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Biomedical subjects

A A Sokolova

Publications and source records attributed to A A Sokolova.

At least 19 recordsLinked to original sources
PubMed1988

[Characteristics of the late components in somatosensory evoked potentials of patients with a pain syndrome in spinal cord involvement].

In spinal trauma patients SSEPs were studied under median carpal nerve stimulation. In cases with pain syndrome, late SSEP waves (180-280 ms) were more pronounced as related to control group of patients without pain and to normal subjects. Psychoemotional personality scaling (MMPI) revealed the increased levels in the first three scales (s.c. "neurotic triad") in the pain group. A correlation was found between the late (P227) SSEP waves and the "neurotic triad" in MMPI.

Adolescent↗
PubMed1984

[Use of a method of recording somatosensory evoked potentials to evaluate the intensity of painful stimulation and the effectiveness of analgesic stimulation].

The authors propose a modified variant of experimental pain stimulation with the attendant registration of somatosensory evoked potentials (EPs) induced by electrocutaneous stimulation via electrodes placed on the ulnar surface of the lower arm. The amplitude of EPs taken from the cranial surface directly correlates with the subjective sensation of pain. These EPs represent superficial positive vibrations with the peak latent period of 240 +/- 23 msec, which are most expressed in leads with saggital electrodes. Transcutaneous antinociceptive stimulation diminishes the amplitude of the recorded EPs in accordance with the subjective analgesic effect. The suggested model may be used for objective evaluation of the pain effect and for selecting the optimum parameters of antinociceptive stimulation.

Cerebral Cortex↗
PubMed1983

[Disorders of higher cortical function and EEG features in patients with spinal cord lesions].

Combined electroencephalographic and neuropsychic studies of 60 patients showed the variable nature of the functional brain disorders associated with spinal cord impairments at the cervical, thoracic and lumbar-sacral levels. Changes in the EEG criteria of brain function were reflected in an altered character of the principal psychic processes. The results obtained are statistically significant.

Adult↗
PubMed1977

[Relationship between blood flow in the motor cortex and neuronal and total bioelectrical activity of the rabbit brain].

In unrestrained rabbits, the local blood flow (LBF), the unit activity in the motor cortex, the EEG, and the EMG of forelimbs were simultaneously recorded during different kinds of stimulation. The EEG arousal response and the increase in the firing rate of unspecific neurons were only followed by the increase in the LBF on adequate stimulation or movement, whereas on inadequate stimulation it was the decrease in the LBF. With the specific neurons, the increase or decrease in their firing rate corresponded either to enhancement or to reduction of the LBF on adequate and inadequate stimulation. The above correlations were only revealed at the normal functional state of the cerebral cortex. The energy expenditure of specific neurons is suggested to be the main factor in the mechanism for the LBF control.

Animals↗
PubMedDate not supplied

[Changes in the somatosensory evoked potentials of patients with complicated spinal trauma after an omentomyelopexy operation].

The purpose of the study was to record somatosensory evoked potentials (SSEP) to objectify the results omentomyelopexy in late spinal cord injury. SSEP were recorded in 25 patients in leads of three levels of the somatosensory tract (from the popliteal fossa, from the lumbar enlargement of the spinal cord, and from the surface of the skull in the region of projection of leg presentation in cerebral hemispherical cortex) before and after surgery. The study indicated that there were no pre- or postoperative records of cortical evoked potentials. At the same time there was improvement in the magnitude of SSEP at the level of the lumbar enlargement (36%). In 4 (16%) and 5 (20%) cases of them SSEP changes were clear and unclear, respectively. The assessment of SSEP changes requires consideration of cases with unclear SSEP. Comparison of the results with clinical findings shows a correlation mainly with urological and urodynamic evidence. Thus, there are minor positive changes in the magnitude of SSEP after omentomyelopexy in the lumbar enlargement lead with unclearly pronounced evoked potentials.

Evoked Potentials, Somatosensory↗
PubMedDate not supplied

[Electroencephalographic reflection of arterial spasm following surgery for saccular cerebral aneurysms].

