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Query: UMLS:C0494475 (tonic-clonic seizure)
 1,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Exercise-induced hyponatremia is commonly believed to be associated only with extraordinary physical efforts, or particularly strenuous exercise. Hyponatremia complicating moderate exercise has not been described previously. The authors describe the characteristics of seven patients with life-threatening hyponatremia associated with mild to moderate exercise. All patients suffered from nausea, vomiting, agitation, and confusion, appearing during or after moderate physical activity. Grand mal convulsions occurred in five of the patients. In laboratory results, hyponatremia was as low as 115 mEq/L, with a relatively high sodium concentration in the urine. High serum creatine kinase activity levels were found in most of the patients. All patients were discharged in good condition, without neurologic sequela. The authors conclude that hyponatremia is a possible complication of moderate exercise, and not only of endurance sports, and that exercise-induced hyponatremia can produce severe neurologic manifestations. The mechanism of the hyponatremia is unclear, but may be due to a hemodynamically inappropriate stimulus for antidiuretic hormone secretion.
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PMID:Case series: hyponatremia associated with moderate exercise. 861 81

A female aged 53 years was found to have a suprasellar lesion, which was shown to be a Rathke's cyst after removal by transsphenoidal surgery. She presented 16 days postoperatively, and following two grand mal seizures was found to be profoundly hyponatraemic (sodium 101 nmol/l). She was initially thought to have the syndrome of inappropriate antidiuretic hormone and was treated accordingly, but central venous pressure measurement revealed the hypovolaemia of cerebral salt wasting syndrome. The patient subsequently developed severe neurological sequelae after the correction of her hyponatraemia, following the development of extrapontine myelinolysis. Cerebral salt wasting syndrome is a rare cause of hyponatraemia following pituitary transsphenoidal surgery, which may mimic the syndrome of inappropriate antidiuretic hormone secretion. This case emphasizes the poor prognosis that may result from the rapid correction of profound hyponatraemia.
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PMID:Hyponatraemia secondary to cerebral salt wasting syndrome following routine pituitary surgery. 881 Jul 41

Water hemlock causes numerous livestock losses in North America every year. Description of pathologic and serum biochemical changes has been lacking in the literature. Tubers of western water hemlock (Cicuta douglasii) induced excessive salivation, tremors, grand mal seizures, skeletal and cardiac myodegeneration, and death in sheep given 1.2-2.7 g fresh tuber/kg body weight by gavage. Seizures were intermittent with periods of relaxation until death occurred from anoxia during seizure activity. In sheep given 1.5-2.5 times the lethal dose of water hemlock by gavage, intravenous administration of sodium pentobarbital at the onset of the first seizure prevented further seizure activity and skeletal and cardiac myodegeneration and resulted in rapid and complete recovery.
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PMID:Water hemlock (Cicuta douglasii) toxicoses in sheep: pathologic description and prevention of lesions and death. 895 35

Desmopressin is used for the treatment of nocturnal enuresis. Side effects reported with intranasal desmopressin are transient headache, nausea, abdominal cramps and water intoxication with hyponatremia and grand mal seizure. We report a case of water intoxication with low serum sodium and grand mal seizure in a healthy child treated for enuresis with desmopressin. The child experienced abdominal cramps and nausea prior to the convulsions. A computerised tomography scan of the brain gave the suspicion of increased intracranial pressure ICP. The child recovered fully. We therefore recommend that parents and child are fully informed about the administration and the risk of desmopressin. If a child on desmopressin treatment experiences abdominal cramps, nausea or headache the drug should be discontinued and a physician contacted for control of serum sodium. Temporary withdrawal of desmopressin should also be considered in cases of acute illness influencing water balance.
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PMID:[Acute water intoxication caused by intranasal desmopression--Minirin]. 919 Jul 22

