Alertness pattern in healthy individuals of various ages.
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Biomedical subjects
Publications and source records attributed to M Matousek.
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Twenty-three patients with major depressive disorders were examined clinically, biochemically and electroencephalographically before antidepressive treatment was initiated. EEG characteristics were related to clinical items and to a serotonin re-uptake indicator. The results suggested that at least three definable EEG patterns were associated with certain specific features of major depressive disorders. Thus, an EEG pattern characterized by increased beta activity was associated with the recurrent type of depression. Another EEG pattern, with signs of decreased alertness, was present in patients with insomnia, agitation and in those without depression in their families. A significant correlation was also found between the alertness indicator and the serotonin accumulation rate. The third type of EEG feature was represented by interhemispheric asymmetry in the EEG which could be seen in patients with high scores of anxiety. The results suggest that the EEG findings may be helpful in defining various subgroups of major depressive disorders.
Muscle sympathetic activity (MSA) was recorded in the peroneal nerve during sleep in 14 sleep-deprived healthy subjects. Continuous noninvasive recordings of finger blood pressure were obtained in 7 subjects. In light sleep (stage 2 sleep) the number of sympathetic bursts/min decreased to 90 +/- 8% (mean +/- SEM) and total MSA (= burst/min x mean burst area) to 89 +/- 5% of the awake value (P less than 0.05, n = 14). In deep sleep (stage 3-4) total MSA decreased further, to 71 +/- 8% of the awake value (n = 5). There was no close correlation between variations of depth of sleep and variations of sympathetic activity but during continuously deepening sleep MSA decreased progressively with time. In stage 2 sleep, high amplitude K complexes were accompanied by short-lasting increases of sympathetic activity. Since these increases of MSA were not preceded by decreases of diastolic blood pressure, which is known to evoke increased sympathetic nerve traffic in muscle nerves, we suggest that K complex related increases of MSA are signs of arousal which elicit both cortical EEG phenomena and activation of cerebral sympathetic centres. During desynchronized (REM) sleep, total MSA increased to 124 +/- 12% of the value in awake state (n = 5). The increases occurred mainly in short irregular periods, often related to rapid eye movements and there was an inverse relationship between the duration of the desynchronized sleep and the increase of total MSA. Our findings are similar to the data obtained in animal experiments and may partly explain changes of blood pressure during synchronized and desynchronized sleep reported previously in man.
New opto-electronic camera systems permit easy quantification of the motor performance during natural acts in freely moving humans. We used a simple test movement (PLM test) to quantify the disturbance in the postural (P), locomotor (L) and manual (M) part of the body movement and the coordination of the different movement phases into a smooth motor act. The test movement time was used to quantify the overall performance. With this technique we have measured the effects of selegiline on the degree of parkinsonism in a double-blind, placebo-controlled pilot study of 5 de novo patients with Parkinson's disease. There was a clear trend that selegiline was superior to placebo in reducing the test movement time.
During the UV irradiation of tamoxifen, isomerization of the trans to the cis isomer takes place and consequently corresponding highly fluorescent phenanthrene derivatives are formed. Their formation can be used for the sensitive and selective detection of tamoxifen in high-performance liquid chromatography (HPLC). The structure of photoproducts was identified by 1H NMR spectroscopy, HPLC, gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. Owing to the variety of products formed and the higher selectivity and fluorescence response, on-line postcolumn photocyclization is preferred to the precolumn mode. A chromatographic system for the separation of isomers and photoproducts is suggested.
The EEG activity was followed during simulated diving to 20 m depth. Altogether 49 EEG records of 5 min length were taken in 5 divers breathing compressed air in a close system. No significant changes of the EEG could be found during either compression or decompression if only conventional indicators, such as the amplitude of theta activity, were tested. However, a complex "normality ratio," based on multivariate analysis of a normal material, was capable of showing significant impairment of the brain activity during the decompression. The indicator has been designed to reflect the abnormality level rather than the short-lasting EEG changes, the latter being mostly dependent on the alertness fluctuations. The EEG changes associated with alertness fluctuations were assessed separately by means of a specific "alertness indicator" and a prominent alertness increase was found during both compression and decompression phases of the diving experiment.
