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)

Barbiturates retain an important place in clinical neurological practice. They are used as both diagnostic and therapeutic drugs, their most common uses being as anticonvulsant and anaesthetic agents. This article explores the current theories explaining the mechanism of action of the barbiturates, with special emphasis on their anaesthetic and anticonvulsant effects. The primary mechanism of action of barbiturates is to increase inhibition through the gamma-aminobutyric acid (GABA) system. Anaesthetic barbiturates also decrease excitation via a decrease in calcium conductance. Phenobarbital (phenobarbitone), the primary anticonvulsant barbiturate, is effective for partial, complex partial and secondarily generalised seizures. While no longer the drug of choice for all these seizure types, it remains an important and useful agent. Mysoline has been shown to be useful in the treatment of essential tremor and several other movement disorders, and as an anticonvulsant. Barbiturates are also used for their sedative-hypnotic properties. A relatively new use is in the evaluation of patients with medically intractable seizure disorders for possible surgical therapy. The roles of methohexital and amobarbital (amylobarbitone) are discussed in the section on barbiturates used as diagnostic agents. The experimental use of barbiturates is also commented on; the most important of these is perhaps the use of barbiturates in cerebral resuscitation.
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PMID:The clinical use of barbiturates in neurological disorders. 172 Mar 79

Besides general complications of immunosuppression such as increased susceptibility to opportunistic infections or malignancy, individual immunosuppressive agents are associated with specific side effects. Nephrotoxicity is the major side effect of cyclosporine (CsA). Various attempts have been made to minimize this toxicity, such as monitoring drug blood levels, modifying the protocol, and coadministering other agents. Other side effects caused by CsA are hepatotoxicity, hyperkalemia, hypertension, tremor, gum overgrowth, and hirsutism. Azathioprine (AZA) causes dose-related bone marrow suppression, commonly leading to leukopenia. Careful monitoring of complete blood cell count and dosage adjustment according to white blood cell count are usually adequate to prevent serious leukopenia. The side effects of corticosteroids are numerous and include slow wound healing and de novo insulin-dependent diabetes mellitus. Many complications are dose related, and with low dosage or discontinuation of steroids, their frequency rapidly decreases. Antilymphoblast and antithymocyte globulins (P-ALG) are foreign antibodies and may cause allergic-type reactions such as fever, chill, and hypotension. The initial side effect of monoclonal antibody (muromonab-CD3, OKT3) is similar to that of P-ALG. It includes high fever, shaking chills, headache, rigors, and hypotension. To prevent it, acetaminophen, an antihistamine, and a steroid usually are administered before injection. Because this agent is also associated with high frequency of pulmonary edema, it should not be given to any patient who has more than 3% body weight gain during the week prior to therapy. In rare case, it causes aseptic meningitis or encephalopathy, which is manifested by fever, severe headache, and seizure.
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PMID:Complications associated with immunosuppressive therapy and their management. 174 17

The effects of two i.v. anesthetics, Saffan and methohexitone (MHX) and two N-methyl-D-aspartate receptor antagonists, MK-801 (Dizocilpine) and 2-aminophosphonoheptanoate (AP7), were tested for activity against the motor excitation (tremor, whole body jerks, and seizures) produced by the K+ channel blocker 4-aminopyridine (4-AP). Saffan increased the dose of 4-AP required for all three endpoints; MHX had no effect on tremor but reduced the 4-AP required to produce jerks and seizures. MK-801 also reduced the 4-AP dose required to produce jerking but did not affect tremor or seizures. In contrast, AP7 increased the amount of 4-AP required to produce all endpoints. The effects of these drugs on 4-AP-induced excitation are similar to their actions on hyperbaric excitation, reported by us previously, and suggest that blockade of K+ channels may contribute to the high pressure nervous syndrome.
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PMID:Effects of four drugs on 4-aminopyridine seizures: a comparison with their effects on HPNS. 174 67

