Vitamin B12 extensive thoracic myelopathy: clinical, radiological and prognostic aspects. Two cases report and literature review.

The myelopathy caused by vitamin B12 deficiency is known as subacute combined degeneration. It is rare, but a well known cause of demyelination of the dorsal columns of the spinal cord. The magnetic resonance imaging is characterized by an increased signal on T2-weighted images involving the posterior columns of cervical and thoracic cord. There have been few cases in literature with extensive lesions (more than seven levels) of the thoracic spinal cord. The clinical and radiological improvements are possible if the replacement of vitamin B12 is initiated precocious. We present two rare cases of extensive thoracic myelopathy due to vitamin B12 deficiency. The first is a young woman with complete clinical recovery and important radiologic improvement after early treatment. In addition, the second case is an older man with partial response to the treatment. Those cases illustrate the importance of considering vitamin B12 deficiency in any patient, who presents with myelopathy.