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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epileptiform seizures occurred in a 34-year-old woman who was receiving amitriptyline and lithium carbonate therapy for treatment of endogenous depression. While receiving amitriptyline maintenance therapy, she was given lithium on two separate occasions, and despite serum levels of lithium in the therapeutic range, grand mal seizures developed. The seizures may represent a toxic reaction either to lithium or to combined drug therapy. Controlled studies are needed to evaluate both the efficacy and toxicity of combined drug therapy in affective disorders.
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PMID:Seizures during lithium-amitriptyline therapy. 11 90

pH regulatory mechanisms in primary cultures of astrocytes from the cerebral cortex of neonatal audiogenic-seizure-susceptible DBA/2J (DBA) and genetically controlled C57BL/6J (C57) mice were studied with [14C]dimethyloxazolidine-2-4-dione (DMO) and [3H]-methyl-D-glucose (MDG). Effects of changing the concentration of Na+, K+, HCO3- or Cl- in medium, and/or of different transport blockers and metabolite inhibitor on intracellular pH (pHi) of cultured astrocytes were also studied. In nominal HCO3(-)-free HEPES-buffered Hanks' balanced salt solution (HEPES HBSS), when the pH of medium (pHo) was maintained at 7.4, the steady-state pHi of cultured astrocytes from DBA mice was 6.98 +/- 0.03, and that from C57 mice was 7.01 +/- 0.03. When the cells were incubated in HBSS containing 25 mM HCO3- and equilibrated with 5% CO2 (HCO3- HBSS, pHo = 7.4), pHi of both DBA and C57 astrocytes was approximately 0.1-0.15 pH units higher than that in HEPES HBSS. Reducing the pH or the Na+ concentration in media (pHo, [Na+]o) of either HEPES HBSS or HCO3- HBSS, pHi of both DBA and C57 astrocytes decreased markedly (0.25-0.45 pH units lower than the controls). The decrease in pHi was greater in HEPES HBSS than in HCO3- HBSS. Reducing the Cl- concentration ([Cl-]o) in either HEPES or HCO3- HBSS, pHi of astrocytes increased by 0.05-0.1 pH units. Increasing the K+ concentration ([K+]o) of or adding Ba2+ to the media increased the pHi of both DBA and C57 astrocytes accordingly. SITS, an anion transport inhibitor, decreased the pHi of both DBA and C57 astrocytes in HCO3- HBSS but not in HEPES HBSS. It enhanced the response of pHi to reduction in pHo. Amiloride, a Na(+)-H+ exchange inhibitor, decreased the pHi of both DBA and C57 astrocytes more in HEPES HBSS than in HCO3- HBSS. It enhanced the response of pHi to reduction in pHo and [Na+]o. Ouabain, an Na+,K(+)-ATPase inhibitor, decreased the pHi of cultured astrocytes in HEPES HBSS, but not in HCO3- HBSS. It also enhanced the response of pHi to changing pHo and [Na+]o in HEPES HBSS. Acetazolamide, a carbonic anhydrase inhibitor, decreased the pHi of astrocytes in both HEPES and HCO3- HBSS. Both bumetanide, an Na+,K+/Cl- cotransport blocker, and KCN, a metabolic inhibitor, produced no significant effect on the steady-state pHi or the response of pHi to changing ionic concentration in media in both DBA and C57 astrocytes.
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PMID:Studies on pH regulatory mechanisms in cultured astrocytes of DBA and C57 mice. 139 16

Carbonic anhydrase (CA) activity plays an important role in controlling cerebrospinal fluid production and also influences neuroexcitation and susceptibility to seizures. Until recently, CA II was the only CA demonstrated in brain. Its distribution is limited to the epithelial cells of the choroid plexus and to the myelin-forming cells, the oligodendrocytes. In this report, we present immunoblots, using an antibody raised to CA IV from rat lung, that show that CA IV is also present in rat and mouse brain. Results of immunohistochemistry and immunoelectron microscopy on sections from rat and mouse brain are presented that show the distribution of CA IV to be quite distinct from that of CA II. CA IV is expressed on and is limited to the luminal surface of endothelial cells of cerebral capillaries. These results establish CA IV as a cytochemical marker associated with the blood-brain barrier and suggest an important role for CA IV in CO2 and HCO3- homeostasis in brain.
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PMID:Carbonic anhydrase IV on brain capillary endothelial cells: a marker associated with the blood-brain barrier. 149 71