Tremor rats (tremor homozygous rats) exhibit spontaneous absence-like seizure, which is characterized by a sudden immobility with staring and the appearance of 5- to 7-Hz spike and wave complexes in cortical and hippocampal electroencephalogram (EEG). In this study, we examined the development of the seizure and the mode of inheritance. All tremor homozygous and heterozygous rats exhibited the seizure by 14 and 26 weeks of age, respectively. The frequency and total duration in tremor heterozygous rats were significantly lower in comparison with those in tremor homozygous rats. None of the seven tremor wild-type homozygous rats exhibited the seizure. In an EEG study of backcross progeny of (BN/fMaiKyo x tremor heterozygous rats)F1 (tm/+) x tremor heterozygous rats at 5 months of age, the ratio of rats with and without the seizure was 23:7 (chi 2 = 0.09 for 3:1 ratio). These results suggest that the absence-like seizure is semidominantly expressed, in contrast to other recessive mutant traits in tremor rats.
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PMID:Semidominant expression of absence-like seizure in tremor rats. 179 28

Neurophysiological interactions between the competitive N-methyl-D-aspartate (NMDA) preferring receptor antagonist, CPP (3-((+-)-2-carboxypiperazine-4-yl)-propyl-1-phosphonate) and the high pressure neurological syndrome (HPNS) have been investigated in the non-human primate Papio anubis. Eight animals were exposed on two occasions to environmental pressures of 81 atmospheres absolute (ATA) in a hyperbaric chamber, using helium and oxygen. One exposure followed pretreatment with CPP (either 5 or 10 mg/kg i.v. plus 5 mg/kg/hr infusion), the other a saline control. Pretreatment with CPP delayed moderate signs of face tremor and myoclonus and abolished severe signs of whole body tremor and seizure activity. By 81 ATA, scores representing severity of HPNS were significantly reduced by CPP to a mean score, reflecting a level of just mild to moderate limb tremoring (P less than 0.001). Changes in the EEG were observed in channels associated with the frontal, parietal and occipital regions of the left cortex. Amplitude and frequency spectra were calculated and changes with pressure in the 4 conventional wavebands were analysed. The most striking change was the complete prevention by CPP of the 100% increase in the amplitude of alpha waves at 81 ATA in the frontal region (P less than 0.001). It is concluded that NMDA transmission has a major role in the expression of HPNS.
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PMID:The effects of the competitive NMDA receptor antagonist CPP on the high pressure neurological syndrome in a primate model. 183 61

Two unrelated patients with macrocephaly, seizures, and mild cerebellar signs had a dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos disease). Both also had autosomal dominant Cowden disease as evidenced by facial, oral, and acral papules. In the two families, 9 sibs demonstrated the mucocutaneous lesions, thyroid disease, breast tumors, and ovarian tumors compatible with the diagnosis of Cowden disease. Some of the sibs also showed various degrees of neurological signs such as macrocephaly, mental retardation, seizures, tremor, and dysdiadochokinesia. Magnetic resonance imaging scans of sibs of one family demonstrated megalencephaly and other mild abnormalities. The occurrence of these two rare disorders in single patients is more than a coincidence, and the clinical findings in the combined condition establishes it as a new phakomatosis.
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PMID:Lhermitte-Duclos disease and Cowden disease: a single phakomatosis. 164 66

The effects of thyrotropin-releasing hormone (TRH) were investigated on absence-like seizures, which are characterized by the sudden appearance of 5-7 Hz spike-wave-like complexes in the cortical and hippocampal EEG, and on tonic convulsions of spontaneously epileptic rats (SER; zi/zi, tm/tm), a double mutant obtained by mating zitter homozygote (zi/zi) with tremor heterozygote rats (tm/+). TRH (5 and 10 mg/kg i.v.) inhibited the appearance of both absence-like seizures and tonic convulsions of SER without inducing obvious changes in the background EEG. The inhibitory effects were seen 5-20 min after injection of 10 mg/kg TRH and were antagonized by pretreatment with haloperidol (0.5 and 1.0/kg i.p.), although haloperidol alone did not affect the seizures. These results suggest that TRH has an antiepileptic effect in the genetically defined animal model, SER, and that the effect is mediated by the central dopaminergic system.
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PMID:Inhibition by thyrotropin-releasing hormone of epileptic seizures in spontaneously epileptic rats. 190 88

