Spinal Vascular Disease

• Aneurysm – usually on anterior spinal artery in cervical spine
• Frequently associated with AVM (feeder)
• NOT at arterial branch point (unlike cerebral aneurysms)
• Usually present with SAH, but can cause compression
• AVM – diagnosed by selective spinal angiography; four types:
• Type I – Dural AVF – acquired; also called angioma racemosum venosum
• most common, acquired
• Account for 80% of spinal AVMs
• Single feeder, rostral drainage, often over several segments
• Represent an acquired fistulous communication between a dural branch of a radicular artery and a dural vein
• Progressive
• 90% have good outcome
• Present in 4^th decade with male predominance
• Chronic stepwise progression
• Usually in T-L spine
• Fistula is at dorsal dural root sleeve where intercostals artery enters thecal sac
• Low flow, rare hemorrhage
• Usually symptomatic from venous hypertension
• Symptoms are graded and low in onset
• Gradually progressive myelopathy and/or step-like exacerbations
• SAH uncommon
• Treatment: interruption of feeding vessels as they penetrate the dural sleeve                   
• Type II – Glomus, congenital
• Young patient (2^nd decade), male=female
• Anywhere in spine (often cervical or at conus)
• Thought to be congenital
• intramedullary, multiple feeders
• Tightly packed vessels covering a short segment in the anterior half of the cord with no intervening cord drains into venous plexus (dorsal)
• Compact intramedullary nidus
• High flow
• Symptoms are generally apoplectic, 30% have associated SAH
• Acutely symptomatic from SAH or intramedullary hemorrhage
• 20% have cutaneous vascular anomalies
• Fed by arterial branches of anterior and posterior spinal arteries
• Treatment: embolization
• Type III – Juvenile
• May be both intra – and extramedullary
• Large and complex, intervening cord parenchyma between abnormal vessels
• Large nidus with intervening cord occupying entire canal (usually thoracic)
• Multiple arterial feeders (more than type II)
• High flow
• Treatment: embolization
• Large (entire cross section of cord)
• Intramedullary, multiple extraspinal feeders
• Associated with arterial and venous aneurysm
• Bidirectional venous drainage
• 50% have good outcome
• Rx:  Surgical excision or. embolization
• Type IV – Intradural Extramedullary AVF
• Abnormal connection between artery and vein (no real nidus) – dilated venous drainage
• Usually anterior cord near conus
• If dorsal, may operate and divide the fistula
• acquired, middle age
• Anterior to cord – from anterior spinal artery
• Foix-Alajouanine Syndrome – subacute necrotizing gray matter myelitis with type 1 (dural) AVF; due to thrombophlebitis of spinal veins; painful flaccid paralysis
• Klippel-Trenaunay-Weber syndrome – enlarged arm due to anomalous development of bone and muscle; associated with spinal cord AVM’s
• Cavernous Malformation – occasionally multiple
• Stroke – from aortic dissection, aortic cross-clamping, atherosclerosis
• Most vulnerable at watershed areas
• Artery of Adamkiewicz supplies most of the blood to the lower 2/3 of the anterior spinal artery