entire brain, and to investigate whether WM deficits were associated with behavioural impairment in three different motor tasks. Lesion symptom mapping analysis suggested that lesions in critical cerebellar regions were related to deficits in savings during an eyeblink conditioning task, as well as to deficits in motor action timing. Diffusion imaging analysis of cerebellar WM indicated that better behavioural performance was associated with higher fractional anisotropy (FA) in the superior cerebellar peduncle, cerebellum's main outflow path. Moreover, voxel-wise analysis revealed a global pattern of WM deficits in patients within many cerebral WM tracts critical for motor and non-motor function. Finally, we observed a positive correlation between FA and savings within cerebello-thalamo-cortical pathways in patients but not in controls, showing that saving effects partly depend on extracerebellar areas, and may be recruited for compensation. These results confirm that the cerebellum has extended connections with many cerebral areas involved in motor/cognitive functions, and the observed WM changes likely contribute to long-term clinical deficits of posterior fossa tumour survivors.

2.
Neurology ; 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33495376

RESUMO

OBJECTIVE: To delineate the full phenotypic spectrum, discriminative features, piloting longitudinal progression data, and sample size calculations of RFC1-repeat expansions, recently identified as causing cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS). METHODS: Multimodal RFC1 repeat screening (PCR, southern blot, whole-exome/genome (WES/WGS)-based approaches) combined with cross-sectional and longitudinal deep-phenotyping in (i) cross-European cohort A (70 families) with ≥2 features of CANVAS and/or ataxia-with-chronic-cough (ACC); and (ii) Turkish cohort B (105 families) with unselected late-onset ataxia. RESULTS: Prevalence of RFC1-disease was 67% in cohort A, 14% in unselected cohort B, 68% in clinical CANVAS, and 100% in ACC. RFC1-disease was also identified in Western and Eastern Asians, and even by WES. Visual compensation, sensory symptoms, and cough were strong positive discriminative predictors (>90%) against RFC1-negative patients. The phenotype across 70 RFC1-positive patients was mostly multisystemic (69%), including dysautonomia (62%) and bradykinesia (28%) (=overlap with cerebellar-type multiple system atrophy [MSA-C]), postural instability (49%), slow vertical saccades (17%), and chorea and/or dystonia (11%). Ataxia progression was ∼1.3 SARA points/year (32 cross-sectional, 17 longitudinal assessments, follow-up ≤9 years [mean 3.1]), but also included early falls, variable non-linear phases of MSA-C-like progression (SARA 2.5-5.5/year), and premature death. Treatment trials require 330 (1-year-trial) and 132 (2-year-trial) patients in total to detect 50% reduced progression. CONCLUSIONS: RFC1-disease is frequent and occurs across continents, with CANVAS and ACC as highly diagnostic phenotypes, yet as variable, overlapping clusters along a continuous multisystemic disease spectrum, including MSA-C-overlap. Our natural history data help to inform future RFC1-treatment trials. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that RFC1-repeat expansions are associated with CANVAS and ACC.

4.
eNeuro ; 7(5)2020.
Artigo em Inglês | MEDLINE | ID: mdl-32883706

RESUMO

Inhibition of the amygdala slows down acquisition of conditioned eyeblink responses (CRs). Based on the two-stage or two-factor theory of aversive conditioning, amygdala-dependent conditioned fear is a necessary prerequisite to acquire eyeblink CRs but is no longer needed after eyeblink CRs are attained. According to the sensory gating hypothesis of the amygdala, on the other hand, the amygdala modulates the salience of unconditioned stimuli (USs) and conditioned stimuli (CSs) in eyeblink conditioning. We tested these two opposing assumptions in five groups of 20 young and healthy men. On day 1, three groups underwent fear acquisition training followed by acquisition of eyeblink CRs. On the next day (day 2), extinction was tested. In group 1, fear and eyeblink extinction trials overlapped; in group 2, fear and eyeblink extinction trials alternated; and in group 3, fear extinction trials were followed by eyeblink extinction trials. Groups 4 and 5 were control conditions testing fear and eyeblink conditioning only. Preceding fear acquisition training facilitated acquisition of conditioned eyeblinks. Concomitant fear extinction impeded extinction of eyeblink CRs, which was accompanied by increased autonomic responses. Fear extinction, however, was not significantly altered by concomitant eyeblink extinction. Recall of fear CRs on day 2 was facilitated in group 1, suggesting additive response summation. Findings are difficult to explain with the two-stage theory of aversive conditioning, which predicts the suppression of conditioned fear once conditioned eyeblinks are acquired. Facilitated acquisition and impeded extinction of eyeblink CRs, however, are in accordance with the sensory-gating hypothesis of the amygdala.

