Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023380 (lethargy)
 5,697 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As shown previously, the electrical function of the brain is critically dependent on cerebral blood flow in the sense that reduction beyond an ischemic threshold of approximately 15 ml/100 gm per minute (approximately 35% of control) in the baboon leads to complete failure of the somatosensory evoked response. This study tests the hypothesis that electrical failure in ischemia may be directly associated with a massive release of intracellular K+ or with a critical degree of extracellular acidosis. By microelectrode techniques, measurements of blood flow, extracellular activity of K+ and H+ as well as evoked potential were made in the baboon neocortex. Reductions in blood flow were obtained by occlusion of the middle cerebral artery and depression beyond the ischemic threshold of electrical function achieved by a reduction of systemic blood pressure which, in the ischemic zones, changed local cerebral blood flow proportionally. Abolition of evoked response could not be explained by depolarization by release of intracellular K+, nor was it critically dependent on cortical pH. However, the massive release of intracellular K+ was by itself critically dependent on cortical blood flow and occurred at 18 greater than 6 greater than 2 ml/100 gm per minute (median with 5% confidence limits). Thus a dual threshold in ischemia for neuronal function is described, the threshold for release of K+ being clearly lower than the threshold for complete electrical failure. Further, the findings support the concept of an ischemic penumbra during which the neurons remain structurally intact but functionally inactive. That neurons can survive for some time in this state of lethargy is evidenced by the observations that an increase in rCBF, if sufficient, can restore evoked potential and normalize extracellular K+ activity as well as pH.
Stroke
PMID:Cortical evoked potential and extracellular K+ and H+ at critical levels of brain ischemia. 1 21

Body fluid gas pressure and electrolytes of patients with ruptured aneurysm were continuously analyzed. Intracranial pressure (ICP) was regulated at the level of 120-100 mm H2O by cerebral ventricular drainage. There was no significant change in the pH, PCO2, HCO3-, Na+, K+, Ca++ in the cerebrospinal fluid (CSF) of patients with slight or moderate disturbance of consciousness (lethargic-drowsy state). The PcsfO2 of the patients with marked disturbances of consciousness (semicoma-coma) was significantly low. PcsfO2 of the patients with cerebral vasospasm was significantly lower than for those without vasospasms. PcsfO2/PaO2 was 0.27 +/- 0.01 in the patients with vasospasm and 0.50 +/- 0.01 in those with vasospasm. PcsfO2 tended to decrease in patients with markedly bloody CSF. When the bloody CSF was cleared by ventricular drainage, PcsfO2 increased. PcsfO2 did not return to a normal value in the patients with marked disturbances of consciousness despite sufficient arterial oxygen tension. This suggests that PcsfO2 and PcsfO2/PaO2 should provide a convenient index for the prognosis of patients with ruptured aneurysm.
Stroke
PMID:Body fluid oxygen tension and prognosis in patients with ruptured aneurysm. 4 45

A simple implanted device was used to occlude acutely the left middle cerebral artery (MCA) of 16 conscious cats. Eight received no treatment and 8 were given intravenous mannitol (1.2 gm/kg) at the time of occlusion. The initial neurological findings in both groups were similar, that is, agitation, forced circling, and right hemiparesis. The treated cats remained alert but the untreated cats became lethargic and drowsy. Perfusion with a mixture of colloidal carbon and buffered paraformaldehyde was carried out from 30 minutes to 6 hours following MCA occlusion. Results of morphological examination of brains from the treated and untreated groups suggested that mannitol had a protective effect upon cerebral tissue during the primary phase of acute focal ischemia. Light microscopic analysis of neuronal alterations demonstrated considerable preservation of neurons in brains of treated cats. Beneficial effect of mannitol was attributed partly to prevention of capillary narrowing and suppression of ischemic cerebral edema.
Stroke
PMID:Modification of acute focal ischemia by treatment with mannitol. 62 43

A case of a 76-year-old man with the syndrome of inappropriate secretion of antidiuretic hormone (ADH) is discussed. The patient was initially treated with fluid restriction followed by the administration of hypertonic saline. After failure to achieve rapid correction of the condition and continued lethargy and muscle weakness in the patient, a trial with lithium carbonate 300 mg three times daily via nasogastric tube was initiated. This resulted in a prompt reversal of the hyperosmolar state and improvement in electrolyte balance. However, despite the apparent success in treating his inappropriate ADH, the patient expired as a result of a massive cerebral vascular accident. The potential benefit of using lithium in the treatment of the syndrome of inappropriate secretion of ADH, and possible mechanisms of action, are reviewed.
 ...
PMID:Lithium carbonate treatment in the syndrome of inappropriate secretion of antidiuretic hormone. 92 Jul 46

