Current Overview of Spinocerebellar Ataxia Type 7 in Mexican Population: Challenges in Specialized Care for a Rare Disease.

Spinocerebellar ataxia type 7 (SCA7) is a rare genetic disease characterized by progressive cerebellar syndrome and macular degeneration. In a previous study, we clinically and genetically characterized a group of Mexican patients, which represented one of the largest cohorts of SCA7 patients worldwide and demonstrated that all patients had a unique genetic origin. Our laboratory developed a program for the diagnosis, medical care, and long-term follow-up of these patients living in Veracruz State, and in this report, we present an update to this research, covering 2013 to 2024.

Structural Brain Correlates of Sleep Microstructure in Spinocerebellar Ataxia Type 2 and its Role on Clinical Phenotype.

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.

Serum S100β Levels Are Linked with Cognitive Decline and Peripheral Inflammation in Spinocerebellar Ataxia Type 2.

Experimental and clinical studies have indicated a potential role of the protein S100β 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 S100β in SCA2 and its relationship with molecular, clinical, cognitive, and peripheral inflammatory markers of the disease.

COVID-19 Impacts the Mental Health and Speech Function in Spinocerebellar Ataxia Type 2: Evidences from a Follow-Up Study.

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.

Peripheral Inflammation Links with the Severity of Clinical Phenotype in Spinocerebellar Ataxia 2.

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.

ConvNets for automatic detection of polyglutamine SCAs from brain MRIs: state of the art applications.

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.

An Exploratory Survey on the Care for Ataxic Patients in the American Continents and the Caribbean.

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.

Erythropoietin in Spinocerebellar Ataxia Type 2: Feasibility and Proof-of-Principle Issues from a Randomized Controlled Study.

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.

Convolutional Neural Networks for Segmenting Cerebellar Fissures from Magnetic Resonance Imaging.

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.

Genetic Distribution of Five Spinocerebellar Ataxia Microsatellite Loci in Mexican Native American Populations and Its Impact on Contemporary Mestizo Populations.

Spinocerebellar ataxias (SCAs) conform a heterogeneous group of neurodegenerative disorders with autosomal dominant inheritance. Five of the most frequent SCAs are caused by a CAG repeat expansion in the exons of specific genes. The SCAs incidence and the distribution of polymorphic CAG alleles vary among populations and ethnicities.

Neurophysiological features in spinocerebellar ataxia type 2: Prospects for novel biomarkers.

Electrophysiological biomarkers are useful to assess the degeneration and progression of the nervous system in pre-ataxic and ataxic stages of the Spinocerebellar Ataxia Type 2 (SCA2). These biomarkers are essentially defined by their clinical significance, discriminating patients and/or preclinical subjects from healthy controls in cross-sectional studies, their significant changes over time in longitudinal studies, and their correlation with the cytosine-guanine-adenine (CAG) repeat expansion and/or clinical ataxia scores, time of evolution and time to ataxia onset. We classified electrophysiological biomarkers into three main types: (1) preclinical, (2) disease progression and (3) genetic damage.

Gene Therapy for Polyglutamine Spinocerebellar Ataxias: Advances, Challenges, and Perspectives.

Polyglutamine spinocerebellar ataxias (SCAs) comprise a heterogeneous group of six autosomal dominant ataxias caused by cytosine-adenine-guanine repeat expansions in the coding region of single genes. Currently, there is no curative or disease-slowing treatment for these disorders, but their monogenic inheritance has informed rationales for development of gene therapy strategies. In fact, RNA interference strategies have shown promising findings in cellular and/or animal models of SCA1, SCA3, SCA6, and SCA7.

Gait Variability in Spinocerebellar Ataxia Assessed Using Wearable Inertial Sensors.

Background: Quantitative assessment of severity of ataxia-specific gait impairments from wearable technology could provide sensitive performance outcome measures with high face validity to power clinical trials.

Objectives: The aim of this study was to identify a set of gait measures from body-worn inertial sensors that best discriminate between people with prodromal or manifest spinocerebellar ataxia (SCA) and age-matched, healthy control subjects (HC) and determine how these measures relate to disease severity.

Methods: One hundred and sixty-three people with SCA (subtypes 1, 2, 3, and 6), 42 people with prodromal SCA, and 96 HC wore 6 inertial sensors while performing a natural pace, 2-minute walk.

Cognitive Decline Is Closely Associated with Ataxia Severity in Spinocerebellar Ataxia Type 2: a Validation Study of the Schmahmann Syndrome Scale.

The cerebellar cognitive affective syndrome scale (CCAS-S) was designed to detect specific cognitive dysfunctions in cerebellar patients but is scarcely validated in spinocerebellar ataxias (SCA). The objective of this study is to determine the usefulness of the CCAS-S in a Cuban cohort of SCA2 patients and the relationship of its scores with disease severity. The original scale underwent a forward and backward translation into Spanish language, followed by a pilot study to evaluate its comprehensibility.

Involvement of the Auditory Pathway in Spinocerebellar Ataxia Type 7.

Background: Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant disorder caused by a mutation in the ATXN7 gene. The involvement of the brainstem auditory pathway in pathogenesis of this disease has not been systematically assessed.

