Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biochemical evidence for hypoparathyroidism and roentgenographic evidence for hyperparathyroidism were present in a 7-year-old girl with seizures and tetany. She was hypocalcemic (4.7 mg/dl), hyperphosphatemic (11 mg/dl), and normomagnesemic, with elevated parathyroid hormone level (2,603 pg/dl and 3,693 pg/dl in immunoassays utilizing two different antisera). Somatic features of pseudohypoparathyroidism were absent. Increased serum alkaline phosphatase activity (335 IU/liter) with evidence of subperiosteal bone resorption suggested parathyroid hormone activity on bone. Intramuscular administration of parathyroid extract caused a rise in serum calcium level (9.6 mg/dl) and a fall in serum phosphorus level (7.9 mg/dl). The serum calcium, phosphorus, and alkaline phosphatase activity became normal during vitamin D therapy. Parathyroid hormone values and bone roentgenograms became normal. With serum calcium and phosphorus levels normal, ethylenediaminetetraacetic acid infusion was followed by an increase in plasma parathyroid hormone level but not in urinary cyclic adenosine monophosphate (AMP) or phosphaturia; in contrast, parathyroid extract induced cyclic AMP excretion and phosphaturia. These results suggest that endogenous parathyroid hormone in this patient affects bone resorption but not renal handling of phosphate. We infer that this represents a defective endogenous parathyroid hormone.
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PMID:Hypo-hyperparathyroidism: evidence for a defective parathyroid hormone. 19 77

Anticonvulsant therapy of seizure disorders in man is associated with the development of complications involving bone and mineral metabolism including hypocalcemia, elevated serum immunoreactive parathyroid hormone levels, and increased amounts of unmineralized bone or osteoid. The latter has been attributed to a reduction in serum-25-hydroxycholecalciferol levels resulting from increased hepatic metabolism of vitamin D. Using an in vitro recycling hepatic perfusion system, we have demonstrated that 5 d of phenobarbital treatment increases the hepatic production of [(3)H]25-hydroxyvitamin D(3) (4.3+/-0.3 vs. 3.3+/-0.2%/h, P <0.025) without affecting the biliary excretion of radioactivity. Furthermore, rachitic livers perfused with blood obtained from animals treated with phenobarbital for 5 d also manifested an increase in [(3)H]25-hydroxyvitamin D(3) production (4.6+/-0.5 vs. 3.3+/-0.2%/h, P < 0.02). Addition of phenobarbital or its major metabolite, p-hydroxyphenobarbital, directly to the perfusion apparatus had no effect on [(3)H]25-hydroxyvitamin D(3) production. Phenobarbital treatment was also attended by a decrease in the intrahepatic content of [(3)H]vitamin D(3) (11.7+/-0.4 vs. 17.5+/-0.7 dpm/mg liver protein, P < 0.001) without alterations in the content of [(3)H]25-hydroxyvitamin D(3). The data collectively suggest that the increased hepatic conversion of [(3)H]vitamin D(3) to [(3)H]25-hydroxyvitamin D(3) attending phenobarbital treatment is secondary to stimulation of the hepatic 25-hydroxylation system(s) by a metabolite of phenobarbital other than p-hydroxyphenobarbital and/or by metabolic alterations resulting from phenobarbital therapy.
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PMID:Phenobarbital-induced alterations in the metabolism of [3H]vitamin D3 by the perfused rachitic rat liver in vitro. 22 52

There is much individual variability in the clinical manifestations of hypocalcemia. The rapidly of the development of hypocalcemia will determine whether or not symptoms will be present. Signs and symptoms of hypocalcemia consisted of tetany (Chvostek's and Trousseau's signs), seizures, diminshed to absent deep tendon reflexes, papilledema, mental changes (weakness, fatigue, irritability, memory loss, confusion, delusion, hallucination), and skin changes. Etiologic factors for hypocalcemia in man include (1) decreased calcium absorption or increased loss from the gastrointestinal tract; (2) parathyroid hormone deficiency; (3) skeletal resistance to parathyroid hormone; (4) ineffective parathyroid hormone; (5) decreased production or increased degradation of 25-hydroxycholecalciferol or 1,25-dihydroxycholecalciferol; (6) increased complex formation with calcium; (7) increased skeletal uptake of calcium; (8) hypomagnesemic state; and (9) direct inhibition of bone resorption. Measurement of total and ionic calcium, magnesium, parathyroid hormone, vitamin D metabolites (25-hydroxycholecalciferol, 1,25-dihydroxycholecalciferol), and nephrogenous cyclic adenosine monophosphate are especially helpful in the laboratory evaluation of the hypocalcemic patient.
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PMID:Hypocalcemia. Differential diagnosis and mechanisms. 22 22

