Isolated Abducens Nerve Palsies from COVID-19 Infections: Clinical Features and Outcomes

Isolated abducens nerve palsies from COVID-19 infections are rarely described in literature. Their clinical features are poorly understood, and guidance on their treatment is lacking.

To describe the clinical features of isolated abducens nerve palsies from COVID-19 infection, and provide guidance on their management.

We performed a literature review and analyzed the clinical features of patients with isolated abducens nerve palsy from COVID-19 infections reported in literature.

In total, 16 cases from 15 studies published between January 2020 and December 2023 were identified. Their median age was 44 years (range 3-71, including two children). Nearly two-thirds (10/16, 63%) were without medical history. Abducens nerve palsies mostly occurred early with COVID-19 symptoms (median of 5.5 days, range 0-21 days). They were all unilateral, and displayed neither clear gender nor left-right predilections. Brain magnetic resonance imaging scans were often unremarkable (9/13, 69%). More than half (9/16, 56%) received no treatment or symptomatic treatment only, while only two received steroids. Regardless, nearly all experienced clinical of diplopia (14/16, 88%), of which most recovery were either complete or near-complete (at least 10/14, 71%) within a median period of 26 days (range 5-240 days).

Isolated abducens nerve palsies are early but uncommon complications of COVID-19, mainly affecting patients with mild infections. Prognosis appears fair even when without corticosteroid treatment, and recovery is significant and early in most. Observation and early outpatient clinical review within a month are reasonable measures. Patients without significant improvement within a month should be re-assessed for other aetiologies.