Epstein Nancy E
Clinical Professor of Neurological Surgery, School of Medicine, State Univeristy of NY at Stony Brook, New York, United States.
Surg Neurol Int. 2020 Oct 2;11:320. doi: 10.25259/SNI_555_2020. eCollection 2020.
Following acute cervical spinal cord decompression, a subset of patients may develop acute postoperative paralysis due to Reperfusion Injury (RPI)/White Cord Syndrome (WCS). Pathophysiologically, this occurs due to the immediate restoration of normal blood flow to previously markedly compressed, and under-perfused/ischemic cord tissues. On emergent postoperative MR scans, the classical findings for RPI/ WCS include new or expanded, and focal or diffuse intramedullary hyperintense cord signals consistent with edema/ischemia, swelling, and/or intrinsic hematoma. To confirm RPI/WCS, MR studies must exclude extrinsic cord pathology (e.g. extramedullary hematomas, new/residual compressive disease, new graft/vertebral fracture etc.) that may warrant additional cervical surgery to avoid permanent neurological sequelae.
In the English literature (i.e. excluding 2 Japanese studies), 9 patients were identified with postoperative RPI/WCS following cervical surgical procedures. For 7 patients, new acute postoperative neurological deficits were appropriately attributed to MR-documented RPI/WCS syndromes (i.e. hyperintense cord signals). However, for 2 patients who neurologically worsened, MR studies demonstrated residual extrinsic disease (e.g. stenosis and OPLL) warranting additional surgery; therefore, these 2 patients did not meet the criteria for RPI/WCS.
The diagnosis of RPI/WCS is one of exclusion. It is critical to rule out residual extrinsic cord compression where secondary surgery may improve/resolve neurological deficits.
Patients with acute postoperative neurological deficits following cervical spine surgery must undergo MR studies to rule out extrinsic cord pathology before being diagnosed with RPI/WCS. Notably, 2 of the 9 cases of RPI/WCS reported in the literature required additional surgery to address stenosis and OPLL, and therefore, did not have the RPI/WCS syndromes.
急性颈椎脊髓减压术后，部分患者可能因再灌注损伤（RPI）/白脊髓综合征（WCS）而出现急性术后瘫痪。从病理生理学角度来看，这是由于先前明显受压且灌注不足/缺血的脊髓组织立即恢复正常血流所致。在术后紧急磁共振成像（MR）扫描中，RPI/WCS的典型表现包括新出现或扩大的、局灶性或弥漫性的髓内高信号脊髓信号，与水肿/缺血、肿胀和/或内源性血肿一致。为确诊RPI/WCS，MR研究必须排除可能需要额外颈椎手术以避免永久性神经后遗症的脊髓外病变（如髓外血肿、新的/残留的压迫性疾病、新的移植物/椎体骨折等）。
在英文文献（即不包括2篇日本研究）中，确定了9例颈椎手术后发生术后RPI/WCS的患者。对于7例患者，新出现的急性术后神经功能缺损被合理归因于MR记录的RPI/WCS综合征（即脊髓高信号）。然而，对于2例神经功能恶化的患者，MR研究显示存在残留的脊髓外疾病（如狭窄和后纵韧带骨化），需要额外手术；因此，这2例患者不符合RPI/WCS的标准。
RPI/WCS的诊断是一种排除性诊断。排除可能通过二次手术改善/解决神经功能缺损的残留脊髓外压迫至关重要。
颈椎手术后出现急性术后神经功能缺损的患者在被诊断为RPI/WCS之前必须接受MR研究以排除脊髓外病变。值得注意的是，文献中报道的9例RPI/WCS病例中有2例需要额外手术来处理狭窄和后纵韧带骨化，因此，并不患有RPI/WCS综合征。
