Temporal sensitivity and perceived timing in unimodal and crossmodal isochronous sequences.

Glioblastoma IDHwt (CNS WHO Grade 4) remains among the most challenging neoplasms, with prognosis remaining poor despite aggressive multimodal therapy. Established predictors of survival include molecular markers such as MGMT promoter methylation, IDH mutation status, extent of resection (EOR), and clinical performance status [–]. Beyond these factors, systemic alterations in the tumor microenvironment are of increasing scientific interest, yet in vivo assessment of contributing components remains limited [, ]. The glymphatic system describes organized neurofluid exchange through convective perivascular CSF influx, mediated by Aquaporin-4 channels on astrocytic end feet, with subsequent drainage towards meningeal lymphatic vessels and cervical lymph nodes. Beyond waste clearance and interstitial fluid homeostasis, the glymphatic system has been proposed to play a role in neuroinflammation and immunosurveillance, rendering it a potentially relevant contributor to the tumor microenvironment in glioblastoma [, ]. In vivo assessment of the glymphatic system is mainly performed via MRI-based techniques, including intrathecal or intravenous contrast agent application and diffusion imaging [, ]. Utilizing diffusion tensor imaging, the analysis along the perivascular space (DTI-ALPS) method quantifies diffusivity along perivascular spaces by calculating tensor direction orthogonally to known fiber tracts in the centrum semiovale, yielding the ALPS index as a surrogate for glymphatic function [].