Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Animal data indicate that serotonin (5-HT) is a major neurotransmitter involved in the control of numerous central nervous system functions including mood, aggression, pain, anxiety, sleep, memory, eating behavior, addictive behavior, temperature control, endocrine regulation, and motor behavior. Moreover, there is evidence that abnormalities of 5-HT functions are related to the pathophysiology of diverse neurological conditions including Parkinson's disease, tardive dyskinesia, akathisia, dystonia, Huntington's disease, familial tremor, restless legs syndrome, myoclonus, Gilles de la Tourette's syndrome, multiple sclerosis, sleep disorders, and dementia. The psychiatric disorders of schizophrenia, mania, depression, aggressive and self-injurious behavior, obsessive compulsive disorder, seasonal affective disorder, substance abuse, hypersexuality, anxiety disorders, bulimia, childhood hyperactivity, and behavioral disorders in geriatric patients have been linked to impaired central 5-HT functions. Tryptophan, the natural amino acid precursor in 5-HT biosynthesis, increases 5-HT synthesis in the brain and, therefore, may stimulate 5-HT release and function. Since it is a natural constituent of the diet, tryptophan should have low toxicity and produce few side effects. Based on these advantages, dietary tryptophan supplementation has been used in the management of neuropsychiatric disorders with variable success. This review summarizes current clinical use of tryptophan supplementation in neuropsychiatric disorders.
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PMID:L-tryptophan in neuropsychiatric disorders: a review. 130 30

This is a case of Ramsay Hunt syndrome with mental disorder. The patient had action myoclonus, grand mal seizure and severe cerebellar ataxia. Schizophrenia-like symptoms including delusion of persecution and self-reference, auditory hallucination and incoherence were characteristically observed before the neurological disturbance became manifest. Subsequently, euphoria, disinhibition, moria and mild dementia appeared with neurological symptoms. The possibility of Ramsay Hunt syndrome to accompany organic mental syndromes and the relationship between cerebellar dysfunction and psychiatric symptoms are discussed.
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PMID:Ramsay Hunt syndrome with mental disorder. 181 81

Clozapine is a novel antipsychotic agent effective in treating refractory schizophrenia. Clozapine produces fewer extrapyramidal effects than other neuroleptics, although agranulocytosis and seizures are significant adverse effects. To characterize the spectrum of clozapine-related electroencephalographic abnormalities, we identified 10 patients who had electroencephalograms (EEGs) performed before and during clozapine treatment. These 10 patients represented a subset of individuals participating in an investigational trial. During clozapine treatment, five developed myoclonus and one experienced a generalized tonic-clonic seizure. Records were retrospectively reviewed by an electroencephalographer blinded to the patient's history and medications. All patients had normal EEGs before clozapine treatment. While receiving clozapine (250-900 mg daily), all patients developed background slowing in the theta and often delta ranges. Additionally, 7 patients exhibited bilateral spike, polyspike and slow wave discharges, one with a photoparoxysmal response. Follow-up EEGs performed in 4 of these 7 patients after a decrease in clozapine dosage and/or addition in valproic acid showed diminished epileptiform activity.
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PMID:Spectrum of EEG abnormalities during clozapine treatment. 752 49

Two cases of basal ganglia calcification involving the globus pallidus are presented. Both patients had cognitive dysfunction, temporal lobe-like symptoms (including amnestic state, perceptual distortions, or complex visual hallucinations), and myoclonus. Patient 1 manifested depression, auditory hallucinations, anxiety, paranoia, and postural tremor; patient 2 manifested multifocal dystonia with dystonic tremor. These cases supplement other reports of psychotic features and dementia associated with pallidal pathology. Additionally, the phenomena encountered in these cases are considered in light of recent advances in our understanding of basal ganglia functional pathways. These cases afford a potential pathophysiological window to the possible role of the globus pallidus in these neuropsychiatric conditions. In concert with other recent findings, these cases suggest specific pathway involvement in hallucinations, paranoia, depression, myoclonus, and dystonia. Further research will indicate if these pathways play a role in schizophrenia, mood disorders, and anxiety disorders.
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PMID:Neuropsychiatric disorders, myoclonus, and dystonia in calcification of basal ganglia pathways. 801 2

Clozapine is an 'atypical' neuroleptic that improves symptoms of many patients with schizophrenia whose illness is resistant to treatment with other neuroleptics. Unlike the 'typical neuroleptics (chlorpromazine, haloperidol), clozapine does not induce extrapyramidal symptoms such as Parkinsonism and tardive dyskinesia in humans or catalepsy in the rat. However, clozapine frequently causes epileptiform EEG changes and causes seizures in 3-5% of patients treated with this drug in therapeutic doses. Clozapine also induces dose dependent myoclonus in the partially restrained rat. In the experiments reported here, partially restrained rats were administered repeated alternate day or weekly low, fixed doses of clozapine (1 mg/kg). This dose initially caused no behavioral change. Following the third and subsequent administrations, the same dose elicited an increasing number of myoclonic seizure-like jerks reaching 140/h following the 15th injection in rats receiving the same low dose of clozapine on alternate days and 160/h following the 9th injection in animals that received the same dose once weekly. These effects are consistent with kindling, i.e. a progressive increase of brain excitability following repeated administration of a fixed subconvulsive dose of an excitatory agent. Clozapine kindled animals exhibited a significantly different pattern of early gene expression in ventral tegmental area, origin of the mesolimbic-mesocortical dopamine system and in the anterior thalamic nuclei, compared with saline treated controls subjected to exactly the same recording conditions. The evidence of central nervous system excitation with clozapine may be important to the unique therapeutic effect of this atypical antipsychotic in the treatment of symptoms, especially the deficit symptoms, of schizophrenia.
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PMID:Kindling with clozapine: behavioral and molecular consequences. 898 8

