A Unique Radiologic Case of Optic Nerve Infarction in a Patient With Mucormycosis

The Algorithmic Role of Critical Radiographic Features in the Treatment of Angioinvasive Fungal Sinusitis

INTRODUCTION

Angioinvasive fungal sinusitis (AIFS) is a rapidly progressive, highly morbid infection. It can be challenging to obtain an early diagnosis, but intervention in the acute period is crucial for prognosis. Previous literature has identified numerous radiographic features with high sensitivity and specificity for AIFS, even in early disease. Bedside nasal endoscopy can substantiate the diagnosis but can also yield false negative results. Initially, these patients may present to the ophthalmologist. Thus, to avoid visual and potentially life-threatening complications, subtle clinical signs in conjunction with suspicious radiographic features must be promptly recognized by the ophthalmologist and escalated appropriately. We review, for the benefit of the ophthalmic community, the salient radiographic features of AIFS and integrate them into a decision-making algorithm for diagnostic workup and management.

METHODS

A literature search was conducted using a comprehensive keyword search in the Pubmed and Embase databases. English studies from 1988 to 2022 describing the radiographic features of AIFS queried. Literature on the newly described entity, COVID-19 COVID-19-associated mucormycosis was included. The authors collected the most frequently reported indicators of AIFS.

RESULTS

The authors review 4 radiographic findings that are frequently associated with AIFS, including in the early stages of disease: 1) loss of contrast enhancement in the nasal turbinate and maxilla (i.e., "black turbinate and maxillary sign"), (2) periantral involvement seen as changes in density, fat stranding or obliteration of the anterior, retromaxillary, or retroantral fat planes on CT, (3) Tissue invasion without bony erosion, (4) Hypointense T2W sinonasal secretions on MRI in the setting of acute sinusitis. The authors additionally propose an algorithm that suggests surgical exploration for patients with clinical concern for AIFS and these radiographic features, even if bedside nasal endoscopy is inconsistent with AIFS.

CONCLUSION

The radiographic signs highlighted herein should heighten suspicion for AIFS in the appropriate clinical setting, prompting urgent surgical exploration regardless of nasal endoscopy findings.

Management of Invasive Infections in Diabetes Mellitus: A Comprehensive Review

Patients with diabetes often have more invasive infections, which may lead to an increase in morbidity. The hyperglycaemic environment promotes immune dysfunction (such as the deterioration of neutrophil activity, antioxidant system suppression, and compromised innate immunity), micro- and microangiopathies, and neuropathy. A greater number of medical interventions leads to a higher frequency of infections in diabetic patients. Diabetic individuals are susceptible to certain conditions, such as rhino-cerebral mucormycosis or aspergillosis infection. Infections may either be the primary symptom of diabetes mellitus or act as triggers in the intrinsic effects of the disease, such as diabetic ketoacidosis and hypoglycaemia, in addition to increasing morbidity. A thorough diagnosis of the severity and origin of the infection is necessary for effective treatment, which often entails surgery and extensive antibiotic use. Examining the significant issue of infection in individuals with diabetes is crucial. Comprehensive research should examine why infections are more common amongst diabetics and what the preventive treatment strategies could be.

Onset of Mucormycosis in Patients with COVID-19: A Systematic Review on Patients' Characteristics

Mucormycosis has a significant impact on patients' standard of living and, therefore, a high clinical suspicion, prediagnosis, and rapid treatment are critical in easing patients' suffering and fast recovery. Our focus is to conduct an organized review based on various variables on the patients' characteristics having mucormycosis in severe novel coronavirus disease 2019 (COVID-19). We examined Embase, PubMed-Medline, LitCovid, Web of Science, Scopus, and the reference lists of included case reports up to September 20, 2021, using the Medical Subject Heading (MeSH) phrases and other keywords related to this topic. Subsequently, we investigated associated comorbidities, patient characteristics, position of mucormycosis, steroids use, body involvements, and outcomes. Overall, 77 studies were conducted and among these, 72 studies mentioned that the patients' age to be 48.13±14.33 (mean±standard deviation [SD]) years. Diabetes mellitus (DM) was reported in 77.9% (n=60) of cases. Studies showed that central nervous system (CNS) and bone involvement were reported in 62.3 (n=48) and 53.2% (n=41), respectively. More fatalities were observed in patients with mucormycosis with the active form of COVID-19. Also, men infected with mucormycosis significantly affected by COVID-19. In the end, mortality was higher in males with mucormycosis. As a result, a solid investigation into the root cause of mucormycosis, especially in COVID-19, should be included in the study plan. If the patient is COVID-19-positive and immunosuppressed, this opportunistic pathogen diagnostic test should not be overlooked.

