Spontaneously Resolving Symptomatic Subdural Hygromas After Cerebellopontine Angle Tumor Surgery.

BACKGROUND: Subdural hygroma is a rare disease most commonly encountered in posttraumatic patients. Even more rarely, it has been described as a complication of cerebellopontine angle tumor requiring surgical evacuation.

CASE DESCRIPTION: This report discusses 2 patients who underwent surgery for cerebellopontine angle tumor and who both developed symptomatic subdural hygromas a few days later. Both became highly symptomatic but symptoms resolved spontaneously and promptly before planned surgery.

CONCLUSIONS: These 2 cases highlight the 2 principal pathogenesis theories for the development of subdural hygromas (arachnoid tear and effusion) and suggest a theory for their sudden and spontaneous resolution: the pressure equilibrium opening the valve created by the arachnoid tear. Eventhough surgical treatment remains the recommended attitude, these cases show that conservative treatment can be an option in some cases.