The Growing Threat of Phaeoid Fungal Brain Infections: A Neurosurgeon’s Call to Action

As we all know, there is an increasing prevalence of central nervous system invasive fungal infections such as cerebral phaeohyphomycosis caused by dematiaceous/phaeoid fungi, which concerns me as a neurosurgeon. Although these infections are relatively uncommon, they can have a catastrophic effect on neurological health, leading to significant diagnostic and therapeutic challenges. To improve patient outcomes and lower disease-associated morbidity and mortality, there is an urgent need for increased awareness, early detection and timely care.

Cladophialophora bantiana, Exophiala and Chaetomium perlucidum are the most common causes of cerebral phaeohyphomycosis with significant neurological abnormalities. These infections generally produce nonspecific neurological symptoms such as headaches, focal neurological signs and seizures, which may be misdiagnosed as other more common neurological disorders, delaying diagnosis and treatment, leading to worse clinical outcomes. It can be challenging to predict and diagnose the disease early, especially in immunocompetent individuals without the usual risk factors for immunosuppression. ¹

Without treatment, fungal infiltration of the brain parenchyma can cause granulomas, abscesses, and tissue necrosis, leading to irreversible neurological impairments or even death. It can be difficult to distinguish fungal granulomas or space-occupying lesions from other primary brain tumours or granulomatous disorders, complicating prompt identification. ² Due to these diagnostic challenges, neurosurgeons must remain vigilant for fungal infections, especially in patients who do not improve with standard care. ²

Effective management of these infections depends on early diagnosis and although neurosurgeons frequently use neuroimaging and histological findings for it, phaeohyphomycosis can be difficult to identify on standard imaging tests, especially in newer agents such as Chaetomium perlucidum. ³ Given the location of the infection in the brain, especially in deep regions, tissue biopsy the gold standard for diagnosis may not always be feasible or safe. Therefore, it is crucial to maintain a high level of suspicion and consider fungal infections in the differential diagnosis, especially when patients exhibit unusual symptoms or do not improve with conventional therapies.

Cerebral phaeohyphomycosis therapy requires a multidisciplinary approach taking into account of causative agent and the degree of brain damage. Large, space-occupying lesions may require surgical resection, but antifungal treatment is equally important. Although antifungal medications such as voriconazole have demonstrated potential in improving outcomes, the prognosis remains uncertain, especially in cases of late diagnosis or severely invasive illness. ⁴ As a neurosurgeon, it is crucial to stay updated on emerging neurosurgical fungal agents and include them as differentials during diagnosis. ⁵

The rise in phaeohyphomycosis cases globally necessitates increased clinical awareness and better, faster diagnostic facilities, especially in areas with higher fungal infection incidence. To ensure prompt diagnosis and treatment, effective collaboration between neurosurgeons and other medical professionals is necessary, alongside better diagnostic procedures and knowledge. ⁶

Final, as a neurosurgeon, I urge my medical colleagues to recognise the growing concern of phaeoid fungal brain infections. To reduce morbidity and mortality, we must have early and specific diagnostic methods, updated knowledge, rapid surgical intervention and appropriate antifungal therapy. Additionally, more studies on the epidemiology, pathogenesis and treatment of cerebral phaeohyphomycosis are needed.