Rapid spontaneous resolution of signs of intracranial herniation due to subdural hematoma--case report.

An 83-year-old female presented with signs of intracranial herniation due to subdural hematoma (SDH) which resolved rapidly and spontaneously. This patient showed bilateral decerebrate postures due to left SDH on admission. Since she had serious neurological symptoms and critical systemic conditions caused by an asthma attack, conservative treatment including osmotherapy and mechanical ventilation was performed instead of surgical intervention. Her signs of intracranial herniation resolved only 6 hours after admission. Although the SDH did not diminish rapidly, she showed excellent neurological improvement even with conservative treatment only. Characteristic serial changes on computed tomography corresponding to the neurological improvements were seen. She was discharged with slight right hemiparesis and slight dementia that were present prior to this admission. The rapid resolution of signs of intracranial herniation was attributable to the spontaneous diminution of SDH. The diminution or disappearance of hematomas probably depended on the redistribution of cerebrospinal fluid into the hematoma in the present case.