Cerebral Venous Outflow Insufficiency: A Study on Symptoms and Venous Stenosis Classification.

Cerebral venous outflow insufficiency (CVOI) is a recently recognized cerebrovascular condition characterized by impaired venous drainage from the brain to the extracranial system. However, its clinical phenotypes and classification criteria remain poorly defined. In this single-center cross-sectional study, we analyzed 245 patients with CVOI using contrast-enhanced CT or MR venography to identify clinical features and propose a novel anatomical classification. We identified 10 major symptoms of cerebral venous congestion, with tinnitus cerebri, neck discomfort, and tinnitus being the most common. A new classification system was proposed based on lesion location and bilateral jugular foramen narrowing rate, categorizing CVOI into intracranial (CV), extracranial (JV), and tandem (CJV) types, each further stratified into four/five subtypes. Receiver operating characteristic (ROC) curve analysis showed that narrowing thresholds of 0.20 and 0.40 offered excellent discriminatory performance for subtype differentiation, with an area under the curve (AUC) approaching 1.0. Notably, tandem-type CVOI (CJV) was the most prevalent (56.7%) and exhibited distinct symptom patterns and pathogenesis. These findings provide a practical framework for diagnosing and stratifying CVOI and may inform individualized treatment strategies.