Al-Mefty O, Harkey L H, Middleton T H, Smith R R, Fox J L
Department of Neurosurgery, University of Mississippi, Jackson.
J Neurosurg. 1988 Feb;68(2):217-22. doi: 10.3171/jns.1988.68.2.0217.
Eighteen cases are presented in which magnetic resonance (MR) imaging demonstrated two types of lesions in patients with cervical spondylotic myelopathy. In the first type, localized spinal cord changes at the level of compression, consistent with myelomalacia, were revealed best with T2-weighted images as high-intensity spinal cord signals. In the second type, lesions consistent with either cystic necrosis or secondary syrinx were noted locally, and/or extending longitudinally up, and/or down inside the spinal cord. These latter lesions were best revealed as low-intensity signals on T1-weighted MR images and as a signal-void sign (moving fluid) on proton-density or T2-weighted MR images. It is suggested that segmental lesions at the level of the spondylotic bar represent early proton changes from pressure in and around the same zones that evolve into gray-matter enhancement regions shown as "snake-eyes" on delayed computerized tomography (CT) after myelography. The longitudinal lesions are thought to be the same pencil-shaped zones of cystic necrosis evolving into a secondary syrinx in the late stages (and usually found in the anterior portion of the dorsal columns during delayed CT after myelography). As spinal MR imaging continues to improve, these lesions will be demonstrated more clearly within the cord substance.
