Background: Surgical treatment for CM without syringomyelia is still under debate. The aim of this study was to evaluate the long-term outcome of surgically treated patients for CM-I without syringomyelia.
Methods: We selected all adult patients who underwent surgery for CM-I without syringomyelia between 1993 and 2010. Only patients with long term follow-up (>5 years) were included. Clinical manifestations, radiologic features, and follow-up data were analyzed. Patient's outcome was assessed using the Chicago Chiari Outcome Scale (CCOS). Patient's outcome was classified also as: "improved," "unchanged," or "worse."
Results: Among 38 patients, 27 were females and 11 were males. Age ranged from 18 to 65 years (mean age 41 years). The average follow-up duration was 75 months (range 60-168 months). The most frequent symptoms of presentation were: headache (60%), neck pain (52.6%), postural or gait instability (47.3%), upper limb paresthesias (44.7%). The most frequent signs of presentation were: nystagmus (44.7%), pyramidal signs (31.5%), gait/balance impairment (23.6%). Surgical treatment resulted in a long-term success rate of 84.2% (32 patients improved at last follow-up). Thirty-one patients (81.5%) achieved a CCOS score between 13 and 16. Headache improved in 86.9% of patients, gait impairment in 83.3%, paresthesias in 70% and neck pain in 65.2%. Two patients (5.2%) were unchanged after surgery, four patients (10.5%) showed recurrence of their symptoms. There was no mortality.
Conclusions: Surgery is a safe and long-term effective treatment for patients with CM-I without syringomyelia in the majority of patients.