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Biomedical subjects

L R Zenkov

Publications and source records attributed to L R Zenkov.

At least 37 records · Page 2Linked to original sources
PubMed1986

[Oscillating visual evoked potential in epilepsy].

The authors studied visual evoked potentials (VEP) at the O, P, C and T leads in response to light flashes of 0.09, 0.18 and 0.36 W/s in 19 normal and 43 epileptic subjects. In 75% of the patients the VEPs were characterized by a high amplitude oscillatory response (OVEP) in the form of a series of 5.5 oscillations with a 10 Hz frequency, the mean latent period of its development being 230 ms. In the normal subjects the OVEP was observed in only 30% of cases and had a lower amplitude, longer latent period and corresponded to the normal after-discharge according to all parameters. Some common features characteristic of the OVEP in epilepsy and the after-discharge in normal conditions suggest that the OVEP is generated by thalamic rhythmogenic mechanisms which are involved in the reaction earlier and more actively as a result of disinhibition of the subcortical multisynaptic systems. The OVEP is an indicator confirming the diagnosis of epilepsy.

Adolescent↗
PubMed1984

[Somatosensory evoked potentials and sensory conduction time along the spinal cord in multiple sclerosis].

Somatosensory evoked potentials were studied upon the stimulation of the hands and legs in 20 patients with disseminated sclerosis and in 10 healthy subjects. The study revealed changes in evoked potentials in the form of a decreased amplitude and increased latent periods of the early components. Calculating the difference between the latent periods of corresponding components of the potentials induced upon stimulating the legs and hands, the authors determined the time of the sensory conduction along the spinal cord which was lengthened in patients with disseminated sclerosis. The results obtained make it possible to use the calculation of the time of sensory spinal conduction in the diagnosis of disseminated sclerosis.

Arm↗
PubMed1983

[Pathogenetic interpretation of changes in cerebral somatosensory evoked potentials in multiple sclerosis].

Somatosensory evoked potentials (SSEP) were studied in 13 healthy persons and in 15 patients with disseminated sclerosis (DS). The amplitude decrease of early components of SSEP (frequently till disappearance of these components), latent period prolongation, asymmetry both of the amplitude and latencies were revealed. Late components with latent periods lasting over 80 ms did not change significantly. In DS, demyelinization is supposed to lead mainly to impairment of well myelinized lemnisc fibers of the somatosensory system in disseminated sclerosis.

Adolescent↗
PubMed1976

[Somatosensory evoked brain potentials in discogenic compressions of the lumbosacral roots].

In 16 patients with discogenic lumbar-sacral radiculitis the author studied somato-sensory evoked potentials from the vertex area in response to electric stimulation of the peripheral nerves corresponding to the affected radicle on the side of the compression and on the intact side. It was established that in discogenic compressions of the radicles there is an expressed drop in the amplitude of early components of evoked potentials II1, H1, especially if the compression leads to disturbances of tacticle, double-range and deep sensitivity. The degree of changes in evoked potentials corresponds to the severity of the compression and may serve as one of the criteria for evaluating the effectiveness of conservative therapy and determination of indications to surgical treatment.

Brain↗
PubMedDate not supplied

[Somatosensory evoked potentials in the sleep-wakefulness cycle in healthy subjects and narcolepsy patients].

Studies of somatosensory evoked potentials (SSEPs) were conducted in various functional states of sleep-alertness cycle (relaxed alertness, 2-nd and delta-stages of slow sleep, rapid sleep) in 7 healthy subjects and 8 patients with polysymptom narcolepsy. Integrated amplitude (IA) was calculated in poststimulus intervals, accordingly to SSEPs division into groups of early (20-80 ms), mean (80-200 ms) and late (200-400 ms) components. It has been shown that in patients with polysymptom narcolepsy IA of all SSEPs components in alertness was lower than in healthy subjects; during sleep higher IA values of earlier components were found in comparison with healthy subjects and lower values--of later negative wave at slow sleep. Psychophysiological interpretation of high amplitude negative shift in the area of late SSEPs components during slow sleep is suggested.

Adult↗