Department of Neurosurgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Lucknow, 226014, India.
Department of Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Lucknow, 226014, India.
Acta Neurochir (Wien). 2019 Jan;161(1):147-159. doi: 10.1007/s00701-018-3721-7. Epub 2018 Nov 20.
Dynamic magnetic resonance imaging (MRI)-based criteria for diagnosing magnitude of tethered cord syndrome (TCS) in occult spinal dysraphism are proposed.
In this prospective, case-control design study, MRI lumbosacral spine was performed in 51 subjects [pilot group (n = 10) without TCS (for defining radiological parameters), control group (n = 10) without TCS (for baseline assessment), and study group (n = 31) with spinal dysraphism (thick filum terminale [n = 12], lumbar/lumbosacral meningomyelocoele [n = 6], and lipomyelomeningocoele [n = 13])]. The parameters compared in control and study groups included oscillatory frequency (OF), difference in ratio, in supine/prone position, of distance between posterior margin of vertebral body and anterior margin of spinal cord (oscillatory distance [OD]), with canal diameter, at the level of conus as well as superior border of contiguous two vertebrae above that level; delta bending angle (ΔBA), difference, in supine/prone position, of angle between longitudinal axis of conus and that of lower spinal cord; and sagittal and axial root angles, subtended between exiting ventral nerve roots and longitudinal axis of cord. An outcome assessment at follow-up was also done.
In the study group (cord tethered), significantly less movement at the level of conus (OF0, p = 0.013) and one level above (OF1, p = 0.03) and significant difference in ΔBA (p = 0.0) were observed in supine and prone positions, compared to controls. Ventral nerve root stretching resulted in sagittal/axial root angle changes. Median OF (0.04) in the lipomyelomeningocoele group was significantly less than that in control group (0.23). Median OF was also lesser in patients with thick filum terminale or meningomyelocele. Difference in median sagittal and axial root angles among the study and control groups was statistically significant (p = 0.00).
New dynamic MRI-based parameters to establish the presence and magnitude of TCS have been defined. OF measured the extent of loss of translational cord displacement in supine and prone positions; ΔBA defined the relative angulation of conus with lower spinal cord, and sagittal and axial root angles represented ventral nerve root stretching. The difference in OF or ΔBA was minimum in the group with thick filum terminale and progressively increased in the groups with lipomyelomeningocele and meningomyelocele.
提出了一种基于动态磁共振成像（MRI）的方法，用于诊断隐性脊柱裂性脊髓栓系综合征（TCS）的严重程度。
在这项前瞻性病例对照设计研究中，对 51 名受试者的腰骶部 MRI 进行了检查[ 试点组（n=10）无 TCS（用于定义影像学参数）、对照组（n=10）无 TCS（用于基线评估）和研究组（n=31）有脊柱裂（厚终丝[n=12]、腰骶部脊膜脊髓膨出[n=6]和脂肪脊膜脊髓膨出[n=13]）]。在对照组和研究组中比较的参数包括振荡频率（OF）、仰卧位/俯卧位比值差、椎体后缘与脊髓前缘之间距离（振荡距离[OD]）与椎管直径的比值，在圆锥水平以及该水平以上连续两个椎体的上缘；弯曲角度差（ΔBA），仰卧位/俯卧位时圆锥和脊髓下段纵轴之间的角度差；矢状面和轴位神经根角度，由腹侧神经根与脊髓纵轴之间的夹角组成。还进行了随访时的结局评估。
在研究组（脊髓受牵拉）中，与对照组相比，在圆锥水平（OF0，p=0.013）和上一个水平（OF1，p=0.03）的运动明显减少，并且在仰卧位和俯卧位时 ΔBA 差异显著（p=0.0）。腹侧神经根拉伸导致矢状/轴位神经根角度发生变化。脂肪脊膜脊髓膨出组的中位 OF（0.04）明显小于对照组（0.23）。终丝增厚或脊膜脊髓膨出患者的中位 OF 也较小。研究组和对照组之间的中位矢状面和轴位神经根角度差异具有统计学意义（p=0.00）。
定义了新的基于动态 MRI 的参数来确定 TCS 的存在和严重程度。OF 测量了仰卧位和俯卧位时脊髓位移平移损失的程度；ΔBA 定义了圆锥与下段脊髓的相对角度，矢状面和轴位神经根角度代表腹侧神经根拉伸。在终丝增厚组中，OF 或 ΔBA 的差异最小，而在脂肪脊膜脊髓膨出组和脊膜脊髓膨出组中逐渐增加。