Acute renal failure secondary to interstitial nephritis caused by therapeutic ingestion of sodium diphenylhydantoins has been reported recently. The interference of sodium diphenylhydantoins on Vitamin D metabolism causing or aggravating ricketts has also been reported. This communication deals with an infant girl who was admitted to the hospital due to seizures. Four months before, she had convulsions and she was treated with diphenylhydantoins until admission. She was found to have renal failure and ricketts. Histological diagnosis of interstitial nephritis was established by means of percutaneous renal biopsy. Clinical and radiological improvement of ricketts was observed after dehydrotachysterol treatment. Clinical and biochemical alterations of renal failure slowly subsided. She had a clear-cut history of vitamin D defficiency ricketts. Seizures were due to hypocalcemia tetany but was erroneusly treated as "grand mal" epilepsy, with diphenylhydantoins. Interstitial nephritis complicated with acute renal failure was probably caused by diphenylhydantoins administration.
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PMID:[Renal failure and rickets]. 46 92

Nutritional, racial, cultural, and environmental factors have combined to produce a resurgence of vitamin D deficiency rickets in urban Philadelphia. Between January 1974 and June 1978, 24 cases were diagnosed at the Children's Hospital of Philadelphia. Patients' ages ranged from 4 to 58 months. Presenting complaints included seizures, swollen wrists, pathologic fractures, and developmental regression. Sixteen patients were below the third percentile for length and weight. Laboratory results indicated vitamin D deficiency in nursing mothers as well as in infants. All infants had been breast-fed and all were black. Ingestion of vitamin D was limited by exclusion of meat and/or dairy products in 21, and no infants had consistently taken supplemental vitamins. Nineteen were members of Muslim or Seventh Day Adventist faiths. Endogenous synthesis of vitamin D was limited by dark skin, by dressing in long garments with hoods and veils, and by air pollution in a densely populated northern city. The return to a more "natural" diet, free of food additives, has been accompanied by the return of a classic disease of industrial society. Effective management required patience and respect for religious convictions. With treatment, there was correction of chemical and skeletal abnormalities, but few patients showed catch-up growth.
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PMID:An outbreak of vitamin D deficiency rickets in a susceptible population. 57 26

Small doses of vitamin D can probably prevent catastrophic skeletal demineralization in patients taking antiseizure medication. Moderate doses of vitamin D can reverse this degree of demineralization once it has occurred. Prophylactic vitamin D therapy was associated with a lowered incidence of seizure patients in the overall fracture census and a decrease in the number of in-hospital days for treatment of seizure patients with fractures. Vitamin D therapy should probably be used as a routine dietary supplement in all seizure patients at dosage levels of approximately 400 units daily. Much larger doses (50,000 units once or twice weekly) should be as necessary when these patients sustain fractures or other injuries.
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PMID:Vitamin D prophylaxis and the lowered incidence of fractures in anticonvulsant rickets and osteomalacia. 60 87

Three children with primary hypomagnesemia are described. First symptoms of the disease were observed, when the children were 35, 19, and 20 days old, resp. The hypomagnesemia was accompanied by a severe hypocalcemia. Therapeutic trials with high doses of calcium given intravenously and vitamin D were without effect on the symptoms. The whole body retention and intestinal resorption of orally administered 28-Mg was greatly reduced in all three patients compared to healthy adults. Symptoms of tetany and seizures ceased immediately after intravenous application of magnesium. An oral Mg substitution with 42--85 mmol per day was necessary to maintain subnormal to normal serum magnesium levels. The patients are now 5, 4 3/12 and 1 5/12 years old, resp. Psychomotor development in all three children is normal. Height and weight are in the lower normal range around the 3rd percentile, while the oral Mg substitution sometimes caused frequent fluid stools. By family studies from these patients and from the literature an autosomal-recessive inheritance for primary hypomagnesemia is proposed.
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PMID:[Primary hypomagnesemia. Clinical, diagnostic and therapeutic studies in three children (author's transl)]. 75 40

