Case Report: Unilateral Cranial Nerve VI Palsy Secondary to Intracranial Hypotension

Abstract

SIGNIFICANCE Intracranial hypotension is a condition that occurs from a cerebrospinal fluid leak. Various visual symptoms have been associated with this condition. Cranial nerve VI (CN VI) palsies are the most common ocular manifestation, as the abducens nerve is prone to injury because of its intracranial anatomical course. PURPOSE This case report presents a CN VI palsy secondary to intracranial hypotension from ventriculoperitoneal shunt overfiltration. Diagnosis, treatment, and management considerations are discussed. No identifiable health information was included in this case report. CASE REPORT A 70-year-old White man was referred to the eye clinic for evaluation of binocular horizontal diplopia. The patient had a recent history of a left ventriculoperitoneal shunt for a persistent cerebrospinal fluid leak after complex mastoid surgery. The patient was also symptomatic for positional headaches, which improved in a recumbent position. He was diagnosed with a left CN VI palsy secondary to intracranial hypotension from a ventriculoperitoneal shunt overfiltration. The patient was followed up by neurosurgery for shunt adjustments to resolve the overfiltration. Binocular horizontal diplopia was managed conservatively with Fresnel prism. CONCLUSIONS Intracranial hypotension should be considered in patients presenting with cranial nerve palsies and positional headaches. Obtaining neuroimaging and comanaging with neurology or neurosurgery are advised to make prompt diagnosis and treatment. Careful clinical monitoring and conservative diplopia therapy are recommended as visual symptoms improve upon resolution of the cerebrospinal fluid leak.