Single-level ossified ligamentum flavum causing a holocord syrinx: illustrative case

BACKGROUND: Syringomyelia is a neurological disorder that is caused by abnormal cerebrospinal fluid flow or circulation. It is an incidental finding in most cases, predominantly presenting with sensory symptoms of insensitivity to pain and temperature. Spinal ossified ligamentum flavum (OLF) leading to syringomyelia is one of the rare causes. The authors report an unusual case of syringomyelia due to a thoracic OLF. OBSERVATIONS: A 54-year-old female presented with backache, difficulty walking, spasticity in the bilateral lower limbs, tingling sensation in the bilateral lower limbs, and paraparesis for 5 years. Her radiological investigations were suggestive of an OLF causing a syrinx. She underwent laminectomy, and her syrinx resolved on subsequent follow-up. LESSONS: A syrinx due to a single-level OLF is rare, and this uncommon cause should be kept in mind while formulating treatment plans.