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Biomedical subjects

B M Gekht

Publications and source records attributed to B M Gekht.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Disorders of autonomic fibers of the peripheral nerves in polyneuropathies].

The conditions of postganglionic fibers and parasympathetic fibers of vagus nerve were studied in 102 patients with varioustypes of polyneuritis and in 43 healthy individuals. In the control group the amplitude of evoked cutaneous sympathetic potential (ECSP) on the hand was 330 +/- 102 microV with 1.42 +/- 0.12 s latency, on the foot 230 +/- 81.7 microV with 2.04 +/- 0.17 s latency. Respiration arrhythmia at rest amounted to 45 +/- 14.7 ms and in forced ventilation 80.6 +/- 28.5 ms. Substantial changes of ECSP parameters and heart periods are characteristics of polyneuropathies. The disorders are especially severe in axonal polyneuropathies of various genesis: hand ECSP amplitude decreased to M + 107.5 +/- 118.3 microV, foot ECSP M-61.9 +/- 79.2 microV. Latencies increased on hand to M-1.8 +/- 0.55 s and on foot to M-2.29 +/- 0.71 s. Heart periods are also changed: M-27.9 +/- 1.1 ms at rest, M-66.9 +/- 56.4 ms in forced ventilation. Demyelinating polynephropathies elicit less pronounced changes in ECSP and respiratory arrhythmia. No clear correlations were detected between heart periods or ECSP parameters and clinical signs.

Adolescent↗
PubMed1988

[Importance of electromyography in assessing the motor unit function of human skeletal muscles in lesions of the peripheral neuromotor apparatus].

Comparison of the parameters of potentials of motor units (PMUs) recorded by a concentric needle electrode and macro-PMUs recorded by a macroelectrode in muscles of 102 patients with various neuromuscular diseases has demonstrated that the results obtained by the given methods of examination provide mutually supportive information about the status of MUs in the patient's muscles, the size of MUs, a possible maximal volume of compensatory innervation and its efficacy.

Adolescent↗
PubMed1987

[Clinico-electrophysiological analysis of mitochondrial myopathy].

Patients with mitochondrial myopathy have been subjected to clinical, electromyographic, mechanographic, morphological and ultrastructural examination. The main syndromes involving the neuromuscular system in these patients have been considered. The authors draw attention to a generalized character of changes in clinically local lesions. The diagnostic value of electromyographic and morphological examinations has been compared. An analysis of the clinical picture and the results of electromyographic and morphological studies have suggested heterogeneity of the given clinical group of patients.

Adolescent↗
PubMed1987

[Mechanisms of functional disorders of the autonomic nervous system in Lambert-Eaton myasthenic syndrome].

The authors have examined the status of sympathetic innervation of the skin structures (by measuring the amplitude and latent period of the appearance of the evoked skin sympathetic potential, ESSP) and the autonomic regulation of the cardiovascular system (by examining the R-R intervals of the ECG at rest and in various functional tests) in 9 patients with the Lambert-Eaton myasthenic syndrome, 10 normal subjects, and in 20 myasthenic patients (a control group). All patients examined before the treatment and 7 patients who were examined following the administration of corticosteroid therapy presented disorders of the latent period and/or the amplitude of ESSP, up to its total absence, as well as signs of cardiac arrhythmias indicative of a marked dysfunction of the cholinergic structures of the peripheral nerves. No correlation has been elicited between the depth of identified vegetative disturbances and the presence of clinical and electromyographic indicators of polyneuropathy. Medicamentous tests serve to confirm the synaptic nature of cholinergic disorders.

Autonomic Nervous System↗
PubMed1986

[Clinical analysis of familial forms of myasthenia].

Having studied 29 cases of myasthenia observed in 12 families, as well as 578 relatives of 59 patients with myasthenia, the authors have identified clinical characteristics of familial forms of myasthenia and the frequency of familial myasthenia among patient's relatives. It has been shown that familial forms of myasthenia are characterized by the appearance of a number of symptoms that are not typical of the common sporadic forms of myasthenia, which indicates the involvement, in addition to synaptic structures, of distal portions of peripheral nerves and/or muscle fibers. In families of myasthenic patients there is an extremely high rate of collagenoses, allergic diseases, diabetes, thyroid disease and malignant tumors.

Adolescent↗
PubMed1986

[Automatic analysis of needle EMG in the differential diagnosis of neuromuscular diseases].

