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.

[Transcranial magnetic stimulation for tinnitus treatment]. / Transkranial'naya magnitnaya stimulyatsiya v lechenii tinnitusa.

High prevalence of tinnitus, its negative influence on the quality of life and psychoemotional status of patients support need and extreme urgency of further research of various treatment methods. Rhythmic transcranial magnetic stimulation (rTMS) is an effective method of therapy in patients with chronic tinnitus. The optimal protocol for rhythmic stimulation is low-frequency (1 Hz) rTMS with low-intensity stimuli (below 110% of the motor threshold) with a limited number of stimuli per series. There is evidence that high-frequency rTMS in the area of relatively thin temporal bones can lead to excessive stimulation of the neural structures of the auditory cortex, which is undesirable considering the pathogenesis of this condition. The use of navigation technology in rTMS has no advantage in chronic tinnitus therapy, whereas the combined use of rTMS and transcranial electrical brain stimulation to increase the treatment efficacy is under active study. Considering the attributable favorable clinical safety profile of rTMS, as well as its known positive effects on anxiety and depression that are often seen in patients with tinnitus, we can recommend more widespread use of this method in real-world settings.

[Age dynamic of the motor evoked potential from the tongue in healthy persons.]

Our aim was to determine parameters of motor evoked potential (MEP), elicited by the transcranial magnetic stimulation (TMS) from the tongue in healthy persons of different age. 62 neurologically healthy individuals without any speech problems (age range from 2 years old to 75 years, 34 females & 28 males) were enrolled. All underwent diagnostic TMS, single-pulse protocol, 90-sm round coil, Neiro-MS-D device. Coil was placed on Fz point, registration was performed by the surface electrode on the middle line of the tongue. Results. MEPs were of different appearance, but were registered in all cases, its average latency was 7,14±0,63 ms, average amplitude - 1,79±1,09 mV. There were no gender differences. Significant age difference (p<0,001) was registered between children (age 2-17 years) and two older groups (18-55 and 56-75 years) both on latency and on amplitude. MEPs latency was in three age groups, respectively, 6,21±0,45; 7,05±0,76, and 7,27±0,64 ms. MEPs amplitudes were 0,81±0,61; 1,88±1,01 and 1,69±0,92 mV, respectively. In healthy people aged 2-75 years MEP from the tongue may be registered in 100% of the cases; its average latency is 7,14±0,63 ms, average amplitude - 1,79±1,09 mV; there are no significant gender differences, but significant age differences. TMS of the tongue according to this protocol is relatively simple, not time-and efforts-consuming & may be widely implemented in clinical neurophysiology. There are significant differences on MEPs latencies and amplitudes in healthy persons, which may reflect age-related changes - lengthening of the cortico-lingual pathways and tongue muscle maturing in the childhood and then fibrous tissue development and other changes in nervous tissue and tongue muscle, developing with age.