When human divers or experimental animals are exposed to high pressure, they develop the High Pressure Neurological Syndrome (HPNS). Male Sprague-Dawley rats were exposed to high pressure in a conventional helium-oxygen breathing mixture to 80 bars. Pressure-induced behavioral motor disturbances including hyperlocomotor activity (HLA), tremor and myoclonia were monitored with a noninvasive piezoelectrical sensor device enabling a without discontinuity long-term analysis. New data were obtained on the development of the HPNS behavioral motor disturbances. Indeed, the present results suggest myoclonia would be more sensitive to constant high pressure exposure, while HLA and tremor would be more sensitive to increasing pressure. Moreover, myoclonia were found to occur significantly later in rats which developed epileptic seizures than in other. The present results constitute the quantitative basis of HPNS motor disturbances for future pharmacological pressure experiments.
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PMID:Quantitative study of behavioral disturbances in rats exposed to high pressure. 191 Mar 48

The ontogeny of epileptic seizures in spontaneously epileptic rats (SER; zi/zi, tm/tm) was studied by examining behaviour and electroencephalogram (EEG) simultaneously. Weight gain and survival time were also studied. Compared with the control Kyo:Wistar rats, SER showed a much smaller increase in body weight. All male and female SER died before 20 and 18 weeks of age, respectively. Body tremor was observed at 2 weeks of age but disappeared after 11 weeks. Staggering gait appeared after 7 weeks of age, and intensified with age. Absence-like seizures characterized by paroxysmal appearance of 5-7 Hz spike-wave-like complexes were observed in the cortical or hippocampal EEG after 5 weeks of age, and tonic seizures with low voltage fast waves were observed after 6 weeks of age. All SER exhibited both absence-like and tonic seizures with high frequencies from 12 weeks of age. Differences with other spontaneous rat models of epilepsy and application methods for estimating seizure-inhibitory effects of anti-epileptic drugs are discussed.
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PMID:Ontogeny of absence-like and tonic seizures in the spontaneously epileptic rat. 192 17

The effect of central serotonergic stimulation on hippocampal and neocortical electrical activity and behavior was studied in freely moving rats by administering: (a) tranylcypromine followed by tryptophan, (b) fluoxetine followed by 5-hydroxytryptophan, or (c) p-chloroamphetamine alone. In all rats, scopolamine-resistant hippocampal rhythmical slow activity (RSA), thought to be dependent on brain serotonin, maintained its normal relation to behavior, occurring in close correlation with Type 1 behaviors (postural changes, turning of the head, walking). This RSA was generally absent during stereotyped behavior (head weaving, forepaw treading, hindlimb splaying and tremor). Scopolamine-resistant neocortical low-voltage fast activity (LVFA), also though to be dependent on brain serotonin, was present during Type 1 behaviors and also during stereotyped behavior. Most rats that developed a full stereotyped behavior syndrome had behavioral and electrocortical seizures which were associated with a reduction in the amplitude of hippocampal activity. These seizures were suppressed by methysergide or benserazide. Metergoline (and methysergide to a lesser extent) suppressed the stereotypic behaviors of the serotonin syndrome, resulting in a striking increase in the locomotion caused by central serotonergic stimulation. Such locomotion was accompanied by RSA and LVFA. It was concluded that increased serotonergic activity in the CNS causes an increase in motor activity and a correlated increase in scopolamine-resistant hippocampal RSA and scopolamine-resistant neocortical LVFA and suggested that metergoline blocks serotonin receptors mediating stereotyped behaviors, thereby permitting the expression of serotonin-mediated locomotion.
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PMID:The effects of serotonergic stimulation on hippocampal and neocortical slow waves and behavior. 193 39


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