Subdural hygromas after bone marrow transplantation - Results of a prospective study

Background: Subdural hygromas after bone marrow transplantation (BMT) have been occasionally found in patients with persisting headache and vomiting, We assessed the incidence of subdural hygromas after BMT and tried to define possible risk factors associated with this complication. Methods. Fifty bone marrow graft recipients surviving more than 30 days were consecutively enrolled into a prospective study. Cranial CT scans were performed before and 30 days after BMT, Clinical data and symptoms were recorded daily during the first 30 days after BMT. In patients with subdural hygromas, a magnetic resonance imaging scan and monthly follow-up cranial computed tomography scans were performed until fluid collections had resolved completely. Results. In 9 of the 50 patients (18%) who survived 30 days after transplantation, newly acquired subdural hygromas were found. Patients with hygromas suffered significantly longer and more severely from headache and vomiting (P=0.01). Application of intra thecal methotrexate and arterial hypertension occurred significantly more often in patients with hygromas (P=0.01). In a stepwise logistic regression model, arterial hypertension and intrathecal methotrexate application were the only independent risk factors for the development of hygromas. Monthly follow-up cranial computed tonography scans showed that all hygromas resolved completely after a median of 60 days after diagnosis (range: 30-120 days). Conclusions: Subdural hygromas are a frequent complication after EMT within the first 30 days after transplantation. They are reversible and disappear within 2-3 months. The need for routine application of intrathecal methotrexate in standard risk leukemia patients should be critically addressed. Furthermore, close monitoring of blood pressure and immediate antihypertensive therapy might contribute to avoid formation of subdural hygromas.