Biology subjects

Hernandez-Castillo, C.

Publications and source records attributed to Hernandez-Castillo, C..

3 recordsLinked to original sources

bioRxiv2026

Neuroanatomical subtypes of Long COVID reveal distinct cognitive profiles alongside longitudinal brain changes

BackgroundLong COVID is characterized by persistent symptoms following SARS-CoV-2 infection, including cognitive deficits among its most disabling manifestations. However, their neurobiological basis is poorly understood. Previous neuroimaging studies reported structural brain alterations, but few have integrated cognitive assessment, network-based analyses, and longitudinal imaging to identify neurobiological subtypes. MethodsWe studied 42 individuals with persistent post-COVID cognitive symptoms and 14 matched healthy controls using cognitive assessment and structural MRI. Multilayer brain networks were constructed from regional morphometric measures, and hierarchical clustering identified patient subgroups. Cross-sectional and longitudinal comparisons of brain structure, cognition, and function were performed, with exploratory brain-behavior correlations over six months. ResultsClustering identified two subgroups with distinct structural patterns. Compared with controls, one subgroup showed reduced gray matter density in cerebellar lobules VIIIa/VIIIb and the putamen (p < 0.05, TFCE-corrected), whereas the other showed no significant alterations. Cognitive differences between clusters did not survive multiple-comparison correction; however, several measures showed medium-to-large effect sizes (d = 0.70-1.01), suggesting meaningful cognitive differences requiring confirmation in larger cohorts. Longitudinal analyses revealed increased medial frontal gray matter density (p < 0.05) associated with visuospatial/executive performance. ConclusionsThese exploratory findings suggest that post-COVID cognitive symptoms are associated with heterogeneous neurobiological profiles rather than a uniform pattern of impairment. Structural alterations involving cerebellar, striatal, and frontal regions may reflect distinct neuroanatomical phenotypes. Longitudinal findings suggest medial frontal structural reorganization with functional relevance. These findings support data-driven stratification for characterizing neurobiological heterogeneity in Long COVID and provide a foundation for future hypothesis-driven studies.

neuroscience↗

bioRxiv2026

SUITPy: A Python-based toolbox for the analysis of cerebellar functional and anatomical imaging data across the human lifespan

The human cerebellum plays a central role in motor, emotional, and cognitive functions, and is implicated in many brain disorders. To improve the analysis of functional and anatomical imaging from the cerebellum, we introduce SUITPy, an improved and fully revised Python implementation of the widely used SUIT toolbox. For this new version, we developed a U-Net based model to automatically isolate the cerebellum from adjacent cortical tissue, which achieves higher fidelity than existing algorithms. The isolation works robustly without manual corrections for imaging data across the lifespan. We show that isolation and subsequent normalization to a cerebellum-only template lead to a more precise alignment of cerebellar structures across participants compared to normalization using a whole-brain template. We also show the utility of the cerebellar mask to prevent contamination of cerebellar functional data from surrounding cortical structures. The toolbox also provides functionality for visualizing cerebellar data on a flatmap, along with a range of anatomical and functional cerebellar atlases, thereby offering an essential tool that enables accurate cerebellar analysis across the lifespan.

neuroscience↗

bioRxiv2019

No evidence for motor recovery-related cortical reorganization after stroke using resting-state fMRI

Cortical reorganization has been suggested as mechanism for recovery after stroke. It has been proposed that a form of cortical reorganization (changes in functional connectivity between brain areas) can be assessed with resting-state fMRI. Here we report the largest longitudinal data-set in terms of overall sessions in 19 patients with subcortical stroke and 11 controls. Patients were imaged up to 5 times over one year. We found no evidence for post-stroke cortical reorganization despite substantial behavioral recovery. These results could be construed as questioning the value of resting-state imaging. Here we argue instead that they are consistent with other emerging reasons to challenge the idea of motor recovery-related cortical reorganization post-stroke when conceived as changes in connectivity between cortical areas.

neuroscience↗