5.
Lancet Neurol ; 19(9): 738-747, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32822634

RESUMO

BACKGROUND: Spinocerebellar ataxias (SCAs) are autosomal dominant neurodegenerative diseases. Our aim was to study the conversion to manifest ataxia among apparently healthy carriers of mutations associated with the most common SCAs (SCA1, SCA2, SCA3, and SCA6), and the sensitivity of clinical and functional measures to detect change in these individuals. METHODS: In this prospective, longitudinal, observational cohort study, based at 14 referral centres in seven European countries, we enrolled children or siblings of patients with SCA1, SCA2, SCA3, or SCA6. Eligible individuals were those without ataxia, defined by a score on the Scale for the Assessment and Rating of Ataxia (SARA) of less than 3; participants had to be aged 18-50 years for children or siblings of patients with SCA1, SCA2, or SCA3, and 35-70 years for children or siblings of patients with SCA6. Study visits took place at recruitment and after 2, 4, and 6 years (plus or minus 3 months). We did genetic testing to identify mutation carriers, with results concealed to the participant and clinical investigator. We assessed patients with clinical scales, questionnaires of patient-reported outcome measures, a rating of the examiner's confidence of presence of ataxia, and performance-based coordination tests. Conversion to ataxia was defined by an SARA score of 3 or higher. We analysed the association of factors at baseline with conversion to ataxia and the evolution of outcome parameters on temporal scales (time from inclusion and time to predicted age at ataxia onset) in the context of mutation status and conversion status. This study is registered with ClinicalTrials.gov, NCT01037777. FINDINGS: Between Sept 13, 2008, and Oct 28, 2015, 302 participants were enrolled. We analysed data for 252 participants with at least one follow-up visit. 83 (33%) participants were from families affected by SCA1, 99 (39%) by SCA2, 46 (18%) by SCA3, and 24 (10%) by SCA6. In participants who carried SCA mutations, 26 (52%) of 50 SCA1 carriers, 22 (59%) of 37 SCA2 carriers, 11 (42%) of 26 SCA3 carriers, and two (13%) of 15 SCA6 carriers converted to ataxia. One (3%) of 33 SCA1 non-carriers and one (2%) of 62 SCA2 non-carriers converted to ataxia. Owing to the small number of people who met our criteria for ataxia, subsequent analyses could not be done in carriers of the SCA6 mutation. Baseline factors associated with conversion were age (hazard ratio 1·13 [95% CI 1·03-1·24]; p=0·011), CAG repeat length (1·25 [1·11-1·41]; p=0·0002), and ataxia confidence rating (1·72 [1·23-2·41]; p=0·0015) for SCA1; age (1·08 [1·02-1·14]; p=0·0077) and CAG repeat length (1·65 [1·27-2·13]; p=0·0001) for SCA2; and age (1·27 [1·09-1·50]; p=0·0031), confidence rating (2·60 [1·23-5·47]; p=0·012), and double vision (14·83 [2·15-102·44]; p=0·0063) for SCA3. From the time of inclusion, the SARA scores of SCA1, SCA2, and SCA3 mutation carriers increased, whereas they remained stable in non-carriers. On a timescale defined by the predicted time of ataxia onset, SARA progression in SCA1, SCA2, and SCA3 mutation carriers was non-linear, with marginal progression before ataxia and increasing progression after ataxia onset. INTERPRETATION: Our study provides quantitative data on the conversion of non-ataxic SCA1, SCA2, and SCA3 mutation carriers to manifest ataxia. Our data could prove useful for the design of preventive trials aimed at delaying the onset of ataxia by aiding sample size calculations and stratification of study participants. FUNDING: European Research Area Network for Research Programmes on Rare Diseases, Polish Ministry of Science and Higher Education, Italian Ministry of Health, European Community's Seventh Framework Programme.