The mechanisms that give rise to ischemic brain damage have not been definitively determined, but considerable evidence exists that three major factors are involved: increases in the intercellular cytosolic calcium concentration (Ca++i), acidosis, and production of free radicals. A nonphysiological rise in Ca++i due to a disturbed pump/leak relationship for calcium is believed to cause cell damage by overactivation of lipases and proteases and possibly also of endonucleases, and by alterations of protein phosphorylation, which secondarily affects protein synthesis and genome expression. The severity of this disturbance depends on the density of ischemia. In complete or near-complete ischemia of the cardiac arrest type, pump activity has ceased and the calcium leak is enhanced by the massive release of excitatory amino acids. As a result, multiple calcium channels are opened. This is probably the scenario in the focus of an ischemic lesion due to middle cerebral artery occlusion. Such ischemic tissues can be salvaged only by recirculation, and any brain damage incurred is delayed, suggesting that the calcium transient gives rise to sustained changes in membrane function and metabolism. If the ischemia is less dense, as in the penumbral zone of a focal ischemic lesion, pump failure may be moderate and the leak may be only slightly or intermittently enhanced. These differences in the pump/leak relationship for calcium explain why calcium and glutamate antagonists may lack effect on the cardiac arrest type of ischemia, while decreasing infarct size in focal ischemia. The adverse effects of acidosis may be exerted by several mechanisms. When the ischemia is sustained, acidosis may promote edema formation by inducing Na+ and Cl- accumulation via coupled Na+/H+ and Cl-/HCO3- exchange; however, it may also prevent recovery of mitochondrial metabolism and resumption of H+ extrusion. If the ischemia is transient, pronounced intraischemic acidosis triggers delayed damage characterized by gross edema and seizures. Possibly, this is a result of free-radical formation. If the ischemia is moderate, as in the penumbral zone of a focal ischemic lesion, the effect of acidosis is controversial. In fact, enhanced glucolysis may then be beneficial. Although free radicals have long been assumed to be mediators of ischemic cell death, it is only recently that more substantial evidence of their participation has been produced. It now seems likely that one major target of free radicals is the microvasculature, and that free radicals and other mediators of inflammatory reactions (such as platelet-activating factor) aggravate the ischemic lesion by causing microvascular dysfunction and blood-brain barrier disruption.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Pathophysiology and treatment of focal cerebral ischemia. Part II: Mechanisms of damage and treatment. 150 80

The disturbances in the central nervous system of rabbits induced by gramoxon poisoning were studied by examination of subcortical electroencephalograms (EEGs) and power spectral analysis of EEGs. The following results were obtained. Administration of the fatal gramoxon (2.0 ml/kg i.p.) resulted in increases of slow frequency discharges from the reticular formation (RF), and from the hippocampus (Hpc) and sensorimotor cortex (Cm) after about 5 minutes and 20 minutes, respectively, detected by power-spectrum array. After about 30 to 40 minutes, the discharges from the Cm changed to rapid frequency discharges. The discharges from the Hpc and Cm decreased after about 50 to 60 minutes, and increased again in the agonal stage, and then seizure discharges developed. Soon after administration of gramoxon solution, the heart rate and respiratory rate increased and the PCO2, base excess (BE) and [HCO3-] decreased transiently. These findings indicate a shift to acute respiratory alkalosis and thereafter a shift to metabolic acidosis. Subsequently, the blood pressure, heart rate, respiratory rate, pH, BE and [HCO3-] decreased and the PCO2 increased. These findings indicate a shift to respiratory and metabolic acidosis. After about 70 minutes, the EEGs from all leads became almost flat, respiration ceased, and the blood pressure decreased to zero. After administration of gramoxon solution, the paraquat concentration in the blood increased rapidly. These results suggest that rapid increase in the paraquat concentration in the blood after gramoxon administration affects the central nervous system from an early stage.
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PMID:Electroencephalographical analysis of acute paraquat poisoning. 211 98

A 6-year-old girl with cerebral palsy developed conscious disturbance and generalized convulsion after one-hour hot herb drug bath. Physical examination on admission revealed rectal temperature 41 degrees C, hot skin, respiration 46/min, regular heart beat 98/min, BP 130/60 mmHg, Glascow coma scale 4 (E2M1V1), soft and flat abdomen, no hepatosplenomegaly, no skin rash, no focal neurological sign, increased generalized muscle ton. Laboratory data showed CBC: WBC 20400 cumm (Neutrophils 31%, Lymphocytes 69%), Hb 11.6gm%, ESR 11 mm/hr, arterial blood gas: PH 7.077, PO2 43mmHg, PCO2 57.1mmHg, HCO3- 16 mEq/L, BE-11.5mEq/L, serum sodium 143 mEq./L, potassium 5.2 mEq/L, chloride 101 mEq/L, free calcium ion 3.8mg%, GOT 63IU/L, GPT 263 IU/L, amylase 193 IU/L, alkaline phosphatase 388 IU/L, LDH 1245 IU/L, CPK 677 IU/L, total bilirubin 0.8 mg/dl, direct type 0.1 mg/dl, BUN 18 mg/dl, Glucose 35 mg/dl. Urinalysis revealed proteinuria( ) trace hematuria and pyuria, but no cast. Lumbar puncture is within normal limits. Bacteriology including blood and CSF are normal. Multiple organ failure was noted at that time. Intensive cooling methods were performed including central and peripheral cooling. We used luminal and valium to control the seizure. Condition didn't improve. Afterwards cardiopulmonary arrest developed. Patient expired 8 hours after admission despite of resuscitation. Heat stroke in infancy and childhood is different from that in adulthood. The predisposing factors are high ambient temperature, dehydration, very young baby, sweat gland dysfunction, or ectodermal dysplasia. Definition of heat stroke includes 1) rectal temperature above 41 degrees C, 2) behavioral change, 3) warm skin, wet or dry.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Status epilepticus induced by prolonged immersion in hot herb bath: report of one case]. 263 19

