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

Stroke-related nonepileptic transient dyskinesias are rare, and the site of ischemia remains often undetermined. Five cases out of 47 consecutive thalamic infarcts (10.6 per cent) are reported. Patients presented with monochorea (1 case), hemiballism-hemichorea (2 cases), choreoathetosis (1 case with subsequent arm painful dystonia and hand tremor), and asterixis (1 case). Magnetic resonance imaging demonstrated that the subthalamic nucleus was spared in all cases. Transient dyskinesias occurred at any time in the course of infarction (as a warning sign in 1 case, as an associated symptom in 3 cases, or during recovery in 1 case). Moreover, this study suggests that: 1) transient dyskinesias are mainly related to thalamic ischemic injury, and 2) small vessels disease is the main etiology.
 ...
PMID:[Transient involuntary movement disorders and thalamic infarction]. 830 59

We studied a large pedigree with dominant spinocerebellar ataxia, genetically and clinically. At now, 27 members over 5 generations have been affected. Linkage study for the disease locus to D6S89 in a total of 44 individuals showed maximum lod scores of 3.99 at theta = 0.000. This result indicates that the disease locus of this pedigree locates near D6S89 on chromosome 6p (SCA 1). We studied 17 patients clinically. Mean age at onset was 37.7 +/- 8.6, and mean duration after onset was 11.3 +/- 6.8 years. Their clinical features were characterized by progressive ataxia, pyramidal involvement with hyperreflexia or spasticity, and mild posterior column involvement. Mild gaze nystagmus at early stage became unclear with the progress of illness. The frequent signs in the advanced stage were diffuse amyotropy, twitching of face or tongue, bulbar palsy, slow saccade, external ophthalmoparesis, mydriasis, coarse postural tremor, and dementia with emotional disturbance. There are so much clinical similarities between our pedigree and other SCA 1 pedigrees in the literature. Generally, SCA 1 shows hyperreflexia, spasticity, and terminal slow saccade. On the other hand, non-SCA 1 type OPCA is characterized by progressive hyporeflexia, slow eye movement from early stage, and frequent choreoathetosis. Gaze nystagmus, external ophthalmoparesis, amyotrophy, and spasticity are common in both SCA 1 and Machado-Joseph disease (MJD). However, they are more frequent in MJD than SCA 1. Moreover, extrapyramidal signs, such as dystonia, are rare is SCA 1. Based on these difference, SCA 1 could be clinically differentiated from other similar hereditary ataxias.
 ...
PMID:[Spinocerebellar ataxia 1--clinical study of 17 patients in a large pedigree]. 836 44

The ability of a neurobehavioral screening battery to differentiate the effects of two pyrethroids, permethrin and cypermethrin, was assessed in this experiment. Although the structures of these pesticides differ only in the alpha-cyano group, the behavioral syndromes associated with the Type I and II pyrethroids are quite different. The tests included a functional observational battery which is a series of subjective and quantitative measures of neurological function and behavior, and an automated measure of motor activity. Our results verified previous reports in the literature describing these different syndromes, i.e., aggressive sparring behavior, fine to whole-body tremor, hyperthermia, and decreased motor activity for the Type I pyrethroid permethrin, and pawing, burrowing, salivation, whole body tremor to choreoathetosis, hypothermia, and lowered motor activity for the Type II pyrethroid cypermethrin. In addition, we report that permethrin produced decreased grip strengths, increased resistance to capture, increased reactivity to a click stimulus, and induced head and forelimb shaking and agitated behaviors, whereas cypermethrin produced pronounced neuromuscular weakness and equilibrium changes, retropulsion, lateral head movements, alterations in responses to various stimuli, and increased urination. Although there were similarities in some effects (e.g., decreased motor activity), the pesticides differed sufficiently in their overall behavioral profiles, and severity and time course of effects, to discriminate these two compounds. Thus, this type of screening approach is sensitive enough to differentiate these pyrethroids for hazard identification purposes.
 ...
PMID:Utility of a neurobehavioral screening battery for differentiating the effects of two pyrethroids, permethrin and cypermethrin. 851 Jun 10

There is a renewed interest in basal ganglia surgery for improvement of motor symptoms in cerebral palsy. Rigidity, choreoathetosis, and tremor can be improved or abolished by a well-placed radiofrequency lesion, either in the ventrolateral nucleus of the thalamus or ventroposterior pallidum. The target is chosen based on the predominance of the symptoms in a given patient. A review of the main reports on surgery of the basal ganglia for cerebral palsy, as well as the author's data, shows that the surgery can have a remarkable impact on patients' quality of life when motor dysfunction is improved. An update of the physiopathology of cerebral palsy motor symptoms related to anatomic findings on experimental work, magnetic resonance imaging, and autopsy is used to rationalize surgery of the basal ganglia. Modern stereotactic technique based on exquisite demonstration of the basal ganglia anatomy by magnetic resonance imaging is described and supported by intraoperative electricophysiologic studies. The author stresses the importance of a multidisciplinary approach to provide the cerebral palsy patient with a comprehensive treatment plan before stereotactic surgery.
 ...
PMID:Role of stereotaxis in the treatment of cerebral palsy. 895 61

