Foix-Alajouanine syndrome

Foix-Alajouanine syndrome refers to subacute, progressive myelopathy due to venous hypertension from a spinal dural arteriovenous fistula.

Clinical presentation

Patients have paraparesis (leg weakness), sensory loss in the legs, and loss of bowel and bladder sphincter control ¹.

Pathology

Spinal dural arteriovenous fistula results in venous hypertension ¹. A direct connection between a radicular artery in the dural nerve root sleeve and the intradural venous system results in arterial pressure in the veins. The perimedullary veins enlarge and undergo fibrous thickening of the wall (so-called arterialization). The spinal cord becomes congested, impairing its function.

Radiographic features

MRI

T2 weighted images show dilated perimedullary flow voids and high signal in the spinal cord ².

Angiography (DSA)

Digital subtraction angiography directly demonstrates the arterial feeder with a characteristic early draining vein going to a large, tortuous spinal vein in the subarachnoid space ³.

History and etymology

In 1926, French neurologists Charles Foix (1882-1927) and Théophile A J Alajouanine (1890-1980) described two patients with subacute necrotic myelitis ¹. Clinically, they presented with slowly ascending, increasingly flaccid paraparesis. Pathologically, they had an endomesovasculitis with vascular wall thickening but no thrombosis. It was not until later that the etiology was proposed to be a dural arteriovenous fistula, an entity that was not known at the time of the original publication. In the ensuing decades, some authors have incorrectly attributed the syndrome to venous thrombosis ^2,3.