Adult-onset spastic paraparesis: an approach to diagnostic work-up

Adult-onset, chronic progressive spastic paraparesis may be due to a large number of causes and poses a diagnostic challenge. There are no recent evidence-based guidelines or comprehensive reviews to help guide diagnostic work-up. We survey the literature on chronic progressive spastic paraparesis, with special emphasis on myelopathies, and propose a practical, MRI-based approach to facilitate the diagnostic process. Building on neuro-anatomic and radiographic conventions, we classify spinal MRI findings into six patterns: extradural; intradural/extramedullary; Intramedullary; Intramedullary-Tract specific; Spinal Cord Atrophy; and Normal Appearing Spinal Cord. A comprehensive differential diagnosis of chronic progressive myelopathy for each of the six patterns is generated. We highlight some of the more common and/or treatable causes of progressive spastic paraparesis and provide clinical pointers that may assist clinicians in arriving at the diagnosis. We outline a practical, comprehensive MRI-based algorithm to diagnosing adult-onset chronic progressive myelopathy.