RESUMO

The influence of brain atrophy on sleep microstructure in Spinocerebellar Ataxias (SCAs) has not been extensively explored limiting the use of these sleep traits as surrogate biomarkers of neurodegeneration and clinical phenotype. The objective of the study is to explore the relationship between sleep microstructure and brain atrophy in SCA2 and its role in the clinical phenotype. Fourteen SCA2 mutation carriers (7 pre-manifest and 7 manifest subjects) underwent polysomnographic, structural MRI, and clinical assessments. Particularly, markers of REM and non-REM sleep microstructure, measures of cerebellar and brainstem atrophy, and clinical scores were analyzed through correlation and mediation analyses. The sleep spindle activity exhibited a negative correlation with the number of trials required to complete the verbal memory test (VMT), and a positive correlation with the cerebellar volume, but the significance of the latter correlation did not survive multiple testing corrections. However, the causal mediation analyses unveiled that sleep spindle activity significantly mediates the association between cerebellar atrophy and VMT performance. Regarding REM sleep, both phasic EMG activity and REM sleep without atonia exhibited significant associations with pontine atrophy and disease severity measures. However, they did not demonstrate a causal mediation effect between the atrophy measures and disease severity. Our study provides evidence about the association of the pontocerebellar atrophy with sleep microstructure in SCA2 offering insights into the cerebellar involvement in cognition via the control of the sleep spindle activity. Therefore, our findings may help to understand the disease pathogenesis and to better characterize sleep microstructure parameters as disease biomarkers.Clinical trial registration number (TRN): No applicable.

RESUMO

Experimental and clinical studies have indicated a potential role of the protein S100ß in the pathogenesis and phenotype of neurodegenerative diseases. However, its impact on spinocerebellar ataxia type 2 (SCA2) remains to be elucidated. The objective of the study is to determine the serum levels of S100ß in SCA2 and its relationship with molecular, clinical, cognitive, and peripheral inflammatory markers of the disease. Serum concentrations of S100ß were measured by enzyme-linked immunosorbent assay in 39 SCA2 subjects and 36 age- and gender-matched controls. Clinical scores of ataxia, non-ataxia symptoms, cognitive dysfunction, and some blood cell count-derived inflammatory indices were assessed. The SCA2 individuals manifested S100ß levels similar to the control group, at low nanomolar concentrations. However, the S100ß levels were directly associated with a better performance of cognitive evaluation within the SCA2 cohort. Moreover, the S100ß levels were inversely correlated with most peripheral inflammatory indices. Indeed, the neutrophil-to-lymphocyte ratio significantly mediated the effect of serum S100ß on cognitive performance, even after controlling for the ataxia severity in the causal mediation analysis. Our findings suggested that, within physiologic concentrations, the protein S100ß exerts a neuroprotective role against cognitive dysfunction in SCA2, likely via the suppression of pro-inflammatory mechanisms.

Assuntos

RESUMO

El objetivo del presente estudio consistió en caracterizar la producción científica relacionada con el campo de las ataxias espinocerebelosas, las cuales constituyen enfermedades neurodegenerativas, manifestadas por cuadros clínicos progresivos e invalidantes. La investigación es de tipo censal-documental y recupera metadatos de Scopus, correspondientes a 5654 investigaciones relacionadas con este problema de salud, durante el período 1961-2020. El procesamiento explora las principales características bibliométricas de los documentos publicados, el ritmo de crecimiento, la paternidad de las obras, el impacto por índice de citas, así como las redes de colaboración y la estructura que sigue el flujo del conocimiento. Se observa un despegue notable de la producción científica desde inicios de los años 90 del siglo pasado, coincidiendo con el desarrollo de investigaciones afines en el campo de la genética. También se constata un predominio en el estudio de los tipos SCA1, SCA2, SCA3, SCA6, y SCA17, donde los cuatro primeros corresponden a las ataxias de mayor prevalencia a escala mundial. El corpus documental refleja la consolidación de grupos de investigación relativamente estables, encabezados por líderes científicos y caracterizados por la ampliación sostenida de la colaboración internacional y por el trabajo colectivo e interdisciplinario. También se aprecia la tendencia hacia el aumento del número de referencias dentro de cada documento. Los mayores volúmenes productivos se concentran en países desarrollados, junto a países en vías de desarrollo donde existen elevados niveles de prevalencia en esta enfermedad(AU)

