The role of the left primary motor cortex in apraxia

Neurological Research and Practice, Journal Year: 2025, Volume and Issue: 7(1)

Published: Jan. 8, 2025

Abstract Background Apraxia is a motor-cognitive disorder that primary sensorimotor deficits cannot solely explain. Previous research in stroke patients has focused on damage to the fronto-parietal praxis networks left hemisphere (LH) as cause of apraxic deficits. In contrast, potential role (left) motor cortex (M1) largely been neglected. However, recent brain stimulation and lesion-mapping studies suggest an involvement M1 cognitive processes—over above its execution. Therefore, this study explored whether plays specific apraxia. Methods We identified 157 right-handed with first-ever unilateral LH sub-acute phase (< 90 days post-stroke), for whom apraxia assessments performed ipsilesional hand lesion maps were available. Utilizing maximum probability map Brodmann area 4 (representing M1) provided by JuBrain Anatomy Toolbox SPM, subdivided into two groups depending their lesions involved (n = 40) or spared 117) M1. applied mixed model ANCOVA repeated measures compare between patient groups, considering factors “body part” “gesture meaning”. Furthermore, we differential effects anterior (4a) posterior (4p) parts correlation analyses. Results Patients without did not differ age time post-stroke but size. When controlling size, total scores significantly groups. showed involving differentially worse when imitating meaningless finger gestures. This effect was primarily driven affecting 4p. Conclusions Even though many current definitions disregard relevant M1, observed lesions, specifically subarea 4p, imitation gestures sample suggests high amounts (motor) attention integration are required.

Language: Английский

Archimedes Spiral Ratings: Determinants and Population‐Based Limits of Normal

Movement Disorders Clinical Practice, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 5, 2024

Abstract Background Tremor is commonly found among healthy humans or prevalently a symptom of neurological dysfunctions. However, the distinction between physiological and pathological tremor dependent on examiner's competence. Archimedes Spiral Rating (ASR) valid reproducible semi‐quantitative method to assess severity action tremor. Objectives (1) To range percentiles ASR in large sample seemingly free tremor‐related conditions symptoms from population‐based CHRIS‐study. (2) analyze influence sex, age, drawing hand ASR. (3) define limits normal. (4) supply exemplary spiral drawings by each rating favor consistent proficient clinical evaluation. Methods Accurately investigated participants were randomly sampled over 14 sex‐age strata. 2686 paired spirals drawn with both hands 1343 expertly assessed scale 0 9. Results had quadratic increase age sexes, while it was relatively lower dominant compared non‐dominant women men. ASRs above specific 97.5th 4 5, below 60 years respectively, conceivably non‐physiological nature. Conclusions In we show steeper as progresses. Relatively higher ratings elderly, males hands, appear compatible “normal” across groups. The current operational evidence may support practitioners differentiating

Language: Английский

Machine Learning-Driven Correction of Handgrip Strength: A Novel Biomarker for Neurological and Health Outcomes in the UK Biobank

medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 28, 2024

Background: Handgrip strength (HGS) is a significant biomarker for overall health, offering simple, cost-effective method assessing muscle function. Lower HGS linked to higher mortality, functional decline, cognitive impairments, and chronic diseases. Considering the influence of anthropometrics demographics on HGS, this study aims develop corrected score using machine learning (ML) models enhance its utility in understanding brain health disease. Methods: Using UK Biobank data, sex-specific ML were developed predict based three anthropometric variables age. A novel biomarker, ∆HGS, was introduced as difference between true (i.e., directly measured HGS) bias-free predicted HGS. The neural basis ∆HGS investigated by correlating them regional gray matter volume (GMV). Statistical analyses performed test their sensitivity longitudinal changes stroke major depressive disorder (MDD) patients compared matched healthy controls (HC). Results: could be accurately demographic features, with linear support vector (SVM) demonstrating high accuracy. Compared showed reassessment reliability stronger, widespread associations GMV, especially motor-related regions. Longitudinal analysis revealed that neither nor effectively differentiated from HC at post time-point. Conclusion: proposed exhibited stronger correlations GMV suggesting it better represents relationship structure. While not effective differentiating time-point, increase pre time-points patient cohorts may indicate improved monitoring disease progression, treatment efficacy, or rehabilitation effects, warranting further validation.

Language: Английский