Objective: Spinal subdural hematomas (SSDHs) are rare. Causes are (1) posttraumatic, (2) iatrogenic (following surgery or lumbar puncture), (3) spontaneous including underlying malformations or coagulation deficits. With a systematic review of literature we want to shed light on the last group: symptomatology, etiology, treatment and outcome will we discussed. Methods: Systematic review of literature on PubMed for cases of acute nontraumatic noniatrogenic SSDHs in adults (>= 18 y of age). A total of 122 cases were reviewed including 2 cases from our hospital. Results: There was a slight preponderance of female patients with spontaneous SSDHs and the mean age was 60 years. Spontaneous SSDHs were mostly located in the thoracic region (40%). Motor symptoms were most frequent (89%), followed by pain. Sensory deficits were present in 64%, of which 81% had a sensory level. In 6% radiculating pain, without any focal neurological deficits, was the presenting symptom. SSDHs were mainly caused by a coagulopathy (48%), predominantly due to the use of coumarins (34%). Other causes were underlying (vascular) malformations and vasculitis. Forty-three percent the SSDHs was idiopathic. 72% of patients underwent a decompressive laminectomy. 59% had a favorable outcome and 34% had a poor outcome. Conclusions: Spontaneous SSDHs were predominantly located in the thoracic spine, presenting with paraparesis/paraplegia, sensory level and pain. Over 40% was caused by a coagulation defect, most frequently due to coumarins. Six percent of patients presented with radiculating pain without any focal neurological deficits.