Assuntos
Progressão da Doença , Mutação/genética , Ataxias Espinocerebelares/diagnóstico por imagem , Ataxias Espinocerebelares/genética , Adulto , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Adulto Jovem
6.
Neurology ; 95(9): e1199-e1210, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32611635

RESUMO

OBJECTIVES: With disease-modifying drugs on the horizon for degenerative ataxias, ecologically valid motor biomarkers are highly warranted. In this observational study, we aimed to unravel and validate markers of ataxic gait in real life by using wearable sensors. METHODS: We assessed gait characteristics of 43 patients with degenerative cerebellar disease (Scale for the Assessment and Rating of Ataxia [SARA] 9.4 ± 3.9) compared with 35 controls by 3 body-worn inertial sensors in 3 conditions: (1) laboratory-based walking; (2) supervised free walking; (3) real-life walking during everyday living (subgroup n = 21). Movement analysis focused on measures of spatiotemporal step variability and movement smoothness. RESULTS: A set of gait variability measures was identified that allowed us to consistently identify ataxic gait changes in all 3 conditions. Lateral step deviation and a compound measure of spatial step variability categorized patients vs controls with a discrimination accuracy of 0.86 in real life. Both were highly correlated with clinical ataxia severity (effect size ρ = 0.76). These measures allowed detecting group differences even for patients who differed only 1 point in the clinical SARAposture&gait subscore, with highest effect sizes for real-life walking (d = 0.67). CONCLUSIONS: We identified measures of ataxic gait that allowed us not only to capture the gait variability inherent in ataxic gait in real life, but also to demonstrate high sensitivity to small differences in disease severity, with the highest effect sizes in real-life walking. They thus represent promising candidates for motor markers for natural history and treatment trials in ecologically valid contexts. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that a set of gait variability measures, even if accessed in real life, correlated with the clinical severity of ataxia in patients with degenerative cerebellar disease.


Assuntos
Análise da Marcha/métodos , Ataxias Espinocerebelares/fisiopatologia , Dispositivos Eletrônicos Vestíveis , Adulto , Idoso , Ataxia Telangiectasia/fisiopatologia , Feminino , Análise da Marcha/instrumentação , Humanos , Masculino , Pessoa de Meia-Idade , Equilíbrio Postural , Índice de Gravidade de Doença , Caminhada , Adulto Jovem
7.
Neurobiol Learn Mem ; 169: 107185, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32061996

RESUMO

In the present study extinction and renewal of cognitive associations were assessed in two experiments in participants with focal and degenerative cerebellar disease. Using a predictive learning task, participants had to learn by trial and error the relationships between food items and the occurrence of stomach trouble in a hypothetical patient. In the first experiment, focus was on renewal effects. Participants with chronic cerebellar stroke (n = 14; mean age 50.9 ± 12 years), participants with degenerative cerebellar disease (n = 16; mean age 58 ± 12 years), age-, sex-, and education matched controls (n = 20; mean age 53.7 ± 10.8 years) and young controls (n = 19; mean age 23.2 ± 2.7 years) were tested. Acquisition and extinction of food-stomach trouble associations took part in two different contexts (represented by restaurants). In a subsequent test phase, food stimuli were presented in both contexts and no feedback was given. This allowed testing for renewal of the initially acquired associations in the acquisition context. Acquisition and extinction learning were not significantly different between groups. Significant renewal effects were present in young controls only. In the second experiment, focus was on extinction. To control for age effects, 19 young participants with chronic surgical lesions of the cerebellum (mean age 25.6 ± 6.1 years), and 24 age-, sex- and education-matched healthy controls were tested. Acquisition and extinction of food-stomach trouble associations took part in the same context. In the extinction phase, the relationship with stomach trouble was reversed in some of the food items. Acquisition and extinction learning were not significantly different between groups. The main finding of the present study was preserved extinction of learned cognitive associations in participants with chronic cerebellar disease. Findings agree with previous observations in the literature that cognitive abnormalities are frequently absent or weak in adults with cerebellar disease. This does not exclude a contribution of the cerebellum to extinction of learned associations. For example, findings may be different in more challenging cognitive tasks, and in participants with acute cerebellar disease with no time for compensation.

