Facial Nerve Palsy Secondary to Syringobulbia in a Pediatric Patient with Chiari I Malformation: Case Illustration and Systematic Literature Review

Introduction: Unlike syringomyelia (SM), syringobulbia (SB) is not commonly observed in pediatric patients with Chiari malformation type 1 (CM-1). Previous series have reported the incidence of SB to lie between 3-4% in these patients. Presentation is typically chronic with slow onset of symptoms including headache, vertigo, and cranial nerve (CN) IX and X palsies resulting from lower brainstem involvement. Pontine involvement is not typical. In fact, we report the first case of a pediatric patient with simultaneous CM-I, SB, and unilateral CN VII palsy.

Methods: We performed a literature search in PubMed using terms “Chiari” and “syringobulbia”.

Results: Our literature review identified 12 studies including 55 reported cases of SB in CM-I patients. Fifty-one (93%) patients exhibited SM. The most common presenting symptoms were headache (33%) and nystagmus (33%). Twenty-four (44%) patients exhibited CN deficits, the most common being CN IX (27%) and X (27%) palsies. There have been just three documented pediatric cases involving CN VII palsy. However, these were bilateral and thus our report is the first to describe CM-1, SB, and unilateral CN VII palsy. Our patient presented with right facial weakness in addition to headaches, ataxia, urinary incontinence and falls. MRI revealed CM-I with syrinx of the cervicothoracic spine and SB. Posterior fossa decompression with duraplasty was performed without complications, and the patient was discharged home on POD 5. At three weeks follow-up the patient’s neurological deficits had largely subsided. At 3 month follow-up his CN VII palsy and SB had completely resolved.

Conclusion : Pediatric CM-1 patients with SM are at increased risk for developing SB and lower brainstem deficits, but a constellation of signs and symptoms can be observed. Though we report the first documented case of pediatric CM-1 with SB and unilateral CN VII palsy, craniocervical decompression with duraplasty proved successful, and the patient made a full recovery.