Internal Jugular Vein Compression: An Underrecognized Contributor to Cerebral Venous Outflow Obstruction in Idiopathic Intracranial Hypertension

Background: Idiopathic intracranial hypertension is frequently associated with transverse dural venous sinus stenosis. Extracranial cerebral venous outflow obstruction caused by internal jugular vein compression between the styloid process and the C1 lateral mass is less commonly recognized and may represent an additional contributor to impaired cerebral venous drainage.

Methods: We present a 56-year-old woman with idiopathic intracranial hypertension and longstanding headache and head heaviness. Venous imaging was reviewed with focused assessment of intracranial dural venous sinuses and extracranial jugular outflow pathways.

Results: Imaging demonstrated transverse dural venous sinus stenosis together with severe bilateral internal jugular vein compression, approaching occlusion at the C1 level between the styloid processes and C1 lateral masses. Extensive collateral venous pathways were identified proximal to the compression sites, providing alternative drainage through posterior cervical and intracranial venous networks, bypassing the areas of obstruction.

Conclusions: This case highlights styloidogenic internal jugular vein compression as a potentially underrecognized extracranial contributor to cerebral venous outflow obstruction in patients with idiopathic intracranial hypertension. Radiologists should systematically evaluate the upper cervical jugular veins in addition to the intracranial dural venous sinuses when assessing patients with idiopathic intracranial hypertension. Recognition of this potentially treatable anatomic abnormality may have important implications for further diagnostic evaluation and management.