Spinal Subdural Hematoma Migration From a Cranial Subdural Hematoma: Two Case Reports and Literature Review.

Spinal subdural hematoma (SSDH) associated with cranial subdural hematoma (CSDH) is considered extremely rare and the etiology remains unclear. Herein, we report two cases of spontaneous SSDH concomitant with CSDH, with no history of trauma. First, a healthy 35-year-old woman suffered from left leg pain following a headache caused by acute CSDH. Magnetic resonance imaging (MRI) of the lumbar spine showed SSDH extending from the L5 to S2 vertebral levels. The leg symptoms were gradually relieved with conservative treatments within two weeks after onset. The SSDH was completely resolved six months after onset on MRI evaluations. Next, a 69-year-old woman developed a headache and right hemiparesis. Brain computed tomography (CT) demonstrated chronic left-sided CSDH and she underwent a single burr-hole craniotomy. Three weeks after surgery, she experienced difficulty walking because of severe leg pain caused by SSDH extending from the L3 to S1. The clinical symptoms were completely resolved with conservative treatment within one month after onset. At 3 months follow-up, SSDH disappeared on MRI evaluation. Herein, we presented two cases of SSDH associated with CSDH. In both cases, the leg symptoms of SSDH developed following the onset of CSDH. Given that both patients remained active during the interval between CSDH onset and the appearance of SSDH symptoms, the SSDH was likely caused by migration of the CSDH contents to the lumbar spine because of gravity.