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Biomedical subjects

V A Shabalov

Publications and source records attributed to V A Shabalov.

31 records · Page 2Linked to original sources
PubMedDate not supplied

[Movement-related brain potentials during the treatment of parkinsonism].

The authors studied motor associated brain potentials (MABP) in patients with disturbed motor function (hypertonia, tremor) due to affection of the basal ganglia (parkinsonism) and studied the changes of these potentials after stereotaxic operations conducted for the correction of the motor pathology. It was found that in a favourable effect of operative treatment manifested by decrease of the tonus and inhibition of tremor in patients with parkinsonism, there was a tendency towards normalization of MABP. Restoration of some of the components of the motor response and in certain cases of the MABP on the whole occurred on the 14-16th postoperative day. No clearly defined changes of motor associated potentials characteristic of different forms of parkinsonism were discovered.

Action Potentials↗
PubMedDate not supplied

[Preliminary results of treatment for spastic forms of infantile cerebral paralysis by chronic epidural neurostimulation of lumbar enlargement].

Six patients with infantile cerebral paralysis following drug-resistant spastic syndrome were operated on. Four children suffered from lower spastic paraparesis; 2 had spastic tetraparesis. All the children were observed to have leg chiasm and myogenic equinus talipes. Electrodes were implanted under X-ray guidance into the posterior epidural cavity of the spinal cord at the level of Th10-Th12 vertebrae and the MATTRIX system. In the postoperative period, all the children had a steady-state decrease in leg and arm muscle tone during 1-2 daily high-frequency electrostimulation sessions. Within the early week, there was a regression of equinus talipes and leg chiasm. A follow-up indicated a steady-state clinical effect in all the patients. Stimulation myography revealed that the H reflex was suppressed and the H/M ratio decreased to the normal level (60-80%) in all the patients. An average of one daily electrostimulation session was sufficient to maintain muscle tone at the near-normal level.

Adolescent↗
PubMedDate not supplied

[Electrostimulation of a subthalamic nuclear area in Parkinson's disease].

The paper presents the results of application of chronic electrostimulation of the subthalamic nucleus in 15 patients with the akinetic-rigid form of Parkinson's disease. Standard UPDRS, Schwab and England, Hoehn and Yahr, and PDQ-39 rating scales were used for the clinical evaluation of motor disorders. The patients were examined before and 6 months after surgery with ON-stimulation in OFF and ON-medication. Positive results as better life quality, ameliorated motor disorders, and fewer complication of drug therapy with a two-fold reduction in the daily dose of L-dopa were obtained in the vast majority of patients (n = 14).

Adult↗
PubMedDate not supplied

[Somatosensory disorders in patients with extrapyramidal pathology: the effect of a stereotaxic intervention].

The authors compared somatosensory evoked potentials (SSEP) recorded in 16 patients with infantile cerebral paralysis (ICP), 16 patients with parkinsonism (P), 18 patients with torticollis (T), and 15 healthy individuals. Structural changes of SSEP were found in all patients with ICP and in most patients with P and T. The structural changes of SSEP in these patients were mainly associated with the absence or suppression of one or two components of SSEP of a healthy individual. It is assumed that one and the same pathological process underlies these three diseases, but it differs in the degree of manifestation in each one. Two groups of patients with parkinsonism which differed in age were distinguished, which represent, probably, two different pathological processes. Certain normalization of the muscular tonus and inhibition of hyperkinesia in most patients as the result of stereotaxic operation was not attended by normalization of the SSEP structure.

Adolescent↗
PubMedDate not supplied

[Somatosensory evoked potentials before and after stereotaxic operations in patients with childhood cerebral palsy].

The somatosensory function in patients with the hyperkinetic form of infantile cerebral paralysis (ICP) was evaluated by means of short-latent somatosensory evoked potentials (SSEP) in the preoperative period and after stereotaxic operations on the thalamic nuclei and structures of the subthalamic region; the evaluation was conducted by comparison with the dynamics of the main manifestations of the disease. The SSEP characteristics in patients in the preoperative period bear evidence of bilateral disorders in the somatosensory system. Stereotaxic operations, leading to certain normalization of the muscular tone and inhibition of hyperkinesis, do not cause positive changes of the SSEP characteristics. The peculiarities of the SSEP characteristics in the preoperative period in patients with ICP may serve as a definite prognostic sign of the efficacy of stereotaxic operations in these patients.

Adolescent↗
PubMedDate not supplied

[Electromyography in patients with spastic torticollis].

