SPINAL-CORD ISCHEMIA DIAGNOSED BY MRI - CASE-REPORT AND REVIEW OF THELITERATURE

The purpose of this paper is to report a case of medullary ischemia di agnosed by MRI and to determine any MRI characteristics that may be us eful for the diagnosis in the light of the published data. The patient was a 60 year-old male with hypertension and diabetes, referred to us for flaccid paraparesis and sphincter disorders of acute onset, Physi cal examination revealed, beside flaccid paraparesis, both superficial and deep hypoes thesia at L1 level and greater on the right. MRI show ed a small area of signal hyperintensity on T2 weighted images and in proton density localized in the posterior part of the spinal cord at t he level of T12 body. The patient was treated with oral antidiabetic, antiaggregant and antihypertensive drugs as well as neuromotor rehabil itation, and his clinical conditions improved; a control MRI, six mont hs later, showed disappearance of the previous finding and only mild m edullary atrophy at the level of the lesion. Medullary ischemia has be en observed in a variety of pathological conditions (inflammatory, neo plastic, traumatic degenerative and iatrogenic), and most frequently i nvolves the dorsal portion of the spinal cord. Four clinical-pathologi cal manifestations of medullary ischemia have been described: infarcti on from occlusion of the anterior spinal artery; ''patchy'' or ''lacun ae infarction''; ''transverse ischemic infarction''; selective ischemi a in the regions of the posterior spinal arteries. A review of the lit erature yielded 61 cases of spinal ischemia diagnosed by MRI for a tot al number of 80 MRI scans, 12 of which were long-term controls. In 41 % of cases, T1 weighted images performed at clinical onset showed enla rgement of the spinal cord and imaged a lesion that was isointense in 70 % of cases, hypointensive in 18 % and hyperintense in 11 %. On T2 w eighted images the, lesion appeared hyperintense in 92.5 % of the case s and isointense in 7.4 %. Intravenous gadolinium produced enhancement in 70 % of cases. Concomitant hyperintensity of the vertebral body im mediately below the medullary lesion proved useful for diagnosis of me dullary ischemia. The finding is appreciable mainly in cases of aortic occlusion and is attributable to bone ischemia secondary to occlusion of the anterior and posterior central arteries. Although some MRI fea tures may be suggestive for the diagnosis of medullary ischemia (isohy pointense area on T1, hyperintense on T2 with i.v. gadolinium enhancem ent more evident around the 5th-6th day after clinical onset; concomit ant hyperintensity on T2 at the level of the vertebral body below the spinal pathology), at the moment a definite diagnosis of medullary isc hemia by MRI does not seem feasible. For this purpose, descriptions of larger case-series will undoubtedly be helpful for solving the proble ms of differential diagnosis connected with this pathology.