Abstract and Introduction
Abstract
A cerebral dural arteriovenous fistula (DAVF) is an acquired abnormal arterial-to-venous connection within the leaves of the intracranial dura with a wide range of clinical presentations and natural history. The Cognard classification correlates venous drainage patterns with neurological course, identifying 5 DAVF types with increasing rates of symptomatic presentation. A spinal DAVF occurs when a radicular artery makes a direct anomalous shunt with a radicular vein within the dural leaflets of the nerve root sleeve. A cervical DAVF is a rare entity, as most spinal DAVFs present as thoracolumbar lesions with myelopathy. In this paper the authors present 2 patients presenting initially with brainstem dysfunction rather than myelopathy secondary to craniocervical DAVF. The literature is then reviewed for similar rare aggressive DAVFs at the craniocervical junction presenting with brainstem symptomatology.
Introduction
Cerebral DAVF is an acquired abnormal arterial-to-venous connection within the leaves of the intracranial dura with a wide range of clinical presentations and natural history. Although many classification systems have been proposed in an attempt to separate benign from aggressive (associated with a future risk of intracranial hemorrhage) fistulas, the most common ones are the Borden and the Cognard classification systems. Both systems have been validated in the literature. The Cognard classification correlates venous drainage patterns on angiography to neurological course, identifying 5 DAVF types with increasing rates of symptomatic presentation. Although Cognard Types I–IV DAVF involve only dural sinus or cortical venous drainage, Type V fistulas are unique in harboring spinal perimedullary venous drainage. These Type V fistulas carry a risk of future neurological decline and are very rare; in large intracranial DAVF series, they typically represent < 5% of all DAVFs. As classically described, a Type V DAVF presents with progressive myelopathy, leading to development of brainstem compromise later in the disease process; only rarely described are the symptoms and signs of initial brainstem dysfunction.
A spinal DAVF occurs when a radicular artery makes a direct anomalous shunt with a radicular vein within the dural leaflets of the nerve root sleeve. A number of overlapping nomenclature systems have been proposed. A cervical DAVF is a rare entity; the majority of spinal DAVFs present as thoracolumbar lesions with myelopathy. Only a small number of cervical lesions have been described, and only 1 has been documented that presented with brainstem dysfunction.
In this paper we present 2 patients with brainstem dysfunction secondary to DAVF. One harbored a Cognard V DAVF and the other a cervical DAVF. We review the literature for similar rare aggressive DAVFs at the craniocervical junction presenting with brainstem symptomatology.