Publications by authors named "Jeremy D Schmahmann"

Objective, sensitive, and meaningful disease assessments are critical to support clinical trials and clinical care. Speech changes are one of the earliest and most evident manifestations of cerebellar ataxias. This work aims to develop models that can accurately identify and quantify clinical signs of ataxic speech.

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A significant barrier to developing disease-modifying therapies for spinocerebellar ataxias (SCAs) and multiple system atrophy of the cerebellar type (MSA-C) is the scarcity of tools to sensitively measure disease progression in clinical trials. Wearable sensors worn continuously during natural behavior at home have the potential to produce ecologically valid and precise measures of motor function by leveraging frequent and numerous high-resolution samples of behavior. Here we test whether movement-building block characteristics (i.

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Scientific interest in the cerebellum has surged in the last few decades with an emerging consensus on a multifaceted functionality and intricate, but not yet fully understood, functional topography over the cerebellar cortex. To further refine this structure-function relationship and quantify its inter-subject variability, a high-resolution digital anatomical atlas is fundamental. Using a combination of manual labeling and image processing, we turned a recently published reconstruction of the human cerebellum, the first such reconstruction fine enough to resolve the individual folia, into a digital atlas with both surface and volumetric representations.

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Article Synopsis
  • Clinical trials for spinocerebellar ataxias (SCA) need better endpoints to measure early disease progression and effectiveness of treatments, as current measures focus on later stages.
  • The READISCA consortium found that advanced multimodal magnetic resonance imaging (MRI) can track changes in brain structure and function over 6 months in participants with early-stage SCA mutations, indicating disease progression.
  • Results showed significant differences in microstructural changes between SCA patients and controls, suggesting that diffusion MRI could reduce the sample size needed for future trials compared to traditional assessments like the Scale for Assessment and Rating of Ataxia (SARA).
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The human cerebellum is increasingly recognized to be involved in nonmotor and higher-order cognitive functions. Yet, its ties with the entire cerebral cortex have not been holistically studied in a whole brain exploration with a unified analytical framework. Here, we characterized dissociable cortical-cerebellar structural covariation patterns based on regional gray matter volume (GMV) across the brain in = 38,527 UK Biobank participants.

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Background And Purpose: Individuals with downbeat nystagmus (DBN) syndrome present with DBN, dizziness, blurred vision, and unsteady gait. Pharmacological intervention with 4-aminopyridine (4-AP) may be effective in improving oculomotor function, but there is minimal evidence to date that it improves gait. This suggests the possible benefit of combining pharmacotherapy with physical therapy to maximize outcomes.

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  • The Scale for Assessment and Rating of Ataxia (SARA) is a key clinical tool for evaluating cerebellar ataxia but has received criticism regarding the relevance of its assessment items.
  • A study involving 850 patients across different types of spinocerebellar ataxias (SCA1, SCA2, SCA3, SCA6) revealed significant differences in progression rates among cohorts, particularly with the EUROSCA cohort showing the fastest rates.
  • The analysis found that not all items on the SARA scale contribute equally to measuring ataxia severity, and while some items are more sensitive to changes early or late in the disease, overall adjustments to the scale did not enhance responsiveness across different patient
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  • Traditional assessment of movement quality in patients with spinocerebellar ataxia relies on subjective scales, making it difficult to detect subtle mobility changes; hence, researchers explored using machine learning to enhance assessment.
  • The study involved a phase 3 trial comparing the effects of the drug troriluzole versus a placebo on gait quality, measured through video analysis and a new stability metric called the Pose Dispersion Index.
  • Results showed that those taking troriluzole had significant improvements in the tandem walk stability measure after 48 weeks, while a trend in natural walking improvement was also noted, and lower scores in baseline stability were linked to a higher fall risk.
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Background And Objective: Spontaneous intracranial hypotension (SIH) from CSF leak commonly produces headache. It also may produce sagging brain syndrome (SBS), often with neurocognitive symptoms indistinguishable from behavioral-variant frontotemporal dementia (bvFTD). The authors describe a new clinical sign that appears to be pathognomonic of SBS.

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Behavioral neurology & neuropsychiatry (BNNP) is a field that seeks to understand brain-behavior relationships, including fundamental brain organization principles and the many ways that brain structures and connectivity can be disrupted, leading to abnormalities of behavior, cognition, emotion, perception, and social cognition. In North America, BNNP has existed as an integrated subspecialty through the United Council for Neurologic Subspecialties since 2006. Nonetheless, the number of behavioral neurologists across academic medical centers and community settings is not keeping pace with increasing clinical and research demand.

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The functional Scale for the Assessment and Rating of Ataxia (f-SARA) assesses Gait, Stance, Sitting, and Speech. It was developed as a potentially clinically meaningful measure of spinocerebellar ataxia (SCA) progression for clinical trial use. Here, we evaluated content validity of the f-SARA.

