Evaluating the evidence for direct central nervous system invasion in patients infected with the nCOVID-19 virus.

The current nCOVID-19 pandemic is raising several questions in the approximately 25% of patients who present with neurological symptoms. While secondary brain injury from the systemic manifestations of the disease account for the majority of non-specific neurological symptoms that include headache, nausea, and progressive confusion, the question that remains unanswered is does the nCOVID-19 virus use the olfactory mucosa as a portal to directly invade the brain? A second question is how common does direct CNS invasion complicate the classical cardiorespiratory severe form of the disease? We know from previous studies that almost all members of the Corona virus family have neurotropism. We also know from the current pandemic that deteriorating consciousness and cerebrovascular accidents are not uncommon. Several previous scattered case reports, and post-mortem examinations of brain tissue, demonstrated nCOVID-19 nucleic acid in the CSF, and brain tissue, of infected and deceased individuals. We performed a PubMed review of the literature to specifically assess the evidence for the direct CNS invasion by the nCOVID-19 virus. This phenomenon would explain the cerebral oedema and encephalitis, that does occur, and bring Neurosurgeons into the management of these patients by for example directed intra-cranial pressure management post insertion of an intra-cranial pressure monitor. Unfortunately, the answers to these questions were not definitively answered by the research reviewed. While suggestive that direct CNS invasion does occur, the exact scale and manifestations of the problem remains, to date, essentially unknown.

Recurring Multicentric Granulomatous Cryptococcomas in the Contralateral Cerebral Hemisphere in an Adult Immunocompetent Patient with Known Previous Disease.

BACKGROUND: Fungal mass lesions in the central nervous system rarely reach a size large enough to directly cause neurologic deterioration. In terms of the etiologic incidence of fungal mass lesions in the central nervous system, whereas cryptococcomas may be the most common, they rarely reach any appreciable size. One form of this specific fungal infection, namely the granulomatous form of cryptococcomatosis, challenges this paradigm, and these lesions can reach an alarming size. CASE DESCRIPTION: We previously reported a case of multicentric granulomatous cryptococcomas occurring in an adult immunocompetent male patient published in WORLD NEUROSURGERY in mid-2018. We now report that despite confirmed gross total resection and subsequent neurologic improvement having been achieved at that time, the patient was not compliant with his prescribed adjuvant antifungal medical therapy, and for 6 months was lost to follow-up. We now report that the same patient again presented to our unit in early-2019 with recurrent granulomatous cryptococcomas, of an alarming even larger size, in the contralateral hemisphere. Fortunately, were again were able to successfully manage him surgically and have now adapted our surveillance plan to include booked follow-up magnetic resonance imaging. CONCLUSIONS: According to our review of the English literature, to our knowledge, this is the first report of recurrent granulomatous cryptococcomas occurring in the contralateral hemisphere within 6 months of surgery. The case illustrates the importance of the adjuvant antifungal medial therapy if recurrence is to be avoided.

Multicentric Cryptococcomas Mimicking Neoplasia in Immunocompetent Patient.

BACKGROUND: Fungal mass lesions in the central nervous system are, as a group, extremely rare. In this group cryptococcomas are the most common mass lesions seen. These cryptococcomas/mucinous pseudocysts are commonly only 3-10 mm in diameter and occur almost exclusively in the basal ganglia through contiguous spread from a basal meningitis through the Virchow-Robbin perivascular spaces. In rare cases a chronic granulomatous process may lead to formation of mass lesions that have a tumoral appearance. CASE DESCRIPTION: A 19-year-old male presented to our Neurosurgical Unit with a 5-month history of progressive morning headaches. He also complained of progressive weakness of his R upper limb of 3 months' duration. The patient was found to be human immunodeficiency virus negative with a CD4 count of 1763. The patient had no other medical problems. Examination revealed a monoplegia of his R upper limb. While being optimized for surgery, the patient demonstrated progression of his upper limb monoplegia despite preoperative steroid therapy aimed at decreasing the perilesional vasogenic edema. He was booked for emergency resection of 2 lobar mass lesions. Histopathology analysis revealed the 2 specimens had similar features. These specimens were representative of gliotic brain parenchyma involved by extensive cryptococcosis. CONCLUSIONS: Diagnosing the tumoral form of cryptococcosis in immunocompetent patients is a challenge. Primary and secondary brain tumors are usually the first hypotheses in these cases. Thorough preoperative investigation through cerebrospinal fluid sampling and detailed magnetic resonance imaging may lead to consideration of this diagnosis before the histopathologic analysis has been conducted.