Idiopathic syringomyelia is a rare, non-syndromic central nervous system malformation characterized by a longitudinally oriented fluid-filled cavity inside the spinal cord parenchyma or the central canal, without any readily identifiably cause. It is usually associated with pain, sensory and/or musculoskeletal disturbances, but it can also be an incidental and asymptomatic finding. The disease is idiopathic syringomyelia (MONDO_0020510).