Long-term outcome of idiopathic hypertrophic thoracic pachymeningitis

摘要

Idiopathic hypertrophic spinal pachymeningitis (IHSP) is a comparatively rare disease characterized by hypertrophic inflammation of the dura mater and clinical symptoms that progress from local pain to myelopathy. We report a case of IHSP followed up for 20 years in a 46-year-old man. Expansive laminoplasty was performed in 1991, and this case has been previously reported by a co-author. After 17 years, the patient’s gait disturbance returned. Physical examination and imaging confirmed IHSP that had developed into syringomyelia at the T2–L1 conus level. This case was diagnosed as adhesive spinal arachnoiditis due to pachymeningitis caused by syringomyelia. T1–T4 laminectomy, a syringo-subarachnoid shunt (S–S shunt), and L2–L3 laminectomy were performed. The patient again developed dysesthesia and gait disturbance 3 years after the second operation. Most reports of IHSP have limited their focus to short-term follow-up after initial treatment with no long-term results. At present, there are only five reports referring to long-term results of greater than 5 years. All but one case needed additional surgery. To the best of our knowledge, this is the first case in which syringomyelia occurred in a patient with IHSP. It is important to note that syringomyelia may be a cause of symptom recrudescence during long-term follow-up in IHSP patients.