We report six patients with glutaric aciduria type 1 in four families. The patients had marked clinical variability, even within families. Three of the patients studied were normal until the onset of neurologic abnormalities, that presented as an encephalitis-like illness in the first year of age. One patient had an early and important developmental delay, but never suffered an encephalopathic crisis. Two patients have intellectual preservation; one of them has a mild tremor and choreoathetosis since the first year of age, and the other had only two afebrile seizures in infancy and no other neurologic signs. Three patients are severely handicapped, with a severe dystonic-dyskinetic disorder and unable to even sit. All the six patients have macrocephaly and in all the computed tomography showed enlarged CSF spaces and sulcal separation over the frontal and temporal lobes. Urine organic acids study of all patients showed large quantities of glutaric acid.
 ...
PMID:[Glutaric aciduria type 1: phenotypic variability. Report of 6 patients]. 985 Jul 48

Leigh disease is a subacute neurodegenerative disorder characterized by symmetric necrotic lesions in the basal ganglia, cerebellum, thalamus, brain stem, and optical nerves and caused by altered oxidative phosphorylation. We describe the clinical, biochemical, neuroimaging, and molecular studies of a 19-year-old boy with early-onset Leigh disease manifesting as severe extrapyramidal disorder with generalized dystonia and choreoathetosis. He was born of healthy parents after an uneventful pregnancy and delivery. At the age of 2 1/2 years, after a minor respiratory infection, he developed unstable, broad-based gait and tremor of the hands. These symptoms persisted for the next several years, when ataxia became more prominent. Difficulty in swallowing, dysarthria, trunk dystonia, and marked dyskinesia of the arms and hands gradually developed. Nystagmus, transient ptosis, and strabismus also appeared. Abnormal laboratory findings included elevated plasma and cerebrospinal fluid lactate and pyruvate, with an abnormal lactate/pyruvate ratio. Cranial computed tomography and magnetic resonance imaging demonstrated signs of cerebellar atrophy, bilateral and symmetric hypodensities in the lentiform nucleus and thalamus, and transient hyperintensities of cerebral peduncles in T2-weighted sequences suggestive of Leigh disease. Muscle biopsy revealed isolated fiber atrophy, necrotic fibers undergoing phagocytosis, and no ragged-red fibers. The measured catalytic activity of cytochrome c oxidase in skeletal muscle homogenates demonstrated a partial cytochrome c oxidase deficiency No abnormalities in the mitochondrial genome and in the SURF-1 gene were found. The boy is currently receiving levodopa therapy, creatine monohydrate, and a high dosage of thiamine and lipoic acid, his condition is stabilized, and extrapyramidal symptoms are less pronounced.
 ...
PMID:Cytochrome c oxidase partial deficiency-associated Leigh disease presenting as an extrapyramidal syndrome. 1151 Sep 39

The Food Quality Protection Act (FQPA) of 1996 requires the United States Environmental Protection Agency to consider the cumulative effects of exposure to pesticides having a 'common mechanism of toxicity.' This paper reviews the information available on the acute neurotoxicity and mechanisms of toxic action of pyrethroid insecticides in mammals from the perspective of the 'common mechanism' statute of the FQPA. The principal effects of pyrethroids as a class are various signs of excitatory neurotoxicity. Historically, pyrethroids were grouped into two subclasses (Types I and II) based on chemical structure and the production of either the T (tremor) or CS (choreoathetosis with salivation) intoxication syndrome following intravenous or intracerebral administration to rodents. Although this classification system is widely employed, it has several shortcomings for the identification of common toxic effects. In particular, it does not reflect the diversity of intoxication signs found following oral administration of various pyrethroids. Pyrethroids act in vitro on a variety of putative biochemical and physiological target sites, four of which merit consideration as sites of toxic action. Voltage-sensitive sodium channels, the sites of insecticidal action, are also important target sites in mammals. Unlike insects, mammals have multiple sodium channel isoforms that vary in their biophysical and pharmacological properties, including their differential sensitivity to pyrethroids. Pyrethroids also act on some isoforms of voltage-sensitive calcium and chloride channels, and these effects may contribute to the toxicity of some compounds. Effects on peripheral-type benzodiazepine receptors are unlikely to be a principal cause of pyrethroid intoxication but may contribute to or enhance convulsions caused by actions at other target sites. In contrast, other putative target sites that have been identified in vitro do not appear to play a major role in pyrethroid intoxication. The diverse toxic actions and pharmacological effects of pyrethroids suggest that simple additivity models based on combined actions at a single target are not appropriate to assess the risks of cumulative exposure to multiple pyrethroids.
 ...
PMID:Mechanisms of pyrethroid neurotoxicity: implications for cumulative risk assessment. 1181 16

