Aggressive Surgical Management of Patients with Chiari II Malformation and Brainstem Dysfunction

Abstract

Background/Aims: Chiari II malformation represents a group of developmental abnormalities involving the caudal displacement of the cervicomedullary junction, pons, fourth ventricle, and medulla. This constellation of malformations is strongly associated with myelomeningocele (MM) and is a known cause of neurologic deterioration in older MM patients. We describe the evaluation and management of 4 adult MM patients who presented with brainstem compression and a retroflexed odontoid who were subject to aggressive surgical management including occipitocervical (OC) fusion with good clinical results. Methods: Four MM patients who underwent OC fusion for new-onset brainstem dysfunction and myelopathy were identified in the practice of the principal investigator (D.W.P.) from 2003 to 2008. Results: The initial evaluation of these patients included consideration of other diagnoses, such as hydrocephalus due to shunt malfunction and tethered cord. These patients were treated with aggressive surgical management. In some cases, multiple surgeries were performed. All 4 patients were treated with cervical decompression and OC fixation and initially had good outcomes. No patients required transoral decompression. Three of the 4 had stable improvement at their last follow-up appointment (mean follow-up of 9 months). Conclusion: Late deterioration in older MM patients may be secondary to brainstem or cervical spinal cord compression from ventral odontoid compression and Chiari II malformation, hydrocephalus, hydromyelia, or tethered cord. These patients may benefit from more than one surgery. Posterior decompression and OC fusion can avoid a morbid transoral odontoid resection, greatly improve patients’ symptoms and prevent further neurologic decline.

Neurosurgery guidelines for the care of people with spina bifida

“…Ongoing research efforts have focused on understanding the optimal thresholds and triggers for intervention along with improving technical aspects of untethering procedures to reduce acute morbidity and the risk for re-tethering. This problem will require particular attention as children undergoing IUMC mature due to the potential for increased risk of TSC from IUMC [40][41][42][43].…”

“…[ [40][41][42][43] 5. Teach families of signs of syringomyelia (back pain, sensory changes in hands).…”

Concepts in the neurosurgical care of patients with spinal neural tube defects: An embryologic approach

“…Failure to intervene in a timely fashion can allow catastrophic brainstem failure that may be fatal. Hydrocephalus is not the sole contributor to symptomatic Chiari II malformation as some patients decline even with optimized HCP management (Rahman, Perkins, & Pincus, ; Rocque et al, ).…”

Treatment of myelomeningocele: a review of outcomes and continuing neurosurgical considerations among adults

“…(A second example of subependymoma was reported in a child in this series of 7 patients.) Rahman et al 73 described 4 adult patients with recurrent hindbrain symptoms after craniocervical decompression in childhood. Presentations included headache, neck pain, diplopia, dysphagia, dysphonia, upper-limb paresis and hypertonia, and gait instability.…”