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At least 19 recordsLinked to original sources
PubMed1978

Consciousness and disturbances of consciousness.

The problem of consciousness is discussed briefly, including the contrary views of consciousness as a transcendental phenomenon and as an animistic fiction. Measurement of consciousness is possible only indirectly by means of quantitative assessment of accompanying behavioral deficits. Knowledge of the structural basis of consciousness is incomplete. The ascending reticular activating system (ARAS) is necessary for the maintenance of the state of consciousness. The monoamine and a great number of descending projections modulate the ARAS. The contents of consciousness depend also on telencephalic structures, primarily on the telencephalic cortex. Certain localized telencephalic lesions bring about disturbances of consciousness. The role of the corpus callosum in the problem of consciousness is discussed (one brain--two minds hypothesis). Then a classification of the various disturbances of consciousness is proposed. The term "disturbances of vigilance" is used for all disturbances of consciousness which are caused by a lesion in or a functional disorder of the ARAS or any of its modulating subsystems. The term "disturbances of the contents of consciousness" refers to disturbances of consciousness due to global or localized lesions or functional disorders of telencephalic structures. A list of characteristic features is given for each class of disturbances of consciousness.

Attention↗
PubMed1987

The consciousness of being conscious.

Starting with the therapeutic advantage gained when insight acquires consciousness, an investigation of the nature and function of consciousness is undertaken. Consciousness is a state of awareness, having a range of higher mental functions serving a regulatory, controlling, and integrating role in mental activity. There are high levels of thinking, reality testing, experiencing, judging, anticipating; self-awareness and self-reflection enter into these controlling activities. Psychoanalysis has rightly been a science that studies the workings and contents of the unconscious portions of the mind. It has perhaps overlooked the important role that consciousness plays in ordinary life and in providing the levels of control and self-awareness individuals both experience and require. That pathology and disturbances of function may accompany normal states of consciousness as well as altered states of consciousness is a common clinical phenomenon. Psychoanalysis as a therapy widens the scope of the conscious control systems.

Awareness↗
PubMed1989

Brain shift, level of consciousness, and restoration of consciousness in patients with acute intracranial hematoma.

Recently, Ropper reported that horizontal brain shift caused by acute unilateral mass lesions correlated closely with consciousness, and suggested that recovery of consciousness was unlikely to occur after surgical evacuation if the shift was insufficient to explain the observed diminution of consciousness. The authors have sought to confirm the correlation of pineal shift with level of consciousness and to assess the prognostic value of brain shift measurements in a prospective study. Forty-six patients (19 with subdural hematoma, 14 with intracerebral hematoma, and 13 with epidural hematoma) were accrued to the study group consecutively. A correlation was found between a decrease in the level of consciousness and a significant increase in the mean lateral brain displacement at the pineal gland (from 3.8 to 7.0 mm) and septum (5.4 to 12.2 mm). When outcome was examined in patients who were stuporous or comatose on admission, a significant increase in septal shift was found among patients with a poor outcome, but there was no significant relationship between outcome and degree of pineal or aqueductal shift. A poor outcome was more likely with effacement of both perimesencephalic cisterns or the ipsilateral cistern, but not the contralateral cistern, although this difference did not reach statistical significance. These results do not substantiate the value of brain shift as an independent prognostic factor after evacuation of an acute unilateral mass lesion. The decision to operate and the determination of prognosis should be based rather on established criteria such as the clinical examination, age of the patient, and the mechanism of injury.

Acute Disease↗
PubMedDate not supplied

Health consciousness and health behavior: the application of a new health consciousness scale.

Self-consciousness has been an important trait in personality research. It seems logical to investigate whether health consciousness, involving a similar self-focusing, might operate in a parallel manner. To this end, I developed the Health Consciousness Scale (HCS), primarily by modifying items of the Self-Consciousness Scale, and also tested it for reliability and validity. My study found the HCS to contain four first-order factors: (1) Health Self-Consciousness, (2) Health Alertness, (3) Health Self-Monitoring, and (4) Health Involvement. I found these four first-order factors, along with the overall HCS second-order factor, to relate to a number of self-reported, health-associated behavioral variables. The study also included comparisons with the Health Locus-of-Control Scale and other measures.

