Spontaneous resolution of a Chiari malformation with syringomyelia

The Chiari I malformation (CM-I) is characterised by overcrowding of the posterior fossa and descent of the cerebellar tonsils and is associated with syringomyelia. With the increasing availability of magnetic resonance imaging, CM-I is placing a growing burden on neurosurgical services. However, its natural history remains poorly understood, and the timing and nature of surgical intervention is controversial. We present a case of a significant, symptomatic CM-I with associated syrinx which underwent complete spontaneous resolution over a 4-year period. Spontaneous regression of Chiari malformation and syringomyelia is exceedingly rare; a literature review reveals 15 other cases and only one case which underwent complete resolution. The present case and literature review suggest a more benign natural history of CM-I and support a more conservative approach to its management. Further studies are required to determine whether any factors can predict resolution for certain patient cohorts.

Early analysis of operative management of Chiari I malformation in pediatric cystic fibrosis patients

INTRODUCTION

Chiari I malformation, defined as herniation of the cerebellar tonsils at least 5 mm below the foramen magnum, can result from congenital or acquired pathology. While the mechanism is not well understood, an association between Chiari I and cystic fibrosis has been described in the literature. The lifelong respiratory status management necessitated by cystic fibrosis creates a greater risk of Chiari symptomatology as well as post-operative CSF-related complications in the setting of duraplasty secondary to recurrent transient increases in intracranial pressure. We will review the literature, describe our experience with these patients, and propose bony decompression as an approach to treatment.

METHODS

A retrospective review of pediatric patients treated at our institution with both cystic fibrosis and Chiari I was performed. Since our first case in 2016, our department has evaluated four patients carrying that dual diagnosis. All four underwent posterior fossa decompression surgery. Two patients had incidental pathology. Two symptomatic patients exhibited headaches and/or coordination difficulty. Half of the patients had associated syringomyelia. All patients were offered posterior fossa decompression utilizing intraoperative ultrasound.

RESULTS

All four patients underwent posterior fossa decompression without duraplasty. Average operative time was 128 min. There were no complications post-operatively. Average hospital stay was 3.8 days. Average surgical length of stay was 2.3 days. Morbidity and mortality were 0%. The longest follow-up to date is 20 months. The two asymptomatic patients remained so post-operatively. The child with headaches and imbalance had complete resolution of his symptoms after surgery, as did the toddler with headaches. Both patients with syringomyelia demonstrated significant decrease in the size of their syrinxes on imaging performed at least 3 months post-operatively.

CONCLUSION

Based on the literature and our experience, we recommend considering posterior fossa decompression without duraplasty as treatment for pediatric cystic fibrosis patients with Chiari I malformation. This approach can be effective for symptomatic and prophylactic cases in this particular patient demographic because their comorbidities predispose them to Chiari pathology and symptomatology as well as certain post-operative complications.