Development, Application, and Mechanistic Investigation of a Novel Minimally-Invasive Bidirectional Epidural Cerebellar Stimulation Technique for Cerebellar Cognitive Affective Syndrome

Inclusion Criteria: * 1\. Clinically and biochemically confirmed ACTH-dependent or ACTH-independent Cushing syndrome (loss of serum cortisol circadian rhythm, elevated 24-hour urinary free cortisol, and failure to suppress on low-dose dexamethasone suppression test). 2\. Cranial MRI demonstrating unequivocal cerebellar atrophy (CCAS imaging criterion: cerebellar hemisphere or vermian volume ≥1.5 SD below age-matched normative data). 3\. Established clinical diagnosis of CCAS (meets Schmahmann criteria, CCAS-S total score ≥20). 4\. Cerebellar ataxia rating scale (SARATA) ≥10, indicating at least moderate motor ataxia. 5\. Positive cognitive impairment screen (MoCA \<26, or Z-scores ≤-1.5 in at least two cognitive domains). 6\. Willingness to undergo minimally invasive epidural cerebellar stimulation and provision of written informed consent. Exclusion Criteria: Patients with significant systemic disease; occurrence of major complications or irreproducible, critical deviations in data collection or experimental procedures; or any circumstance rendering continued participation inappropriate-including clinical deterioration, serious adverse events, or poor compliance-will result in discontinuation of the subject's enrollment.