Anticoagulation is used to prevent thromboembolic events. It is a common practice to hold anticoagulation in the first few days following a traumatic brain injury (TBI) with intracranial hemorrhage. However, traumatic subdural hematomas (SDH) are prone to re-hemorrhage long after the trauma. Data are scarce in the literature on the best timing to resume anticoagulation following a TBI.

Review of 95 consecutive patients admitted to a level 1 trauma center with a diagnosis of traumatic SDH and requiring anticoagulation. The reasons for anticoagulation, the amount of time without anticoagulation, CT characteristics, and the incidence of thromboembolic events or SDH re-hemorrhage were collected.

41.3% used anticoagulation for coronary artery disease and peripheral vascular disease, 24% for atrial fibrillation, 12% for cardiac valve replacement, and 12% for venous thromboembolic events. Anticoagulation was held a median of 67 days. For most patients (82.1%), anticoagulation was re-introduced once the SDH had completely resolved. For 17.9%, anticoagulation was restarted while the SDH had not completely resolved. One (1.1%) patient suffered from an atrial clot while anticoagulation was held. For those with residual SDH, 41.2% suffered from a SDH re-hemorrhage and 17.6% required surgery. The risk of re-hemorrhage climbed to 62.5% if the SDH remnant was large.

Anticoagulation while there is a residual SDH was associated with a significant risk of re-hemorrhage. This risk should be weighed against the risk of holding anticoagulation.

Interhemispheric subdural hematomas (IHSDHs) are thought to be rare. Surgical management of these lesions presents a challenge as they are in close proximity to the sagittal sinus and bridging veins. IHSDHs are poorly characterized clinically and their exact incidence is unknown. There are also no clear guidelines for the management of IHSDH.

This is a retrospective review of all admitted patients with a diagnosis of traumatic brain injury over a 4-year period at a Level I trauma centre. Clinical characteristics of all patients with subdural hematoma (SDH) and IHSDH were collected.

Of 2165 admissions, 1182 patients had acute traumatic SDHs, 420 patients had IHSDHs (1.9% of admissions and 35.5% of SDH), 35 (8.3% of IHSDH) were ≥8 mm in width. IHSDH was isolated in 16 (3.8%) of the cases. Average age was 61.7 ± 21.5 years for all IHSDHs and 77.1 ± 10.4 for large IHSDH (p < 0.001). For large IHSDH, a transient loss of consciousness (LOC) occurred in 51.5% of individuals, post-traumatic amnesia (PTA) in 47.8% of cases, and motor weakness in 37.9% of patients. Five of the large IHSDH patients presented with motor deficits directly related to the IHSDH, and weakness resolved in four of these five individuals. None were treated surgically. Progression of IHSDH width occurred in one patient.

IHSDHs are often referred to as rare entities. Our results show they are common. Conservative management is appropriate to manage most IHSDHs, as most resolve spontaneously, and their symptoms resolve as well.