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Biomedical subjects

L R Zenkov

Publications and source records attributed to L R Zenkov.

At least 19 recordsLinked to original sources
PubMed2005

[Cognitive potential P300 in dementia with Levy's bodies and Alzheimer's disease].

Neurodegenerative diseases accompanied by cognitive impairment (dementia with Levy's bodies--DLB and Alzheimer's disease--AD) and others) are becoming more widespread due to increasing population life expectancy. The paper addresses use of cognitive event-related potential P300 to verbal and nonverbal stimuli with an assessment of interhemispheric asymmetry and topographic distribution of P300 in patients with DLB and AD comparied to age-matched healthy controls. Specific alterations of P300 amplitude and latency suggest a use of cognitive event-related potential P300 in differential diagnosis of DLB and AD.

Aged↗
PubMed2004

[Use of ketogenic diet in treatment of pharmacoresistant epilepsy].

Ketogenic diet (KD) is one of the most effective methods of epilepsy non-drug therapy. Ten patients with pharmacoresistant epilepsy, aged 1.5-18 years, were treated with individually matched and strictly controlled KD with high fat content and restricted amount of proteins and carbohydrates. After 1 year, only 4 patients kept the diet. Factors of efficacy, causes of withdrawal and side effects of KD are discussed.

Adolescent↗
PubMed2003

[Contingent negative deviation in children with headaches].

Contingent negative deviation (CND) was studied in 26 children with migraine and in 20--with headache, tension-type, aged 7-14 years. A control group included 16 healthy subjects. The study was conducted during pain-free intervals, with a 3 s interval between the warning stimulus--S1 and the imperative one--S2. Children with migraine had a higher negative wave amplitude than those with headache, tension type, and controls. Patients suffering from headache had a characteristic postimperative negative wave in the postimpulse period. CND may be considered as an additional index of migraine diagnosis in childhood.

Adolescent↗
PubMed2003

[Cognitive potential p300 in Parkinson disease].

Cognitive evoked potential P300 in response to visual verbal and non-verbal stimuli was examined in 40 patients with idiopathic Parkinson's disease (PD) without cognitive impairment and 8 age- and sex matched normal controls. All the patients were subjected to clinical and neuropsychological evaluation. The influence of patient's age, duration, type and severity of the disease, debut's lateralization and anti-parkinsonic therapy efficacy on P300 was evaluated. Compared to controls, PD patients exhibited a significantly prolonged P300 latency and decreased P300 peak amplitude. The topography of PD maximum P300 amplitude indicated a frontal distribution with no between-hemispheres differences. Overall, the P300 changes in PD patients without dementia can be interpreted as a decrease of directed activity level and the partial defect of mental recognition processes and stimuli differentiation related mostly to the nonverbal image-spatial cognitive processes. The results show that P300 recording may be useful for diagnosis of subclinical cognitive disturbances in PD without dementia.

Adult↗
PubMed2002

[Clinical importance of EEG changes during the treatment of epilepsy with valproate (depakene chrono)].

In 24 patient with epilepsy in the age fo 6-46 years the EEG was studied before treatment and after stabilization of the initial and corrected dozes of valproate (depakine chrono). The manual analysis with the formalized quantitative estimation of indexes of epileptic activity (El) and computerized mapping of spectral power in the main bands of EEG was carried out. In 18 patients remission of a half-year and more was achieved. Average El before treatment in all group was 15.1 +/- 1.9, on the initial stabilized doze (10-15 mg/kg/day)--4.3 +/- 1.2 (p = 0.000), at increase of a doze > 15 mg/kg/day, on the average it was not revealed of the further change of El. There was significant positive correlation between epileptic activity in EEG, expressed by El and number of attacks in the patient per one month on the moment of EEG research (r = 0.65, t = 6.58). In 6 patients with farmacoresistence the index of epileptic activity was significantly higher (El = 11.7 +/- 4.3), than in the patients with good effect (El = 1.9 +/- 0.8, p < 0.002). In data of the computer analysis under influence of depakine chrono the reduction of power in all bands and leads was observed, except occipital lobes where the increase of alpha-power was observed. This reflects reduction of epileptic activity and restoration of normal EEG, which accompanied the improvement of social and psychic adaptation. The results of the study demonstrate that automated or manual EEG control is important factor of correct selection of a valproate doze during treatment, that allows not only to suppress effectively the attacks, but on the minimal but sufficient doze to reach improvement of psycho-social functioning and to reduce terms of treatment, at the expense of control of an unpredictable relapse of attacks.

Adolescent↗
PubMed2001

[Contingent negative variations in headache in children].

The paper presents a study concerning contingent negative variation (CND) in period between the attacks in 29 children with migraine, in 26 cases with a headache of tension (HAT) and in 16 healthy children. The age of the children examined was 7-14 years. The role of the age factor was shown in dynamics of the behavioral and electrophysiological CND parameters. Differences of electrophysiological CND parameters in children with migraine, in children with HAT and in healthy children of the same age are discussed as well as the results of the complex clinical-neurophysiological estimation of the efficiency of the prophylactic therapy in groups. CND method was considered to be quite perspective for differential diagnosis of primary headache in children.

Adolescent↗
PubMed1995

[Familial paroxysmal ataxia].