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Spinocerebellar ataxias (SCA) are rare inherited neurodegenerative disorders characterized by a progressive impairment of gait, balance, limb coordination, and speech. There is currently no composite scale that includes multiple aspects of the SCA experience to assess disease progression and treatment effects. Applying the method of partial least squares (PLS) regression, we developed the Spinocerebellar Ataxia Composite Scale (SCACOMS) from two SCA natural history datasets (NCT01060371, NCT02440763).

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Article Synopsis
  • * The three-day agenda featured keynote speakers, abstract presentations, and discussions on topics such as patient experiences, cerebellar function, cognition, and recent research findings.
  • * As a result of the meeting, special interest groups established research priorities aimed at guiding studies before their next meeting scheduled for spring 2024.
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Recent studies have reported that cerebellar lesions can cause cognitive, behavioral, and affective symptoms. This constellation is called the cerebellar cognitive affective syndrome (CCAS). A bedside instrument, the CCAS-Scale, has been developed to screen for this clinical presentation.

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  • This study investigates how well standing balance conditions and digital sway measurements can distinguish between people with Friedreich's ataxia (FRDA) and healthy controls (HC).
  • Twenty-eight individuals with FRDA and twenty healthy participants performed various standing tests while their postural sway was measured using a wearable sensor.
  • Findings showed that specific sway measures reliably differentiated FRDA patients from healthy individuals, with some correlations found between these measures and clinical scores related to balance.
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Background: Fatigue is a prevalent and debilitating symptom in neurological disorders, including spinocerebellar ataxias (SCAs). However, the risk factors of fatigue in the SCAs as well as its impact have not been well investigated.

Objectives: To study the prevalence of fatigue in SCAs, the factors contributing to fatigue, and the influence of fatigue on quality of life.

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Definitive diagnosis of multiple system atrophy of the cerebellar type (MSA-C) is challenging. We hypothesized that rates of change of pons and middle cerebellar peduncle diameters on MRI would be unique to MSA-C and serve as diagnostic biomarkers. We defined the normative data for anterior-posterior pons and transverse middle cerebellar peduncle diameters on brain MRI in healthy controls, performed diameter-volume correlations and measured intra- and inter-rater reliability.

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Background: Maintaining balance is crucial for independence and quality of life. Loss of balance is a hallmark of spinocerebellar ataxia (SCA).

Objective: The aim of this study was to identify which standing balance conditions and digital measures of body sway were most discriminative, reliable, and valid for quantifying balance in SCA.

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Background: Genetic prion diseases, including Gerstmann-Sträussler-Scheinker disease (GSS), are extremely rare, fatal neurodegenerative disorders, often associated with progressive ataxia and cognitive/neuropsychiatric symptoms. GSS typically presents as a rapidly progressive cerebellar ataxia, associated with cognitive decline. Late-onset cases are rare.

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Article Synopsis
  • * The study assessed how early life events, such as maternal difficulties during pregnancy and participation in school sports, influence AAO, severity, and progression using a social determinant of health approach.
  • * Findings revealed that maternal difficulties and sports participation were linked to an earlier AAO by over 13 years, while higher education levels led to slower disease progression and less severity, highlighting the impact of non-genetic factors on SCA6 outcomes.
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The Cerebellar Cognitive Affective/Schmahmann Syndrome (CCAS) manifests as impaired executive control, linguistic processing, visual spatial function, and affect regulation. The CCAS has been described in the spinocerebellar ataxias (SCAs), but its prevalence is unknown. We analyzed results of the CCAS/Schmahmann Scale (CCAS-S), developed to detect and quantify CCAS, in two natural history studies of 309 individuals Symptomatic for SCA1, SCA2, SCA3, SCA6, SCA7, or SCA8, 26 individuals Pre-symptomatic for SCA1 or SCA3, and 37 Controls.

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Article Synopsis
  • Telehealth and telemedicine have rapidly expanded during the COVID-19 pandemic, enhancing patient access to care, especially for those far from medical facilities.
  • Clinicians in behavioral neurology & neuropsychiatry at Massachusetts General Hospital (MGH) have begun using telemedicine for cognitive exams, which were traditionally done in person, outlining their methods and experiences.
  • The article discusses the goals, benefits, and limitations of telemedicine exams, highlighting issues such as technology access for patients, limitations on clinician technology, and the need for in-person assessments when necessary.
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Objective: Late-onset GM2 gangliosidosis (LOGG) subtypes late-onset Tay-Sachs (LOTS) and Sandhoff disease (LOSD) are ultra-rare neurodegenerative lysosomal storage disorders presenting with weakness, ataxia, and neuropsychiatric symptoms. Previous studies considered LOTS and LOSD clinically indistinguishable; recent studies have challenged this. We performed a scoping review to ascertain whether imaging and clinical features may differentiate these diseases.

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