9.
Sci Rep ; 10(1): 22434, 2020 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-33384434

RESUMO

Cerebellar transcranial direct current stimulation (tDCS) has been reported to enhance the acquisition of conditioned eyeblink responses (CR), a form of associative motor learning. The aim of the present study was to determine possible long-term effects of cerebellar tDCS on the acquisition and extinction of CRs. Delay eyeblink conditioning was performed in 40 young and healthy human participants. On day 1, 100 paired CS (conditioned stimulus)-US (unconditioned stimulus) trials were applied. During the first 50 paired CS-US trials, 20 participants received anodal cerebellar tDCS, and 20 participants received sham stimulation. On days 2, 8 and 29, 50 paired CS-US trials were applied, followed by 30 CS-only extinction trials on day 29. CR acquisition was not significantly different between anodal and sham groups. During extinction, CR incidences were significantly reduced in the anodal group compared to sham, indicating reduced retention. In the anodal group, learning related increase of CR magnitude tended to be reduced, and timing of CRs tended to be delayed. The present data do not confirm previous findings of enhanced acquisition of CRs induced by anodal cerebellar tDCS. Rather, the present findings suggest a detrimental effect of anodal cerebellar tDCS on CR retention and possibly CR performance.

10.
Elife ; 82019 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-31464686

RESUMO

Prediction errors are thought to drive associative fear learning. Surprisingly little is known about the possible contribution of the cerebellum. To address this question, healthy participants underwent a differential fear conditioning paradigm during 7T magnetic resonance imaging. An event-related design allowed us to separate cerebellar fMRI signals related to the visual conditioned stimulus (CS) from signals related to the subsequent unconditioned stimulus (US; an aversive electric shock). We found significant activation of cerebellar lobules Crus I and VI bilaterally related to the CS+ compared to the CS-. Most importantly, significant activation of lobules Crus I and VI was also present during the unexpected omission of the US in unreinforced CS+ acquisition trials. This activation disappeared during extinction when US omission became expected. These findings provide evidence that the cerebellum has to be added to the neural network processing predictions and prediction errors in the emotional domain.


Assuntos
Antecipação Psicológica , Cerebelo/fisiologia , Medo , Adulto , Mapeamento Encefálico , Condicionamento Clássico , Feminino , Voluntários Saudáveis , Humanos , Imagem por Ressonância Magnética , Masculino , Adulto Jovem
11.
Cerebellum ; 18(6): 1064-1097, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31165428

RESUMO

The cerebellum is best known for its role in controlling motor behaviors. However, recent work supports the view that it also influences non-motor behaviors. The contribution of the cerebellum towards different brain functions is underscored by its involvement in a diverse and increasing number of neurological and neuropsychiatric conditions including ataxia, dystonia, essential tremor, Parkinson's disease (PD), epilepsy, stroke, multiple sclerosis, autism spectrum disorders, dyslexia, attention deficit hyperactivity disorder (ADHD), and schizophrenia. Although there are no cures for these conditions, cerebellar stimulation is quickly gaining attention for symptomatic alleviation, as cerebellar circuitry has arisen as a promising target for invasive and non-invasive neuromodulation. This consensus paper brings together experts from the fields of neurophysiology, neurology, and neurosurgery to discuss recent efforts in using the cerebellum as a therapeutic intervention. We report on the most advanced techniques for manipulating cerebellar circuits in humans and animal models and define key hurdles and questions for moving forward.


Assuntos
Cerebelo/fisiologia , Consenso , Estimulação Encefálica Profunda/métodos , Modelos Animais , Animais , Cerebelo/citologia , Estimulação Encefálica Profunda/tendências , Humanos
12.
Mov Disord ; 34(8): 1220-1227, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31211461