The paper provides clinical and paraclinical findings on 3 patients from one family (two brothers and father) suffering from familial paroxysmal ataxia. The authors observed psychosensory disturbances not typical, according to the literature for attacks of ataxia, dysarthria and nystagmus. The evidence obtained on cerebral and spinal evoked potentials made it possible to diagnose multilevel impairment of nervous impulse conduction in the somatosensory system which may be due to metabolic disturbances underlying the disease.

Acetazolamide↗
PubMed1993

[Cerebral complications in cardiac myxomas].

The authors analyze injuries to the central nervous system in patients with heart myxomas due to tumorous embolism of brain vessels with the development of acute or "delayed" cerebral symptomatology. Stress the difficulty of correct interpretation of acute disorders of cerebral circulation with no other signs of intracavitary heart neoplasm and the possibility of the asymptomatic form of cerebrovascular embolism or its consequences in association with a remarkable clinical picture of heart myxoma. Emphasis is laid on the necessity of carrying out all-round examination of the brain to reveal injuries that may occur under such conditions, to determine the prognosis and treatment policy in the given patients' group, especially in the long-term period after resection of intracavitary heart neoplasm.

Adolescent↗
PubMed1993

[The painful leg and moving toe syndrome].

The paper reports a case of painful-legs-and-moving-toes syndrome in a 75-year-old woman who developed it after a paralytic ischias attack at the age of 70. The syndrome was characterized by persistent pains in distal parts of the legs and feet and constant involuntary flexion-extension wave-like toe movements. SSEP studies revealed a defect of conduction in high-speed myelinated fibers of the lumbo-sacral radices of both sides. A cortical motor potential corresponding to the toe hyperkinetic movement was present. It the base of the hyperkinesis a reflectory mechanism may underlie initiated from radiculo-spinal nociceptive systems disinhibited in consequence of the deficiency of inhibitory control from high speed rear column afferents. Neurophysiological data suggest participation of cerebral mechanisms in realization of the hyperkinesis.

Action Potentials↗
PubMed1991

[Somatosensory evoked potentials and the spinal cord conduction velocity in multiple sclerosis].

Somatosensory evoked potentials (SSEP) on n. medianus and n. tibialis stimulation were studied in 25 patients with multiple sclerosis (MS) and 30 normals (N). Sensory conduction velocity (SVC) calculated by indirect method using formula of Eisen and Nudelman (1979) in which instead of time parameters of F- and M-responses latencies of the N13 and N21 for hand and leg, respectively, of spinal SSEP was used. Normal spinal cord SCV was 60.8 +/- 1.3 m/s, SCV in MS was 51.9 +/- 10.7 m/s. Extreme dispersion of data in MS is caused by false "normal and paradoxically "increased" SCV values in patients. The causes of false results are analysed. In difference of Eisen and Nudelman methods, the proposed approach allows proper clinical interpretation of the false values and excludes possibility of diagnostic mistakes, as in each case the whole set of the data from cerebral and spinal SSEP is interpreted systematically.

Diagnostic Errors↗
PubMed1990

[Neurophysiological mechanisms of aphasia in epilepsy].

The EEG, visual and auditory evoked potentials were examined in 4 patients with aphasia-epilepsy. All the examined manifested focal discharges of high-amplitude acute waves, peaks and peak-wave complexes in the temporal leads on the left or on the side of assumed dominance according to speech. The same leads showed transformation of auditory and visual evoked potentials to peak-wave complexes. The intensity of epileptic focal discharges on the EEG correlated with the gravity of aphasia, whereas effective treatment bringing about suppression of epileptic discharges in the temporal parts favoured speech recovery. Obviously, speech disorders in patients with aphasia-epilepsy are caused by neurodynamic disorders of information transfer and processing in the speech zones of the temporal lobe.

Aphasia↗
PubMed1989

[Spectrum analysis of the EEG in children and adolescents with epilepsy: general characteristics and pathophysiological interpretation of the data].

Spectral EEG analysis (fast Fourier transform) was performed in 48 patients with epilepsy, 4 patients after one epileptic seizure, 12 sibs of epileptic patients, 18 children with febrile convulsions, 18 patients with vasoautonomic dystonia, and 23 normal children. Means, standard deviations, standard errors of the means were calculated for the spectra. A distinct EEG type was found characteristic of the epileptic patients: power increase by the factor of 5 to 10 as compared to normals, predominantly in theta band. This EEG type was shared by epileptic patients and their sibs. Both had peculiar patterns on hyperventilation.

Adolescent↗
PubMed1989

[Possibilities of the diagnosis and the evaluation of epilepsy risk based on the data of EEG spectrum analysis in children and adolescents].

Using spectral analysis data of the previous study a trial was undertaken to develop criteria for diagnosis and risk assessment of epilepsy. To the spectral parameters++, differentiating groups of epilepsy and normals, the diagnostic weights from 1 to 10 were attributed, according to the probability "p" from 0.01 to 0.001 using "t" criterion. Sums of the weights formed "epilepsy indexes" (EL) for each normal and patient. From these EI confidence intervals for p less than 0.034 and less than 0.003 were obtained. The criteria were checked on a mixed group of patients differing by the degree of epileptic charge. Positive EI were found only in the patients with high risk of epilepsy (febrile convulsions and epileptic siblings) and in patients with actual epileptic seizures, corresponding in the latter mostly to p less than 0.003.

Adolescent↗