A case-control study was performed to investigate the significance of arteriosclerosis, heredity and some infections in the etiology of Parkinson's disease. The study group consisted of all traceable patients with Parkinson's disease living in a defined area, a total of 444 patients, and of control subjects for each patient, matched in sex and age, chosen from among the general population residing in the same area. No significant differences were found between the patients and the controls concerning the occurrence of cardiac insufficiency, coronary heart disease, or stroke. The Parkinsonian patients, however, had a significantly lower incidence of clinical arterial hypertension when compared with the controls. In addition, the patients more often had low systolic blood pressures and more rarely high pressures than the controls. Even the mean systolic blood pressure was significantly lower in the patients than in the controls. The low blood pressure seems to be an effect of Parkinson's disease itself with a minor contribution of levodopa therapy. The observations above are considered to indicate that arteriosclerosis and Parkinson's disease are probably only concurrent disorders and not in etiological relationship with each other. There was no statistically significant difference in the proportion of the patients and the controls with relatives with Parkinson's disease or essential tremor, which suggests that genetic factors do not have a significant role in Parkinson's disease and on the other hand that essential tremor and Parkinson's disease are two separate disease entities. No other encephalitis than a lethargic one was found to precede Parkinson's disease and the occurrence of meningitis was rare both among the patients and the controls. The history of Spanish influenza was found to be as frequent in the patients as in the controls, thus not supporting the idea that influenza has etiological importance in Parkinson's disease.
 ...
PMID:Arteriosclerosis, heredity, and some previous infections in the etiology of Parkinson's disease. A case-control study. 100 13

The interrelationships between cerebral edema, intracranial pressure (ICP), and cerebral blood flow (CBF) were studied in acute and chronic triethyl tin sulfate treated rats. Prior to pentobarbital anesthesia behavioral observations were made. ICP and regional CBF were measured under steady state conditions and brain water content was determined by vacuum drying of the right cerebral hemisphere. Control and chronic animals were neurologically normal. There were two distinct acute groups: (1) acute low pressure (ALP) animals - alert but tetraperetic, and (2) acute high pressure (AHP) animals - deeply stuporous, with minimal pain response and gross EEG slowing. ICP was significantly elevated only in AHP animals. Hemispheric CBF was significantly reduced in AHP and chronic animals. The interaction of increased pressure and edema (AHP) produced the greatest decrease in CBF, although deep white flows were significantly affected in all experimental groups. Chronic animals had significantly lower flow in four of seven regions compared to ALP animals despite no significant difference in ICP. Water content was significantly increased in all experimental groups with the greatest increase in the chronic animals. In the absence of any significant increase in ICP, cerebral edema appears to cause a significant reduction in cerebral blood flow and this reduction corresponds with the magnitude and location of the edema.
Stroke
PMID:Alterations in behavior, brain electrical activity, cerebral blood flow, and intracranial pressure produced by triethyl tin sulfate induced cerebral edema. 125 1

Current neurologic assessments consider idling neurons and ischemic penumbras to be metabolically lethargic and electrically nonfunctional or nonviable. Diagnosis, prognosis, and therapeutics of central nervous system dysfunctions require differentiation between viable and nonviable neurons. It is necessary to develop and document efficacious and safe techniques for reactivating idling neurons. The authors present a case study of a near drowning 12 years earlier. Areas of cortical hypometabolism were identified by using SPECT imaging in conjunction with hyperbaric oxygen therapy (HBOT). Delayed imaging after HBOT (1 hour, 1.5 atm abs) suggested viable but metabolically lethargic neurons. After HBOT (80 1-hour treatments, monoplace chamber, 1.5 atm abs), marked improvements in cognitive and motor functioning were demonstrated. The data support the hypothesis that idling neurons and ischemic penumbras, when given sufficient oxygen, are capable of reactivation. Thus, changes in tracer distribution after a single exposure to HBOT may be a good prognostic indicator of viable neurons. HBOT may be valuable not only in recovery from anoxic encephalopathy but also from other traumatic and nontraumatic dysfunctions of the central nervous system, including stroke. HBOT in conjunction with physical and rehabilitative therapy may help reactivated idling neurons to remain permanently active.
 ...
PMID:Identification of hypometabolic areas in the brain using brain imaging and hyperbaric oxygen. 161 42

