Sixth Nerve Palsy in Paediatric Intracranial Hypertension

Abstract

The purpose of this study was to report the incidence and describe the characteristics of sixth cranial nerve (CN VI) palsy in paediatric patients with intracranial hypertension (IH). A retrospective chart review of central Ohio children diagnosed with IH over the 3-year period from 2010 to 2013 was conducted. IH without identifiable cause was defined as idiopathic intracranial hypertension (IIH), whereas IH with identifiable pathologic aetiology was deemed secondary intracranial hypertension (SIH). A subset of patients with CN VI palsy was identified. Data collected included patient age, gender, past medical history, aetiology of SIH, ophthalmic examination, lumbar puncture results, neuroimaging results, and response to treatment. Seventy-eight children with intracranial hypertension were included in the study. Nine (11.5%) children (four males, five females; median age 14, range: 3-18) were found to have a unilateral (n = 2) or bilateral (n = 7) CN VI palsy. Five children had IIH; the remaining four had SIH from cerebral venous sinus thrombosis (n = 2) and infection (n = 2). The mean lumbar puncture opening pressure for the nine patients with CN VI palsy was 40 cm H₂O (range: 21-65 cm H₂O). Papilloedema was present in 8/9 (89%) patients. One patient required a lumboperitoneal shunt, and two others required optic nerve sheath fenestrations in addition to medical management. All cases of CN VI palsy resolved with treatment. In our primary service area, the incidence of CN VI palsy is approximately 12% among paediatric IH patients. The majority of cases with CN VI palsy presented with papilloedema and all cases resolved with treatment of intracranial hypertension.

Keywords: Paediatric intracranial hypertension; paediatric pseudotumor cerebri; sixth nerve palsy.