The purpose of the investigation was to study the electrophysiological manifestations of arterial spasm developing following surgical interventions for cerebral arterial aneurysms. Repeated EEG-recording was undertaken for this purpose in 40 patients with aneurysms of different localization. The EEG data were compared with the results of a neurological examination and angiography performed pre- and postoperatively. It was found that with an uneventful postoperative course no focal changes develop in the bioelectrical activity, and EEG returns to the initial (preoperative) state or to the normal pattern as soon as by the 15th-20th day. In the presence of postoperative arterial spasm, verified clinically and angiographically, the latter is reflected in EEG tracings as peculiar focal changes in the biopotentials. These changes have a nature of a periodically occurring delta-activity recorded predominantly in the zone of ischaemia. Along with a regress of the spasm its EEG manifestations were found to decrease as well. The focal EEG changes observed in postoperative spasm differ from the localization of those EGG changes that are caused by other factors (haematoma, cicatrical processes, etc.).

Adult↗
PubMedDate not supplied

[Changes in the permeability of amphibian embryo envelope for fluorochromes under the action of ultrasound].

It was determined whether high-frequency ultra sound can change the permeability of gray toad Bufo bufo and grass frog Rana temporaria under the action of high-frequency ultrasound. The changes in the permeability of embryonic envelope were assessed by using slowly penetrating fluorochromes ANS, FDA, and fluorescein. It was found that the ultrasound of 0.88 MHz and 0.4 - 0.7 W/cm2 intensity increased the permeability of amphibian embryonic envelope for ANS and FDA, whereas the ultrasound of 2.64 MHz and the same intensity increased that for fluorescein with the retention of low permeability for FDA. Embryos continued the normal development after treatment with ultrasound under these conditions.

Animals↗
PubMedDate not supplied

[The role of somatosensory evoked potentials in prognosis of efficacy of tibial neuromodulation in patients with hyperactive urinary bladder].

Registration of evoked brain potentials was used as a non-invasive and an objective method of diagnosis of the CNS diseases. Somatosensory evoked potentials (SSEP) in response to stimulation of the tibial nerve were studied in patients with hyperactive urinary bladder (HUB) to clarify SSEP role in prognosis of tibial neuromodulation (TNM) efficacy. Urodynamic parameters and SSEP were examined in 13 patients with symptoms of urinary accumulation disorders. Neurogenic HUB was diagnosed in 6 patients, idiopathic one--in 7 patients. TNM was delivered in 30-min weekly sessions (n = 12). Six of seven patients with a cortical potential responded to TNM. Of six cortical nonresponders a positive result was achieved only in two. Thus, patients with the cortical potential demonstrate better effect of TNM than those without the potential. It is suggested that TNM influences both sacral and supraspinal center of urination.

Adult↗
PubMedDate not supplied

[Changes in the somatosensory evoked potentials of patients with trauma to the cervical spinal cord].

Study of somatosensory induced potentials (SSIP) occurring in response to stimulation of the median nerve in a group of patients with damage (traumatic) to the cervical segment of the spine and spinal cord (34) showed a dependence of the degree of changes of the SSIP on the type of injury to the spinal cord. It was found that the changes of SSIP were more marked in transverse damage to the spinal cord than in ventral damage, and in a higher (C5-6) than in a lower (C7-8) level of the trauma. Under conditions of traumatic damage to the nervous system the produced IP will be more clear in changes of the stimulation parameters: reduction of the frequency of the stimulus and the number of summations in averaging.

Electric Stimulation↗
PubMedDate not supplied

[Short-latency somatosensory evoked potentials in injuries of the cervical division of the spinal cord].

Short-latent cortical potentials and induced potentials (IP) recorded from the cervical spine in response to electrical stimulation of the median nerve on the wrist were studied in patients with injury to the cervical parts of the spine and spinal cord. The changes in the pronounced character of the somatosensory induced potentials (SSIP) proved to be more marked than those in the controls. A group of patients with considerable increase of peak N1 and corresponding increase of the time of conduction along the central nervous system (up to 20 msec) was distinguished. The latent period (LP) of IP recorded in the region of the cervical parts of the spinal cord was also prolonged in these patients. The pronounced character of the SSIP changes corresponded to that of the neurological disorders in these patients and the course of the subsequent restorative period.

Evoked Potentials, Somatosensory↗