Adult↗
PubMed1986

Concentrations of glycine and serine in cerebrospinal fluid during disturbed consciousness; a study of the therapeutic effect of thyrotropin-releasing hormone on the consciousness level.

The concentrations of aliphatic amino acids (glycine, serine, valine, threonine, alanine, leucine, isoleucine) in lumbar cerebrospinal fluid from patients with consciousness disturbances and normal controls were measured. Thyrotropin-releasing hormone (TRH) was administered to patients and the changes of levels of consciousness and amino acid concentrations were followed before and after TRH administration. The concentrations of glycine and serine from patients were significantly higher than those from controls; they returned to the control values with improvement of consciousness disturbances. The influence of TRH upon these amino acid concentrations was not observed. These results suggest that within the central nervous system, an alteration of the level of consciousness is associated with a distortion of glycine and serine metabolism and that TRH itself has no influence upon these amino acid concentrations.

Adolescent↗
PubMed1989

[Clinical study of bruxism. Comparison of muscle activity during sleep between patients conscious of bruxism and those not conscious of the condition].

Bruxism has been considered to be one of the most important factors in accelerating the progression of established periodontal lesions. However the objective diagnostic method has not yet been established. At present, diagnosing bruxism might mainly be dependent on interview. The purpose of this study was to compare and analyze the differences in frequency and duration of bruxism between a group of patients conscious of the problem and a group not conscious of bruxism. After interviewing, the subjects were divided into two groups; 1) group A consisted of 8 subjects who were conscious of bruxism and 2) group B of 8 subjects who were not conscious of bruxism. The frequencies and durations of muscle activity during sleep at night were compared between groups A and B using EMG with a telemetric method. In the one-night observation, muscle activity supposed to be bruxism was observed in both groups. Significant differences in frequencies of muscle activity were not found between the two groups. A similar result was obtained in the durations of muscle activity. In a seven-day observation, muscle activity was seen in all three volunteers, although marked differences were not found among them. A long duration of muscle activity was found under conditions of physical or mental stress. The results of this study showed the difficulty of diagnosing bruxism by interview and the necessity of an objective method.

Bruxism↗
PubMed1991

Postischemic myocardial "stunning". Identification of major differences between the open-chest and the conscious dog and evaluation of the oxygen radical hypothesis in the conscious dog.

Recent studies suggest that oxygen-derived free radicals contribute to the pathogenesis of postischemic myocardial dysfunction (myocardial "stunning"). This concept, however, is predicated exclusively on results obtained in open-chest preparations, which are subject to the confounding influence of many unphysiological conditions. The lack of supporting evidence in more physiological animal models represents a major persisting limitation of the oxy-radical hypothesis of myocardial stunning. The goal of this study was to address two fundamental (and related) questions: 1) Does the open-chest animal model alter the phenomenon of myocardial stunning? 2) If so, how valid are the concepts, derived from such a model, regarding the pathogenetic role of oxy-radicals? In part 1 of the study, myocardial stunning after a 15-minute coronary occlusion was compared in 30 pentobarbital-anesthetized open-chest dogs and in 19 conscious dogs. For any given level of collateral flow during occlusion, the recovery of systolic wall thickening after reperfusion was markedly less in open-chest animals. In an additional group of five open-chest dogs, a close inverse relation was noted between body temperature and postischemic wall thickening, indicating that the recovery of the stunned myocardium in acute experiments may vary markedly depending on how temperature is controlled. Because of these major differences between open-chest and conscious dogs, the oxy-radical hypothesis needs to be tested in the latter model. Thus, in part 2 of the study, conscious unsedated dogs undergoing a 15-minute coronary occlusion were randomized to an intravenous infusion of either saline (19 coronary occlusions) or superoxide dismutase (SOD) plus catalase (CAT) (21 coronary occlusions). Despite the fact that the plasma levels of SOD and CAT declined rapidly after reperfusion, postischemic wall thickening was significantly greater in treated compared with control dogs throughout the first 6 hours of reflow. Thus, a brief (60-minute) infusion of SOD and CAT produced a sustained improvement of recovery of contractility. The magnitude of this beneficial effect was a function of the severity of ischemia: the lower the collateral perfusion, the greater the improvement effected by the enzymes. The accelerated recovery produced by SOD and CAT was not followed by any deterioration of contractility, suggesting that postischemic dysfunction is not a teleologically "protective" phenomenon. In conclusion, the severity of myocardial stunning is greatly exaggerated by the unphysiological conditions present in the barbiturate-anesthetized open-chest dog.(ABSTRACT TRUNCATED AT 400 WORDS)

