Lumbar Epidural Fistula: A Unique Cause of Foix Alajouanine Syndrome

Introduction: Foix Alajouanine Syndrome is a rare neurologic condition manifesting as progressive myelopathy due to spinal cord ischemia typically in the setting of venous hypertension. First described in 1926 by two French neurologists treating patients with subacute necrotic myelitis, advancements in diagnostic modalities have clarified the etiology, which is often linked to spinal vascular malformations such as dural arteriovenous fistulas (dAVFs). Anatomically, there is an aberrant connection between a radiculomedullary artery and vein, leading to increased pressure within the venous network resulting in ischemic changes to the spine.

Methods: Here, we present a case of Foix Alajouanine caused by a lumbar epidural fistula. JS is a 70 year old male with a past medical history significant for a prior lumbar 2 to sacral 1 posterior decompression, who presented to our facility with progressive lower extremity weakness, sensory disturbances, and urinary and bowel retention.

Results: Magnetic resonance imaging (MRI) revealed venous pouch dilatation, suspicious for a venous fistula, with early myelopathic signal change in his thoracic and lumbar spinal cord. MR angiogram was performed that demonstrated a pathologic lumbar vessel originating from the aorta and extending into the left lumbar 3 – lumbar 4 neural foramen. A spinal angiogram was completed, displaying the epidural fistula at the level of left lumbar 3 with both epidural and intradural venous connections, a rare presentation of a spinal epidural fistula. The fistulous connection was embolized using Onyx. Following the intervention, JS reported improvement in his symptoms.

Conclusion : Review of the literature demonstrates remarkable outcomes in patients with this spinal pathology. Endovascular or open-surgical procedures can be performed to disconnect these aberrant connections and restore normalized blood flow within the spinal cord. In patients where this pathology is diagnosed accurately and in a timely manner, neurologic deficits improve remarkably, such as the case with our patient.