Traumatic subdural hygroma.

The authors report a series of 80 cases of traumatic subdural hygroma and discuss the clinical and radiological features, management, surgical results, and pathogenesis. Changes in mental status without focal signs of brain damage were noted in over 50% of the cases. A clinical course marked by stabilization without complete recovery of neurological function was found in over 40% of the cases of "simple hygroma." The lumbar cerebrospinal fluid often showed hemorrhage and elevation of the protein content. Skull fractures were found in 39% of the cases, and subdural hygromas were associated with cerebral atrophy, cortical contusions, subdural hematomas, and overlying epidural hematomas. The characteristic angiographic and computed tomographic scan findings are discussed, as are surgical pathology and outcome. Several theories of pathogenesis are presented. The authors advocate simple burr hole drainage as the treatment of choice. Significant reaccumulation may occur occasionally.