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.

[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.

Geometrical-optics computer model of metal-knitted mesh for calculations of solar pressure on space deployable antenna reflectors.

A novel computer 3D model is presented for calculations of optical parameters (transmittance, reflectance, and absorbance) of a metal-knitted mesh textile as a structural element of deployable antenna reflectors for space satellites. The model is based on geometrical-optics ray tracing upon diffuse scattering of a broadband light source (Sun) at a complex knitted mesh structure with different inclinations to the radiative source. The proposed computer model is built for the special type of metal-wire textile (two-bar large void tricot) possessing extremely high transmittance and is verified by comparison with the experimental measurements of light scattering parameters of real antenna mesh samples of data-relaying satellites (Russian series "Loutch"). The model is used for calculations of solar radiation pressure exerted on a knitted mesh antenna reflector and gives the maximal pressure value of about 0.28 µN/m2.

[Age-related changes of peripheral nerve system and muscles of the limbs in healthy persons].

Our aim was to present and analyze age-related changes of peripheral nerves and muscles of limbs on a huge population of healthy persons of different ages. Persons aged from 2 months to 87 years were studied by conduction studies (EMG) during the period 2009-2016 years in Scientific Research Institute of Children's Infection. Data of those 1 121confirmed healthy was included in our study. Conduction along n. Medianus, n. Ulnaris, n. Musculocutaneus, n. Axillaris, n. Facialis, n. Tibialis, n. Peroneus et n. Femoralis was registered, with latency and amplitude of compound muscle action potential (CMAP) being analyzed. There were significant differences on latencies and amplitudes of CMAPs between different age groups. Significant lengthening of CMAP latency was registered in older age groups. We marked CMAP amplitude increase from the early childhood until adolescence and later it dropped in persons aged 55 years old and older. These changes may reflect, concerning latency, the lengthening of the peripheral nerves in the age 0-25 years, and later on age-related slowing of conduction starting from 55 years. Amplitude of CMAP may rise with the growing of muscles and drop in later life with age-related muscle atrophy and fibrous changes.

[Age-related changes of sensory peripheral nerve system in healthy subjects.]

Our aim was to present and evaluate age-related changes of peripheral nerves of limbs on a huge population of healthy subjects of different ages. In 2009-2016 subjects aged from 1months to 90 years were studied by nerve conduction velocity studies (NCV). Data of those confirmed healthy was included in our study. In total there were 372 healthy subjects. NCV for nn. Medianus et Ulnaris was registered, with NCV and amplitude of compound sensory action potential (CSAP) being analyzed. There were significant differences on both these parameters between different age groups. Since the childhood the improvement of conduction (which was reflected in rising of CSAP amplitudes and NCV quickening) was registered; from 40-50 years steady decline of both these parameters were observed in both nerves. Conduction studies of peripheral nerves may be implemented in gerontology for early detection of neurophysiology patterns reflecting physiological aging. Also our results may be implemented for accelerated aging detection.

[Neurosonography of the facial nerve in children with idiopathic neuropathy of facial nerve]. / Neirosonografiia litsevogo nerva u detei s idiopaticheskoi neiropatiei.

AIM: To find the correlation between neurophysiological and neurosonographic (NSG) parameters of the facial nerve of children with idiopathic neuropathy of the facial nerve (NLN) in the acute period with good and poor prognosis of recovery of facial nerve function. MATERIAL AND METHODS: Sixty-five children with NLN (mean age 11.5±4.9 years) and 57 children of control group (mean age 12.5±5.2 years) were examined. All children with NLN were studied using NSG with the measurement of the diameter of the facial nerve in the area of processus stylomastoideus and in the parotid gland. Stimulation electroneuromyography of the facial nerve with the registration of the M-response from the m. orbicularis oculi and evaluation of the degree of paresis of facial muscles using the 6-point House-Brackmann scale on the 10-15 day were performed. On the 30th day after manifestation of paresis, children with NLN were divided into two groups: the good recovery group 1 (n=54) and the poor prognosis recovery group (n=11). Correlation between NSG and electroneuromyography indicators with good and poor prognosis of recovery of facial nerve function was analyzed. RESULTS AND CONCLUSION: Based on the results obtained, 85% sensitivity and 77% specificity of measuring the diameter of the facial nerve using NSG in predicting poor prognosis of recovery of facial nerve function was shown. Normative and thresholds NSG parameters of the facial nerve in children were obtained.

[Ultrasonography in evaluating the character of lesions of the median nerve in carpal tunnel syndrome]. / Ul'trazvukovoe issledovanie kharaktera porazheniya sredinnogo nerva pri sindrome zapyastnogo kanala.

AIM: To correlate the cross-sectional area of the median nerve proximal and distal to carpal tunnel and the character of nerve lesion - axonotmesis and neurapraxiain in carpal tunnel syndrome. MATERIAL AND METHODS: Twenty-six hands with carpal tunnel syndrome and 30 hands of controls were examined. In all cases, median nerve cross-sectional areas were measured using ultrasonography and electromyography. The diagnosis and categorization of carpal tunnel syndrome were based on electrophysiological criteria. In all patients with confirmed carpal tunnel syndrome, needle electromyography of m. abductor pollicis brevis was used. Patients with carpal tunnel syndrome were divided into two groups according to the type of lesion of the median nerve - axonotmesis or neurapraxia. Correlation of ultrasound parameters with the character of the nerve lesion was evaluated. RESULTS AND CONCLUSION: Sensitivity and specificity of measurements of cross-sectional area of the median nerve after tunnel in the diagnosis of carpal tunnel nerve lesion by axonotmesis type were estimated as 89% and 85%, respectively. Thresholds of cross-sectional area with respect to the character of lesions of the median nerve were established.

