Peculiarities of the development of analgesic effect during transcutaneous dynamic electrical stimulation.

The effect of transcutaneous dynamic electrical neurostimulation on the development of analgesia was studied in behavioral and electrophysiological experiments on rats. A 30-min dynamic electrical stimulation elevated the nociception threshold in tail-flick and hot plate tests, increased the threshold of the late nociceptive flexor reflex, and decreased the number of bursts in the response. Intraperitoneal injection of naloxone (2 mg/kg) abolished the analgesic effect of dynamic electrical neurostimulation. It is concluded that the key role in reflex analgesia during dynamic electrical neurostimulation is played by the endogenous cerebral opioid system, which inhibits the nociceptive signals traveling to CNS via unmyelinated C-fiber afferents.

Effect of bioresonance therapy on antioxidant system in lymphocytes in patients with rheumatoid arthritis.

We measured activities of superoxide dismutase, catalase, and glutathione peroxidase and content of nonprotein thiol groups (reduced glutathione) in blood lymphocytes from patients with rheumatoid arthritis before and during bioresonance therapy. The state of the antioxidant system in lymphocyte from patients receiving standard pharmacotherapy was characterized by activation of the key antioxidant enzymes and decreased content of thiol groups. Bioresonance therapy increased the content of thiol groups and normalized activities of superoxide dismutase and glutathione peroxidase. However, catalase activity remained above the control. Changes in the lymphocyte antioxidant system indicate that bioresonance therapy activates nonspecific protective mechanisms in patients with rheumatoid arthritis.

[Neurophysiological analysis of analgesic effect of phentanyl and moradol]. / Neirofiziologicheskii analiz analgeticheskogo deistviia fentanila i moradola.

The central mechanisms of analgesic action of phentanyl and moradol are compared using analysis of changes in the early and late components of somatosensory evoked potentials (SSEP) of the brain in normal volunteers in response to pain stimulation. Phentanyl and moradol differently affect the changes in the early components of SSEP: phentanyl reduces their amplitude, whereas moradol increases it. Both drugs similarly influenced changes in the late components of SSEP. Specific effects of the drugs on the sensory and psychoemotional components of pain perception by man are discussed.

[Multimodal evoked potentials and central mechanisms of afferentation in trigeminal neuralgia]. / Raznomodal'nye vyzvannye potentsialy i tsentral'nye mekhanizmy afferentatsii pri nevralgii troinichnogo nerva.

Multimodal evoked potentials in patients with trigeminal neuralgia are analyzed in the paper. The comprehensive studies of cortical trigeminal somatosensory evoked potentials, visual evoked potentials, and brainstem auditory evoked potentials have revealed their changes that are indicative of the impaired central mechanisms of afferentation in patients with trigeminal abnormality. The findings are discussed in the light of the theory of generator mechanisms of neuropathological pain syndromes.

[A neurophysiological analysis of the sensory disorders in trigeminal nerve neuropathy]. / Neirofiziologicheskii analiz sensornykh narushenii pri nevropatii troinichnogo nerva.

52 patients with various types of trigeminal nerve neuropathy were examined in terms of trigeminal somatosensory evoked potentials (TSEP). The increase of latent periods and the decrease of N5-N33 amplitude components as well as disappearance of some separate components of this period were observed in patients with moderate facial pain and hypersthesia when sore side was stimulated. Meanwhile the alterations level of TSEP correlated with trigeminal hypesthesia severity. In a course of such stimulation all TSEP components disappeared in patients with severe sensory deficit and this turned out to be unfavourable prognostic sign pointing out the small perspectivity of conservative antianalgesic therapy. TSEP investigation in patients with trigeminal nerve neuropathy promoted objectivity of face and oral cavity sensory insufficiency that permitted to estimate both the alteration degree and algesic syndrome severity.

[Neurophysiologic analysis of the effects of the centrally acting analgesics moradol, tramal and nubain]. / Neirofiziologicheskii analiz deistviia tsentral'nykh anal'getikov moradola, tramala i nubaina.

The analysis of measurements of early and late components of somatosensory (SSEP) and visual evoked potentials (VEP) in healthy examinees was used to compare the central mechanisms responsible for the analgesic action of moradol, tramal, and nubain. As compared to tramal and nubain, moradol was found to cause a more profound increase in the amplitude of early SSEP components. With this, all three agents were equal in suppressing the amplitude of late SSEP and VEP components. The effects of the drugs on SSEP and VEP, as well as on the sensory and psychoemotional components of human pain perception were also evaluated. The potential features of anesthesiological application of the drugs under study were discussed.

[The dynamic clinico-physiological indices of sexual function during the management of vertebrogenic pain syndromes]. / Dinamika kliniko-fiziologicheskikh pokazatelei sostoianiia polovoi sfery pri kupirovanii vertebrogennykh bolevykh sindromov.

