Cranial nerve involvement in mucormycosis in post-COVID patients: a case series

Extra-axial cranial nerve enhancement: a pattern-based approach

Cranial nerve enhancement is a common and challenging MRI finding that requires a meticulous and systematic evaluation to identify the correct diagnosis. Literature mainly describes the various pathologies with the associated clinic-radiological characteristics, while the radiologist often needs a reverse approach that starts from the radiological findings to reach the diagnosis. Therefore, our aim is to provide a new and practical pattern-based approach to cranial nerve enhancement, which starts from the radiological findings and follows pattern-driven pipelines to navigate through multiple differential diagnoses, guiding the radiologist to reach the proper diagnosis. Firstly, we reviewed the literature and identified four patterns to categorize the main pathologies presenting with cranial nerve enhancement: unilateral linear pattern, bilateral linear pattern, unilateral thickened pattern, and bilateral thickened pattern. For each pattern, we describe the underlying pathogenic origin, and the main radiological features are displayed through high-quality MRI images and illustrative panels. A suggested MRI protocol for studying cranial nerve enhancement is also provided. In conclusion, our approach for cranial nerve enhancement aims to be an easy tool immediately applicable to clinical practice for converting challenging findings into specific pathological patterns.

Radiological review of rhinocerebral mucormycosis cases during the COVID-19 Pandemic: A single-center experience

Mucormycosis is caused by the fungi belonging to the order Mucorales and class Zygomycetes. The incidence of mucormycosis has increased with the onset of the severe acute respiratory syndrome coronavirus 2 infections leading to the coronavirus disease 2019 (COVID-19) pandemic. This rise is attributed to the use of immunosuppressive medication to treat COVID-19 infections. Authors have retrospectively collected data of our cases of mucormycosis diagnosed from April 2020 to April 2021 at our institute. A total of 20 patients with rhinocerebral mucormycosis were studied. Most of the study subjects were male patients (90%) and were of the age group 41-50 years. Most patients in the review had comorbidities (85%) with diabetes being the most common comorbidity. Para nasal sinuses were involved in all the cases. Involvement of the neck spaces was present in 60% of the cases. Involvement of the central nervous system was present in 80% of the cases. Orbital involvement was present in 90% of the cases. The authors reviewed the various imaging findings of mucormycosis on computed tomography and magnetic resonance imaging in this article.

MR imaging spectrum in COVID associated Rhino-Orbito-Cerebral mucormycosis with special emphasis on intracranial disease and impact on patient prognosis

In the wake of the ongoing Coronavirus Disease 2019 (COVID-19) pandemic, a new epidemic of COVID associated mucormycosis (CAM) emerged in India. Early diagnosis and prompt treatment of this deadly disease are of paramount importance in improving patient survival. MRI is the cornerstone of diagnosis of early extrasinus disease, particularly intracranial complications which have traditionally been associated with a high mortality rate. In this review, we depict the sinonasal, perisinus, orbital and intracranial involvement in CAM. Special emphasis is laid on intracranial disease which is categorized into vascular, parenchymal, meningeal, bony involvement and perineural spread. Vascular complications are the most common form of intracranial involvement. Some unusual yet interesting imaging findings such as nerve abscesses involving the optic, trigeminal and mandibular nerves and long segment vasculitis of the internal carotid artery extending till its cervical segment are also illustrated. In our experience, patient outcome in CAM (survival rate of 88.5%) was better compared to the pre-pandemic era. Presence of intracranial disease also did not affect prognosis as poorly as traditionally expected (survival rate of 82.8%). Involvement of brain parenchyma was the only subset of intracranial involvement that was associated with higher mortality (p value 0.016). The aim of this review is to familiarise the reader with the MR imaging spectrum of CAM with special focus on intracranial complications and a brief account of their impact on patient prognosis in our experience.