Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The clinical profile of neurotoxicity caused by immunosuppression has changed. When toxic levels are reached, both cyclosporine and tacrolimus may produce a clinical spectrum that varies from tremor and acute confusional state to status epilepticus and major speech or language abnormalities. Coma has become an unusual manifestation. Magnetic resonance imaging has been better defined, and abnormalities may be more widespread than those in the posterior lobes. These white matter lesions are caused by vasogenic edema, but may lead to apoptosis and cytotoxic edema if exposure is prolonged. Recent evidence suggests inhibition of a drug-efflux pump and dysfunction of the blood-brain barrier by enhanced nitric oxide production.
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PMID:Neurotoxicity of immunosuppressive drugs. 1169 28

Thirty-five years since its introduction into clinical use, valproate (valproic acid) has become the most widely prescribed antiepileptic drug (AED) worldwide. Its pharmacological effects involve a variety of mechanisms, including increased gamma-aminobutyric acid (GABA)-ergic transmission, reduced release and/or effects of excitatory amino acids, blockade of voltage-gated sodium channels and modulation of dopaminergic and serotoninergic transmission. Valproate is available in different dosage forms for parenteral and oral use. All available oral formulations are almost completely bioavailable, but they differ in dissolution characteristics and absorption rates. In particular, sustained-release formulations are available that minimise fluctuations in serum drug concentrations during a dosing interval and can therefore be given once or twice daily. Valproic acid is about 90% bound to plasma proteins, and the degree of binding decreases with increasing drug concentration within the clinically occurring range. Valproic acid is extensively metabolised by microsomal glucuronide conjugation, mitochondrial beta-oxidation and cytochrome P450-dependent omega-, (omega-1)- and (omega-2)-oxidation. The elimination half-life is in the order of 9 to 18 hours, but shorter values (5 to 12 hours) are observed in patients comedicated with enzyme-inducing agents such as phenytoin, carbamazepine and barbiturates. Valproate itself is devoid of enzyme-inducing properties, but it has the potential of inhibiting drug metabolism and can increase by this mechanism the plasma concentrations of certain coadministered drugs, including phenobarbital (phenobarbitone), lamotrigine and zidovudine. Valproate is a broad spectrum AED, being effective against all seizure types. In patients with newly diagnosed partial seizures (with or without secondary generalisation) and/or primarily generalised tonic-clonic seizures, the efficacy of valproate is comparable to that of phenytoin, carbamazepine and phenobarbital, although in most comparative trials the tolerability of phenobarbital was inferior to that of the other drugs. Valproate is generally regarded as a first-choice agent for most forms of idiopathic and symptomatic generalised epilepsies. Many of these syndromes are associated with multiple seizure types, including tonic-clonic, myoclonic and absence seizures, and prescription of a broad-spectrum drug such as valproate has clear advantages in this situation. A number of reports have also suggested that intravenous valproate could be of value in the treatment of convulsive and nonconvulsive status epilepticus, but further studies are required to establish in more detail the role of the drug in this indication. The most commonly reported adverse effects of valproate include gastrointestinal disturbances, tremor and bodyweight gain. Other notable adverse effects include encephalopathy symptoms (at times associated with hyperammonaemia), platelet disorders, pancreatitis, liver toxicity (with an overall incidence of 1 in 20,000, but a frequency as high as 1 in 600 or 1 in 800 in high-risk groups such as infants below 2 years of age receiving anticonvulsant polytherapy) and teratogenicity, including a 1 to 3% risk of neural tube defects. Some studies have also suggested that menstrual disorders and certain clinical, ultrasound or endocrine manifestations of reproductive system disorders, including polycystic ovary syndrome, may be more common in women treated with valproate than in those treated with other AEDs. However, the precise relevance of the latter findings remains to be evaluated in large, prospective, randomised studies.
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PMID:Pharmacological and therapeutic properties of valproate: a summary after 35 years of clinical experience. 1226 62

The primary structure of cangitoxin (CGX), a 4958 Da peptide from the sea anemone Bunodosoma cangicum, was determined: GVACRCDSDGPTVRGNSLSGTLWLTGGCPSGWHNCRGSGPFIGYCCKK. CGX contains all the 11 residues that are conserved and the 5 that are conservatively substituted within or between the type 1 and type 2 sequences of sea anemone peptides with specific action on voltage-sensitive sodium channels. Furthermore, it also has 6 identities (Asp9, Arg14, Asn16, Leu18, Trp33 and Lys48) and 1 homology (Arg36) in the 8 residues of the pharmacophore of the sea anemone ApB which are essential for interaction with mammalian sodium channels. The intrahippocampal injection of CGX induces several sequential behavioral alterations--episodes of akinesia alternating with facial automatisms and head tremor, salivation, rearing, jumping, barrel-rolling, wet dog shakes and forelimb clonic movements--and the electroencephalography analysis shows that they were followed by important seizure periods that gradually evolved to status epilepticus that lasted 8-12 h, similar to that observed in the acute phase of the pilocarpine model of epilepsy. These results suggest that CGX may be an important tool to develop a new experimental model of status epilepticus which may contribute to understanding the etiology of epilepsy and to test the effects of new antiepileptic drugs.
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PMID:Primary structure, behavioral and electroencephalographic effects of an epileptogenic peptide from the sea anemone Bunodosoma cangicum. 1562 70

