Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with the onset of neurological and psychiatric symptoms during and after the acute phase of illness. Inflammation and hypoxia induced by SARS-CoV-2 affect brain regions essential for fine motor function, learning, memory, and emotional responses. The mechanisms of these central nervous system symptoms remain largely unknown. While looking for the causes of neurological deficits, we conducted a study on how SARS-CoV-2 affects neurogenesis. In this study, we compared a control group with a group of patients diagnosed with COVID-19. Analysis of the expression of neurogenesis markers showed a decrease in the density of neuronal progenitor cells and newborn neurons in the SARS-CoV-2 group. Analysis of COVID-19 patients revealed increased microglial activation compared with the control group. The unfavorable effect of the inflammatory process in the brain associated with COVID-19 disease increases the concentration of cytokines that negatively affect adult human neurogenesis.

We describe a case of 52-year-old woman with a medical history of Crohn's disease presented abrupt fever, asymmetrical multiple cranial nerve palsies and focal neurological symptoms localized to the brainstem. The patient was initially diagnosed with ischaemic stroke, because of acute clinical course and results of neuroimaging. Cerebrospinal fluid analysis revealed mild infection with negative Gram staining and culture. Final diagnosis of Listeria monocytogenes brainstem infection (rhombencephalitis) was set up on the basis of further clinical course and positive blood cultures. Listerial rhombencephalitis should be kept in mind in immunocompromised adult patients who develop fever, asymmetrical multiple cranial nerve palsies and focal neurological symptoms localized to the brainstem even without typical neuroimaging, cerebrospinal fluid findings and negative cultures. Early diagnosis and adequate antibiotic treatment is of crucial importance.

Progress in establishing environmental risk factors and, consequently, prophylactic measures for glial tumors, particularly for glioblastomas, is of utmost importance, considering the dismal prognosis and limited treatment options. This report surveyed updates on established and recently identified factors that can predispose a patient to glioma formation while highlighting possible mechanistic links and further research directions. In addition to established factors that increase the risk of glioma, i.e., brain irradiation and several genetic syndromes, another group consists of likely factors contributing to such risks, such as the use of tobacco and those yielding ambiguous results (e.g., UV exposure). Oxidative stress is a common denominator for several types of exposure, and a mechanistic background for other factors remains elusive. Nevertheless, the analysis of clinical and basic research strongly suggests that, apart from the effect of environmental stressors on DNA alterations and mutation burden, the impact of modifying the tumor microenvironment should be considered. Identifying the involvement of environmental hazards in gliomagenesis and glial tumor progression would lower overall risk by modifying clinical practice, patient management, and lifestyle choices. Further verifying the environmental hazards in glioma formation and progression would have far-reaching implications for neurologists, neurosurgeons, and patients.

Subacute sclerosing panencephalitis (SSPE) is a fatal, slowly progressive brain disorder caused by a mutated measles virus. Both subacute inflammatory and neurodegenerative mechanisms appear to play significant roles in the pathogenesis. TAR DNA-binding protein 43 (TDP-43) inclusions are a common co-pathology in several neurodegenerative disorders with diverse pathogenesis. In the present study, we examined brains of 16 autopsied SSPE patients for the presence of TDP-43 pathology and possible associations with tau pathology. Immunohistochemical staining identified TDP-43 inclusions in 31% of SSPE cases. TDP-43 pathology was widely distributed in the brains, most severely in the atrophied cerebral cortex (temporal and parietal), and most frequently as tangle- and thread-like neuronal cytoplasmic inclusions. It was associated with longer disease duration (>4 years) and tau pathology (all TDP-43-positive cases had tau-positive neurofibrillary tangles). This study demonstrates for the first time an association between TDP-43 pathology and SSPE. The co-occurrence of TDP-43 and tau aggregates and correlation with the disease duration suggest that both pathological proteins are involved in the neurodegenerative process induced by viral inflammation.