RESUMO

BACKGROUND: Spinocerebellar ataxias are rare dominantly inherited neurodegenerative diseases that lead to severe disability and premature death. OBJECTIVE: To quantify the impact of disease progression measured by the Scale for the Assessment and Rating of Ataxia on survival, and to identify different profiles of disease progression and survival. METHODS: Four hundred sixty-two spinocerebellar ataxia patients from the EUROSCA prospective cohort study, suffering from spinocerebellar ataxia type 1, spinocerebellar ataxia type 2, spinocerebellar ataxia type 3, and spinocerebellar ataxia type 6, and who had at least two measurements of Scale for the Assessment and Rating of Ataxia score, were analyzed. Outcomes were change over time in Scale for the Assessment and Rating of Ataxia score and time to death. Joint model was used to analyze disease progression and survival. RESULTS: Disease progression was the strongest predictor for death in all genotypes: An increase of 1 standard deviation in total Scale for the Assessment and Rating of Ataxia score increased the risk of death by 1.28 times (95% confidence interval: 1.18-1.38) for patients with spinocerebellar ataxia type 1; 1.19 times (1.12-1.26) for spinocerebellar ataxia type 2; 1.30 times (1.19-1.42) for spinocerebellar ataxia type 3; and 1.26 times (1.11-1.43) for spinocerebellar ataxia type 6. Three subgroups of disease progression and survival were identified for patients with spinocerebellar ataxia type 1: "severe" (n = 13; 12%), "intermediate" (n = 31; 29%), and "moderate" (n = 62; 58%). Patients in the severe group were more severely affected at baseline with higher Scale for the Assessment and Rating of Ataxia scores and frequency of nonataxia signs compared to those in the other groups. CONCLUSION: Rapid ataxia progression is associated with poor survival of the most common spinocerebellar ataxia. Theses current results have implications for the design of future interventional studies of spinocerebellar ataxia. © 2019 International Parkinson and Movement Disorder Society.


Assuntos
Ataxias Espinocerebelares/mortalidade , Ataxias Espinocerebelares/fisiopatologia , Adulto , Idoso , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/fisiopatologia , Estudos de Coortes , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/fisiopatologia , Progressão da Doença , Distonia/etiologia , Distonia/fisiopatologia , Feminino , Humanos , Estudos Longitudinais , Doença de Machado-Joseph/complicações , Doença de Machado-Joseph/mortalidade , Doença de Machado-Joseph/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Ataxias Espinocerebelares/complicações , Taxa de Sobrevida , Fatores de Tempo
13.
Brain Stimul ; 12(5): 1177-1186, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31040077

RESUMO

BACKGROUND: Cerebellar transcranial direct current stimulation (ctDCS) is increasingly used to modulate cerebellar excitability and plasticity in healthy subjects and various patient populations. ctDCS parameters are poorly standardized, and its physiology remains little understood. Our aim was to compare the physiological effects of three different non-target electrode positions (buccinator muscle, supraorbital region, deltoid muscle). METHODS: In the first experiment, physiological after-effects of ctDCS were compared based on cerebellar-brain inhibition (CBI) in a group of 15 healthy right-handed participants. In the second experiment, CBI after-effects of ctDCS were assessed using different transcranial magnetic stimulation (TMS) intensities in 14 participants (CBI recruitment curve). The electric field distribution was calculated for each of the electrode montages based on a single anatomically accurate head model. RESULTS: Anodal and cathodal ctDCS polarities significantly decreased cerebellar-brain inhibition (CBI) with no substantial differences between the montages. Lower cerebellar TMS intensities resulted in decreased CBI following cathodal and increased CBI after anodal ctDCS. Computational modeling revealed minor differences in the electric field distribution between non-target electrode positions based on the effect size. CONCLUSION: Our results show that the non-target electrode position has no significant impact on modeling results and physiological ctDCS after-effects. The recruitment of the cerebellar-M1 connection, however, varied depending on ctDCS polarity and cerebellar transcranial magnetic stimulation intensity, possibly due to diverse effects on different cell populations in the cerebellar cortex. This may be one of the reasons why ctDCS effects on functional measures are difficult to predict.


Assuntos
Cerebelo/fisiologia , Inibição Neural/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto , Feminino , Humanos , Masculino , Distribuição Aleatória , Adulto Jovem
14.
Brain Stimul ; 12(5): 1169-1176, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30987860