Thirty-eight patients with normal pressure hydrocephalus were examined by CT before and after a ventriculo-peritoneal shunt operation. Evans ratio, periventricular hypodensity and width of hemispheric sulci, sylvian fissures, cella media, temporal horns and third and fourth ventricle were examined. Twenty-eight patients improved after the operation while 10 were unchanged (non responders). Those patients who improved had more often enlarged third ventricle, enlarged temporal horns and normal sylvian fissures than those who did not improve. No single CT parameter or combination of CT parameters alone could identify responders and non-responders. The ventriculo-peritoneal shunt operation reduced ventricular size (Evans ratio, cella media width), abolished periventricular hypodensity and reduced width of the temporal horns and third ventricle in both responders and non-responders. Reduction of the width of the third ventricle correlated to clinical improvement.
We examined 35 patients, aged from 37 to 76 years, with impairment of intellectual functions due to normotensive hydrocephalus of varied origin. Axial tomography showed an enlarged ventricular system, with or without cortical atrophy. As a rule, the patients having no cortical atrophy displayed a significantly lower alertness level than the patients with cortical atrophy, who were more alert. Because the clinical picture was similar in both subgroups, it was postulated that the impairment of cortical function due to organic lesions resulted in symptoms similar to those due to chronic decrease of alertness. According to this hypothesis, there are two types of symptoms in patients with organic brain syndromes, one type being dependent on the alertness decrease and not on the organic lesion itself. Although the two types cannot be easily distinguished during clinical examination, the prognosis is substantially different for "organic" and "functional" symptoms. The hypothesis was supported by observations in 19 patients selected for ventriculoperitoneal shunt operation. Reexamination 3 months after the operation showed that the improvement was not related to changes in the organic substrate, i.e., to the diminished size of the lateral ventricles and of the third ventricle. On the other hand, the clinical improvement was significantly correlated to the increase of the alertness level after treatment.
Continuing investigations of the influences of the hyperbaric pressure upon EEG record in divers during simulated diving. The hyperbaric ecological system exerts influences on brain bioelectric activity manifesting itself by changes of alpha frequency and appearance of slow waves. The changes in the brain activity are mostly observable at the changes in chamber pressure values. The changes in EEG recordings are smallest at constant pressures. EEG examination can be used as a measure of the safety of newly developed decompression schedules.
Twenty-five patients with major depressive disorder according to RDC were examined with computerized quantitative EEG before antidepressive treatment. Normal EEGs were found in 20 patients and slight abnormality in five cases. Relationships between various EEG variables and pretreatment accumulation rate of 14C-5-HT and 3H-NA in rat synaptosomes, incubated in patients' plasma, and 5-HT in whole blood were studied. Age and current treatment with benzodiazepines were taken into account. There was an inverse relationship between alpha-1 amplitude in all derivations and beta-2 amplitude in the parieto-occipital derivation on one hand and pretreatment 14C-5-HT synaptosomal accumulation rate on the other. This result indicates that low 14C-5-HT synaptosomal accumulation rate is related to increased EEG alertness. This EEG pattern is suggested to be associated with a serotonergic subgroup of depression. The relationships between the other biochemical variables and the EEG patterns did not show any consistent pattern.
The sedative or excitatory effects of drugs are difficult to evaluate in patients with depression, where sleep disturbances and tiredness in the daytime belong to the clinical manifestations of the psychiatric disorder. A refined method of vigilance measurement, based on the EEG spectra, together with proper statistical analysis of the data, is helpful for correct interpretation of the data. In two groups of patients with depression, the intensity of sleep disturbances was considered as a background variable in partial correlations, reflecting the relationships between vigilance and drug concentration in a more specific way. It was shown that the sedative effect of maprotiline interferes with the increased vigilance in the patients, with improved night sleep after treatment. As a result, the patients do not experience decreased vigilance although maprotiline has a sedative action. The results obtained in the patients treated with beta-blockers suggest that the drug itself has no sedative effect but the patients suffer from decreased vigilance in the daytime, caused by the sleep disturbances and depression.