Movement disorders induced by central nervous system trauma are well recognized. However, over the last few years, attention has been drawn to the role of peripherally induced movement disorders. We describe three patients presenting respectively dystonia, tremor and choreoathetosis associated with tremor and dystonia of the body parts previously exposed to traumatic injuries. Pathophysiological mechanisms underlying these phenomena are not entirely known, but functional changes in afferent neuronal input to the spinal cord and secondary affection of higher brain stem and subcortical centers are probably involved.
 ...
PMID:Movement disorders induced by peripheral trauma. 1196 3

Lesch-Nyhan syndrome (LNS) is a rare X-recessive disorder that leads to virtually complete deficiency of the purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT). Partial HPRT deficiency results in uric acid overproduction with subsequent hyperuricemia, nephrolithiasis, renal failure and gouty arthritis. In contrast, at complete HPRT deficiency, besides overproduction of uric acid neurological problems appear including spasticity, choreoathetosis, mental retardation, and compulsive self-mutilation. The cause for the uric acid overproduction has been clarified, but the connection between the enzyme deficiency and the neurological manifestations in LNS remains unclear. A hypothesis, which explains this relation, is proposed in the paper. The hypothesis has several important points most substantial of which is the accelerated biosynthesis of semiessential amino acid histidine that against the background of accelerated purine de novo biosynthesis results in 5-aminoimidazole-4-carboxamideribotide (AICAR) and histamine accumulation. The histamine and AICAR were determined to be the compounds that cause the neurobehavioral symptoms of LNS for several reasons. First, in the basal ganglia a balance between the direct (activating) and the indirect (inhibiting) pathways arising on the basis of the antagonistic and reciprocal dopamine-adenosine interactions normally exists. This balance can tonically regulate smooth voluntary movements and the activity of the thalamus, which, in turn, processes the afferent sensorimotor signals from the whole body to the all areas of the cerebral cortex and is concerned to modulate mental development and bring sensory information into awareness. Second, histamine is known to induce a selective damage in dopaminergic neurons inhibiting the direct dopaminergic pathway, which could lead to muscular rigidity, and slowness in initiating movements as well as tremor that are characteristic of Parkinsonism in LNS. Third, AICAribosid (AICAR breakdown product) is a potent adenosine A2a receptor antagonist inhibiting the indirect dopamine-adenosinergic pathway and, therefore, could be responsible for the choreoathetosis, dystonia and ballismus found in LNS. The excitatory-inhibitory disbalance in the basal ganglia could result in inadequate modification of the thalamus activity with subsequent mental retardation and symptoms that include the patients not being aware for their own bodies that could give rise to self-mutilation. Finally, a possibility for the creation of a new animal model that could exactly match the human LNS is proposed in the paper.
 ...
PMID:The biochemical basis of the neurobehavioral abnormalities in the Lesch-Nyhan syndrome: a hypothesis. 1519 65

We describe a 24-year-old Japanese woman with pantothenate kinase-associated neurodegeneration (PKAN) whose only early symptom was postural tremor in the right hand at around 18 years of age, leading to a diagnosis of essential tremor at age 21. Although she was treated with arotinolol hydrochloride and clonazepam, she gradually progressed to extrapyramidal and pyramidal signs several years later. T2-weighted magnetic resonance images (MRI) showed bilaterally marked hypointensity with a central region of hyperintensity in the globus pallidus, or the so-called "eye-of-the-tiger" sign. Six years have passed since the initial appearance of postural tremor, whereas she has not shown choreoathetosis, retinitis pigmentosa, optic atrophy, or seizure. Direct sequencing of the patient's genomic DNA revealed homozygous base substitutions in the pantothenate kinase gene (PANK2): the A764-->G substitution (N245S) due to consanguinity of her parents. Although the heterozygous form of this mutation has already been reported among several families, this is the first report of the homozygous mutation in a patient with atypical-type PKAN. This detailed description of the clinical features of a Japanese patient with PKAN arising from homozygous N245S mutations in PANK2 would be useful for elucidating the pathogenesis of PKAN.
 ...
PMID:Pantothenate kinase-associated neurodegeneration initially presenting as postural tremor alone in a Japanese family with homozygous N245S substitutions in the pantothenate kinase gene. 1546 96


<< Previous 1 2 3 4 5 6 Next >>