Diffusion-weighted MRI of spinal cord infarction. Description of two cases and review of the literature

Spinal cord infarctions occur rarely and are due to various aetiologies. In an emergency setting with acute spinal cord symptoms, magnetic resonance imaging (MRI) is used to exclude space-occupying lesions which require neurosurgical intervention. We report on two patients presenting with an anterior spinal artery syndrome caused by infarction of the thoracolumbar spinal cord including the conus medullaris. While T2-weighted images 4 h and 28 h after onset of clinical symptoms showed only slight unspecific signal changes, diffusion-weighted imaging revealed clear infarction and detected spinal cord ischaemia in an early stage, showing signal intensity conversion comparable to that in acute cerebral stroke.     

Post-epidural analgesia spinal cord infarction: MRI correlation

Permanent neurological deficits after epidural analgesia are rare, but have long been believed to be caused by cord ischaemia when no obvious cause is demonstrable. The mechanisms of this injury are uncertain, but a literature review suggests important risk factors. We report a first case of extensive spinal cord infarction confirmed by magnetic resonance imaging (MRI) following post-thoracotomy epidural analgesia and review the literature to explain the mechanism underlying this devastating complication.     

Diffusion-weighted imaging of the spinal cord

Spinal cord DWI may be useful in providing information not available with conventional MR imaging. More work, however, is required to explain what the qualitative and quantitative results actually represent. Computer simulations and detailed radiologic-histologic correlations will therefore be necessary.     

Diffusion-weighted MRI and the evaluation of spinal cord axonal integrity following injury and treatment

Diffusion-based magnetic resonance imaging (MRI) (DWI) has been shown experimentally to detect both injury and functionally significant neuroprotection of injured spinal cord white matter that would otherwise go undetected with conventional MRI techniques. The diffusion of water in the central nervous system (CNS) is thought to be affected by both its location (intracellular or extracellular), and by diffusion barriers formed by cell membranes and myelin sheaths. There is, however, controversy concerning how to obtain, interpret, and present DWI data. Computer simulations and MR microscopy have been helpful in resolving some of these issues, as well as determining exact histologic correlates to DWI findings.     

脊髓梗死的临床和MRI特点分析

目的 探讨脊髓梗死的临床及MRI特点. 方法回顾分析11例脊髓梗死病例的临床及MRI资料. 结果脊髓梗死急性起病,呈卒中样病程.主要表现为疼痛、瘫痪、分离性感觉障碍及括约肌功能障碍.MRI T1WI低信号,T2WI高信号,DWI高信号.横轴位显示病变位于脊髓前2/3区域.结论 脊髓梗死表现为脊髓前动脉综合征,MRI可多方位、多参数扫描,为诊断提供重要依据.     

Role of diffusion MRI in diagnosis of spinal cord infarction in children

Anterior spinal artery (ASA) infarction is a rare but well-described cause of flaccid paraparesis in adults, presenting with a high thoracic spinothalamic sensory level and preservation of dorsal column function. Careful sensory examination, demonstrating loss of spinothalamic modalities with preservation of dorsal column modalities, supports a clinical diagnosis of ASA infarction. Findings on conventional MRI of the spinal cord are often non-specific, and diffusion-weighted imaging (DWI) is not routinely performed. We describe four children with ASA infarction after minor trauma. DWI was performed in all cases and confirmed the clinical diagnosis.     

Diffusion-weighted imaging of the spinal cord and optic nerve

The optic nerve and spinal cord are technically challenging to investigate with any magnetic resonance imaging (MRI) technique due to the effect of the surrounding cerebrospinal fluid and lipid, and the presence of nearby bony structures. Motion and the relatively small cross-section of the structures make diffusion-weighted imaging even harder. With careful choice of pulse sequence and parameters, however, apparent diffusion coefficient (ADC) measurements are now possible in the optic nerve, and both ADC and diffusion tensor imaging (DTI) measurements are becoming available in the spinal cord.     

MRI of spinal cord in MS

Over the last 10 - 15 years, magnetic resonance imaging techniques have had a major impact in understanding and managing multiple sclerosis. The present review briefly summarises the current usefulness of spinal cord MRI in MS disease, examining the frequency, distribution and main characteristics of spine MS plaques; the differential diagnosis with other spinal cord disease was also described. Finally we considered how newer imaging sequences when added to semi-automated quantitative methods, may give us a putative tool to reliably quantify subtle changes which develop on the spinal cord of MS patients over time.     

Cholinergic enzymes in spinal cord infarction

Activities of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) were studied in the ventral and dorsal horns and the intermediate zone of the rabbit lumbar spinal cord (L 4–7) 24 and 96 h after ischemia caused by 20 or 40 min occlusion of the abdominal aorta. Changes of AChE and butyrylcholinesterase (BChE) activities were also detected histochemically by the direct thiocholine method. No significant changes were found immediately after ischemia. The most remarkable change after 20 min ischemia and 1 or 4 d of reperfusion was heterogenous decrease in ChAT and AChE activities in the examined parts of gray matter. The highest loss of enzyme activities was found in the ventral horns and the lowest in dorsal horns. Following 40 min ischemia and reperfusion the significant depletion in enzyme activities in all investigated zones of the gray matter was accompanied with necrotic degenerative changes. There was a relatively greater decrease in ChAT and AChE activities in the ventral horns that corresponded with a more prominent morphological damage of the cholinergic neurons in this zone of the spinal cord.     

Nonhemorrhagic venous infarction of the spinal cord

A 71-year-old man experienced gradually progressive leg weakness, urinary retention, and mild loss of sensation in dermatomes T8 through T12 bilaterally. After 5 to 6 weeks of illness, he developed flaccid paraplegia and sensory loss below T8. He died 16 weeks after onset of neurological symptoms. Neuropathologically, there was widespread, subtotal necrosis of the spinal cord, largely of nonhemorrhagic character, from T8 downward. Dorsal and anterior median spinal veins were occluded by a partially organized thrombus. Comparison of this case with 19 previously recorded examples of venous infarction of the spinal cord (8 hemorrhagic, 7 nonhemorrhagic, and 4 embolic) suggests major differences in clinical presentation, rate of progression, and length of survival among the three groups.     

Hypotensive central infarction of the spinal cord.

A case of selective necrosis of the central grey matter of the caudal spinal cord secondary to severe prolonged hypotension is presented. The hypotension was due to localised dissection of the ascending aorta which did not interfere structurally with any of the spinal cord vasculature.     

Peripheral neurophysiology of acute distal spinal cord infarction

F-wave abnormalities, in the presence of normal distal motor nerve conduction, most often are the first indicators of proximal peripheral nerve dysfunction in demyelinating polyradiculoneuropathies. However, a 15-year-old female-who developed lumbosacral spinal cord infarction with paraplegia, sensory loss, and incontinence beginning 15 hours after a fall-studied electrophysiologically at 2 days postparaplegia manifested absent lower-extremity f-waves and H-reflexes and normal compound muscle action potentials and distal motor and sensory conduction velocities. Subsequent evaluations demonstrated permanent loss of compound muscle action potentials, f-waves, and H-reflexes and prominent acute denervation in paralyzed lower-extremity muscles. Thus early f-wave and H-reflex loss can also occur in spinal cord disease, thereby representing the first evidence of motoneuron destruction.