Are isolated linear fractures over major dural venous sinuses a risk factor for sinus thrombosis in mild TBI?

Cerebral venous sinus thrombosis (CVST) can increase intracranial pressure and cause secondary brain injury. There is uncertainty in the literature regarding the risk of traumatic CVST (tCVST) following fractures over a major sinus, the need and timing for venous imaging, and treatment. The current study aims to review our experience with tCVST when treating patients with isolated linear fractures over the major sinuses. Methods. This is a retrospective study of 95 adult patients, treated between January 2017 and March 2023, with mild, blunt, isolated traumatic head injury (GCS 13-15) and cranial fracture traversing the major dural venous sinus. Data regarding presentation, radiological features, hospitalization, and follow-up course of CVST were collected and analyzed. Images suspected to show a CVST were retrospectively reviewed by two teams blinded to the radiological interpretation. Results. Of 95 patients, 31 (32%) were identified as having or suspected to have CVST as interpreted by the radiologists. Among them, 14 were treated with anticoagulation, and 1 was treated with anti-aggregate for concomitant arterial dissection. There were no long-term symptoms or newly diagnosed CVST amongst the entire cohort. No major morbidity or mortality occurred. Upon analyzing the images retrospectively, the inter-rater reliability varied. The agreement was fair for definite cases of CVST, slight for uncertain cases that showed epidural hematoma compression and narrowing of the sinus, or arachnoid granulations, and almost perfect for patients without thrombosis. Conclusions. Amongst patients with mild, isolated, blunt traumatic head injury, with fractures traversing major dural venous sinus, true CVST may be over-diagnosed, with some of the lesions being local epidural hematomas mimicking CVST. The outcome of CVST was excellent, whether or not they were treated with anti-thrombotic medications.