The relationship between gait characteristics and clinical ataxia severity, after accounting for walking speed, remains insufficiently characterized following cerebellar stroke. We examined direction-specific trunk acceleration and lower-limb kinematics during comfortable walking. This multicenter cross-sectional study included 55 patients with subacute cerebellar stroke and 56 healthy controls. Inertial measurements quantified lower-limb kinematics, trunk acceleration root mean square (RMS; without speed normalization), and sample entropy (SampEn). Analyses included group-by-speed models, speed-matched one-dimensional statistical parametric mapping, and exploratory patient-only, speed-adjusted regressions and partial Spearman correlations with the Scale for the Assessment and Rating of Ataxia (SARA). Patients walked more slowly, with lower anteroposterior and mediolateral RMS but higher anteroposterior and vertical SampEn. After speed adjustment, each five-point higher SARA score was associated with smaller peak limb flexion (− 1.01°; 95
The dentate (lateral) nucleus (DN) of the cerebellum is one of the major sources of afferent input to the ventrolateral (VL) thalamus, and further to the motor cortex. Signals conveyed via this pathway are essential for neural control of movements, including accurate vision-guided stepping on complex terrain. The neuronal mechanisms underlying visual control of steps are not well understood. The goal of this study was to elucidate the integration of motor and visual information in the DN during locomotion on complex terrain by characterizing the components of DN activity that reflect overall locomotion movement, components related to visual guidance of feet to desired locations, and the integration of the two. Experiments were conducted on chronically implanted cats using an extracellular single-neuron recording technique. We found that during locomotion on a flat surface, a task that does not require visual control of feet placement, 63
Outcome prediction after Gamma Knife thalamotomy for essential tremor remains largely guided by baseline tremor severity, target anatomy, radiosurgical dose parameters, and institutional experience rather than individualized estimates of functional improvement, latency to benefit, and adverse radiation effect risk. We developed THINKERS-ET, a mixture-of-experts (MoE) artificial intelligence framework for personalized functional outcome prediction and dose-policy evaluation after Gamma Knife thalamotomy. We performed a retrospective single-center treatment-level study of patients with medically refractory essential tremor treated with Gamma Knife thalamotomy. Variables available before or at treatment were used to train a MoE neural network. Maximum dose was incorporated as a queryable input to enable repeated candidate dose evaluation. Internal validation used holdout testing and 5-fold cross-validation. Performance was assessed using AUC and Brier score for binary outcomes, and MAE, RMSE, and R² for continuous outcomes. The cohort included 163 Gamma Knife thalamotomy procedure. Clinical benefit was observed in 152 procedures (93.3
Cognitive and affective disturbances due to cerebellar lesions are termed cerebellar cognitive affective syndrome (CCAS). Although CCAS is frequent after acute cerebellar stroke, CCAS-Scale responsiveness during acute hospitalization remains unclear. Objective: To examine longitudinal changes and responsiveness of the CCAS-Scale and compare its changes with global cognitive function, ataxia, and activities of daily living (ADL). In this single-center prospective observational study, 21 patients with first-ever cerebellar stroke were assessed 7 days after onset and at discharge (median, 21 days) using the CCAS-Scale, Mini-Mental State Examination (MMSE), Scale for the Assessment and Rating of Ataxia (SARA), and Functional Independence Measure (FIM). Changes were analyzed using the Wilcoxon signed-rank test, standardized response mean (SRM), and Spearman’s rank correlation. Median CCAS-Scale score increased from 71 to 72 (p = 0.018), and failed items decreased from 4 to 3 (p = 0.035). Definite CCAS decreased from 81.0
The relationship between the cerebellum and cerebrum remains poorly understood in the neuroimaging literature, despite decades of functional magnetic resonance (fMRI) research. In this opinion article, we argue that this gap reflects fundamental methodological constraints rather than merely a lack of scientific interest. We first discuss challenges in acquiring fMRI data and analysis, with an emphasis on the cerebellum. We then critically evaluate the most common analysis approaches including functional connectivity, univariate contrasts, multivariate pattern analysis, and encoding models, examining the contributions and limitations of each to identify and quantify cortico-cerebellar networks. Through the lens of language processing, we briefly review how these approaches have been applied to characterize cortico-cerebellar networks underlying cognitive function. We conclude by proposing that encoding model frameworks, combined with ecologically valid naturalistic paradigms, offer advantages that can help resolve longstanding debates about cortico-cerebellar network function and organization.
