A Rare and Treatable Cause of Medullar Claudication: Spinal Dural Arteriovenous Fistula

Abstract

Background: Spinal dural arteriovenous fistula is a rare and underdiagnosed disorder. Because of the nonspecific clinical presentation of the condition, patients are often referred to different specialists, resulting in delayed diagnosis. Case Report: A 76-year-old male presented with a 1-month history of gait trouble. His impairment was asymmetric, distally predominant, sensitive, and motor. Symptoms worsened with standing and walking. The patient also had sphincterial dysfunction. Classic spinal cord magnetic resonance imaging (MRI) showed an extended hypersignal indicating nonspecific myelopathy. Repeat spinal cord MRI that included a T2 spin echo sequence revealed abnormalities suggesting dural arteriovenous fistula. Medullar angiography confirmed the diagnosis, and endovascular treatment was successfully performed. Six months posttreatment, the patient reported resolution of his neurologic disabilities except for some residual paresthesia in his inferior limbs. Conclusion: Physicians should be aware of the specific abnormalities shown on spinal cord MRI that indicate dural arteriovenous fistula, as well as the criteria for performing medullar angiography, so that the condition can be diagnosed and treated in a timely manner. Early therapeutic treatment is the principal prognosis factor.

Keywords: Angiography; central nervous system vascular malformations; dural arteriovenous fistula; embolization–therapeutic; intermittent claudication; spinal cord diseases.

Figure 1.

Sagittal magnetic resonance imaging with (A) T2 spin echo (TSE) sequence reveals hypersignal of the spinal cord from T6 to the terminal cone (arrows) and flow voids behind the spinal cord that are (B) enhanced with gadolinium injection. The hypersignal of the spinal cord on TSE sequence corresponds to chronic hypoxic congestive myelopathy attributable to venous hyperpressure hindering venous return and caused by an arteriovenous shunt in spinal cord vascularization. The arrows in views A and B correspond to congested small venous vessels that are hard to visualize because they are quite thin.

Figure 2.

Images from the (A) first and (B to F) second medullar angiographies performed on the patient. During the first angiography, the end of the anterior artery injection was visible (A, dark arrow), but the venous return of the spinal cord could not be visualized because it was slowed by a dural arteriovenous fistula (A, white arrow). During the second angiography, an uncommon vessel on T4 left level was visualized (B), draining in the spinal vein (C) and corresponding to the dural arteriovenous fistula. Endovascular treatment was performed by catheterization (D, black arrow) of the fistula point (D, white arrow). Injection of the embolic agent (E, white arrow) resulted in the disappearance of the dural arteriovenous fistula (F, black arrow).