Foix-Alajouanine syndrome: an uncommon cause of myelopathy from an anatomic variant circulation

Abstract: Foix-Alajouanine syndrome is a rare cause of myelopathy caused by dural arteriovenous malformation of the spinal cord, mostly lower thoracic and lumbar. Patients are usually over 50 years of age and can present with acute lower extremity dysesthesias or intermittent sciatica. Progression to paraplegia may be slow. Spinal angiography is needed for definitive diagnosis, based on the clues provided by the symptoms. If diagnosed early, vascular embolization or neurosurgical excision may be curative.

Key Words: arteriovenous malformation, Foix-Alajouanine syndrome, myelopathy

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Foix-Alajouanine syndrome was first described in two young men (ages 31 and 37 years) in 1926. Until the middle of the 20th century, this pathologic entity was only an autopsy phenomenon. The underlying pathology was believed to be a dural arteriovenous (AV) fistula, usually in the thoracic cord. This remained the case for many decades, until the advent of high-resolution magnetic resonance imaging (MRI) and associated modern spinal angiography (Fig. 1). Even today, the true incidence of Foix-Alajouanine syndrome (FAS) is unknown and often underappreciated. (1-5)

Case Report

An 82-year-old white male was referred by his wife for progressive lower extremity weakness, worsening with exercise or standing. He reported no pain, fever, or trauma. The medical history included hypertension, paroxysmal atrial fibrillation, benign prostatic hyperplasia, and coronary artery disease. Medication included Coumadin, tamsulosin, metoprolol, and topiramate for bipolar disorder. Review of systems was significant only for shortness of breath, and recurrent chest pain was relieved with nitroglycerin. He was a retired administrator currently living in New Jersey, who did not smoke, drink, or use drugs. Examination was remarkable only for some distal sensory loss in the stocking pattern.

A preliminary thoracolumbar MRI did not show any evidence of myelopathy or vascular malformation (Fig. 2). A follow-up thoracic spine MRA showed an extensive array of blood vessels along the superior and posterior surface of the spinal cord, extending from cervical to thoracic region with associated abnormal signal intensity in the spinal cord compatible with a dural vascular fistula. Interestingly, the AV malformation was being fed by a communicating vessel from the posterior internal...