A behavior questionnaire was used retrospectively in 21 manic-depressive children to quantitate manic-depressive behaviors before and after treatment with lithium carbonate. The study children were matched with 21 control children for age, race, sex, and socioeconomic status. The study children had significantly more seizures, relatives with psychotic disorders, allergies, food sensitivities, headaches, and abnormal behaviors in all categories measured. During treatment, manic-depressive children had a statistically significant reduction in disturbed behavior. This behavior, however, was still significantly more disturbed than normal control children.
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PMID:Manic-depressive illness in children: treatment with lithium carbonate. 311 Feb 60

Myoclonus has been infrequently observed in patients receiving lithium therapy, and associated electroencephalographic (EEG) changes have not been well described. We report two women, ages 35 and 48, who, after the initiation of lithium carbonate therapy, had several generalized tonic-clonic seizures followed by myoclonic seizures. In both, myoclonus was associated with repetitive sharp waves on the EEG. Although the epileptogenicity of lithium remains controversial, the occurrence of myoclonic seizures associated with lithium treatment suggests a proconvulsant effect of lithium in susceptible individuals.
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PMID:Myoclonic seizures with lithium. 311 23

The use of ion-sensitive microelectrodes enabled us to follow the dynamic changes in extracellular pH (pHe) together with those in the extracellular concentration of some biologically important ions, particularly K+ and Ca2+. Activity-related changes in pHe were studied in isolated spinal cords of frogs and in spinal cords of rats in vivo. Repetitive electrical stimulation of an afferent input led either to triphasic alkaline-acid-acid changes (90% of frogs) or to triphasic alkaline-acid-alkaline changes (10% of frogs and rats) with the greatest changes in the lower dorsal horns. The transient acid shift by as much as 0.15-0.25 pH units is dominant and builds up during the stimulation. The changes in pHe were also found in response to various adequate stimuli applied to the skin on the hind limb. Using specific inhibitors of Na+/H+ exchange, K+-Cl- co-transport, Cl-/HCO3- exchange, the Na+/K+ pump and carbonic anhydrase, we found pHe homeostasis to be impaired and stimulation-induced changes in pHe decreased. We conclude that the pHe changes evoked by electrical or adequate stimulation of an afferent input are not determined by changes in extracellular strong ion concentration differences due to accumulation of lactate, since we found no effect of NaF, a metabolic blocker of lactate production. However, lactate accumulation has been demonstrated during seizures, spreading depression and anoxia. Recently, it has been recognized that the observed pHe changes can affect permeability of membrane ionic channels, neuronal excitability and glial cell function.
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PMID:Extracellular pH and stimulated neurons. 320 66

This article reviews normal acid-base regulation, related laboratory tests, and the potential disorders if the body's ability to compensate is disrupted. Acid derived from the oxidation of proteins and through tissue metabolism must be excreted or neutralized daily by the kidneys and lungs to maintain a proper acid-base balance. Acid-base homeostasis is normally maintained by chemical buffering, changes in renal hydrogen-ion excretion, and alterations in the rate and volume of alveolar ventilation. Metabolic disorders are characterized by disturbances in bicarbonate (HCO3-) concentration, and respiratory disorders develop with primary alterations in the partial pressure of carbon dioxide (Pco2). Metabolic acidosis is characterized by low pH, low serum HCO3- concentrations, and a compensatory decrease in Pco2 with hyperventilation. Bicarbonate administration can correct this disorder, and equations for calculating the necessary amount of HCO3- are presented. Metabolic alkalosis is characterized by a primary increase in HCO3-, compensatory hypoventilation, and an increase in Pco2 (hypercapnia). The drug therapy for this disorder is directed at either saline-responsive alkalosis or saline-resistant alkalosis. Formulas for estimating the volume requirements of patients and appropriate doses of acidifying agents are presented. Respiratory acidosis and alkalosis are also discussed. The initial therapy for the hypercapnia associated with respiratory acidosis requires reversing the underlying pulmonary disease with steroids, bronchodilators, or antibiotics. The increased Pco2 in this conditions must be lowered slowly to avoid precipitating cardiac arrhythmias and seizures. The correction of respiratory alkalosis requires elevating the Pco2 and again treating the underlying disease. Pharmacists should be knowledgeable about acid-base regulation and the disorders that frequently occur with disease because drugs are capable of inducing or exacerbating these disorders and are often key elements in therapy.
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PMID:Simple acid-base disorders. 393 55


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