In September and October, 2004, an outbreak of encephalopathy of unknown etiology occurred in certain areas of Japan including Yamagata, Akita, and Niigata prefectures. These patients had a history of chronic renal failure, most of them had undergone hemodialysis, and also had a history of eating Sugihiratake (Pleurocybella porrigens), an autumn mushroom without known toxicity. Since clinical details of this type of encephalopathy remain unknown, we analyzed the clinical, radiological and electroencephalographic (EEG) features of ten cases of this encephalopathy in Yamagata prefecture. The summary of the present study is as follows: 1. Ten patients had chronic renal failure, and seven underwent hemodialysis. 2. Each patient had a history of eating Sugihiratake within 2-3 weeks of the onset of neurological symptoms. 3. The onset was subacute; the initial symptoms were tremor, dysarthria, and/or weakness of the extremities, which lasted an average of 4.5 days (ranging from 2 to 11 days), followed by severe consciousness disturbance and intractable seizures, resulting in status epilepticus in 5 patients. Myoclonus was also seen in 4 patients and Babinski reflex in 3. 4. Brain CT and MRI examinations were unremarkable in the early stages of the disease. Three to eight days after onset, however, conspicuous lesions appeared in the areas of the insula and basal ganglia in 6 patients. On MRI, these brain lesions were hyperintense on T2-weighted and FLAIR images, and hypointense on T1-weighted images. 5. EEG examination was performed in 6 patients, all of whom showed abnormal EEG findings. Periodic synchronous discharge (PSD) was seen in 2 patients, spike and wave complex in one patient, and non-specific slow waves in 3. 6. Prognosis was different from case to case. Three patients died at 13, 14, and 29 days after onset. Two patients still showed persistent disturbance of consciousness one month after onset. One patient showed parkinsonism after recovering from consciousness disturbance. Four patients recovered nearly completely around one month after onset In 3 of the 4 recovered patients, renal failure was not severe and they did not need to undergo hemodialysis. This suggests that the degree of renal failure is a key for the prognosis of this type of encephalopathy. The present study suggests that this endemic disease is a newly recognized clinical entity of encephalopathy.
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PMID:[An outbreak of encephalopathy after eating autumn mushroom (Sugihiratake; Pleurocybella porrigens) in patients with renal failure: a clinical analysis of ten cases in Yamagata, Japan]. 1572 76

Wet dog shakes (WDS) and head shakes (HS) are associated with experimentally induced convulsive seizures. We sought to determine whether these behaviors are correlated or not with major (status epilepticus (SE) or fully kindled animals) or minor (non-SE or partially kindled animals) seizure severity. WDS are directly correlated with SE induced by intracerebral star fruit extract (Averrhoa carambola) injection and with kindled animals in the amygdala fast kindling model. On the other hand, WDS are inversely correlated with SE induced by intracerebral bicuculline and pilocarpine injections. Systemic pilocarpine in animals pretreated with methyl-scopolamine barely induced WDS or HS. The role of shaking behaviors may vary from ictal to anticonvulsant depending on the experimental seizure model, circuitries involved, and stimulus intensity. The physical presence of acrylic helmets may per se inhibit the HS response. Also, methyl-scopolamine, a drug incapable of crossing the blood-brain barrier, can induce HS in animals without acrylic helmets.
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PMID:Correlation between shaking behaviors and seizure severity in five animal models of convulsive seizures. 1582 Mar 39

This chapter assesses probable epileptic syndromes within the idiopathic generalized epilepsies (IGE) that have not yet been recognized by the International League Against Epilepsy (ILAE). Jeavons syndrome, a purely reflex IGE that predominantly manifests with eyelid myoclonia and electroencephalogram (EEG) abnormalities on eye closure, is the most distinct and undisputed of the syndromes. Another is autosomal-dominant cortical tremor, myoclonus, and epilepsy, a purely monogenic disorder that has been documented in numerous reports, mainly from Japan and Italy. Perioral myclonia with absences is certainly a seizure type that may constitute an IGE syndrome when it is associated with a number of other clinical and EEG manifestations. Similarly, many patients suffer for years from phantom absences, a type of mild absence, before a first generalized tonic-clonic seizure that usually occurs in adulthood. Both perioral myoclonia with absences and phantom absences are clinically significant because they are probably lifelong and are associated with a very high incidence (around 50%) of absence status epilepticus that may escape diagnosis and appropriate treatment. The position of early childhood IGE, which manifests mainly with typical absence seizures that are distinctly different from childhood absence epilepsy and other recognized IGE syndromes, is less clear. The prevalence of these syndromes is significant. Their identification allows better clinical management and is important for genetic research and counselling. In addition, their recognition permits application of exclusion criteria for a more purified definition and a better understanding of the true boundaries of the other IGE syndromes already accepted by the ILAE.
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PMID:Syndromes of idiopathic generalized epilepsies not recognized by the International League Against Epilepsy. 1630 76

