MediAI

  Keywords: Hirayama disease MRI, Hirayama disease imaging, cervical flexion myelopathy, monomelic amyotrophy MRI, Hirayama disease diagnosis, cervical spine flexion MRI Abstract Hirayama disease—also known as juvenile muscular atrophy of the distal upper extremity or monomelic amyotrophy —is a rare cervical myelopathy affecting young males, typically during adolescence and early adulthood. The disorder is characterized by progressive unilateral distal upper limb weakness caused by dynamic cervical spinal cord compression during neck flexion . Advances in dynamic cervical MRI imaging have significantly improved the diagnostic accuracy of Hirayama disease, particularly by demonstrating anterior displacement of the posterior dura and engorgement of the posterior epidural venous plexus during neck flexion. This column presents a comprehensive expert-level review based on the provided imaging case of a 22-year-old male with progressive hand weakness , integrating modern literatu...