RESUMO

BACKGROUND: In a seminal paper, Galea et al. (Modulation of cerebellar excitability by polarity-specific noninvasive direct current stimulation. 2009. J Neurosci 29, 9115-9122) showed that cerebellar transcranial direct current stimulation (ctDCS) alters cerebellar-M1 connectivity. This effect has been explained by ctDCS-related changes of excitability of the cerebellar cortex with consecutive modulation of its main output, the dentate-thalamo-cortical pathway. OBJECTIVES: The aim of this functional magnetic resonance imaging (fMRI) study was to provide evidence that cathodal ctDCS decreases the activity of the cerebellar cortex, resulting in increased activity of the cerebellar nuclei, whereas anodal ctDCS has the opposite effect. METHODS: A total of 48 participants (female/male: 23/25, age: 23.8 ±â€¯4.1yrs., mean ±â€¯standard deviation) performed a finger tapping task with the right hand in a 3T MRI scanner. Functional MR images were acquired prior, during and after tDCS of the right cerebellum. Participants were assigned randomly to anodal, cathodal or sham ctDCS. RESULTS: No significant difference of cerebellar cortical activation was found after comparing the three modes of stimulation. On the level of the dentate nuclei, however, a significant increase of activation was detected during and after cathodal stimulation. Furthermore, dentate nuclei activation was suppressed on a trend level following anodal stimulation. CONCLUSIONS: The present findings support the hypothesis that cathodal ctDCS leads to a disinhibition of the dentate nucleus, whereas anodal ctDCS may have the opposite effect.


Assuntos
Cerebelo/diagnóstico por imagem , Cerebelo/fisiologia , Imagem por Ressonância Magnética/métodos , Destreza Motora/fisiologia , Desempenho Psicomotor/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto , Córtex Cerebelar/diagnóstico por imagem , Córtex Cerebelar/fisiologia , Núcleos Cerebelares/diagnóstico por imagem , Núcleos Cerebelares/fisiologia , Feminino , Humanos , Masculino , Adulto Jovem
15.
J Neurol ; 266(5): 1260-1266, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30840144

RESUMO

We aimed to provide proof-of-principle evidence that intensive home-based speech treatment can improve dysarthria in complex multisystemic degenerative ataxias, exemplified by autosomal recessive spastic ataxia Charlevoix-Saguenay (ARSACS). Feasibility and piloting efficacy of speech training specifically tailored to cerebellar dysarthria was examined through a 4-week program in seven patients with rater-blinded assessment of intelligibility (primary outcome) and naturalness and acoustic measures of speech (secondary outcomes) performed 4 weeks before, immediately prior to, and directly after training (intraindividual control design). Speech intelligibility and naturalness improved post treatment. This provides piloting evidence that ataxia-tailored speech treatment might be effective in degenerative cerebellar disease.


Assuntos
Disartria/etiologia , Disartria/reabilitação , Espasticidade Muscular/complicações , Fonoterapia/métodos , Ataxias Espinocerebelares/congênito , Retroalimentação Sensorial/fisiologia , Feminino , Humanos , Masculino , Avaliação de Resultados em Cuidados de Saúde , Projetos Piloto , Ataxias Espinocerebelares/complicações , Estatísticas não Paramétricas
17.
Nervenarzt ; 90(2): 197-210, 2019 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-30645659

RESUMO

Rare genetic movement disorders are a heterogeneous group of diseases. The causes of many of these rare movement disorders could be resolved due to the progress in molecular genetic diagnostics. This led to a better pathophysiological characterization of rare movement disorders and also to the fact that many phenotypical overlaps could be found between different diseases. The classification of genetic results requires a close cooperation between neurologists and geneticists. Therefore, modern diagnostic procedures cannot replace the clinical classification of genetic movement disorders and the exact patient history. This article provides the reader with an overview of the most important groups of genetic movement disorders. Genetic Parkinson syndromes, dystonia, essential tremor, genetic chorea, cerebellar ataxia and hereditary spastic paraplegia are dealt with in detail. For a better understanding individual genetic terms are explained and differences in molecular genetic diagnostics are presented.


Assuntos
Transtornos dos Movimentos , Humanos , Transtornos dos Movimentos/diagnóstico , Transtornos dos Movimentos/genética
18.
Neurol Genet ; 5(6): e369, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32042905