[POLYNEUROPATHY IN CRITICALLY ILL CHILDREN WITH INFECTIOUS DISEASES].

14 pediatric critically ill patients with various infectious pathologies were assessed. Electroneuromyography was carried out in all patients. Polyneuropathy of critical states were revealed in 10 children. It is shown that the frequency of severeform of this state was 40%. Polyneuropathy mostly affects the peripheral nerves of the lower extremities. Polyneuropathy developed typically on 5-7 day from the start of mechanical ventilation.

Diagnostic transcranial magnetic stimulation as a prognostic tool in children with acute transverse myelitis.

STUDY DESIGN: We performed transcranial magnetic stimulation (TMS) in children with sequelae of acute transverse myelitis. Single-pulse TMS protocol was implemented. Twenty controls and 24 patients with myelitis were enrolled. TMS was performed on 12-24 day after the onset of the first symptoms, average on 16th day. OBJECTIVES: The objective of our study was to evaluate motor pathways in children with viral myelitis using the TMS technique. SETTING: All investigations were performed in Scientific Research Institute for Children's Infections, Russia. RESULTS: There were statistically significant differences between the groups on central motor conduction time and motor evoked potential (MEPs) amplitudes. MEP thresholds were elevated, and MEP shape was abnormal in 96% of patients with myelitis (n=23). Three neurophysiologic patterns were observed: the presence of both cortical and spinal MEP, the absence of cortical MEP with the spinal MEP present and the total absence of both cortical and spinal MEP. Last finding was associated with paraplegia, resistant to any sort of treatment. CONCLUSION: Thus, myelitis in 96% of the cases causes neurophysiologic changes, which may be detected by TMS; the method may be used as a predicting tool.

Diagnostic transcranial magnetic stimulation as a method of objective evaluation of motor pathways in patients with neoplastic and infectious brain damage.

The aim of our study was to evaluate validity of transcranial magnetic stimulation as evaluation tool of motor pathways condition dynamics in patients with gliomas and meningitis. There were included 91 patients: 40 children with aseptic meningitis, 26 matching age controls, 10 adults with gliomas and 16 matching controls. All patients underwent transcranial magnetic stimulation (TMS) before and after the treatment. TMS showed good tolerability in all groups. Significant improvement of central motor pathways conductivity (MEPs amplitudes) was seen in both groups. In meningitis group significant rising of functional state of motoneurons was seen as well. We propose that TMS proved to be effective evaluation tool of motor pathways condition dynamic in patients with gliomas and meningitis.

[Ischemic resistance of motor axons in children with viral meningitis and Guillain-Barré syndrome].

The effect of temporal local ischemia at the forearm on ulnar motor nerve conduction velocity in the control (n = 26 children), group of patients with acute period viral meningitis (VM) (n = 16 children), 14 days after the clinical manifestation of VM (n = 11 children) and children with Guillain-Barre syndrome (GBS) in catamnesis (n = 11 children) was evaluated. Less pronounced reactivity of neural conduction on ischemia for 10 minutes (by 50%, p < 0.00001), was seen in children with GBS in catamnesis, comparing to the controls. In the acute period VM also less pronounced reactivity of neural conduction by 29%, than in the controls, was registered. We propose, that ischemic resistance in immune-mediated neuropathy and in the acute period of infection may happen due to cytokine-mediated channelopathy.

[Objective evaluation of rehabilitation efficiency in patients with upper limbs occupational vegetosensory polyneuropathy].

Clinical and neurophysiologic study covered efficiency of rehabilitation in 40 patients with upper limbs occupational vegetative-sensory polyneuropathy. Each patient underwent infrared thermography and electroneuromyography of hands before and after the treatment. Findings are that post-treatment nerve impulse velocity in right median nerve has improved considerably, thermovisual pictures of both upper limbs also have reliably improved. Electroneuromyography and infrared thermography for evaluation of rehabilitation efficiency are justified. Applied rehabilitation protocol was clinically effective, reliable improvement in the patients state was registered.

[The comparative pattern of neuromidin and magnetic stimulation influence on neuroplasticity in experimental traumatic neuropathy].

OBJECTIVE: Traumatic neuropathies are among the most actual problems in neurology due to the severe neurological deficit in most cases and poor prognosis of recovery. We evaluated the effect of ipidacrin (cholinesterase inhibitor) and magnetic stimulation on neuroplastic axonal changes after experimental neurotmesis of rat's sciatic nerve. MATERIAL AND METHODS: Animals (20 rats) were stratified into 3 groups. There was no treatment in the control group; in the second -group experimental animals underwent 3-5 min daily rhythmic magnetic stimulation (0,8-1T, 3 Hz) The third group of animals received intramuscular 0,035 mg of ipidacrin daily within 1 month. RESULTS AND CONCLUSIONS: Based on the received data on the restoration of myelin, axons, myelin nodes structure and lemmocyte ultrastructure), we have concluded that both magnetic stimulation and ipidacrin can trigger restorative and compensative processes in traumatic neuropathies.

[Central motor pathways in children with multiple sclerosis].

AIM: To evaluate motor pathways involvement in children with multiple sclerosis. PATIENTS AND METHODS: We used transcranial magnetic stimulation method. 9 children with relapsing-remitting multiple sclerosis (mean duration 1,68 years) and 20 controls were enrolled. RESULTS: In most of the cases findings in multiple sclerosis group were abnormal. More often polyphasic changes of the motor evoked potentials (MEP) shape (78% of the cases) and elevation of MEP threshold (88%) were seen. CONCLUSIONS: Transcranial magnetic stimulation demonstrated high sensitivity in children with multiple sclerosis. Main neurophysiologic findings in multiple sclerosis in children may reflect altering membrane excitability of motor neurons and demyelinating lesions. Axonal damage in children with multiple sclerosis are less apparent.