Sexual changes were registered electrophysiologically in 52 patients with low back pain of vertebrogenic origin. M-response of the bulbocavernous muscle emerged at low threshold. There were shifts in the latency and amplitude of the somatosensory evoked potentials of the brain. These confirm participation of disintegrated functioning of the segmentary and central nervous structures in the genesis of sexual diseases. Treatment-induced positive trends in the above parameters may be used prognostically in relation to the patients' sexual activity.

[An analysis of the analgesic action of electroacupuncture]. / Analiz analgeticheskogo deistviia élektroakupunktury.

The analgetic effect of electroacupuncture (EAP) was assessed by changes in subjective feelings, amplitude of somatosensory evoked potentials (SSEP) and testing of monosynaptic transmission of spinal neurons. Following EAP changes in psychophysical and psychological characteristics of stimulation perception in healthy subjects corresponded to a decrease in late SSEP components, threshold of H-reflex appearance and maximum amplitude, which was not observed in patients before surgery. Changes in subjective sensitivity registered in the latter patients did not significantly differ from baseline values and were of opposite direction, which presupposes obligatory combination of EAP with the use of psychoactive drugs during preparation for surgery.

[Somatosensory evoked potentials in patients with lesions of the trigeminal nerve system]. / Somatosensornye vyzvannye potentsialy u bo'lnykh s porazheniem sistemy troinichnogo nerva.

These are results of comparison of clinical data and parameters of early components of somatosensory evoked potentials (SSEP) in patients with various pathological disorders in the trigeminal nerve system. The investigations evidenced that neurologic patients have different degrees of disorders in structural-functional organization of trigeminal nerve system resulting from the disease itself and previous therapeutic interventions. Some of the peculiarities of SSEP changes, e.g., their amplitude and/or temporal asymmetry under stimulation of the sites of intact and afflicted sides of the face are believed to correspond to pathological changes in trigeminal nerve system. These features can serve as diagnostic and prognostic tests.

[Somatosensory evoked potentials and their dynamics among trigeminal neuralgia patients during reflexotherapy]. / Somatosensornye vyzvannye potentsialy i ikh dinamika u bol'nykh nevralgiei troinichnogo nerva v protsesse refleksoterapii.

The study of somatosensory evoked potentials (SSEP) in patients with trigeminal neuralgia made it possible to elucidate their characteristic changes as compared to those in healthy subjects. After a course of acupuncture 75% of the patients showed correlation between some parameters of SSEP and positive clinical results. The authors discuss pathophysiological mechanisms of impairment of cortico-subcortical interactions in patients with trigeminal neuralgia and analyze the possibility of using SSEP for dynamic evaluation of the brain status in the process of treatment.

[Functional architectonics of neuronal antinociceptive mechanisms during the electroacupuncture method of reflex action]. / Funktsional'naia arkhitektonika neironal'nykh antinotsitseptivnykh mekhanizmov pri élektroakupunkturnom sposobe reflektornogo vozdeistviia.

The peculiarities of neurone bioelectric activity of sensory thalamic nuclei under electroacupuncture (EAP) stimulation have been studied in acute experiments on cats. EAP stimulation has been established to change spontaneous and evoked activity of neurones of sensory thalamic nuclei, that testifies to the development of a new functional state. The functional state of the cortex, in particular the second somatosensory region has been shown to determine the nature of neurone activation of sensory thalamic nuclei during the EAP stimulation. Schemes of possible organization of functional pools realizing the mechanisms of inhibition of nociceptive signals on central neurones during EAP way of reflex stimulation are suggested.

Cortical projections to the periaqueductal grey in the cat: a retrograde horseradish peroxidase study.

Stereotaxic fluid microinjections of horseradish peroxidase into different parts of the rostral and caudal periaqueductal grey (PAG) in cats have provided substantial retrograde evidence that the somatosensory cortex (I and II), frontal cortex, insular and cingular cortex are the principal sources of cortical-PAG projections. The somatosensory cortex II projects to all the regions of the rostral and caudal PAG. The frontal cortex projects to dorso-lateral quadrant of the PAG. The same projections were determined from insular and cingular cortex to PAG. The findings revealed a morphological substratum of corticofugal effects on PAG.

[Corticofugal projections to the periaqueductal gray matter in the cat midbrain]. / Kortikofugal'nye proektsii v periakveduktal'noe seroe veshchestvo srednego mozga koshki.

Stereotaxic microinjections of horseradish peroxidase (HP) were made into different parts of the rostral and caudal periaqueductal gray (PAG) in cats to study corticofugal projections to the PAG. The method of retrograde axonal transport of HP demonstrated labeled neurons in the I and II somatosensory areas, frontal, cingular and insular cortex of the brain. It was shown that the II somatosensory cortex projects to all the areas of the rostral and caudal PAG. The frontal cortex projects to the dorsolateral quadrant of the PAG. The findings obtained enabled the detection of the morphological substrate of the corticofugal effects on one of the antinociceptive brain structures--the PAG.