MRI in vitamin B-12 deficiency myelopathy

Background: Little is known about vitamin B-12 deficiency myelopathy's magn etic resonance imaging (MRI) manifestations and their relationship to the o nset, evolution, and resolution of neurologic signs and symptoms. Methods: We present a case and review eleven additional reported cases of subacute c ombined degeneration of the spinal cord detected by MRI, Results: Our patie nt had increased T2-weighted signal and gadolinium contrast enhancement of the posterior columns in the cervical and thoracic regions and enhancement of the lateral columns in the high cervical region. This is a case with ima ging evidence for lateral column lesions. Two prior reports have shown post erior column enhancement. T1-weighted images may show decreased signal in t he posterior columns and sometimes demonstrate reversible spinal cord swell ing. MRI abnormalities typically improve after vitamin replacement therapy. However, clinical signs may persist despite resolution of imaging abnormal ities, and these abnormalities do nor always resolve completely. In additio n, symptoms may precede the imaging abnormality. Conclusions: Vitamin B-12 deficiency may produce an increased T2-weighted signal, decreased T1-weight ed signal, and contrast enhancement of the posterior and lateral columns of the spinal cord, mainly of the cervical and upper thoracic segments. Becau se the symptoms may precede any imaging abnormality, it is clear that spina l cord MRI may not be a highly sensitive, early test for subacute combined degeneration.