Spinal artery

In blockade of the anterior spinal artery, ischemia of the medial medulla may occur with contralateral hemiparesis, ipsilateral tongue weakness and contralateral loss of posterior column sensation (Ho and Meyer 1981). 

Vertebral arteries vary in size and symmetry, where mostly the left vertebral artery is the dominant one. The coincidence of vertebral fenestrations and aneurysms is well known. The anterior spinal artery receives tiny vessels from the vertebral arteries which are physiologically not depicted by MRA due to their size. The posterior inferior cerebellar artery (PICA) as the largest, most important and most variable cerebellar artery however, under normal conditions it is constantly depictable with TOF and CE-MRA. 

Medullary infarcts can be medial, lateral or combined (Fig. 14.6). The medial territory is supplied by penetrating vessels from the anterior spinal artery and the distal vertebral artery. The lateral territory main arterial supply comes from penetrating arteries from the distal vertebral artery and the posterior inferior cerebellar artery. The small posterior territory is supplied by the posterior spinal artery and the posterior inferior cerebellar artery. Medial... 

Fig. 17.2. a Superficial arteries of the spinal cord. X-ray film of an injected specimen in a.p. view. The anterior spinal artery system is visible on the ventral surface of the cord, b Intrinsic spinal cord arteries. X-ray microangiogram of a transverse section (lumbar enlargement). The sulcal or central artery within the anterior fissure (arrow) is dominant. Note the posterior and posterolateral spinal arteries at both sides of the posterior root entry zone (arrowheads). AST, anterior spinal artery... 

Those spinal radicular arteries that are radiculo-medullary arteries, supplying nerve root, pial plexus and medulla, branch in a very typical way to form the anterior spinal artery. The ascending branch continues the direction of the radicular artery in the midline of the anterior surface. The descending branch, being the larger one at thoracolumbar levels, forms a hairpin curve as soon as it reaches the midline at the entrance of the anterior fissure (Fig. 17.3). The artery runs above the vein. The maximum diameter of a spinal radiculomedullary artery or the anterior... 

Fig. 17.3. Selective spinal DSA in a 59-year-old woman, p.a. projection. Injection of the 12th left thoracic segmental artery. Filling of the radiculomedullary arteries T12 and T10 on the left side (arrows) and the anterior spinal artery system. Collateral filling of the right-sided segmental arteries via retrocorpo-ral anastomoses (arrowheads). These extradural anastomoses can compensate for focal vessel occlusions at the level of the radicular artery...

Compared with brain ischemia spinal cord strokes are caused by more diverse etiologies. Up-to-now there is no satisfactory and accepted classification of spinal infarcts. Etiologies include circulatory arterial and venous disorders. From a clinical and pathoanatomical point of view it seems reasonable to differentiate between acute ischemic myelomalacia and subacute to chronic vascular myelopathy (Table 17.1). In most cases MRI enables the differentiation of these two main etiologies. A deficient spinal arterial blood flow generally has various causes, ranging from the occlusion of intercostal or lumbar arteries to affection of the intrinsic arteries of the spinal cord. ... 

AVMs of the perimedullary fistula type are direct AV shunts that are located on the ventral or dorsal surface of the spinal cord or the conus medullaris, usually in the thoracolumbar area, occasionally thoracic, and rarely cervical. Their location thus is intradural, intra- or extramedullary. They are always supplied by spinal cord vessels, either by the anterior spinal artery (ventrally) or by a posterolateral artery (dorsally), depending on their location. They drain into spinal cord veins (Fig. 17.12). Drainage may even ascend up to the foramen magnum or into the posterior fossa. 

Even if spatial and contrast resolution of these imaging modalities will increase in the future, it might be difficult to differentiate the artery from the vein on the anterior surface of the cord. The anterior spinal artery and vein run very close together. The branching of a radicular artery or vein has a very similar hairpin-configuration, and the level at which a segmental in- or outflow occurs cannot be predicted in a given case. 

Selective spinal DSA has a better spatial resolution and plays a main role in the exclusion of spinal vascular malformations. In selected cases affection of the radicular artery and occlusion of the anterior spinal artery system can be demonstrated as well as collateral supply even in the later course of the ischemia (Mull et al. 2002). Thus, spinal DSA helps to identify pathologic vascular conditions in spinal cord ischemia. The main indication remains to exclude a spinal vascular malformation. Angiographic information about the acute phase of spinal cord ischemia is not yet available. 

Aminoff MJ, Barnard RO, Logue V (1974) The pathophysiology of spinal vascular malformations. J Neurol Sci 23 255-263 Backes W, Nijenhuis R, Mull M, Thron A, Wilmink J (2004) Contrast-Enhanced MR Angiography of the Spinal Arteries Current Possibilities and Limitations. Rivista di Neuro-radiologia 17 (3) 282-291... 