The objective of the present study was to characterize the scientific production related to the field of spinocerebellar ataxias, which constitute neurodegenerative diseases, manifested by progressive and disabling clinical conditions. The research is census-documentary type and recovers metadata from Scopus, corresponding to 5,654 investigations related to this health problem, during the period 1961-2020. The processing explores the main bibliometric characteristics of the published documents, the pace of growth, the authorship of the works, the impact by citation index, as well as the collaboration networks and the structure that follows the flow of knowledge. A notable takeoff in scientific production has been observed since the beginning of the 90s of the last century, coinciding with the development of related research in the field of genetics. There is also a predominance in the study of the types SCA1, SCA2, SCA3, SCA6, and SCA17, where the first four correspond to the most prevalent ataxias worldwide. The documentary corpus reflects the consolidation of relatively stable research groups, headed by scientific leaders and characterized by the sustained expansion of international collaboration and collective and interdisciplinary work. There is also a trend towards increasing the number of references within each document. The largest productive volumes are concentrated in developed countries, along with developing countries where there are high levels of prevalence of this disease(AU)

Assuntos

RESUMO

Limited evidence suggests that the SARS-CoV-2 infection can accelerate the progression of neurodegenerative diseases, but this has been not verified in the spinocerebellar ataxias (SCA). The objective of this study is to assess the impact of COVID-19 on the mental health and motor features of SCA2. A follow-up study was carried out in 170 Cuban SCA2 subjects and 87 community controls between 2020 and 2021. All subjects underwent a structured questionnaire to assess the risks of exposure to COVID-19, the confirmation of COVID-19 diagnosis, and the Hospital Anxiety and Depression Scale (HADS). Moreover, 36 subjects underwent the Scale for the Assessment and Rating of ataxia (SARA). The risk of exposure to SARS-CoV-2 and the frequency of COVID-19 were similar between the ataxia cohort and the community controls. Within the ataxia group, significantly increased HADS scores existed at the 2nd visit in both groups, but this increase was more evident for the infected group regarding the depression score. Moreover, a significant within-group increase of SARA score was observed in the infected group but not the non-infected group, which was mainly mediated by the significant increase of the speech item score in the infected group. Similar results were observed within the subgroup of preclinical carriers. Our study identified no selective vulnerability nor protection to COVID-19 in SCA2, but once infected, the patients experienced a deterioration of mental health and speech function, even at preclinical disease stage. These findings set rationales for tele-health approaches that minimize the detrimental effect of COVID-19 on SCA2 progression and identify SCA2 individuals as clinical model to elucidate the link between SARS-CoV-2 infection and neurodegeneration.

RESUMO

BACKGROUND: The role of peripheral inflammation in spinocerebellar ataxia type 2 (SCA2) is unknown. OBJECTIVE: The objective of this study was to identify peripheral inflammation biomarkers and their relationship with the clinical and molecular features. METHODS: Blood cell count-derived inflammatory indices were measured in 39 SCA2 subjects and their matched controls. Clinical scores of ataxia, nonataxia, and cognitive dysfunction were assessed. RESULTS: The neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), the Systemic Inflammation Index (SII), and the Aggregate Index of Systemic Inflammation (AISI) were significantly increased in SCA2 subjects compared with controls. The increases in PLR, SII, and AISI were even observed in preclinical carriers. NLR, PLR, and SII were correlated with the Scale for the Assessment and Rating of Ataxia speech item score rather than with the total score. The NLR and SII were correlated with the nonataxia and the cognitive scores. CONCLUSIONS: Peripheral inflammatory indices are biomarkers in SCA2, which may help to design future immunomodulatory trials and advance our understanding of the disease. © 2023 International Parkinson and Movement Disorder Society.

