Isolated Lower Motor Neuron Facial Nerve Palsy as a Presenting Sign in COVID-19 Associated Orbital Mucormycosis Patients: A Retrospective Observational Study

Abstract

Purpose: The main purpose of this study is to emphasize that isolated facial nerve involvement can be the first presenting symptom in patients suspected of COVID-associated Mucormycosis (CAM). Methods: This study is a retrospective observational study conducted at a tertiary care referral center which included patients with a history of CAM, who presented with isolated facial nerve palsy as initial presentation between March 2021 to March 2022 along with their follow-up. All the patients were managed with combined modality treatment with antifungal therapy and debridement of the necrotic tissue and fungal debris. Results: There were 184 eyes of 148 patients diagnosed with CAM. All patients developed rhino-orbital mucormycosis (ROM) following the COVID-19 infection and the duration between diagnosis of COVID-19 and ROM was 36±23 days. 42(28%) patients presented with isolated Facial Nerve Palsy (FNP) as the initial presentation. The mean age was 48.5 years (range 38 to 67years) with a male predominance of 29 (69%). All were unilateral cases and were of Lower motor neuron type presentation. All the patients (100%) were treated with systemic Liposomal amphotericin-B and sinus debridement. At a mean follow-up of 13.1 months, 19 (45%) of the patients had improvement in Facial Nerve function and 23 (55%) had static functioning. None of them had worsened. With medical intervention and tarsorrhaphy, the corneal condition was improved in all patients. Conclusion: Isolated FNP is an unusual but important sign in the presentation of mucormycosis which can be misdiagnosed with a cerebrovascular accident leading to delay in the management. This is a large case series with isolated FNP in CAM cases. A high index of suspicion for mucormycosis in diabetic patients presenting with isolated facial palsy can save the life and salvage the eye.