A total of 112 muscles were studied in 68 patients with different neuromuscular diseases (7 nosological forms). The study was performed using an original programme of an automatic analysis of needle real-time electromyography and a specially designed automatic system on the basis of Soviet microcomputer "Electronika-60". On the basis of an automatic analysis of 17,834 potentials the authors identified 1,619 individual potentials of motor units. Measurement of all parameters (amplitude, duration, the number of phases in the potential and area) and calculation of correlations between individual parameters revealed significant differences of the mean values of the above parameters for each group of patients.

Adolescent↗
PubMed1986

[Features of the clinical picture, course and treatment of myasthenia in late middle-aged and aged persons].

On the basis of many-year observation of 345 patients with myasthenia (M) developing in elderly and old age (from 50 to 82 years) the authors analyzed the characteristics of the clinical picture of myasthenia in this age group and determined changes in the ratio between males and females first presenting M at this age. The effect of different types of treatment and their combinations employed in these patients was determined. The authors recommend the use of pathogenetic methods of M treatment (thymectomy, X-ray therapy, and prednisolone therapy) in this age group. The most effective method is a combination of thymectomy and X-ray therapy with prednisolone administration.

Age Factors↗
PubMed1985

[Analysis of disordered muscle contractile function by assessments of the degree of potentiation of evoked mechanical response of the muscle].

A study was made of the evoked mechanical response of the adductor under supramaximal stimulation of the ulnar nerve in 24 normal test subjects, 10 patients with the involvement of motoneurons and their axons, 30 patients with chronic derangement of the neuromuscular transmission (myasthenia) and 8 patients with hypothyrosis. A reverse dependence was found of the Pt/Po ratio on the magnitude of post-tetanic potentiation in all the examined. The capacity of the muscle to potentiate the tension in response to the double stimulus and during the post-tetanic periods inversely related to the initial amplitude of the evoked mechanical response of the muscle and the time of the muscle contraction. It is assumed that the universal mechanism of the regulation of muscle contractile function in health and disease underlies the regularities described.

Axons↗
PubMed1985

[Myasthenic syndromes linked to mediator secretion disorders].

On the basis of clinical and electrophysiological examinations of 23 patients with an impaired secretion of the mediator, the following 5 groups of patients with myasthenic syndromes (MS) characterized by disturbances of the neuromuscular transision were identified: patients with bronchogenic carcinoma of the lung; males with a clinical picture closely resembling the one described in bronchogenic cancer of the lung; young males and females with an abnormal thyroid gland; patients with a mild subcortical syndrome and with ataxia; patients with chronic botulinic intoxication. Correlation of the results of electrophysiological examination did not reveal any specificity for any of the identified groups of patients.

Acetylcholine↗
PubMed1985

[Strategy for using glucocorticoid preparations in neuromuscular diseases].

A total of 1630 patients with various neuromuscular diseases of autoimmune genesis were treated. Glucocorticoid drugs taken every other day were shown to be highly effective. On the basis of a large experience the authors propose recommendations for the management of patients in relation to the form, severity and course of the disease with the objective of achieving the maximum therapeutic effect.

Autoimmune Diseases↗
PubMed1984

[Typology of motor unit potentials and muscle fiber density in neuromuscular diseases].

The potentials of muscle motor units were measured in 146 normal subjects, 943 patients with primary muscular diseases, 2114 patients with neuropathy, 887 patients with neuronopathies, and 1057 patients with impaired neuromuscular transmission. Analysis of the findings helped to establish certain types of potentials most frequently registered in various forms of neuromuscular diseases at different stages of the process. A parallelly conducted study (using a microelectrode) of the potentials of individual muscle fibers determined in motor units elicited changes in the nature of the distribution of muscle fibers in motor units, and an increase in their density and also established the role of the readjustment of motor units and compensatory reinnervation in the formation of various types of motor unit potentials.

Diagnosis, Differential↗
PubMed1984

[Muscle contractility in chronic disorders of neuromuscular transmission].

Muscle contractility of the thumb was studied in 24 normal subjects, 84 patients with myasthenia and 4 patients with hypothyrosis in response to supramaximal stimulation, on the basis of the time of contraction and semi-relaxation, staircase phenomena, and posttetanic potentiation. During hormonal therapy, the patients with myasthenia and those with hypothyrosis treated by substitution therapy manifested the normalization of the staircase and posttetanic potentiation, reduction of the contraction force and twitch time during single contraction. The comparison of the changes seen in the contraction force, staircase and posttetanic potentiation during examination of the patients over time suggested that the muscle has a regulatory system that determines the force and twitch time of muscle contraction.

Adolescent↗