It is widely agreed that after two or more seizures patients should be given antiepileptic treatment, but there is still controversy about the treatment of patients after a first unprovoked seizure. In a multicenter, randomized, open trial, patients with a first tonic-clonic seizure were randomized to immediate treatment (carbamazepine, phenytoin, phenobarbital, or sodium valproate) or to treatment only after another seizure. Fifty-two (24%) of the 215 patients randomized to immediate treatment and 85 (42%) of the 204 randomized to delayed treatment experienced seizure recurrence during follow-up. Age, acute treatment of the seizure with benzodiazepines, remote etiologic factors, and EEG abnormalities were significant predictors of relapse. Of the immediately treated patients, 87% had no seizures for a year and 68% had no seizures for 2 years, whereas only slightly fewer initially untreated patients (83% and 60%) achieved these endpoints. Patients treated after the first seizure and those treated after seizure relapse had the same time-dependent probability of achieving 1 and 2 seizure-free years. None of the variables that were prognostic predictors of relapse was significantly associated with the probability of having 1 or 2 years of seizure control. Anticonvulsants in patients presenting a first tonic-clonic seizure reduce the risk of relapse; however, 50% of patients who are not treated will never experience a second seizure. Moreover, the probability of long-term remission is not influenced by treatment of the first seizure.
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PMID:Treatment of first tonic-clonic seizure does not improve the prognosis of epilepsy. First Seizure Trial Group (FIRST Group). 933 78

We reported a case of reversible posterior leukoencephalopathy syndrome (RPLS) that occurred during cyclosporin A (CyA) therapy for fulminant hepatitis. A 22-year-old man was given an intravenous drip of interferon-beta, metylprednisolone sodium succinate and CyA, and also received plasma exchange and hemodiafiltration. On the 7th day of the intravenous CyA therapy, in which its dose had been increased from 60 mg/day to 84 mg/day, he became somnolent and had headache, double vision, hallucination and then a generalized tonic-clonic seizure. The blood CyA concentration increased to a level as high as 455 ng/ml. Brain computed tomography (CT) scan without contrast medium revealed symmetric low-density areas in the bilateral occipital white matter and partly in the cortex. T2-weighted magnetic resonance imaging (MRI) showed an increased signal intensity, and single-photon emission CT using 99 mTc showed a hypoperfusion of cerebral blood flow in those areas. After CyA administration was changed to 100 mg/day orally to decrease its uptake in the blood, his consciousness and vision recovered within 4 weeks. Then abnormalities in MRI findings completely disappeared. On the basis of the clinical course and time-sequential change of serum CyA level in this patient, he was diagnosed as having RPLS caused by CyA therapy. Recently, the number of cases of RPLS has increased in the Western countries. However, there are few reports of RPLS after CyA therapy in Japan. From this case, we emphasize that careful following up the patient's neurological findings during CyA therapy is very important and that a cranial MRI is an essential tool for the diagnosis of RPLS.
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PMID:[Reversible posterior leukoencephalopathy in a patient receiving cyclosporin therapy]. 1039 Oct 82

We aimed to characterize the clinical profile and to establish the prevalence of juvenile myoclonic epilepsy (JME) among 939 consecutive patients referred to our epilepsy clinic. Inclusion criteria in the study were: a) myoclonic jerks, preferably on awakening; b) beginning of the symptoms between 8 and 26 year-of-age; c) typical pattern of electroencephalographic discharges; and d) good response to sodium valproate (VPA). In a retrospective design, 26 cases of JME were identified (prevalence 2.8%). Most of these patients were female (73.1%). Mean age at onset of symptoms was 13 (range 7-18). Tonic-clonic seizures were reported in 92.3% and absence seizures in 19.2%. Besides, 92.3% of the patients had typical EEG epileptiform activity and 76.9% had good response to VPA with daily dose ranging from 500 mg to 1500 mg.
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PMID:[Clinical-epidemiological study of patients with juvenile myoclonic epilepsy in Santa Catarina State, Brazil]. 1045 Mar 46

