Venous Congestive Myelopathy and Secondary Infarction: A Delayed Diagnosis of Spinal Dural Arteriovenous Fistula

A man in his 70s with known vascular risk factors presented with acute onset of bilateral lower limb weakness and urinary retention. Initial spinal magnetic resonance imaging (MRI) revealed a longitudinally extensive myelopathy. It was initially interpreted as transverse myelitis, prompting treatment with high-dose corticosteroids. However, the clinical response was minimal. Over the following months, progressive symptom worsening led to a repeat MRI, which showed interval progression of spinal cord edema and T2 hyperintensity from T6 to T12, which was indicative of chronic venous congestion without distinct flow voids. Subsequent spinal angiography confirmed a spinal dural arteriovenous fistula (SDAVF) at the T10-T11 level. The clinical course and imaging findings led to a diagnosis of venous congestive myelopathy (VCM), complicated by secondary spinal cord infarction (SCI) attributable to the SDAVF. After surgical disconnection of the fistula, the patient began intensive rehabilitation. Despite successful fistula closure, substantial residual neurological deficits persisted, likely due to irreversible damage from both chronic venous hypertension and secondary infarction, compounded by delayed diagnosis. This case underscores the importance of considering SDAVF in patients with progressive or steroid-refractory myelopathy. It also illustrates that VCM can lead to secondary infarction, complicating both diagnosis and prognosis.