A case of bacterial meningitis with burst waves of local onset on ictal Electroencephalography

Quantitative Electroencephalography Indicators in Children with Acute Purulent Meningitis

The aim of the present work was to assess the state of brain bioelectrical activity in children during the acute period of bacterial purulent meningitis, with quantitative mathematical analysis of the changes found. The studies included 31 children on days 1 and 6 from onset of illness: 16 children (8.9 ± 2.4 years) admitted to the Pediatric Scientific Clinical Center for Infectious Diseases with laboratory confirmation of diagnoses of purulent meningitis (due to Neisseria meningitidis) (n = 11) or Streptomyces pneumoniae (n = 2) or unidentified pathogen (n = 3)), along with 15 healthy children. Electroencephalogram (EEG) traces were recorded from all these children in the state of calm waking using a Neuron-Spectrum 4/VP 16-channel electroencephalograph. Clinical assessment of the EEG included analysis of background rhythms, zonal differences, and detection of pathological types of activity. Quantitative analysis consisted of the mean power (μV²) and amplitude (μV) of the α, θ, and δ rhythms, along with mean power ratios – α/θ and α/δ. Visual analysis of the EEG in 100% of children in the acute period of purulent meningitis showed diffuse slowing with detection of δ and θ waves. Focal changes in the form of sharp waves were seen in 18.8% of cases (three patients). No cases displayed periodic activity. Meningitis patients showed significant reductions in the α/δ (p = 0.001) and α/θ (p = 0.048) spectral ratios. ROC analysis showed that the α/θ value was <0.18 and the α/δ value was <0.02 (sensitivity 100% and specificity 80%, AUROC 0.9), which may be evidence of the likely development of cerebral edema. Thus, pediatric patients with acute purulent meningitis showed significant impairments to the normal α/θ and α/δ rhythm power ratios on the EEG, which is presumptively explained by suppression of the functional activity of the thalamus and thalamocortical pathways, as well as the reticular formation of the brain.