What Is the Evidence?

Abstract

ProblemA 9-year-old spayed female Miniature Pinscher was evaluated at the University of Illinois Small Animal Clinic because of a 1-month history of progressive weakness of all 4 limbs. At that time, physical examination revealed a body condition score of 5/9 (ideal) and the dog had nonambulatory tetraparesis. A neurologic examination revealed an absence of conscious proprioception in all 4 limbs. A pain response was elicited during flexion, extension, and lateral manipulation of the dog' s neck. All other physical and neurologic findings were unremarkable. A tentative diagnosis of compressive cervical intervertebral disk disease was made. To confirm this diagnosis and devise an optimal treatment plan, diagnostic imaging was necessary.The owners were willing to pursue any necessary diagnostic testing and treatment for their pet; finances were not an issue. Their expectations included the best patient care with the least amount of pain and complications. Diagnostic imaging methods available at the University of Illinois for evaluation of the cervical aspect of the spinal cord consisted of survey radiography, myelography, computed tomography (CT), and lowfield magnetic resonance imaging (MRI). Formulation of the Clinical QuestionThe problem identified was a potential disk compression of the cervical spinal cord. The desired outcome was accurate identification of the site of suspected spinal cord compression. Ability to assess the extent of the extrusion of intervertebral disk material was also needed. This diagnostic information was considered of high importance for planning a surgical procedure for spinal cord decompression and was therefore critical for a successful outcome. Clinical QuestionFor the diagnosis of cervical intervertebral disk disease in dogs, which imaging method is most accurate in identifying the location and assessing the extent of a lesion? Evidentiary Search StrategyTo make a well-informed decision, an evidencebased approach was used. A targeted literature search,In cooperation with directed by the supervising clinician, was used to obtain recent and relevant articles for evaluation.The PubMed database was searched on July 16, 2009, with the full term canine cervical intervertebral disk disease and diagnosis. A 20-minute search yielded 30 reports; however, none of these reports included information on all of the imaging methods in question. Therefore, a broader search was performed with the abbreviated term canine intervertebral disk disease, resulting in the identification of 135 items in the English language, including 21 literature reviews. Titles were used first, followed by abstracts, to narrow the search focus by eliminating review articles and case series reports and including only studies in which diagnostic test performance was evaluated by direct comparison between 2 tests, deriving the sensitivity and specificity of a given test relative to a criterion-reference (gold) standard, or comparing testing process-associated complications between tests. Review of the EvidenceRetrospective ...