Topographic Syndromes

Spinal cord infarction is much rarer than cerebral stroke, but its early recognition is important as it may signify serious aortic conditions. The most frequent type is anterior spinal artery syndrome, presenting with bilateral weakness (usually paraparesis), impairment of spinothalamic sensation and preservation of deep sensation. Depending on its level, it may present with respiratory dysfunction. More rarely, posterior infarcts sparing spinothalamic sensation but involving lemniscal sensation may be encountered. Unilateral, central or transverse infarction may also be seen probably on account of different mechanisms. Other rarer forms of spinal ischemia also include spinal TIAs, venous infarction, fibrocartilaginous embolism and decompression sickness. Copyright © 2012 S. Karger AG, Basel Spinal cord ischemia is much rarer than brain ischemia, it was found to represent only 1% of all strokes in an autopsy series [1]. Aortic diseases are the most frequent cause [2–4]. Diagnosis can be challenging as its clinical manifestations can mimic other myelopathies (mostly inflammatory or infectious) and there is currently no test that is specific and sensitive enough to ascertain the diagnosis. Spinal MR imaging can indeed often detect an acute lesion (67–85% of the cases [3–5]), but diffusion weighted sequences are still too susceptible to artifacts to reliably confirm whether it is ischemic. The spinal vasculature is also impossible to investigate without using invasive angiographic techniques. However, prompt recognition of typical clinical pictures of spinal cord infarction can be lifesaving as they may point a lifethreatening aortic disease (dissection, thrombosis or rupture of an aneurysm) that is potentially treatable if detected early. Spinal cord infarction can be restricted in an arterial territory or be more widespread according its pathogenesis (single artery occlusion versus regional or global hypoperfusion). Spinal cord vascular anatomy is important to understand the semiology of spinal cord ischemia. The spinal cord is supplied by 3 spinal arteries running discontinuously along the spinal cord (fig. 1, left). These arteries (one anterior and two posterior) are supplied by several radicular arteries (often arising from direct aortic branches) accompanying nerve roots mostly in cervical and low thoracolumbar regions (fig. 1, right). The spinal arteries are interconnected by a thin but widespread plexus at the surface of the spinal cord. The anterior spinal artery gives unilateral alternating branches (sulcal arteries). The anterior spinal artery may be duplicated in some regions which could explain the occurrence of unilateral anterior infarction. The anterior spinal artery supplies the anterior twothirds of the spinal cord, the remaining posterior third being supplied by the posterior arteries. We will review here the manifestations of spinal cord infarction and other rarer spinal ischemic conditions. D ow nl oa de d by : S ta nf or d U ni v. M ed . C en te r 19 8. 14 3. 34 .1 1 2/ 11 /2 01 5 9: 27 :1 6 A M