Citations

Purpose: Neuroinvasive West Nile virus (WNV) is rare, occurring in less than 1% of those infected, and may manifest as meningitis, encephalitis, and/or acute flaccid paralysis. Patients may present initially with nonspecific symptoms including fevers. Although rare, neuroinvasive WNV is associated with significant morbidity and mortality. The mainstay of treatment is supportive care. Electroencephalography (EEG) allows for identification of nonconvulsive status epilepticus and other epileptiform and nonepileptiform patterns suggestive of underlying cognitive dysfunction. Our aim was to describe specific EEG patterns observed in WNV neuroinvasive disease. Methods: A retrospective chart review was conducted. West Nile virus was confirmed with serum and/or cerebrospinal fluid markers. Patients with a history of abnormal EEG were excluded. Electroencephalography reports were classified into categories based on the presence of epileptiform activity, focal slowing, generalized periodic discharges with triphasic morphology, and frontally predominant generalized rhythmic delta activity. Results: In our cohort of 34 patients, 60% of focal EEG abnormalities were anterior-predominant, seen as epileptiform discharges, focal slowing, or frontally predominant generalized rhythmic delta activity. Nonepileptiform EEG patterns included nonspecific slowing and generalized periodic discharges with triphasic morphology. Two patients had electrographic seizures, one arising from the frontocentral head region. Conclusions: EEGs are important in the evaluation of WNV infection to rule out seizures or alternative causes of encephalopathy, and because of the risk of nonconvulsive seizures or status epilepticus in encephalitis. Although an anterior predominance of EEG abnormalities was seen in our cohort, this most likely is more correlative to encephalopathy than WNV itself. Although a specific correlative EEG pattern may not accompany all cases of WNV neuroinvasive disease, WNV should be considered as a possible etiology in patients presenting with an encephalitic or meningitic syndrome in the presence of abnormal EEG findings including encephalopathic patterns, particularly those with anterior predominant EEG changes.

Following acute West Nile virus (WNV) infection in humans, there is upregulation of pro-inflammatory molecules that promote neuroinflammation, including S100 calcium binding protein B (S100B), high-mobility group box-1 (HMGB1), and osteopontin (OPN). The effects of S100B and HMGB1 are transduced by the receptor for advanced glycation end products (RAGE). Interestingly, the same immunoregulatory proteins that fuel neuroinflammation can also promote tumorigenesis. We present 2 cases of glial neuronal tumors, a glioblastoma multiforme and dysembryoplastic neuroepithelial tumor, in patients with severe West Nile neuroinvasive disease (WNND). In these cases, the viral infection was a precursor to the development of the aggressive brain tumors. We describe a potential mechanism where the presence of tumorigenic proteins in the microenvironment induced by WNV, and subsequent RAGE and OPN signaling, may contribute to development or aggressive growth of these tumors. Although it is certainly possible that the occurrence of primary brain tumors following WNND is coincidental, the ability of WNV to alter cellular signaling and increase expression of pro-inflammatory and tumorigenic molecules merits further investigations to determine whether there is an association between these disease processes or implications for brain tumor patients who develop WNV infection.

Abstract Little is known about the clinical presentation and outcomes associated with spinal implant infections. Here, we describe a single center's experience in a retrospective cohort of 109 individuals with spinal implant infections, including clinical, microbiological, therapeutic, and outcome data.