Aim: To determine involvement of the brainstem auditory pathway in SCA7 patients and its relationship to clinical features of the disease.

Impacts of the COVID-19 Pandemic on the Mental Health and Motor Deficits in Cuban Patients with Cerebellar Ataxias.

Although there are no convincing evidences of detrimental effect of SARS-CoV2 infection on the cerebellum, the COVID-19 pandemic could impact the life quality of patients with cerebellar ataxias, but few studies have addressed this concern. To assess the motor and mental health changes caused by the COVID-19 pandemics in Cuban patients with cerebellar ataxias, three hundred four patients with cerebellar ataxias and 167 healthy controls were interviewed for risks of exposure to COVID-19, and the self-perception of the pandemics' impact on the disease progression and on the mental health. All subjects underwent the Hospital Anxiety and Depression Scale.

Weight loss is correlated with disease severity in Spinocerebellar ataxia type 2: a cross-sectional cohort study.

Background: Body weight changes occur frequently during advanced stages of Spinocerebellar Ataxia type 2 (SCA2), nevertheless limited information exists on biomarkers of nutritional status of these patients.

Objective.: To assess changes in surrogate nutritional markers of SCA2 patients; to explore their associations with expanded CAG repeats and disease severity.

Prodromal Spinocerebellar Ataxia Type 2 Subjects Have Quantifiable Gait and Postural Sway Deficits.

Background: The search for valid preclinical biomarkers of cerebellar dysfunction is a key research goal for the upcoming era of early interventional approaches in spinocerebellar ataxias. This study aims to describe novel preclinical biomarkers of subtle gait and postural sway abnormalities in prodromal spinocerebellar ataxia type 2 (pre-SCA2).

Methods: Thirty pre-SCA2 patients and their matched healthy controls underwent quantitative assessments of gait and postural sway using a wearable sensor-based system and semiquantitative evaluation of cerebellar features by SARA (Scale for the Assessment and Rating of Ataxia) score.

A hybrid unsupervised-Deep learning tandem for electrooculography time series analysis.

Medical data are often tricky to get mined for patterns even by the generally demonstrated successful modern methodologies of deep learning. This paper puts forward such a medical classification task, where patient registers of two of the categories are sometimes hard to be distinguished because of samples showing characteristics of both labels in turn in several repetitions of the screening procedure. To this end, the current research appoints a pre-processing clustering step (through self-organizing maps) to group the data based on shape similarity and relabel it accordingly.

Features of speech and swallowing dysfunction in pre-ataxic spinocerebellar ataxia type 2.

Objective: To determine whether objective and quantitative assessment of dysarthria and dysphagia in spinocerebellar ataxia type 2 (SCA2), specifically at pre-ataxic and early disease phases, can act as sensitive disease markers.

Methods: Forty-six individuals (16 with pre-ataxic SCA2, 14 with early-stage ataxic SCA2, and 16 healthy controls) were recruited in Holguin, Cuba. All participants underwent a comprehensive battery of assessments including objective acoustic analysis, clinician-derived ratings of speech function and swallowing, and quality of life assessments of swallowing.

EMG Rectification Is Detrimental for Identifying Abnormalities in Corticomuscular and Intermuscular Coherence in Spinocerebellar Ataxia Type 2.

Corticomuscular and intermuscular coherence (CMC, IMC) reflect connectivity between neuronal activity in the motor cortex measured by electroencephalography (EEG) and muscular activity measured by electromyography (EMG), or between activity in different muscles, respectively. There is an ongoing debate on the appropriateness of EMG rectification prior to coherence estimation. This work examines the effects of EMG rectification in CMC and IMC estimation in 20 spinocerebellar ataxia type 2 (SCA2) patients, 16 prodromal SCA2 gene mutation carriers, and 26 healthy controls during a repetitive upper or lower limb motor task.

Automated Detection of Presymptomatic Conditions in Spinocerebellar Ataxia Type 2 Using Monte Carlo Dropout and Deep Neural Network Techniques with Electrooculogram Signals.

Application of deep learning (DL) to the field of healthcare is aiding clinicians to make an accurate diagnosis. DL provides reliable results for image processing and sensor interpretation problems most of the time. However, model uncertainty should also be thoroughly quantified.

Hereditary Ataxias in Cuba: Results and Impact of a Comprehensive, Multidisciplinary Project.

Spinocerebellar ataxia type 2 is a degenerative disease that causes physical disability and, ultimately, prostration and death. Globally, reported prevalence is around 3 cases per 100,000 population and Cuba has the world's highest rates of the disease, affecting both patients and their at-risk descendants. In Holguín Province, which has the country's highest concentration of cases, incidence is 4.

Founder Effects of Spinocerebellar Ataxias in the American Continents and the Caribbean.

Spinocerebellar ataxias (SCAs) comprise a heterogeneous group of autosomal dominant disorders. The relative frequency of the different SCA subtypes varies broadly among different geographical and ethnic groups as result of genetic drifts. This review aims to provide an update regarding SCA founders in the American continents and the Caribbean as well as to discuss characteristics of these populations.