The subject of experimental, saturated dividing to 20 m depth was alertness level measured by means of spectral analysis of EEG records. Air was served as breathing mixture compressed to a given depth in closed circulating system. Altogether 49 EEG records made during compression, plateau and decompression, were analysed. Two methods of analysis were applied. "Normality ratio" combined the information from 20 different EEG values and "EEG alertness indicator" showed in three cases pathological slowing and fluctuations of the alertness. According to index of alertness, the most prominent changes were seen during the compression and decompression phase. During the plateau phase sleepiness was recorded. The applied method could provide information when slowing is due to metabolic impairment of brain activity from that of sleepiness.
Twenty-five patients with major depressive disorder (MDD) according to RDC were examined with computerized EEG before antidepressive treatment was initiated. Relationships between EEG parameters and clinical characteristics were studied. Age and pharmacological treatment were taken into account. Primary MDD was associated with an increase of delta amplitude. Retarded MDD was associated with an increase of delta and theta amplitudes and EEG variability. Recurrent unipolar MDD was related to a decrease of total alpha symmetry. Thus, subdiagnoses according to RDC were validated. The anxiety subsyndrome and to some extent vital symptoms, depressed mood, and CPRS total sum, were associated with asymmetry of the EEG pattern, whereas retardation was not. The number of former depressive episodes was positively correlated to amplitude of beta activity and negatively correlated to symmetry of EEG in the delta frequency band.
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The aim of this study was to investigate the changes of vigilance caused by beta-blockers. A recently developed method to measure the vigilance fluctuations, based on the EEG spectra, was employed together with self-rating. Repeated vigilance measurements were made in 20 healthy volunteers before and after administration of placebo, propranolol and metoprolol in random sequence. Both EEG analysis and self-rating confirmed that the vigilance level was significantly decreased after administration of beta-blockers compared to placebo. No significant difference between propranolol and metoprolol could be found. The results suggest that the decrease in systolic blood pressure after beta-blockade may be responsible for the drug-induced drowsiness. However, some of the observations made in the study can be interpreted as indirect proof that central mechanisms are also involved, and that both propranolol and metoprolol have sedative properties comparable to those observed with conventional psychotropic drugs.
Two groups of mothers who underwent elective cesarean section under epidural analgesia, were studied with the aim of comparing the analgesic potency and side effects of two solutions: morphine-bupivacaine and morphine-saline. Each group comprised 100 patients. The intraoperative anesthesia was established with bupivacaine plain, 5 mg/ml, in amount 85-125 mg. Immediately after the infant was delivered, the mothers received a single epidural dose of 3 mg of preservative-free morphine chloride mixed with either 5 ml of 0.25% bupivacaine (Group I) or 0.9% saline (Group II). The intraoperative observations showed "good effect" without need for supplementation of analgesia in 82 mothers in Group I, compared with 61 mothers in Group II (p less than 0.001). The postoperative observations showed that 82 mothers in Group I were satisfied with a single dose of morphine for more than 24 hours, while in Group II the corresponding number was 63 (p less than 0.01). A significant difference in the incidence of nausea and vomiting was found between the groups; 7 of the mothers experienced nausea and 4 vomited in Group I and 17 experienced nausea and 13 vomited in Group II (p less than 0.05, for both variables). Respiratory depression was seen in one mother during surgery immediately after supplementation of morphine-bupivacaine analgesia with ketamine. Other side effects, such as itching, bradycardia and Horner's triad were rare. It may be concluded that a single epidural dose of morphine in bupivacaine will augment intraoperative analgesia and prolong postoperative analgesia. Less favorable results were obtained when morphine in saline was used. Synergism between bupivacaine and morphine is suggested.