We compared clinical presentation and course of exercise-associated hyponatremia with heat exhaustion among summertime hikers in Grand Canyon National Park. Cases were selected from among hikers who requested medical help from the National Park Service Emergency Medical Service (EMS) or who presented to the medical clinic on the rim of the canyon with complaints related to exercise in the heat. Of 44 patients who had serum samples analyzed, 7 had hyponatremia with clinically significant symptoms and serum sodium levels <130 mmol/L: 3 had grand mal seizures, 2 had other major central nervous system disorders, and 2 had minor neurological symptoms. Seizures and change of mental status distinguished hyponatremia, (P = 0.0002). Indirect evidence suggests that hyponatremic patients were hyperhydrated. Other common symptoms included nausea, vomiting, headache, and dizziness, but these symptoms did not predict the level of serum sodium. When exercise in the heat is prolonged, hyponatremia is suggested either by altered mental status or by seizures without hyperpyrexia or hypoglycemia. No mortality or long-term morbidity occurred in any of these cases of hyponatremia.
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PMID:Exertional heat illness and hyponatremia in hikers. 1053 May 29

A 42-year-old female with von Willebrand's disease was managed with desmopressin and tranexamic acid to aid haemostasis following a vaginal hysterectomy. Severe acute hyponatraemia (134 to 108 mmol/l) developed over two days, culminating in a generalized tonic-clonic seizure and cerebral oedema. Fluid restriction, cessation of desmopressin and hypertonic saline administration led to a full recovery. Desmopressin is known to reduce free water elimination and produce hyponatraemia, but its extent and rate of development in this patient was surprising. Close monitoring of serum sodium and fluid balance is recommended in these patients.
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PMID:Severe hyponatraemia secondary to desmopressin therapy in von Willebrand's disease. 1078 75

Sustained inward currents in neuronal membranes underlie tonic-clonic seizure discharges and spreading depression (SD). It is not known whether these currents flow through abnormally operating physiological ion channels or through pathological pathways that are not normally present. We have now used the NEURON simulating environment of Hines, Moore, and Carnevale to model seizure discharges and SD. The geometry and electrotonic properties of the model neuron conformed to a hippocampal pyramidal cell. Voltage-controlled transient and persistent sodium currents (I(Na,T) and I(Na,P)), potassium currents (I(K,DR) and I(K,A)), and N-methyl-D-aspartate (NMDA) receptor-controlled currents (I(NMDA)), were inserted in the appropriate regions of the model cell. The neuron was surrounded by an interstitial space where extracellular potassium and sodium concentration ([K(+)](o) and [Na(+)](o)) could rise or fall. Changes in intra- and extracellular ion concentrations and the resulting shifts in the driving force for ionic currents were continuously computed based on the amount of current flowing through the membrane. A Na-K exchange pump operated to restore ion balances. In addition, extracellular potassium concentration, [K(+)](o), was also controlled by a "glial" uptake function. Parameters were chosen to resemble experimental data. As long as [K(+)](o) was kept within limits by the activity of the Na-K pump and the "glial" uptake, a depolarizing current pulse applied to the cell soma evoked repetitive firing that ceased when the stimulating current stopped. If, however, [K(+)](o) was allowed to rise, then a brief pulse provoked firing that outlasted the stimulus. At the termination of such a burst, the cell hyperpolarized and then slowly depolarized and another burst erupted without outside intervention. Such "clonic" bursting could continue indefinitely maintained by an interplay of the rise and fall of potassium and sodium concentrations with membrane currents and threshold levels. SD-like depolarization could be produced in two ways, 1) by a dendritic NMDA-controlled current. Glutamate was assumed to be released in response to rising [K(+)](o). And 2) by the persistent (i.e., slowly inactivating) Na-current, I(Na,P). When both I(NMDA) and I(Na,P) were present, the two acted synergistically. We conclude that epileptiform neuronal behavior and SD-like depolarization can be generated by the feedback of ion currents that change ion concentrations, which, in turn, influence ion currents and membrane potentials. The normal stability of brain function must depend on the efficient control of ion activities, especially that of [K(+)](o).
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PMID:Simulated seizures and spreading depression in a neuron model incorporating interstitial space and ion concentrations. 1089 22


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