A calvarial acute subdural hematoma migrating into the spinal canal in a young male.

It is not common for an acute subdural hematoma (SDH) in the supratentorial region to show rapid resolution or migration during the clinical course. In this report, we present a rare case where the SDH in the supratentorial region was observed to rapidly migrate into the lumbar spinal canal, leading to severe radiculopathy. A 20-year-old male patient was admitted to the emergency department with severe headache after head trauma. The patient's overall condition was good, whereas his Glasgow Coma Scale score was 15 and blood pressure was normal. He had vomited 3 times after the onset of pain. No stiff neck was found, and the computed tomography showed an ASDH over the outer layer of the right hemisphere, causing a 7- to 8-mm shift. During the follow-up, the headache regressed and eventually resolved after 12 hours; however, another severe pain occurred in the lumbar region and in both legs. The pain worsened over time, progressing to sciatica in both legs. Acute SDH associated with a minor head trauma may migrate from the supratentorial compartment into the spinal canal by the help of elastic cerebral tissues in young adults and children.