Keegan, B. Mark

Objective To highlight a specific under‐recognized radiological feature of spondylotic myelopathy often resulting in misdiagnosis. Methods Patients evaluated between January 1, 1996 and December 31, 2012 who met the following criteria were included: (1) spondylotic myelopathy was suspected, (2) gadolinium enhancement was detected, and (3) spinal surgery was performed. Results Fifty‐six patients (70% men) whose median age was 53.5 years (range = 24–80) were included. Spinal cord magnetic resonance imaging (cervical in 52; thoracic in 4) revealed longitudinal spindle‐shaped T2‐signal hyperintensity (100%) and cord enlargement (79%) accompanied by a characteristic pancakelike transverse band of gadolinium enhancement in 41 (73%), typically immediately caudal to the site of maximal spinal stenosis. Forty (71%) patients were initially diagnosed with neoplastic or inflammatory myelopathies, and decompressive surgery was delayed by a median of 11 months (range = 1–64). Spinal cord biopsy in 6 did not reveal any alternative diagnosis. Ninety‐five percent were stable or improved. Gadolinium enhancement persisted in 75% at 12 months, raising concern about the accuracy of the initial diagnosis. Twenty patients required a gait aid (36%) at last follow‐up (median = 60 months, range = 10–172). The need for a gait aid preoperatively ( p = 0.005), but not delay of surgery, predicted the need for gait aid at final follow‐up. Interpretation Transverse pancakelike gadolinium enhancement associated with and just caudal to the site of maximal stenosis and at the rostrocaudal midpoint of a spindle‐shaped T2 hyperintensity suggests that spondylosis is the cause of the myelopathy. Persistent enhancement for months to years following decompressive surgery is common. Recognition is important to prevent inappropriate interventions or delay in consideration of a potentially beneficial decompressive surgery. Ann Neurol 2014;76:54–65