Becerra J L, Puckett W R, Hiester E D, Quencer R M, Marcillo A E, Post M J, Bunge R P
Department of Radiology, University of Miami School of Medicine, FL 33101.
AJNR Am J Neuroradiol. 1995 Jan;16(1):125-33.
To describe the MR manifestations and temporal course of wallerian degeneration that occurs above and below a spinal cord injury, and to compare the MR findings with postmortem histopathology.
Twenty-four postmortem spinal cords from patients with cervical (n = 14), thoracic (n = 6), and lumbar (n = 4) cord injuries were studied with axial T1- and T2-weighted spin-echo MR imaging. Injury-to-death intervals varied from 8 days to 23 years. The images were examined for alteration of signal above and below the injury site. Histologic studies of these cords with axon, myelin, and connective tissue stains were performed at levels equivalent to the MR sections. Immunohistochemical analysis using antibodies to glial fibrillary acetic protein was also performed on 19 cords. Pathologic-imaging comparisons were made.
MR images showed increased signal intensity in the dorsal columns above the injury level and in the lateral corticospinal tracts below the injury level in all cases in which cord injury had occurred 7 or more weeks before death. In early postinjury survival times (8 days and 12 days) MR findings were normal; histologically there was early wallerian degeneration in only the dorsal columns at 8 days and in both the lateral and dorsal columns at 12 days. MR showed wallerian degeneration in all cases examined at 7 weeks after injury and thereafter.
Wallerian degeneration was demonstrated by histology and MR in all specimens in which the injury-to-death interval was greater than 7 weeks. Recognition of wallerian degeneration on MR allows complete analysis of the injury, explains abnormal MR signals at sites remote from the epicenter of the injury, and may be useful in the future in the timing and planning of therapeutic interventions.
描述脊髓损伤上下方发生的华勒氏变性的磁共振成像（MR）表现及时间进程，并将MR表现与尸检组织病理学结果进行比较。
对24例颈椎（n = 14）、胸椎（n = 6）和腰椎（n = 4）脊髓损伤患者的尸检脊髓进行轴向T1加权和T2加权自旋回波MR成像研究。损伤至死亡的间隔时间从8天到23年不等。检查图像中损伤部位上下方的信号改变。对这些脊髓在与MR切片相当的层面进行轴突、髓鞘和结缔组织染色的组织学研究。还对19例脊髓进行了使用抗胶质纤维酸性蛋白抗体的免疫组织化学分析。进行了病理成像比较。
在所有死亡前7周或更长时间发生脊髓损伤的病例中，MR图像显示损伤水平上方的后索和损伤水平下方的外侧皮质脊髓束信号强度增加。在伤后早期存活时间（8天和12天），MR表现正常；组织学上，仅在8天时后索出现早期华勒氏变性，12天时外侧和后索均出现早期华勒氏变性。在损伤后7周及之后检查的所有病例中，MR均显示华勒氏变性。
在所有损伤至死亡间隔大于7周的标本中，组织学和MR均显示了华勒氏变性。在MR上识别华勒氏变性有助于对损伤进行全面分析，解释远离损伤中心部位的异常MR信号，并且在未来可能对治疗干预的时机和规划有用。
