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Biomedical subjects

B N Beĭn

Publications and source records attributed to B N Beĭn.

At least 37 records · Page 2Linked to original sources
PubMedDate not supplied

[Electroencephalogram dynamics in Matas' compression test as a criterion of the efficacy of reconstructive operations on the vessels of the carotid basin].

EEG recording with Matas' compression test makes it possible to specify the immediate contribution of the carotid artery to the activity of the cerebral cortex neurons. This supplements the quantitative study of the linear and volume blood flow in the carotid bed. The positive result in compression of the carotid artery is characterized by a stereotype reconstruction of the brain biopotentials on the EEG reflecting the beginning of nerve cell hypoxia. Change of the EEG response in Matas' test after reconstructive operations--endarterectomy of the carotid artery and formation of extra-intracranial microvascular anastomosis--points to the contribution of the carotid artery to the general cerebral blood flow under the new conditions. It is noted that the significance of the newly formed vascular bed in the cerebral blood supply increases gradually and individually in different patients. This is evidently determined by the differences in the severity and spread of atherosclerosis of the cerebral vessels, the arterial pressure level in various vascular beds of the brain, the degree of development of anastomoses and synangioses between the branches of the internal and external carotid arteries, etc.

Adult↗
PubMedDate not supplied

[Movements homolateral to the discharge focus in the structure of an epileptic seizure].

The author studied the types and frequency of ipsilateral movement phenomena in the structure of a seizure in patients with different localization of the focus discharge in the brain. The ipsilateral phenomena were not components of the initial symptom of an epileptic seizure as a rule and were evidently linked with the secondary spread of the epileptic discharge from the focus. The article discusses some mechanisms in early secondary ipsilateral epileptic movement phenomena and late phenomena at the end of the seizure on the basis of the stereotactic indepth electroencephalographic study of the time course of the seizure discharge.

Electroencephalography↗
PubMedDate not supplied

[Motor function compensation in patients with infantile residual encephalopathy and epilepsy following hemispherectomy].

The author studied the time-course of motor function in the paretic and healthy limbs of 12 patients who underwent hemispherectomy. The neurological symptomatology, H-reflex parameters, and the results of a series of motor tests were appraised. In the acute postoperative period, the short-lived signs of central shock in the paretic limbs were observed, which were then replaced by increased excitability of the central nervous system on the side of the hemiparesis. Besides cessation of attacks and epileptic activity on the ECG in the late period, the author recorded total rise of the threshold of H-reflex production and improvement in the performance of the motor tests in unispheric patients, which were regarded as signs of epilepsy compensation.

Adolescent↗
PubMedDate not supplied

[EEG and deep stereotaxic EEG in the diagnosis of bitemporal epilepsy].

Bitemporal epilepsy is characterized by complex hierarchical relationships between the contralateral temporal foci. On the basis of the clinical and electrophysiological examination of 61 patients with the clinical form of the disease which is discussed, the authors singled out definite characteristics the comprehensive evaluation of which allowed three possible types of subordination of the bitemporal foci that was studied to be identified. The authors believe that the singled out variants in the interrelationships of the foci of epileptic activity are not the only specific features in the organization of the epileptic system in bitemporal epilepsy.

Adult↗
PubMedDate not supplied

[Dynamics of cerebral blood filling in epileptic patients during seizure activation].

The interrelationship of cerebral hemodynamics and cerebral vascular tonus was studied in 36 patients with epilepsy during activation of discharges and provocation of epileptic seizures by hyperventilation and intravenous corazol infusion by simultaneous EEG and REG recording. It was found that regional functional hyperemia in the brain corresponding to the side of the epileptogenic focus increases during activation of the discharges despite a certain increase in the tonus of the cerebral vessels. During and immediately after an epileptic seizure angiospasm is replaced by vasodilation with further growth in blood filling of the brain. The possible mechanisms of the vascular reaction are discussed.

Brain↗
PubMedDate not supplied

[Cerebral blood-filling, tonus of cerebral vessels and intracranial pressure in epileptic patients during a single seizure].

On the basis of simultaneous measurement of the rheosubcorticogram, polarogram, intracerebral pressure (ICP), ECoG and subcorticogram in patients with electrodes and sensors implanted in the brain, it was established that with the development of the seizure a rapidly reversible growth in the amplitude of deep rheoencephalogram, pO2 and ICP occurs beginning from the subclinical phase of epileptogenesis augmentation. According to the findings of deep rheoencephalography, the values of the tonic-elastic properties of the cerebral vessels undergo two-phase changes with the development of stable vasoparesis. The results of the study show that reactive hyperemia of the brain is the cause of the increased ICP; the cerebral perfusion pressure decreases in this case. A close correlation has been established between the values that were studied, particularly in the period of post-seizure coma.

Brain Chemistry↗
PubMedDate not supplied

[Dynamics of spinal cord motor neuron excitability in epileptic patients following surgical elimination of seizures].

H-reflex testing in epileptics with frequent seizures reveals both an increase and decrease of the activity of the spinal cord motoneurons. A surgical removal of the epileptogenic focus and the disappearance of seizures is followed by a significant elevation of the H-reflex induction threshold, which may be a reflection of the compensatory process. The dynamics of the stimulation EMG data pertains to the H-reflex alone, and is not true in case of the tendon reflexes. In this connection a dystony of the supraspinal regulation of the alpha- and gamma-motoneurons is suggested in epilepsy with a prevailing involvement of the alpha-cells.

Epilepsy↗