Anticonculsant drug-induced disorders in mineral and bone metabolism are apparently quite common. Current evidence indicates that these drugs derange bone metabolism, both through induction of increased hepatic catabolism of vitamin D and its biologically active products, as well as by direct effects on membrane cation transport systems. The significant clinical manifestions of the disorder include rickets with defective bone development, decreased bone mass with increased risk of pathological fracture and reductions in serum calcium levels which may predispose to increased seizure frequency. There is a broad range of clinical presentation with a number of factors -- drug dose, duration of therapy, vitamin D intake, amount of sunlight exposure, degree of physical activity and presence of other concurrent diseases -- which appear to determine the severity of the clinical manifestations. Current evidence indicates that appropriate vitamin D and calcium supplementation can significantly reduce the clinical manifestations of this disorder. All patients receiving chronic anticonvulsant drug therapy should be carefully evaluted for the presence of drug-induced osteomalacia and treated appropriately with vitamin D. This is especially important in those patients in whom the presence of multiple risk factors indicates an increased likelihood of deranged mineral metabolism.
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PMID:Bone complications of anticonvulsants. 78 46

Vitamins contain reactive functional groups necessary to their established roles as coenzymes and reducing agents. Their reactive potential may produce injury if vitamin concentration, distribution, or metabolism is altered. However, identification of vitamin toxicity has been difficult. The only well-established human vitamin neurotoxic effects are those due to hypervitaminosis A (pseudotumor cerebri) and pyridoxine (sensory neuropathy). In each case, the neurological effects of vitamin deficiency and vitamin excess are similar. Closely related to the neurological symptoms of hypervitaminosis A are symptoms including headache, pseudotumor cerebri, and embryotoxic effects reported in patients given vitamin A analogs or retinoids. Most tissues contain retinoic acid (RA) and vitamin D receptors, members of a steroid receptor superfamily known to regulate development and gene expression. Vitamin D3 effects on central nervous system (CNS) gene expression are predictable, in addition to the indirect effects owing to its influence on calcium and phosphorus homeostasis. Folates and thiamine cause seizures and excitation when administered in high dosage directly into the brain or cerebrospinal fluid (CSF) of experimental animals but have rarely been reported to cause human neurotoxicity, although fatal reactions to i.v. thiamine are well known. Ascorbic acid influences CNS function after peripheral administration and influences brain cell differentiation and 2-deoxyglucose accumulation by cultured glial cells. Biotin influences gene expression in animals that are not vitamin-deficient and alters astrocyte glucose utilization. The multiple enzymes and binding proteins involved in regeneration of retinal vitamin A illustrate the complexity of vitamin processing in the body. Vitamin A toxicity is also a good general model of vitamin neurotoxicity, because it shows the importance of the ratio of vitamin and vitamin-binding proteins in producing vitamin toxicity and of CNS permeability barriers. Because vitamin A and analogs enter the CNS better than most vitamins, and because retinoids have many effects on enzyme activity and gene expression, Vitamin A neurotoxicity is more likely than that of most, perhaps all other vitamins. Megadose vitamin therapy may cause injury that is confused with disease symptoms. High vitamin intake is more hazardous to peripheral organs than to the nervous system, because CNS vitamin entry is restricted. Vitamin administration into the brain or CSF, recommended in certain disease states, is hazardous and best avoided. The lack of controlled trials prevents us from defining the lowest human neurotoxic dose of any vitamin. Large differences in individual susceptibility to vitamin neurotoxicity probably exist, and ordinary vitamin doses may harm occasional patients with genetic disorders.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Vitamin neurotoxicity. 146 88

We present a case of a one-month-old infant with hypocalcemia and rickets, with symptoms of focal seizures. The ictal EEG showed left occipital spikes spreading over all of the left hemisphere. From the laboratory studies, we concluded that a low maternal circulating level of vitamin D would cause infantile hypocalcemia and rickets, while immature renal response to parathyroid hormone and transient hypoparathyroidism in infancy would induce hyperphosphatemia. Hypocalcemia may be an important factor in the cause of focal seizures which start even after the age of one month. Further, investigation of maternal vitamin D levels should be done in infantile hypocalcemia.
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PMID:Hypocalcemic focal seizures in a one-month-old infant of a mother with a low circulating level of vitamin D. 189 19


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