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.

COVID-19-Related Rhino-Orbito-Cerebral Mucormycosis Complicated by the Optic Nerve and Optic Tract Ischemia With Ischemic Neuropathy

Mucormycosis is a life-threatening invasive fungal infection usually seen in immunocompromised patients and patients with poorly controlled diabetes mellitus with or without diabetic ketoacidosis. We present a rhino-orbito-cerebral mucormycosis (ROCM) case in a coronavirus disease 2019 (COVID-19) patient complicated by the optic nerve and optic tract ischemia with ischemic neuropathy. Both CT and MRI played an essential role in diagnosing ROCM and the accompanying complications in our patient.

CT showed sinonasal sinusitis and MRI showed the sinusitis and its progression to ROCM. MRI also showed necrosis involving the bilateral orbits, basal ganglia, thalamus, internal capsule, hypothalamus, optic chiasm, optic nerves, olfactory bulbs, and skull base. ROCM associated with optic nerve ischemia is a rare but life-threatening complication of COVID-19, especially in patients with underlying diabetes and/or those treated with corticosteroids. Physicians should be aware of this complication as early diagnosis may improve the chances of survival in such patients.

Rhino-orbito-cerebral Mucormycosis: Pictorial Review

Mucormycosis (MCR) is a fulminant, potentially lethal, opportunistic fungal infection. Diabetes, immunocompromised states and elevated serum iron levels are the most important risk factors for contracting MCR infection. Recently, MCR co-infections have been observed in patients with COVID-19 disease owing to a complex interplay of metabolic factors and corticosteroid therapy. Rhino-orbito-cerebral mucormycosis (ROCM) is the most common clinical form of MCR infection and refers to infection of the nasal cavities, paranasal sinuses, neck spaces, orbits and intracranial structures. Sinonasal inoculation is typically the primary site of infection; the necrotising and angioinvasive properties of the fungus facilitate its spread into adjacent structures. In this review, we discuss the pertinent mycology and risk factors of MCR infection. The review also aims to acquaint the reader with the cross-sectional imaging appearances of ROCM and its complications. All the cases discussed in this pictorial essay are microbiologically and/or histopathologically proven cases of ROCM with concomitant COVID-19 infection.

Mucormycosis: An opportunistic pathogen during COVID-19

The pandemic of coronavirus disease 2019 (COVID-19) still remains on an upsurge trend. The second wave of this disease has led to panic in many countries, including India and some parts of the world suffering from the third wave. As there are no proper treatment options or remedies available for this deadly infection, supportive care equipment's such as oxygen cylinders, ventilators and heavy use of steroids play a vital role in the management of COVID-19. In the midst of this pandemic, the COVID-19 patients are acquiring secondary infections such as mucormycosis also known as black fungus disease. Mucormycosis is a serious, but rare opportunistic fungal infection that spreads rapidly, and hence prompt diagnosis and treatment are necessary to avoid high rate of mortality and morbidity rates. Mucormycosis is caused by the inhalation of its filamentous (hyphal form) fungi especially in the patients who are immunosuppressed. Recent studies have documented alarming number of COVID-19 patients with mucormycosis infection. Most of these patients had diabetes and were administered steroids for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and were consequently more prone to mucormycosis. Hence, the present review emphasizes mucormycosis and its related conditions, its mechanism in normal and COVID-19 affected individuals, influencing factors and challenges to overcome this black mold infection. Early identification and further investigation of this fungus will significantly reduce the severity of the disease and mortality rate in COVID-19 affected patients.