Management of acute cranial nerve 3, 4 and 6 palsies: Role of neuroimaging

Purpose of review: This article will discuss the management of isolated, acute cranial nerve 3,4 and 6 palsies with special focus on the role of neuroimaging in older adults based on recently published data. Recent findings: Acute cranial nerve palsies affecting the third, fourth or sixth cranial nerves in isolation or in combination with other neurological signs and symptoms can be due to a variety of causes such as ischemia, inflammation, infection and compression of the ocular motor nerves. Although neuroimaging is generally recommended in all individuals presenting with ocular motor nerve palsies that occur in association with other neurological signs and symptoms, the indications for neuroimaging in older individuals (age > 50 years) who present with acute isolated ocular motor nerve palsies are less clear and controversial. Past and recent studies have attempted to address this question. A recent prospective study found that overall 16.5% of adult patients presenting with acute ocular motor mononeuropathy had structural lesions on MRI scan and 4.6% with fourth and sixth nerve palsies and no risk factors were found to have positive MRI scans. Summary: On the basis of recently published data, we recommend contrast-enhanced MRI for all patients presenting with acute, isolated ocular motor mononeuropathies irrespective of age. Studies have clearly shown a small but significant prevalence of important findings in this group of patients thus favoring neuroimaging at the time of diagnosis.