The article describes the results of electromyographic examination of the muscles of the neck in 26 patients with spasmodic torticollis. Electromyography was performed before and after stereotaxic operative interventions on the nucleus of Cajal or in combination with the diencephalic structures. It is shown that electromyographic examination of patients, especially with the use of functional motor and oculomotor tests, widens essentially the possibilities of the diagnosis by facilitating the identification or specification of the predominantly involved group of muscles. The discovery of concurrent oculographic and electromyographic changes in the dominant muscles of the neck during oculomotor tests is evidence of the connection of the system of concurrent movements of the eyes and head with the motor systems participating in the pathology of torticollis. Analysis of the dynamics of electromyographic changes in patients with predominance of the tonic component in the early and late postoperative periods is indicative of gradual increase of positive changes in the motor sphere, which, evidently, is due to the dynamic reorganizations in the previously formed stable pathological system.

Action Potentials↗
PubMedDate not supplied

[Identification of nuclei of the pretectal area during stereotaxic surgery for spastic torticollis].

The neurons of mesencephalic nuclear structures were studied by microelectrode techniques for functional identification of the interstitial nucleus of Cajal during 18 stereotaxic operations on patients with torticollis. It is shown that the use of microneuronography for functional identification of structures of the pretectal region and mesencephalic structures bordering it is promising. The functional cellular complexes of these structures which respond selectively to voluntary movements of the eyes and head, rapid voluntary movements of the eyes, fixation and maintenance of the gaze, and combined movements of the eyes and head are characterized for the first time. In comparison with intracerebral radiological guiding points, the registration of these data makes possible intraoperative active search for functional neuronographically identified zones linked with the pathological mechanisms of torticollis and the performance of selective destruction with minimum volume of damage.

Adolescent↗
PubMedDate not supplied

[Stereotaxic destruction of the interstitial nucleus of Cajal on spastic torticollis].

Intraoperative clinical effects and the results of destruction were demonstrated in 31 patients with various forms of torticollis spastica subjected to operation on the interstitial nucleus of Cajal. The intraoperative clinical complex of symptoms was formed of changes of the toxic and clonic activity of the neck muscles and transient oculomotor and vestibular signs. The favourable postoperative results are evidence of the direct relation of the nuclear structures in the region of the posterior commissure to the mechanisms regulating the posture of the head and neck. Their exclusion may be one of the components of surgical correction of motor abnormalities in patients with torticollis spastica. These operations are more effective in the tonic form of the disease and in prevalence of the rotatory component in the impaired posture of the head.

Adolescent↗
PubMedDate not supplied

[Treatment of complex forms of infantile cerebral palsy using multiple intracerebral electrodes].

On the example of treating patients suffering from infantile cerebral paralysis (ICP) by means of multiple intracerebral electrodes, the authors demonstrate one of the approaches to solving the main methodological problems of stereotaxic neurosurgery: whether or not destruction in the given subcortical structure in the given patient is indicated; what volume of destruction is required for producing the maximum clinical effect. Mechanomyographic recording of the muscle tone was used along with the clinical evaluation as one of the principal methods for appraising the changes in the patient's motor sphere. Changes were shown inthe mechanomyographic characteristics of the muscle tone in response to diagnostic or therapeutic effect on the chosen subcortical structures. It is not possible to recommend a universal combination of structures promising for destruction even in clinically similar cases of ICP on the basic of the material presented. It is necessary to thoroughly appraise the results of the diagnostic effects (polarizations) in every patient and then implement selected dosaged destruction in the chosen subcortical structures.

Adolescent↗
PubMedDate not supplied

[The use of selective dorsal rhizotomy for treating spasticity in patients with infantile cerebral palsy].

The paper gives the results of using selective dorsal rhizotomy at the lumbosacral level in 15 children with infantile cerebral paralysis, 12 of whom were at the age of 6 to 15 years. It also discusses surgical techniques, the use of intraoperative stimulation, and the impact of selective dorsal rhizotomy on muscle tone. The paper provides evidence for the benefits of surgery reducing the muscle tone at the expense of its spastic component. Based on the relationship between the number of cut fibers as part of each root and the degree of decreased muscle tone, a procedure is proposed for conservative surgical interventions to be used in patients employing spasticity for support.

Adolescent↗
PubMedDate not supplied

[The use of computed tomography in stereotaxic operations in dyskinesia patients].

Experience with 366 CT-stereotactic operations in varying movement disorders (Parkinson's disease, cerebral palsy, torsion dystonia, torticollis, hemihyperkinesis) is presented. Different deep structures, such as thalamic nuclei, subthalamic structures, palladium, putamen, caudate nucleus, dentate nucleus, and brachium conjunctivum or combination of these structures, were selected as a stereotactic target point. Anodic or radiofrequency stimulation, implantation of chronic intracerebral electrodes and neurotransplantation were used as methods of exposure. A procedure for CT-stereotactic determination of supratentorial and subtentorial target points is described. CT-guided stereotactic procedures in the treatment of dyskinesia are precise and less traumatic than ventriculography-guided procedures.

Adolescent↗