Raising Awareness for Overlooked Intracranial Venous Sinus Stenoses: A Quality Improvement Proposal

Purpose: Idiopathic intracranial hypertension (IIH) refers to elevated intracranial pressure with no cause on neuroimaging or other evaluations. While the pathogenesis remains largely unknown, literature has found links between dural venous sinus abnormalities and IIH. On imaging, venous sinus stenosis is often unrecognized due to MRV’s technical and interpretive challenges as more preference is often given to the presence or absence of frank thrombosis or occlusion rather than degrees of stenosis. Our goal is to suggest the significance of undercalling venous sinus stenosis in the context of IIH and to raise awareness for the importance of this finding.

Methods/Materials: We conducted a retrospective chart review of 125 MR venograms reported as normal examinations that occurred over the last 5 years at an outpatient center for patients presenting with headache or tinnitus, common features of IIH. An attending neuroradiologist with CAQ in neuroradiology reviewed all studies independently with a second attending available for indeterminate case review. Patient and original reporting radiologists were anonymized. Upon review, cases were categorized as normal (no significant findings), abnormal (contributory findings identified retrospectively), or indeterminate (findings of uncertain significance).

Results: Of the 125 MR venograms, 68 (56.8%) were confirmed normal upon review, 35 (28%) studies revealed significant abnormalities, and 19 (15.2%) studies were indeterminate. Common findings included large internal jugular bulb diverticula > 1 cm, sigmoid sinus wall diverticula, and intrinsic and extrinsic venous sinus stenoses. Notably, all patients received adequate and suitable care related to their presentation.

Conclusions: The prominent undercalling of venous sinus abnormalities in this review suggests a role for careful examination in patients presenting with IIH. Patients with IIH suffer from severe headaches and are at risk for permanent vision loss. In most patients, symptoms progressively worsen over time if untreated. Detection of venous findings is critical, as venous sinus stenosis is treatable with venous sinus stenting in select patients, alleviating symptoms and reducing the recurrence of IIH.