Assuntos

RESUMO

Polyglutamine spinocerebellar ataxias (polyQ SCAs) are a group of neurodegenerative diseases, clinically and genetically heterogeneous, characterized by loss of balance and motor coordination due to dysfunction of the cerebellum and its connections. The diagnosis of each type of polyQ SCA, alongside with genetic tests, includes medical images analysis, and its automation may help specialists to distinguish between each type. Convolutional neural networks (ConvNets or CNNs) have been recently used for medical image processing, with outstanding results. In this work, we present the main clinical and imaging features of polyglutamine SCAs, and the basics of CNNs. Finally, we review studies that have used this approach to automatically process brain medical images and may be applied to SCAs detection. We conclude by discussing the possible limitations and opportunities of using ConvNets for SCAs diagnose in the future.

Assuntos

RESUMO

Little is known about access of rare disease carriers to health care. To increase this knowledge, the Pan American Hereditary Ataxia Network (PAHAN) conducted an exploratory survey about care for hereditary ataxias in American continents and the Caribbean. A questionnaire was sent to health professionals about the hereditary ataxias identified; access to care; and local teaching and research. The number of ataxics under current care per 100,000 inhabitants was subtracted from the expected overall prevalence of 6/100,000, to estimate the prevalence of uncovered ataxic patients. Local Human Development Indexes (HDI) were used to measure socio-economic factors. Twenty-six sites participated. Twelve sites had very high, 13 had high, and one site had medium HDI. Participants reported on 2239 and 602 patients with spinocerebellar ataxias and recessive forms under current care. The number of patients under current care per inhabitants varied between 0.14 and 12/100,000. The estimated prevalence of uncovered ataxic patients was inversely proportional to HDIs (rho = 0.665, p = 0.003). Access to diagnosis, pre-symptomatic tests, and rehabilitation were associated with HDIs. More and better molecular diagnostic tools, protocols and guidelines, and professional training for ataxia care were the top priorities common to all respondents. Evidence of inequalities was confirmed. Lower HDIs were associated with high potential numbers of uncovered ataxic subjects, and with lack of molecular diagnosis, pre-symptomatic testing, and rehabilitation. More and better diagnostic tools, guidelines, and professional training were priorities to all sites. PAHAN consortium might help with the last two tasks.

Assuntos

RESUMO

El objetivo del estudio fue caracterizar el potencial investigador cubano en el ámbito de las ataxias y su evolución temporal. Se realizó una búsqueda en la base de datos Web of Science y se obtuvieron todos los documentos publicados entre 1993 y 2020. Se aplicaron indicadores bibliométricos para explorar la producción, dispersión, distribución y crecimiento anual de los documentos (ley de Price, ley de Lotka, índice de transitoriedad y modelo de Bradford). Se calculó el índice de participación y colaboración de países e instituciones y, por cartografía bibliométrica, se exploraron las redes de coocurrencia de los términos más utilizados. La producción científica de Cuba sobre ataxias hereditarias es alta (219 documentos) y se ajusta a un crecimiento lineal (r= 0,7580). El período estudiado concentra el 47,95 por ciento de los registros con un ritmo anual de publicaciones del 6,6 por ciento y tiempo de duplicidad de 10,8 años. El total de citas fue de 3807 (índice medio: 131,27; índice -h: 31). Se concluye que el crecimiento de la literatura científica cubana sobre ataxias fue lineal para el período estudiado, lo que confirma el incumplimiento de la ley de Price de crecimiento de la literatura científica. El estudio también corrobora la importante red de integración y cooperación internacional entre los diferentes autores y la interdisciplinariedad de los trabajos, evidencia del éxito del Centro para la Investigación y Rehabilitación de las Ataxias Hereditarias (CIRAH), al planificar una estrategia de colaboración científica con objetivos definidos(AU)