Anesthesia, General↗
PubMed1983

Ventricular refractory periods in relation to rate and test-site VT intervals in anesthetized and conscious dogs: a canine model for conscious state measurements.

The functional relationship of ventricular effective refractory period (ERP) with basic cycle length (BCL) of stimulated ventricular depolarization and VT intervals of test-site unipolar ventricular electrograms were studied in five conscious and eight anesthetized (sodium pentobarbital, 30 mg/kg) open-chested dogs. The range of BCLs studied was 300 to 1000 ms, achieved through ventricular stimulation following chemically-induced complete AV block. In the conscious animal model developed for this study, two-to-four ventricular electrode leads were exteriorized and the ventricular rate was maintained by an implanted programmable VVI pacemaker. In all animals studied, the BCL-ERP relation was closely represented by the empirical equation ERP = A-B.Exp(-k.BCL), and the VT-ERP relation over the same range of BCLs was linear: ERP = C + D.VT. The correlation coefficients were in the range of 0.991 to 0.999. The mean values of the parameters in the above equations determined by the appropriate non-linear or linear regression analysis showed significant differences between the two groups of animals studied. In three conscious animals a strong linear correlation between the test-site VT intervals and simultaneously measured QT intervals measured from the lead II surface electrogram was demonstrated (r = 0.993 to 0.998). For a fixed site of stimulation, the morphology of ventricular depolarization complexes as well as the corresponding T-waves remained essentially unaltered with BCL for both myocardial and surface electrograms. The possible applications of developed canine model and the results of the present study include: (1) the study of the rate-dependent effects of cardioactive drugs on ventricular electrophysiology and, (2) the improved design of electronic refractory periods of rate programmable pacemakers.

Anesthetics↗
PubMed1985

Cognition and states of consciousness: the necessity for empirical study of ordinary and nonordinary consciousness for contemporary cognitive psychology.

Recent criticisms of the place and function of "consciousness" in "cognitive science" are considered and rejected. Contrary to current orthodoxy subjective experience during abstract cognitive activity, especially when placed in its natural series with phenomenal accounts of so-called "altered states of consciousness," can provide unique and crucial evidence concerning just that core of "semantics" which eludes the automatized "syntax" of computer simulation. The "noetic" aspect of extreme altered states can be placed in relation to introspective descriptions of "insight." Various altered state features--synaesthesias, geometric/mandala imagery, reorganizations of "perceptual" dimensions and enhanced "self-reference"--can be taken as direct "exteriorizations" of abstract symbolic processes as discussed by Neisser, Geschwind, Mead, and Arnheim. A genuine cognitive psychology cannot continue to ignore the qualitative-experiential bases of symbolization. More specifically, the sense that insight just comes to us as if from "outside," its preliminary microgenetic processes masked, does not show the failure of introspective phenomenology but rather offers a unique and positive clue to the imaginal dialogic structure of higher mental processes. Thinking, as one phase of imaginal "conversation," must be "sent" from the phenomenal "other" to an attenuated, receptive phenomenal "self." A reconsideration of the Würzburg controversy, adding closely related altered state phenomena to the transitional series between "impalpable awareness" and specific imagery, suggests that the normally masked processes underlying the "felt meaning" or "insight" state are most directly exteriorized as what Klüver termed "complex" or geometric-dynamic synaesthesias. Finally, a reinterpretation of classical introspectionism's "sensation" shows the "mechanism" by which the metaphorical/synaesthetic processes of cognition are generated. Titchener's "sensation" plays the crucial role in metaphor it so conspicuously lacked in functional perception.

