Layton, Kennith F.

Object Enhancement of pathological entities in the central nervous system is a common finding when the blood–brain barrier has been compromised. In the brain, the presence or absence of gadolinium enhancement is often an indicator of tumor invasiveness and/or grade. In the spinal cord, however, contrast enhancement has been shown in all tumor types, regardless of grade. In this study the authors explore the incidence of nonenhancing tumors of the spinal cord and the clinical course of patients with these lesions. Methods A retrospective analysis was conducted in which investigators examined the patterns of enhancement of histologically proven intramedullary spinal cord tumors that had been evaluated at the Mayo Clinic between 1998 and 2002. The tumors that did not enhance were the subject of this report. Results A total of 130 patients with intramedullary tumors were evaluated. Of those, 11 patients (9%) had tumors that did not enhance. Histologically, a majority of tumors were astrocytomas (eight low-grade and two high-grade lesions); one tumor was a subependymoma. Morphologically, most of the tumors were diffuse and none had associated cysts. Tumors spanned from two to seven levels and were located throughout the spinal cord (four cervical, three cervicothoracic, one thoracic, and three thoracolumbar). Biopsy procedures were performed in eight patients, subtotal resection was performed in two, and gross-total resection in one. After a mean follow-up period of 19 months, tumors remained stable in eight patients but progressed in three, two of whom died. Conclusions A number of intramedullary spinal cord tumors will not enhance after addition of contrast agents. The absence of enhancement does not imply the absence of tumor.

Abstract Vertebroplasty alters spinal biomechanics and may lead to incident vertebral fractures. The endplate localization of prevalent and incident fractures was evaluated in 86 patients. In the absence of vertebroplasty, superior endplate fractures predominate. After the procedure, inferior endplate fractures are disproportionately common in adjacent vertebrae immediately above the treated level, potentially supporting a causative relationship between vertebroplasty and incident fractures. Introduction: To determine retrospectively whether new-onset fractures after vertebroplasty tend to cluster in the endplate immediately adjacent to the cemented vertebra. Materials and Methods: Institutional Review Board approval and patient consent for use the use of medical records were obtained for this study. We performed a retrospective review of patients with new (incident) vertebral fractures after vertebroplasty. The median age for these patients was 72.5 years, and 58 (67.4%) were women. Fractures were diagnosed on the basis of MRI or bone scan and were catalogued based on their location within the vertebral body (superior endplate, inferior endplate, or holo-vertebral). χ2 and generalized estimating equation (GEE) analyses were used to compare the distribution of fracture subtypes among pre-existing (prevalent) and incident fractures. Results: The patients had 313 prevalent osteoporotic vertebral fractures and were treated at 137 vertebral levels. Among prevalent fractures, superior endplate fractures predominated (57% superior, 11% inferior; p < 0.0001). After vertebroplasty, 186 incident fractures developed in these 86 patients. Seventy-seven (41%) of these incident fractures occurred adjacent to treated vertebrae. Nonadjacent, incident fractures, like prevalent fractures, occurred predominantly along superior endplate. Incident fractures immediately above treated levels, however, localized disproportionately to the inferior endplate (30% superior, 57% inferior; p < 0.0001). Conclusions: There are an increased number of inferior endplate fractures of the vertebral body immediately cephalad to the treated level.