Acute and subacute myelopathy.

Myelopathy is a term referring to any pathologic process affecting the spinal cord, and encompasses a broad spectrum of etiologies. The first step is to categorize myelopathy, according to the time to reach maximum deficit. Myelopathies are commonly classified as acute, subacute or chronic, for which the etiologies are totally different. Myelopathy is considered acute when the symptoms progress to their nadir in maximum 21 days after onset. Due to heterogeneity in pathogenesis, and the overlap in the clinical and imaging presentation among etiologies, acute myelopathy is considered as a diagnostic dilemma. A simple and efficient algorithm for timely identification of the underlying cause is thus useful. In this review, we provide a simplified approach for the differential diagnosis among all causes of acute myelopathies, and describe the principal clinical and imaging features of the main etiologies in adults, including recently characterized antibody-mediated myelitis, and its mimics.