Spontaneous-Onset Delayed Spinal Arachnoiditis With Dorsal Cord Herniation in a 29-Year-Old Paraplegic Patient: A Case Report.

Spinal adhesive arachnoiditis is a rare occurrence with a diverse etiology. The clinical picture is not universal, and varying degrees of neurodeficit have been mentioned. Spontaneous spinal cord herniation or idiopathic spinal cord herniation occurs due to displacement of the cord through a dural or arachnoid defect. We report a case of a 29-year-old male paraplegic patient with a nontraumatic spinal cord injury (SCI) following surgery for an intradural extramedullary lesion at T10-T11 level who developed loss of truncal balance after two years of the index surgery. After a thorough clinical examination and MRI as well as other investigations, the patient was diagnosed as having spontaneous-onset delayed spinal arachnoiditis with dorsal cord herniation through the laminectomy window with effacement of neural tissue and ascending edema up to T6 level. A new-onset weakness or the development of an ascending loss of sensory level with a loss of truncal balance should alarm the therapist about some new pathology happening at the cord level in patients with SCI. In this regard, spinal adhesive arachnoiditis with or without cord herniation should always be suspected in a paraplegic patient with delayed-onset deterioration of neurology. Differential diagnoses like arachnoid web and arachnoid cysts should also be kept in mind.