Awareness↗
PubMed1986

Contributions of glomerular and tubular mechanisms to antidiuresis in conscious domestic fowl.

Recently developed radioimmunoassay (RIA techniques were employed in a quantitative investigation of the renal actions of the avian antidiuretic hormone arginine vasotocin (AVT) in the conscious domestic fowl. Constant intravenous infusion of AVT at doses of 0.125-1.00 ng . kg-1 . min-1 was used to produce plasma AVT (PAVT) concentrations (verified by RIA) over the entire range of physiological PAVT levels in the domestic fowl. Comparison of the dose-response relationships between PAVT and glomerular and tubular mechanisms of antidiuresis revealed that tubular mechanisms are of primary importance and glomerular mechanisms of secondary importance in the conservation of water by the avian kidney. The greatest proportion of the total AVT-induced reduction in renal water excretion occurred at low physiological PAVT levels (less than 5 microU/ml), prior to any significant reduction in glomerular filtration rate (GFR), and appeared to be the exclusive result of tubular mechanisms of antidiuresis. At high PAVT levels (5-16 microU/ml), glomerular and tubular mechanisms overlapped, and their effects on water conservation could not be separated. Although GFR was reduced by nearly 30% at the highest dose of AVT, only minor additional amounts of water were conserved by the combined actions of glomerular and tubular mechanisms. The glomerular mechanisms appear to have only a minor secondary effect on water-conserving ability of the avian kidney.

Animals↗
PubMedDate not supplied

Reversal of central nervous system effects by flumazenil after intravenous conscious sedation with midazolam: report of a multicenter clinical study. The Flumazenil in Intravenous Conscious Sedation with Midazolam Multicenter Study Group I.

Flumazenil, a benzodiazepine antagonist, reverses the residual central nervous system effects of benzodiazepines. In this US double-blind, multicenter study, the efficacy of flumazenil was compared with that of placebo in antagonizing the effects of midazolam, a benzodiazepine used to induce intravenous conscious sedation. The mean dose of flumazenil was 0.7 mg, administered intravenously. At 5 minutes posttreatment, 82% of 131 flumazenil-treated patients, compared with 15% of 65 placebo-treated patients, demonstrated complete reversal of sedation. In 85% of patients who responded to flumazenil, this reversal of sedation was maintained throughout the 180-minute observation period. Psychomotor performance returned to prestudy levels 5 minutes posttreatment in 87% of the flumazenil-treated patients, compared with 28% of the placebo-treated patients. At the doses administered, flumazenil was less effective in reversing midazolam-induced amnesia, with only 60% of patients demonstrating partial recovery of memory. It was, nevertheless, more effective than placebo. Flumazenil was well tolerated. Dizziness (10%) and nausea (9%) were the most frequently reported adverse effects. Results of this study demonstrate that flumazenil antagonizes the central nervous system effects of midazolam after intravenous conscious sedation.

Adolescent↗
PubMedDate not supplied

Reversal of central benzodiazepine effects by flumazenil after conscious sedation produced by intravenous diazepam. The Flumazenil in Intravenous Conscious Sedation with Diazepam Multicenter Study Group I.

