Discussion
Rhinocerebral mucormycosis is an aggressive infection and failure to diagnose or treat can lead to high mortality. [1]. Mucormycosis has five different spread sites: rhinocerebral, gastrointestinal, cutaneous, respiratory, and disseminated. ROCM is the predominant manifestation of the infection which can progress to the orbital and deeper sites of the brain through paranasal sinuses[1, 5] and could result in uncommon presentations such as seizures, reduced LOC, or ophthalmic involvement. Mucormycosis infects the nervous system in 20% of hematological cases and brain abscess occurs rarely in 2 of 43 patients with mucormycosis[5, 6]. Unfortunately, It has been observed that mucormycosis has been rising since the COVID-19 pandemic began, and recently it has become an issue of concern for our health care system[1]. The condition could be a consequence of a dysregulated immune system due to a reduction in T cell count, altered CD4/CD8 ratio, and overuse of immunosuppresses like corticosteroids following the COVID-19 which is exacerbated by uncontrolled blood sugar in people with undetermined diabetes cases[1]. Sharma et al . in their prospective study believe diabetes is the most common risk factor for the ROCM after COVID-19 which 57% of the cases presenting with uncontrolled diabetes (HBA1c > 6.5 mg/dl)[7].
Diagnosis of ROCM is based on the clinical finding including headache, nasal or sinus congestion, and blackish discoloration within the nose or palate. Radiological findings such as CT or MRI and pathological investigations are crucial for confirmation of the diagnosis. Involvement of the paranasal sinuses and at the top of them ethmoid sinus is the highly common form. However, it could progress to the other sinuses and infect the orbit, extraocular muscles, and finally the brain[8].
Rhinorage and the blackish plate were the most common presentation of mucormycosis in our center during the COVID-19, however, the common presentation was absent in our recent cases. Instead, these two patients suffered from neurological problems such as seizures, low LOC, and OAS which means we should be concerned more about mucormycosis in immunosuppressed patients especially in tumor mimicking masses and always keep it in our differential diagnosis.
visual defects were reported in mucormycosis cases, this may be caused by infarctions in blood vessels supplying the retina or optic nerve, in addition to the compression of the nerve through the cavernous sinus, as well as infection and necrosis[8].
Amphotericin B plus posaconazole was the regimen commonly used in previous studies [1]. consistent with our cases, other studies found intraorbital and retrobulbar injection of amphotericin B useful[1, 9]. However surgical debridement is the final and crucial approach for these patients.