A combination of clozapine and lithium can be used in the treatment of refractory schizophrenia, schizoaffective disorder and bipolar disorder with rapid cycling. We report a patient with refractory bipolar disorder who developed side-effects after combination therapy with clozapine and lithium at usual therapeutic dosages. Reversible neurotoxicity developed twice during the therapeutic course, once with the restarting of lithium, the other with increasing the dose of lithium, despite the lithium concentrations being less than 0.5 mEq/l. Neurotoxicity manifested as ataxia, coarse tremor, myoclonus, facial spasm and increased deep tendon reflex. While the mechanism causing toxicity is not clear, interaction between the serotonergic effect of clozapine and lithium may be the cause. This report is evidence that a combination of clozapine and lithium may increase the risk of neurotoxicity. We suggest the need to keep clozapine and lithium at lower dosages and closely monitor their side-effects as necessary when these drugs are used concomitantly.
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PMID:Reversible neurotoxicity induced by a combination of clozapine and lithium: a case report. 1022 8

It has been proposed that sleep disturbances, especially reduced delta sleep, are related to a poor outcome in schizophrenia. To determine whether long-term treatment with neuroleptics can promote sleep disturbances by increasing the risk of a nocturnal myoclonus syndrome (NMS) (=periodic movements in sleep) related insomnia, we performed all-night polysomnography in 10 chronically ill schizophrenic patients who had been under neuroleptic therapy for a mean of 27 years. NMS-related insomnia was detected in all 10 patients. Potential pathophysiological relationships between long-term neuroleptic therapy and NMS occurrence are discussed. Our findings suggest that long-term administration of neuroleptics favours the appearance of insomnia.
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PMID:Can chronic neuroleptic treatment promote sleep disturbances in elderly schizophrenic patients? 1067 48

We report a case of myoclonus induced by quetiapine. A 64-year-old man with schizophrenia developed myoclonic jerks when given higher doses of quetiapine. These movements were dose-related and completely abated on reducing the dose. To our knowledge, these movements have not been reported previously as an adverse effect of quetiapine.
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PMID:Quetiapine-induced myoclonus. 1572 90

Duplications and triplications of the alpha-synuclein (SNCA) gene have been reported in Parkinson's disease patients belonging to the Southern Swedish "Lister family". Further genealogical research has now shown that these individuals are descended from a large kindred characterized by Herman Lundborg in 1901-1913. In the expanded pedigree, a total of 25 individuals had Parkinson's disease with an autosomal dominant pattern of inheritance. Hereditary dementia, and, historically, dementia praecox have been described in other family members. Furthermore, an autosomal recessively inherited pediatric disease with nocturnal tonic-clonic fits, subsequent progressive myoclonus, startle reactions, tremor and muscle rigidity was described by Lundborg in the same pedigree. The entity was later designated Unverricht-Lundborg disease (ULD) or progressive myoclonus epilepsy type 1 (EPM1). However, Lundborg's clinical description of this disease, based on 17 patients within this kindred, differs from the modern definition of EPM1, which relies on patients with a mutation in the cystatin B (CSTB) gene. We hypothesize that the former pediatric disease, as well as the parkinsonism and dementia phenotypes, are associated with duplications, triplications and possibly higher-order multiplications of the alpha-synuclein (SNCA) gene. This hypothesis is supported by the distribution of afflicted family members within the pedigree and by recently obtained genealogical information.
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PMID:Alpha-synuclein multiplications with parkinsonism, dementia or progressive myoclonus? 1882 90

Tetrabenazine (TBZ), a catecholamine-depleting agent initially developed for the treatment of schizophrenia, when tested for other indications, has proven to be more useful for the treatment of a variety of hyperkinetic movement disorders. These disorders include neurological diseases characterized by abnormal involuntary movements such as chorea associated with Huntington's disease, tics in Tourette's syndrome, dyskinesias and dystonias in tardive dyskinesia, also primary dystonias and myoclonus. This review will include and discuss studies published during the period of 1960-2006 regarding the clinical efficacy and tolerability of TBZ in Huntington's disease (HD). It will also review the chemistry, pharmacokinetics and dynamics of the drug and its mechanism of action compared to that of reserpine, the only similar compound. This review emphasizes the advantage of TBZ over dopamine-depleting compounds used in the treatment of chorea and reveals its clinical efficacy and side effects.
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PMID:Tetrabenazine in the treatment of Huntington's disease. 1938 Dec 78


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