Cervical spondylotic myelopathy due to chronic compression: the role of signal intensity changes in magnetic resonance images.

Abstract

Although there is agreement that low-intensity signal changes on T1-weighted magnetic resonance (MR) images are a prognostic factor for poor outcome after surgical treatment of cervical myelopathy due to chronic cord compression, the role of high-intensity signal changes on T2-weighted images is still controversial. The aim of the present study was to determine whether T2-weighted MR imaging can help assess the prognosis of the disease. A prospective case series study was conducted. The population comprised 67 patients who underwent surgery between 1994 and 2004 to treat myelopathy caused by chronic cervical cord compression. The mean follow-up period was 39 months. Preoperative and postoperative functional status was evaluated using a modified Japanese Orthopaedic Association scale, and the recovery rate was calculated using the Hirabayashi method. Magnetic resonance images were acquired 3 months or less before surgery. High-intensity signal changes were evaluated according to the extent of these changes on T2-weighted sequences; low-intensity T1-weighted signal changes were also evaluated. In patients with low-intensity changes on T1-weighted images and in those with high-intensity changes spanning multiple levels on T2-weighted images, the authors documented a poor functional recovery. Multisegmental high-intensity change on T2-weighted MR imaging is a more sensitive indicator of outcomes than T1-weighted signal changes because of its higher frequency in patients with advanced myelopathy.