A chronic canine model of hyperdynamic sepsis was achieved by cecal ligation and puncture (SEP) in conjunction with continuous high-volume fluid resuscitation. Cardiac function was evaluated using ultrasonic cardiac crystals placed across the major, minor, and wall thickness axes of the left ventricle, together with simultaneous arterial and ventricular pressure measurement. Seven to 10 days after crystal implantation, animals were randomized to either SEP (n = 10) or sham laparotomy control (n = 7). SEP dogs became febrile and lethargic, with elevated leukocyte counts and positive blood cultures for enteric organisms. They were also hyperdynamic, with significant increases in heart rate and cardiac output and a fall in systemic vascular resistance. Systolic blood pressure, stroke volume, and ejection fraction remained stable. Relative to control, the SEP group demonstrated a significant reduction in intrinsic contractility during systole, as measured by the heart rate and load-independent index of left ventricular performance Emax (P less than 0.01), confirming the observations of others. In addition, however, diastolic function also became markedly abnormal with a progressive increase in unstressed and end-diastolic ventricular volumes (P less than 0.05) and a significant decrease in myocardial compliance as quantitated by transmural pressure vs. volume-strain analysis. It is hypothesized that this increase in diastolic volume helps to maintain global cardiac performance during the hyperdynamic response to sepsis in the presence of adequate volume support.
 ...
PMID:Sepsis-induced diastolic dysfunction in chronic canine peritonitis. 231 77

To assess the effects of moderate exercise [40-70% maximal oxygen uptake (VO2max)] on resting blood pressures, the presence of cerebrovascular lesions, and the life spans of stroke-prone hypertensive rats, nontrained and trained male and female rats were assigned to two experimental groups. The first (n = 48) were exercise trained after 38 days of age, whereas the second (n = 44) initiated exercise training when the animals were 134 days of age. To facilitate cerebrovascular lesions, the sodium concentrations in the rat chow and in the drinking solutions were increased. Symptoms utilized to denote the presence of cerebrovascular lesions were irritability, hyperresponsiveness, ataxia, lethargy, unwillingness to run, and combinations thereof. All brains were removed immediately after death, fixed, and evaluated grossly and microscopically for lesions. In the study with the younger animals, training was associated with a 7-9% increase in VO2max that was statistically significant only in animals with no histological evidence of cerebrovascular lesions. For the older animals, a significant 5-8% increase in VO2max was noted for animals with or without lesions. After 42 days of training for both groups, resting blood pressures for the trained groups with histological lesions were significantly lower. However, this trend did not continue, and the older trained rats appeared to have strokes earlier and to die sooner than their nontrained controls. Although 83% of the older animals had subjective evidence for a stroke before they died, the percentage of animals with lesions ranged from 42 to 58%, with the trained groups having higher percentages.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Exercise training and incidence of cerebrovascular lesions in stroke-prone spontaneously hypertensive rats. 234 35

Eighty-one patients undergoing carotid endarterectomy were divided into two groups based on the degree of stenosis of the carotid artery. Group I, 37 patients, was defined as having severe carotid stenosis (greater than 70%). Group II, 44 patients, was defined as having mild (less than 40%) or moderate (40% to 70%) carotid artery stenosis. Both groups were evaluated for neurologic and psychologic changes in the postoperative period. Prospective analysis demonstrated no significant differences between groups I and II in the areas of cardiac disease, history of preoperative stroke, preoperative and postoperative hypertension, diabetes, or postoperative computed tomography changes. Group II had a significantly higher percentage of carotid artery ulceration (p less than 0.01). Postoperative analysis revealed 34 group I patients had 6 to 8 weeks of lethargy versus two group II patients (p less than 0.01). Eleven group I patients had headaches for the first week postoperatively versus three patients in group II (p less than 0.05). Four group I patients had paranoid ideation, and another four patients had clinical depression, but not one patient in group II (p less than 0.01) had these psychiatric disturbances. These data suggest that significant, reversible neurologic and psychologic changes can occur because of reperfusion after relief of severe stenosis of the carotid artery.
 ...
PMID:Postoperative somnolence in patients after carotid endarterectomy. 235 8


1 2 3 4 5 6 7 8 Next >>