Rhino orbital cerebral mucormycosis

The second COVID-19 wave in India has been associated with an unprecedented increase in cases of COVID-19 associated mucormycosis (CAM), mainly Rhino-orbito-cerebral mucormycosis (ROCM).

Rhino orbital cerebral mucormycosis rapidly became an epidemic following the COVID-19 pandemic ¹⁾

Gutiérrez-Delgado et al searched PubMed database from 1964 to 2014 for all available articles in the English language related to rhino-orbital-cerebral chronic infections caused by fungi of the order Mucorales and found 22 cases ²⁾.

Rhino-orbital-cerebral mucormycosis is usually associated with a poor prognosis and is almost exclusively seen in immunocompromised patients.

59 patients were diagnosed with COVID-19 associated mucormycosis (CAM). The median duration from the first positive COVID-19 RT PCR test to the diagnosis of CAM was 17 (IQR: 12,22) days. 90% of patients were diabetic with 89% having uncontrolled sugar level (HbA1c >7%). All patients were prescribed steroids during treatment for COVID-19. 56% of patients were prescribed steroids for non-hypoxemic, mild COVID-19 (irrational steroid therapy) while in 9%, steroids were prescribed in inappropriately high dose. Patients were treated with a combination of surgical debridement (94%), intravenous liposomal Amphotericin B (91%) and concomitant oral Posaconazole (95.4%). 74.6% of patients were discharged after clinical and radiologic recovery while 25.4% died. On Relative risk analysis, COVID-19 CT severity index ≥ 18 (p=0.017), presence of orbital symptoms (p=0.002), presence of diabetic ketoacidosis (p=0.011), and cerebral involvement (p=0.0004) were associated with increased risk of death.

CAM is a rapidly progressive, angio-invasive, opportunistic fungal infection that is fatal if left untreated. The combination of surgical debridement and antifungal therapy leads to clinical and radiologic improvement in the majority of cases ³⁾.

A 53-year-old male with diabetes presented with altered mental status. He had been recently discharged from admission for COVID-19 pneumonia treated with remdesivir and methylprednisolone. Imaging demonstrated a large left frontal mass with a midline shift suspicious for a primary brain neoplasm. His neurologic exam rapidly declined and the patient was taken to the operating room for decompressive hemicraniectomy. Post-operatively, the patient remained comatose and failed to improve. An autopsy revealed a cerebral mucormycosis infection.

Despite concern for a primary brain neoplasm the patient has diagnosed postmortem with a mucormycosis infection. Other features supporting this diagnosis included nasal sinusitis on initial scans, his fulminant clinical decline, rapidly progressive imaging findings, and persistent hyperglycemia throughout his clinical course.

In an era of high steroid usage to treat COVID-19, mucormycosis infection must be considered in high-risk patients demonstrating a disproportionate clinical decline ⁴⁾.

A unique case of isolated intracranial mucormycosis of a slowly progressive nature in a healthy immunocompetent child. A 4-year-old girl with a clear medical and surgical history presented with complaints of right side facial asymmetry and unsteady gait for a period of 10 months. Clinical and radiographic investigations revealed right-sided lower motor neuron facial palsy caused by an infiltrative lesion on the right cerebellopontine angle. Initial surgical debulking was performed, a biopsy was sent for histopathological examination, and a course of prophylactic antibiotic and antifungal drugs was prescribed. The pathological report confirmed the mucormycosis fungal infection, and intravenous amphotericin B was administered for 3 weeks. One month after admission, the patient left the hospital with complete recovery. Follow-ups after 4, 8 and 12 weeks revealed no sensory or motor neurological deficits. In conclusion, this is a unique case of mucormycosis with regard to the nature and location of the infection, along with the host being a healthy child. Initial surgical exploration is a very critical step in the early diagnosis and treatment of such rare conditions ⁵⁾.

A 42-year-old man who developed a cerebellar mucor abscess after undergoing hematopoietic stem cell transplant for the treatment of myelodysplastic syndrome. In the post-operative period he was admitted to the neurocritical care unit and received liposomal amphotericin B intravenously and through an external ventricular drain. This patient demonstrates that utilization of an external ventricular drain for intrathecal antifungal therapy in the post-operative period may warrant further study in patients with difficult to treat intracranial fungal abscesses ⁶⁾.

A case of mucormycosis presenting with extensive necrosis of the maxilla with extension into the retrobulbar and infrabulbar region in an otherwise healthy patient. He underwent extensive debriding surgery followed by amphotericin B first and then oral antifungal therapy, but unfortunately, even after extensive surgery and medical treatment, he did not survive ⁷⁾.

Yoon et al describe a case of Rhino-orbital-cerebral (ROC) mucormycosis with pericranial abscess occurring in a female patient with uncontrolled diabetes mellitus. The infection initially developed in the right-sided nasal sinus and later progressed through the paranasal sinuses with the invasion of the peri-orbital and frontotemporal region, due to the delayed diagnosis and treatment. Numerous non-septate hyphae of the zygomycetes were identified by a punch biopsy from the nasal cavity and by an open biopsy of the involved dura. The patient was treated successfully with extensive debridement of her necrotic skull and surrounding tissues, drainage of her pericranial abscess and antifungal therapy, including intravenous amphotericin B for 61 days and oral posaconazole for the following 26 days. She returned to a normal life and has had no recurrence since the end of her treatment 15 months ago ⁸⁾.

A 59-year-old immunocompetent white man sustained a high-pressure water jet injury to the right inner canthus while cleaning an air conditioner filter. He later had “orbital cellulitis” develop that did not respond to antibiotics and progressed to orbital infarction. Imaging studies and biopsy results led to a diagnosis of mucormycosis. Tissue culture grew Apophysomyces elegans, a new genus of the family Mucoraceae first isolated in 1979. Orbital exenteration and radical debridement of involved adjacent structures, combined with intravenous liposomal amphotericin, resulted in patient survival.

After orbital exenteration and debridement of involved adjacent structures along with intravenous liposomal amphotericin, our patient has remained free from relapse with long-term follow-up.

The agent causing this case of rhino-orbital-cerebral mucormycosis (Apophysomyces elegans) contrasts with the three genera most commonly responsible for mucormycosis (Rhizopus, Mucor, and Absidia) in that infections with this agent tend to occur in warm climates, by means of traumatic inoculation, and in immunocompetent patients. Rhino-orbital-cerebral mucormycosis should be considered in all patients with orbital inflammation associated with multiple cranial nerve palsies and retinal or orbital infarction, regardless of their immunologic status. A team approach to management is recommended for early, appropriate surgery and systemic antifungal agents ⁹⁾.