The Neurotropic Varicella Zoster Virus: a Case of Isolated Abducens Nerve Palsy without Skin Rash in a Young Healthy Woman

Introduction: Varicella Zoster Virus (VZV) is a neurotropic virus whose reactivation can affect the central nervous system (CNS) and manifest as different neurological syndromes usually with dermatological involvement. Extraocular muscle palsies are not commonly described associated with VZV and their presence in the absence of a typical zoster rash is even rarer. Methods: Case report of a young immunocompetent patient with unilateral abducens nerve palsy, as an isolated manifestation of VZV infection. Results: A 25-year-old healthy female presented to the emergency department with a subacute onset of painless horizontal binocular diploplia, over a month. Ophthalmological and neurological examination revealed an isolated right abducens nerve palsy, and polymerase chain reaction of the cerebrospinal fluid identified a VZV infection. There was no skin rash involvement. Other infectious, inflammatory, and autoimmune diseases were excluded. Treatment with intravenous acyclovir and dexamethasone improved but not completely resolved the diplopia and strabismus. The patient was submitted to a medial rectus recession surgery. Discussion: VZV manifestations in the CNS can occur in healthy young individuals and can manifest in the absence of the typical skin rash. Isolated sixth nerve palsy is a very rare manifestation of VZV infection. Young patients with isolated ocular motor mononeuropathies, even with cardiovascular risk factors, benefit from a CNS-based approach and MRI and lumbar puncture should be considered. Reports show that extraocular muscle palsy associated with VZV is a transient condition and resolve partially or completely after few weeks.