Progressive necrotic myelopathy

Objective: To review the clinical, laboratory, and radiological findings of 9 patients who had progressive idiopathic myelopathy with evidence of spin al cord necrosis. Design and Methods: We reviewed personally examined cases of myelopathy tha t fulfilled the following criteria: (1) regional loss of reflexes, flaccidi ty, and muscle atrophy; (2) magnetic resonance imaging showing a shrunken o r cavitated cord without evidence of aterio-venous malformation; (3) electr omyogram showing denervation over several contiguous spinal cord sgements w ith preservation of sensory potentials in some cases; and (4) the absence o f evidence of systemic disease or neoplasm. Results: The illness began in these patients after the age of 40 years, wit h prominent burning or tingling limb pain, occasionally with radicular feat ures or with less well-defined back, neck, or abdominal pain. Leg or infreq uently arm weakness appeared concurrently or soon after the onset of pain. The most distinctive feature was a saltatory progression of symptoms, punct uated by both acute and subacute worsenings approximately every 3 to 9 mont hs, culminating in paraplegia or tetraplegia. The distinguishing clinical f indings, together indicative of destruction of gray matter elements of the cord, were limb atrophy, persistent areflexia, and flaccidity. The concentr ation of cerebrospinal fluid protein was typically elevated between 500 g/L and 1000 g/L, without oligoclonal bands, accompanied infrequently by pleoc ytosis. Magnetic resonance imaging showed features suggesting cord necrosis , specifically swelling, T2-weighted hyperintensity, and gadolinium enhance ment over several spinal cord segments, succeeded months later by atrophy i n the same regions. Necrosis of the cord was found in biopsy material from one patient and postmortem pathology in another case, but inflammation and blood vessel abnormalities were absent. Only 2 patients had prolonged visua l evoked responses. The disease progressed despite immune-modulating treatm ents although several patients had brief epochs of limited improvement. Conclusions: The saltatory course, prolonged visual evoked responses in 2 p atients, and a cranial abnormality on magnetic resonance imaging in another , raised the possibility of a link to multiple sclerosis. However, the norm al cranial magnetic resonance imaging scans in 6 other patients, uniformly absent oligoclonal bands, and poor response to treatment were atypical for multiple sclerosis. On the basis of shared clinical and laboratory features , idiopathic progressive necrotic myelopathy is indistinguishable from a li mited form of Devic disease.