Angiographically Occult Vascular Malformation of the Cauda Equina Presenting Massive Spinal Subdural and Subarachnoid Hematoma

back pain, left leg pain and headache with left leg weakness. She had no history of trauma, physical exertion, or anticoagulant therapy. The routine blood investigations were normal. A neurological examination revealed grade III/V and IV/V motor weakness in the proximal and distal left leg, respectively. There were no sensory abnormalities including touch, pain and vibration. Deep tendon reflexes were decreased at the left leg and no Babinski signs were noted. She had bladder retention, but the anal sphincter tone was intact. Magnetic resonance (MR) imaging revealed an area of slightly high signal intensity on the T1-weighted image and a low signal area on the T2-weighted image from T7 to S1, suggesting an acute SSDH and/or SSAH (Fig. MR imaging did not show any evidence of vascular abnormalities within the lesion levels.