Flumazenil is a competitive benzodiazepine antagonist that rapidly reverses the residual effects of benzodiazepines following intravenous conscious sedation. In a double-blind, multicenter study, postoperative patients who had been sedated with intravenous diazepam were randomly allocated to receive intravenous doses of flumazenil (0.4 mg to 1 mg) or placebo. Levels of sedation and psychomotor impairment were evaluated prestudy, at baseline, and at 6 intervals from 5 to 180 minutes posttreatment. A global evaluation of effectiveness was made at the 5-minute assessment, and memory was assessed at the 180-minute assessment. Flumazenil (mean dose: 0.73 mg [7.3 ml]) was significantly more effective than placebo (mean dose: 8.9 ml) in reversing sedation, psychomotor impairment, and amnesia within 5 minutes after the start of administration. At the 5-minute posttreatment assessment, 84% of 102 flumazenil-treated patients (compared with 42% of 52 placebo-treated patients) experienced complete reversal of sedation. Ninety-two percent of 93 flumazenil-treated patients (compared with 41% of 46 placebo-treated patients) had normal psychomotor function. Reversal of amnesia at the 5-minute assessment was achieved in 75% of 101 flumazenil-treated patients and in 20% of 51 placebo-treated patients. Statistically significant differences between flumazenil and placebo were also observed at the 15-minute assessment. Thereafter there were no significant differences between the two treatment groups. Most (70%) flumazenil-treated patients exhibited no recurrence of sedation during the 180-minute assessment period. The most frequent adverse reaction in the flumazenil group was dizziness (6%). There were no serious adverse experiences related to the test drug. Flumazenil provided prompt, controlled reversal of residual effects, especially sedation, in the majority (84%) of patients recovering from intravenous conscious sedation induced by diazepam. For most (70%) of these flumazenil-treated patients, the reversal was maintained throughout the 180-minute assessment.

Adolescent↗
PubMed1991

Cardiovascular effects of elgodipine in conscious pigs with a normal coronary circulation and in conscious pigs with a healed myocardial infarction.

The cardiovascular effects of the phenyldihydropyridine derivative elgodipine (0.3, 1, 3, 10, and 30 microgram/kg/min) were studied in normal conscious pigs and in pigs with chronic left ventricular dysfunction (LVD, caused by coronary artery occlusion) without and after beta-adrenoceptor blockade with propranolol (0.5 mg/kg + 0.5 mg/kg/h). In normal pigs, elgodipine increased cardiac output from 2.57 +/- 0.09 to 5.21 +/- 0.24 L/min (p less than 0.05) as a result of a doubling of the heart rate. Mean arterial blood pressure decreased from 94 +/- 2 to 76 +/- 3 mm Hg (p less than 0.05) as a result of a decrease in systemic vascular resistance. Left ventricular (LV) dP/dtmax increased (by up to 78 +/- 9%), but left ventricular end-diastolic pressure (LVEDP) remained unchanged. After propranolol administration elgodipine did not increase LV dP/dtmax, and the increase in heart rate was attenuated, resulting in a smaller increase in cardiac output (from 2.11 +/- 0.13 to 3.09 +/- 0.23 L/min, p less than 0.05), but an unchanged vasodilator response. In pigs with LVD, elgodipine increased cardiac output and LV dP/dtmax less than in normal animals, but the vasodilator response was not affected. LVEDP decreased from 14.6 +/- 1.6 to 11.7 +/- 2.5 mm Hg (p less than 0.05). In animals with LVD, propranolol caused a more severe depression of systemic hemodynamics, but did not modify the cardiovascular responses to elgodipine. Its cardiovascular profile suggests that elgodipine may not only be useful in the treatment of cardiovascular disorders for which other dihydropyridines are already in use, but also in mild chronic heart failure.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Reversal of central benzodiazepine effects by intravenous flumazenil after conscious sedation with midazolam and opioids: a multicenter clinical study. The Flumazenil in Intravenous Conscious Sedation with Midazolam Multicenter Study Group II.

