Perineural Spread in COVID-Associated Rhino-Orbito-Cerebral Mucormycosis: A Single Tertiary Care Center Study

BACKGROUND: Infection with rhino-orbito-cerebral mucormycosis (ROCM) has increased in the coronavirus disease (COVID) era, especially in diabetic patients. Rapid extension from the nose and paranasal sinuses to the orbit and brain is noted by osseous erosion, vascular invasion, and infrequently documented perineural spread. OBJECTIVE: To determine the incidence of perineural spread in ROCM cases and evaluate the common neural pathways involved, which help in prognosticating and triaging patients. METHODS AND MATERIALS: We evaluated demographic, clinical, and radiological findings of 270 patients of histopathologically diagnosed ROCM. Imaging signs were used along cranial nerves for diagnosing perineural spread on magnetic resonance imaging (MRI). RESULTS: The perineural spread was observed in 30.4% patients. The most common nerves involved are the infra-orbital (20%), optic (19.2%), and maxillary (16.2%) nerves. Ischemic neuropathy was noted in 13.3% patients, predominantly along the optic nerve. CONCLUSION: We documented a substantial incidence of perineural spread and common nerves involved in ROCM cases, which has not been previously described in the literature. Perineural spread determines the true extent of disease spread which can bring about better management in this rapidly fatal infection.