The objective of this study was to characterize the Cuban research potential in the field of ataxias and its temporal evolution. A search was carried out in the Web of Science database and all the documents published from 1993 to 2020 were retrieved. Bibliometric indicators were applied to explore the production, dispersion, distribution and annual growth of the documents (Price's law, Lotka's law, transience index and Bradford model). The participation and collaboration index of countries and institutions was calculated and, through bibliometric cartography, the co-occurrence networks of the most used terms were explored. The Cuban scientific production on hereditary ataxias is high (219 documents) and it adjusts to a linear growth (r = 0.7580). The period studied concentrates 47.95percent of the records with an annual publication rate of 6.6percent and 10.8 years' duplication time. The total number of citations was 3807 (mean index: 131.27; h-index: 31). Growth of the Cuban scientific literature on ataxias was concluded to be linear for the period studied, which confirms the non-compliance with Price's law of growth of scientific literature. The study also corroborates the important network of integration and international cooperation among the different authors and the interdisciplinarity of the papers, marking the success of the Center for Research and Rehabilitation of Hereditary Ataxias (CIRAH), when planning a strategy of scientific collaboration with objectives defined(AU)

Assuntos

RESUMO

BACKGROUND: Several pieces of evidence have shown the neurotrophic effect of erythropoietin (EPO) and its introduction in the therapeutic practice of neurological diseases. However, its usefulness in the treatment of spinocerebellar ataxia type 2 (SCA2) has not been proven despite the fact that it is endogenously reduced in these patients. OBJECTIVE: The study aims to investigate the safety, tolerability, and clinical effects of a nasally administered recombinant EPO in SCA2 patients. METHODS: Thirty-four patients were enrolled in this double-blind, randomized, placebo-controlled, phase I-II clinical trial of the nasally administered human-recombinant EPO (NeuroEPO) for 6 months. The primary outcome was the change in the spinocerebellar ataxia functional index (SCAFI), while other motor, neuropsychological, and oculomotor measures were assessed. RESULTS: The 6-month changes in SCAFI score were slightly higher in the patients allocated to NeuroEPO treatment than placebo in spite of the important placebo effect observed for this parameter. However, saccade latency was significantly decreased in the NeuroEPO group but not in placebo. The frequency and severity of adverse events were similar between both groups, without evidences of hematopoietic activity of the drug. CONCLUSIONS: This study demonstrated the safety and tolerability of NeuroEPO in SCA2 patients after 6 months of treatments and suggested a small clinical effect of this drug on motor and cognitive abnormalities, but confirmatory studies are warranted. © 2022 International Parkinson and Movement Disorder Society.

Assuntos

RESUMO

The human cerebellum plays an important role in coordination tasks. Diseases such as spinocerebellar ataxias tend to cause severe damage to the cerebellum, leading patients to a progressive loss of motor coordination. The detection of such damages can help specialists to approximate the state of the disease, as well as to perform statistical analysis, in order to propose treatment therapies for the patients. Manual segmentation of such patterns from magnetic resonance imaging is a very difficult and time-consuming task, and is not a viable solution if the number of images to process is relatively large. In recent years, deep learning techniques such as convolutional neural networks (CNNs or convnets) have experienced an increased development, and many researchers have used them to automatically segment medical images. In this research, we propose the use of convolutional neural networks for automatically segmenting the cerebellar fissures from brain magnetic resonance imaging. Three models are presented, based on the same CNN architecture, for obtaining three different binary masks: fissures, cerebellum with fissures, and cerebellum without fissures. The models perform well in terms of precision and efficiency. Evaluation results show that convnets can be trained for such purposes, and could be considered as additional tools in the diagnosis and characterization of neurodegenerative diseases.

Assuntos