RESUMO

Objective: To determine the clinical, radiologic, and molecular characteristics of RNA polymerase III-related leukodystrophy (POLR3-HLD) caused by biallelic POLR1C pathogenic variants. Methods: A cross-sectional observational study involving 25 centers worldwide was conducted. Clinical and molecular information was collected on 23 unreported and previously reported patients with POLR3-HLD and biallelic pathogenic variants in POLR1C. Brain MRI studies were reviewed. Results: Fourteen female and 9 male patients aged 7 days to 23 years were included in the study. Most participants presented early in life (birth to 6 years), and motor deterioration was seen during childhood. A notable proportion of patients required a wheelchair before adolescence, suggesting a more severe phenotype than previously described in POLR3-HLD. Dental, ocular, and endocrine features were not invariably present (70%, 50%, and 50%, respectively). Five patients (22%) had a combination of hypomyelinating leukodystrophy and abnormal craniofacial development, including 1 individual with clear Treacher Collins syndrome (TCS) features. Brain MRI revealed hypomyelination in all cases, often with areas of pronounced T2 hyperintensity corresponding to T1 hypointensity of the white matter. Twenty-nine different pathogenic variants (including 12 new disease-causing variants) in POLR1C were identified. Conclusions: This study provides a comprehensive description of POLR3-HLD caused by biallelic POLR1C pathogenic variants based on the largest cohort of patients to date. These results suggest distinct characteristics of POLR1C-related disorder, with a spectrum of clinical involvement characterized by hypomyelinating leukodystrophy with or without abnormal craniofacial development reminiscent of TCS.

19.
Cerebellum ; 18(1): 67-75, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29916048

RESUMO

The cerebellum and the prefrontal cortex are assumed to play a role in the pathophysiology of essential tremor (ET). Trace eyeblink conditioning with a long interstimulus interval relies on an intact function of the hippocampus, prefrontal cortex (PFC), and, although marginally, of the cerebellum. The aim of the present study was to evaluate whether long trace eyeblink conditioning is impaired in patients with ET. In 18 patients with ET and 18 controls, a long trace conditioning paradigm was applied. Following 100 paired conditioned response-unconditioned response trials, 30 conditioned response alone trials were given as extinction trials. The degree of tremor and the presence of accompanying cerebellar signs were determined based on clinical scales. The acquisition of conditioned eyeblink responses was not impaired in the group of all patients compared to controls (mean total incidences of conditioned responses in patients 23.3 ± 14.5%, in controls 24.1 ± 13.9%; P = 0.88). In the subgroup of six patients with cerebellar signs, incidences of conditioned responses were numerically but not significantly lower (16.4 ± 9.9%) compared to patients without cerebellar signs (26.8 ± 15.5%; P = 0.16). Trace eyeblink conditioning with a long interstimulus interval was not impaired in subjects with ET. Patients with clinical cerebellar signs presented slightly reduced conditioning. Areas of the PFC contributing to trace eyeblink conditioning appear less affected in ET. Future studies also using a shorter trace interval should include a larger group of subjects in all stages of ET.


Assuntos
Condicionamento Palpebral , Tremor Essencial/fisiopatologia , Adulto , Idoso , Aprendizagem por Associação/fisiologia , Condicionamento Palpebral/fisiologia , Tremor Essencial/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
20.
Cerebellum ; 18(2): 166-177, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30155831

RESUMO

Extinction of conditioned aversive responses (CR) has been shown to be context-dependent. The hippocampus and prefrontal cortex are of particular importance. The cerebellum may contribute to context-related processes because of its known connections with the hippocampus and prefrontal cortex. Context dependency of extinction can be demonstrated by the renewal effect. When CR acquisition takes place in context A and is extinguished in context B, renewal refers to the recovery of the CR in context A (A-B-A paradigm). In the present study acquisition, extinction and renewal of classically conditioned eyeblink responses were tested in 18 patients with subacute focal cerebellar lesions and 18 age- and sex-matched healthy controls. Standard delay eyeblink conditioning was performed using an A-B-A paradigm. All cerebellar patients underwent a high-resolution T1-weighted brain MRI scan to perform lesion-symptom mapping. CR acquisition was not significantly different between cerebellar and control participants allowing to draw conclusions on extinction. CR extinction was significantly less in cerebellar patients. Reduction of CR extinction tended to be more likely in patients with lesions in the lateral parts of lobule VI and Crus I. A significant renewal effect was present in controls only. The present data provide further evidence that the cerebellum contributes to extinction of conditioned eyeblink responses. Because acquisition was preserved and extinction took place in another context than acquisition, more lateral parts of the cerebellar hemisphere may contribute to context-related processes. Furthermore, lack of renewal in cerebellar patients suggest a contribution of the cerebellum to context-related processes.


Assuntos
Doenças Cerebelares/fisiopatologia , Condicionamento Palpebral/fisiologia , Extinção Psicológica , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Cerebelares/diagnóstico por imagem , Doenças Cerebelares/psicologia , Extinção Psicológica/fisiologia , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Adulto Jovem
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