A case report of isolated abducens nerve palsy: idiopathic or ophthalmoplegic neuropathy?

Abstract

Background: Abducens nerve is the most common nerve affected among other cranial nerves in terms of isolated ocular palsy. Despite its prevalence and progression made in neuroimaging, incidence of idiopathic cases continues to rise. Case presentation: We report a young adult male with no previous illnesses, who presented with sudden onset of binocular diplopia and headache and was later diagnosed with an isolated ipsilateral abducens nerve palsy secondary to an unknown cause and treated with steroids. The palsy and diplopia had resolved in 2-month time but the patient still continued to suffer from a migraine, such as headache. Conclusion: Although, we labelled the patient as idiopathic initially, another plausible cause for this kind of presentation could be recurrent painful ophthalmoplegic neuropathy (RPON) owing to the nature of the presentation. Cases labelled as idiopathic could be attributed to a defined pathogenesis with detailed history and follow-up. Follow-up is vital for all patients, especially those labelled as idiopathic as recurrence of the illness have the chance of changing the diagnosis if supported by the detailed history and physical examination findings.