Haddad MC, Aabed al-Thagafi MY, Djurberg H (1996) MRI of spinal cord and vertebral body infarction in the anterior spinal artery syndrome. Neuroradiology 38 161-162 HasslerW, Thron A, Grote EH (1989) Hemodynamics of spinal dural arteriovenous fistulas. An intraoperative study. JNeu-rosurg 70 360-370... 

Mascalchi M, Cosottini M, Ferrito G, Salvi F,Nencini P, Quilici N (1998) Posterior spinal artery infarct. AJNR Am J Neuroradiol 19 361-363... 

Rosenblum B, Oldfield EH, Doppman JL, Di Chiro G (1987) Spinal arteriovenous malformations a comparison of dural arteriovenous fistulas and intradural AVM s in 81 patients. J Neurosurg 67 795-802 Rosenkranz M, Grzyska U, Niesen W, Fuchs K, Schummer W, Weiller C, Rother J (2004) Anterior spinal artery syndrome following periradicular cervical nerve root therapy. J Neurol 251 229-231... 

Spiller W (1909) Thrombosis of the cervical anterior median spinal artery. I Nerv Ment Dis 36 601 Stein SC, Ommaya AK, Doppman JL, Di Chiro G (1972) Arteriovenous malformation of the cauda equina with arterial supply from branches of the internal iliac arteries. Case report. J Neurosurg 36 649-651 Stepper F, Lovblad KO (2001) Anterior spinal artery stroke demonstrated by echo-planar DWI. Eur Radiol 11 2607-2610 Suh T.H., Alexander L (1939) Vascular system of the human spinal cord. Arch Neurol Psychiat 41 659-677 Suzuki T, Kawaguchi S, Takebayashi T, Yokogushi K, Takada J, Yamashita T (2003) Vertebral body ischemia in the posterior spinal artery syndrome case report and review of the literature. Spine 28 E260-264... 

The posterior cerebral artery supplies the occipital lobe and portions of the medial and inferior temporal lobe. The arterial supply of the spinal cord is derived from the vertebral arteries and the radicular arteries. The brain is supplied by the internal carotid arteries (the anterior circulation) and the vertebral arteries, which join at the pon tomedullary junction to form the basilar artery (collectively termed the posterior circulation). The brainstem is supplied by the posterior system. The medulla receives blood from branches of the vertebral arteries as well as from the spinal arteries and the posterior inferior cerebellar artery (PICA). The pons is supplied by paramedian and short circumferential branches of the basilar artery. Two major long circumferential branches are the anterior inferior cerebellar artery (AICA) and the superior cerebellar artery. The midbrain receives its arterial supply primarily from the posterior cerebral artery as well as from the basilar artery. The venous drainage of the spinal cord drains directly to the systemic circulation. By contrast, veins draining the cerebral hemispheres and brain stem drain into the dural sinuses. Cerebrospinal fluid also drains into the dural sinuses through unidirectional valves termed arachnoid villi. 

The authors suggested that the neurological deficit had been due to anterior spinal artery insnfficiency secondary to intrathecal bupivacaine and adrenahne. They questioned the use of adrenaline in patients with mnlti-organ vascular disease. 

Communications between bronchial arteries and systemic vessels are ubiquitous, and can sometimes complicate an embolization procedure. The most commonly seen communication is that of a right intercostobronchial trunk with an anterior medullary artery that contributes to the vascular supply of the spinal cord through the anterior spinal artery. The anterior medullary arteries have a characteristic hairpin configuration, and follow a course... 

Fig. 16.6. a Selective angiography of right inter-costobronchial trunk, early phase, b Selective angiography of right intercostobronchial trunk, late phase demonstrating thin arterial structure, with course parallel to vertebral column anterior spinal artery (arrowheads)... 

Because transvenous embolization is not feasible for spinal lesions, transarterial embolization with glue is the treatment of choice for a spinal DAVM with an arterial feeder that allows safe and distal catheterization and does not supply the anterior spinal artery. Glue should be pushed until it reaches the draining vein (Fig. 4.18) (Cognard et al. 1996 Song et al. 2001). Clinical outcome seems to dependent on the severity of the symptoms at the time of treatment (Nagata et al. 2006). 

The treatment of spinal DAVM by surgery is easy, safe, and effective and requires interruption of the draining vein at its dural entrance only (Anson and Spetzler 1992). Therefore, embolization of spinal DAVM should be offered only if the feeding pedicle provides a safe approach to a position close to the fistula site and it does not give rise to radiculomedullary branches supplying the anterior spinal artery. If there is a risk of reflux into the anterior spinal artery, surgery is significantly safer and should be performed. 

Saccular aneurysms of spinal arteries are rare. The clinical features of spinal SAH are usually associated with those of a transverse spinal cord lesion but may mimic SAH due to an intracranial aneurysm (Mohsenipour et al. 1994, Kocak et al. 2006). 

Lavoie P, Raymond J, Roy D, Guilbert F, Weill AJ (2007) Selective treatment of an anterior spinal artery aneurysm with endosaccular coil therapy. Case report. Neurosurg Spine 6(5) 460-464... 

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