The efficacy and safety of flumazenil in antagonizing the central effects of the benzodiazepine midazolam was demonstrated in patients in whom conscious sedation was induced with midazolam plus an opioid (fentanyl, meperidine, or morphine). In a double-blind, multicenter study, 240 patients were administered flumazenil postoperatively at an average intravenous dose of 0.7 mg (7 ml) and 114 patients were administered an average dose of 9 ml placebo. Complete reversal of sedation was observed in 80% of flumazenil-treated patients and 30% of placebo-treated patients 5 minutes posttreatment. In 87% of patients who responded to flumazenil, the level of alertness was maintained throughout the 180-minute observation period. Midazolam-impaired psychomotor performance returned to normal 5 minutes posttreatment in 80% of the flumazenil-treated patients and 28% of the placebo-treated patients. Flumazenil was less effective in reversing midazolam-induced amnesia, with only 70% of flumazenil-treated patients (and 15% of placebo-treated patients) able to recall the picture shown them at the 5-minute assessment, and fewer patients able to recall pictures shown at later times. Flumazenil was well tolerated, although adverse effects were reported slightly more often than in the placebo group. The most frequent adverse events in both groups were dizziness and nausea. Vital signs were not affected.

Adolescent↗
PubMedDate not supplied

Reversal of central benzodiazepine effects by flumazenil after intravenous conscious sedation with diazepam and opioids: report of a double-blind multicenter study. The Flumazenil in Intravenous Conscious Sedation with Diazepam Multicenter Study Group II.

The efficacy and safety of a new benzodiazepine antagonist, flumazenil, were assessed in a double-blind multicenter study. Flumazenil (mean dose, 0.76 mg) or placebo (mean dose, 8.9 ml) was administered intravenously to 130 and 67 patients, respectively, who had been given diazepam in conjunction with an opioid (fentanyl, meperidine, or morphine) for the induction and maintenance of intravenous conscious sedation for diagnostic or therapeutic surgical procedures. The group assessable for efficacy comprised 122 patients treated with flumazenil and 64 patients given placebo. After 5 minutes, 80/115 (70%) flumazenil-treated patients, compared with 21/63 (33%) placebo-treated patients, were completely awake and alert, as indicated by a score of 5 on the Observer's Assessment of Alertness/Sedation Scale. Ninety-five percent of patients in each group who attained a score of 5 at the 5-minute assessment showed no loss of alertness throughout the 180-minute assessment period. Flumazenil-treated patients also performed significantly better on the Finger-to-Nose Test and the recall of pictures shown at the 5-minute assessment. Flumazenil was well tolerated, with no serious adverse effects reported. Thirty-nine (30%) of flumazenil-treated patients, compared with 17 (25%) of placebo-treated patients had one or more drug-related adverse experiences. The most common adverse effects were nausea and vomiting in the flumazenil group and nausea and injection-site pain in the placebo group. Flumazenil was found to promptly reverse sedation induced by diazepam in the presence of opioids.

Adolescent↗
PubMed1979

The action of angiotensin II on the baroreflex response of the conscious ewe and the conscious fetus.

1. In conscious non-pregnant and pregnant ewes and in chronic fetal lamb preparations, the beat by beat relationship between pulse interval and systolic pressure was studied during acute elevations in arterial pressure induced by phenylephrine. Baroreflex sensitivity, which was defined as the slope of the pressure-pulse interval relationship when phenylephrine was used to raise pressure, was abolished by atropine and increased by propranolol. Baroreflex sensitivity was less in pregnant ewes and in foetal lambs compared with non-pregnant ewes. 2. These findings suggest that the vagus nerve is responsible for the reflex bradycardia that occurs in the foetus and the ewe when arterial pressure is increased. 3. In both fetal and adult sheep, actue hypertension due to I.V. injection of angiotensin II was not associated with a consistent and progressive bradycardia, such as was seen with acute hypertension caused by phenylephrine. Angiotensin II has no direct chronotropic effect on heart rate in either the adult or the fetus. 4. No linear relationship between arterial pressure and pulse interval was seen when angiotensin II was used to raise pressure in sheep which were treated with propranolol. Therefore the lack of cardiac slowing with pressor doses of angiotensin II was not due to concomitant activation of the sympathoadrenal system. 5. It is concluded that in both fetal and adult sheep angiotensin II reduces the increase in vagal tone which is responsible for slowing of heart rate in response to acute rises in arterial pressure.

Angiotensin II↗