Spontaneous Spinal Cord Herniation: MR Imaging and Clinical Features in Six Cases

Abstract

Spontaneous spinal cord herniation (SSCH) is a rare but important differential diagnosis of spinal cord disorder. The aim of this study was to evaluate the topography and lesion pattern in six patients with SSCH by magnetic resonance imaging (MRI) and their correlation with clinical symptoms. MRI was evaluated according to intramedullary hyperintense signal changes, alterations of the posterior vertebra and dorsal subarachnoid space at the level of the herniation. Neurologic symptoms as well as their progression were analyzed. SSCH occurred between the level of T3–T7 and were demonstrated best on sagittal and axial T2-weighted images (T2-WI). Hyperintense signals on T2-WI were seen in five patients. Dorsal margins of the vertebra at the level of herniation were scalloped in three patients and one patient showed a sagittal cleft. Mean time from the initial clinical symptoms to diagnosis was 4.2 years. Incomplete Brown-Sequard’ syndrome was the most common clinical presentation in our patients (four cases). SSCH is best diagnosed using multiplanar T2-WI with characteristic imaging findings of herniation and adjacent structures. Coexistent notches or even sagittal clefts in the dorsal vertebra raise the hypothesis that SSCH might originate from malfusion of the notochord.