Introduction Type 1 spinal arteriovenous malformations (AVMs) are typically characterized by dural fistulas that manifest as progressive congestive myelopathy. However, acute hemorrhage resulting in spinal subdural hematoma is extremely uncommon, with only three documented cases reported to date.

Materials and Methods A 46-year-old female presented with rapidly progressive paraplegia that developed over the course of several hours. There was no history of anticoagulant use, trauma, fever, or infection. Upon examination, the patient exhibited bilateral lower extremity weakness (graded as 0/5) and decreased sensation to pinprick below the T6 level on both sides. Loss of bowel and bladder control was also noted. MRI revealed the presence of an intradural extramedullary lesion situated anteriorly, causing significant compression on the spinal cord from the T4 down to T7 level. The patient underwent thoracic laminectomy from T4-T7, followed by the evacuation of a well-organized subdural hematoma that was exerting significant mass effect on a distorted spinal cord upon dural opening. During the procedure, a large abnormal artery was identified, leading into a dilated serpiginous vein located on the dorsal aspect of the spinal cord at the T7 level. Further examination utilizing indocyanine green angiography confirmed our suspicion of a dural arteriovenous fistula, which was then successfully disconnected.

Results Based on the findings from the literature review (table 1), all patients who presented with the rapid onset of neurological symptoms were female. Due to the complex clinical presentation, treatment was delayed. Out of the three cases, only one was confirmed to have a dural AVF with angiography, while the other two required exploratory spinal decompression for diagnosis. However, all patients achieved full recovery to their prior level of functioning. These data suggest that patients who present with back or neck pain and neurological symptoms should undergo comprehensive evaluations to determine the presence of hemorrhages that may lead to spinal cord compression. In cases where hematomas are identified, surgical intervention may be necessary to prevent neurological deficits. Additionally, vascular abnormalities, such as AVFs, should be considered as potential causes of spinal hemorrhage.

Conclusion In rare instances, type I spinal arteriovenous malformations (AVMs) may present acutely as a subdural hematoma and should thus be considered as a possible differential diagnosis for acute paraplegia.

Disclosures A. Naeem: None. A. Shamisa: None.