Hashimoto's encephalopathy (HE) is a severe but treatable condition that rarely complicates Hashimoto's thyroiditis. Clinically it is characterized by progressive or relapsing symptoms, including tremor, myoclonus, stroke-like episodes, seizures, impairment of consciousness, and dementia. We describe a patient presenting with recurrent generalized convulsive status epilepticus (GCSE), despite antiepileptic medications, who was successfully treated with methylprednisolone. Our observation confirms that the clinical spectrum of HE at presentation is heterogeneous and diagnosis is often difficult. This case highlights the crucial importance of antithyroid antibody measurement in patients presenting with otherwise unexplained episodes of GCSE with or without adjunctive signs of encephalopathy or thyroiditis.
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PMID:Recurrent status epilepticus as the main feature of Hashimoto's encephalopathy. 1634 98

An outbreak of acute encephalopathy has occurred among patients with renal dysfunction after ingestion of "sugihiratake" mushroom (angel's wings mushroom) in the northern area of Japan between the end of September and the middle of October in 2004. Most of the patients had varying degree of renal dysfunction. Patients initially presented with asthenia in legs, shaking limbs, and difficulty in ambulation. Several days later, tremor-like involuntary movements or myoclonus developed, which were frequently followed by intractable status epilepticus. Eleven patients were dead. CSF examination showed elevated protein levels without pleocytosis. Brain CT and MRI studies revealed abnormal signal intensities in bilateral external capsule and claustrum, and in the cortical white matter. All of the patients had a history to have ingested sugihiratake in varying quantities and frequencies prior to the onset of the illness. Although no similar patients have been reported in the past, this edible mushroom must have induced acute toxic encephalopathy. The characteristic features of clinical signs and symptoms, and laboratory findings of this encephalopathy were briefly summarized.
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PMID:[Acute encephalopathy after ingestion of "sugihiratake" mushroom]. 1644 34

This article reviews relevant pharmacologic and clinical information gathered for valproate since it was introduced into clinical practice 37 years ago and the application of this information for the treatment of childhood epilepsy. Valproate is available for oral and parenteral use. Oral forms are almost completely bioavailable but the rate of absorption varies between formulations. The Chrono tablet formulation has not been adapted for children aged <6 years, in whom the oral solution or syrup, requiring two or three daily administrations, has been used until recently. A new formulation specifically adapted for children, Chronosphere, administrated once or twice daily, is a modified-release formulation of valproate that minimizes fluctuations in serum drug concentrations during a dosage interval. Plasma protein binding is 80-94% and tends to decrease with increasing drug concentration. Valproate elimination is markedly decreased in newborns compared with older children and adults. Elimination by glucuronidation only becomes fully effective by the age of 3-4 years. In children aged 2-10 years receiving valproate, plasma clearances are 50% higher than those in adults. Over the age of 10 years, pharmacokinetic parameters approximate those of adults. Valproate can increase plasma concentrations of concomitant drugs, such as phenobarbital and lamotrigine, by inhibiting their metabolism. As a result of its broad spectrum of efficacy in a wide range of seizure types and epilepsy syndromes, valproate is a drug of choice for children with newly diagnosed epilepsy (focal or generalized), idiopathic generalized epilepsy, epilepsies with prominent myoclonic seizures or with multiple seizure types, and photosensitive epilepsies. In the group of cognitive epilepsies, in which severe spike and wave discharges are accompanied by cognitive deterioration, valproate, ethosuximide, or both should be tested before using corticosteroids. In comparative trials with carbamazepine, phenytoin, and phenobarbital in focal epilepsy and with ethosuximide in absence epilepsy, valproate was as effective and showed a favorable tolerability profile, with minimal adverse cognitive and CNS effects. The low potential for paradoxical seizure aggravation and the long-term efficacy of the drug are additional important factors that contribute to its excellent profile. Intravenous valproate may be effective for the treatment of convulsive and non-convulsive status epilepticus that is refractory to conventional drugs. In infants, potential benefits should be carefully weighed against the risk of liver toxicity. Gastrointestinal intolerance is a relatively frequent, dose-related adverse effect of the drug in children. Bodyweight increase and tremor may be observed in older children and adolescents. Despite the challenge of newer drugs, valproate remains a gold standard antiepileptic drug for the treatment of children.
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PMID:Valproate as a mainstay of therapy for pediatric epilepsy. 1660 72

Epilepsia partialis continua (EPC) is a rare form of focal status epilepticus. It may have vascular, immune-mediated, neoplastic or metabolic-toxic causes. The origin of EPC has been linked with the motor cortex. This has been solidly supported by sophisticated electrophysiological studies. Here, a series of video sequences from patients with EPC (due to Rasmussen encephalitis, early-stage multiple sclerosis, and steroid responsive encephalopathy with autoimmune thyroiditis), and other cases with repetitive myoclonic jerks or movement disorders (myoclonic epilepsy associated with ragged-red fibers, Jacksonian march, myoclonic seizures in other types of frontal lobe or idiopathic generalized epilepsies, and different types of tremor) is presented. [Published with video sequences].
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PMID:Epilepsia partialis continua: semiology and differential diagnoses. 1836 24


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