I read with interest the article by Katz and Ropper1 on progressive necrotic myelopathy (PNM). The authors are to be congratulated for providing an informed description of these patients. The authors propose that, based on the clinical, magnetic resonance imaging (MRI), and pathologic findings, these patients lie on a spectrum of diseases linking multiple sclerosis (MS), myelitis, and Devic disease. I agree with their contention. In a recent MRI series,2 we described 22 patients with myelitis imaged by MRI. Similar to the PNM cases, our non-MS myelitis patients showed large longitudinal lesions on T2-weighted images extending over multiple contiguous spinal levels (mean, 7.5 segments) that accompanied spinal cord swelling and normal brain MRI. These cases emphasize that solitary inflammatory demyelinating diseases may appear tumorlike on spinal MRI studies, so caution must be used in selecting patients for biopsy.
Bakshi R. Solitary Inflammatory Demyelination in the Brain or Spinal Cord With Tumor-like MRI Presentations. Arch Neurol. 2001;58(4):677. doi: