Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rett syndrome, a progressive neurodegenerative disorder described only in female subjects, is manifested by a wide spectrum of behavioral and motor abnormalities. We studied 32 patients with this disorder, ages 30 months to 28 years old, and characterized their extrapyramidal disturbance. The most common motor abnormalities were stereotyped movements and gait disturbance, seen in all patients. Bruxism, oculogyric crises, parkinsonism, and dystonia were also common, but myoclonus and choreoathetosis were seen only infrequently. The hyperkinetic movement disorders tended to dominate in younger patients, while bradykinetic disorders were more evident in the older patients. This study provides evidence that movement disorders seen in Rett syndrome reflect age-related neurodegenerative changes in the basal ganglia.
 ...
PMID:Rett syndrome and associated movement disorders. 238 36

The author reports eight cases of the Rett syndrome, or dementia-ataxia-autism, in girls. The cases satisfy the following criteria: Normal development in the first mos of life. Profound deterioration of the mental status over a period of several mos. Behavioral pseudoautistic abnormalities. Presence of neurological signs such as ataxia, myoclonus and hyperreflexia. Normal head circumference at birth, but subsequent subnormal growth. EEG abnormalities. Slow progression of the disease after the period of rapid deterioration. The constellation of the signs and symptoms, and the occurrence only in girls, make this clinical picture quite distinct. There is no definitely known biochemical or chromosomal abnormality. The psychological profile, though homogeneous in all the patients, is not pathognomonic, and a very similar behavioral pattern can be observed in other organic brain syndromes.
 ...
PMID:Rett syndrome: report of eight cases. 406 60

Neuroimage studies of thirty-eight infants and children with mitochondrial disorders were reviewed: 24 ultrasound (US), 21 computed tomography (CT), and 27 magnetic resonance image (MRI) examinations were analyzed. Patients included seventeen with Leigh syndrome, two with Kearns-Sayre syndrome (KSS), one with myoclonus, epilepsy, and ragged red fibers (MERRF), one with Alpers disease, five with Menkes disease, two with fatty acid metabolic defect, two with Rett syndrome, and eight with unspecified mitochondrial disorders. KSS and MERRF tended to occur in older children, whereas Leigh syndrome, Menkes disease, and Alpers disease occurred in infants and young children. The deep cerebral nuclei and the cerebral white matter were commonly involved in Leigh syndrome and KSS. Subdural hematomas or effusions with profound cerebral atrophy was found in Alpers disease and Menkes disease. Tortuosities of basilar, Willis circle, and cerebral vessels were also noted in Menkes disease. MRI and CT examinations of Rett syndrome, fatty acid metabolic defect, and most of the unspecified mitochondrial disorders were normal. Our results indicate that neuroimage studies have characteristic findings for specific mitochondrial syndromes.
 ...
PMID:Neuroimage in infants and children with mitochondrial disorders. 893 6

Rett syndrome (RS) is one of the most frequent causes of mental retardation in females. As there are no known biochemical, genetic, or morphological markers, diagnosis is based on clinical phenotype including severe dementia, autism, truncal ataxia/apraxia, loss of purposeful hand movements, breathing abnormalities, stereotypies, seizures, and extrapyramidal signs. Myoclonus, although reported in some series, has never been characterized. We studied 10 RS patients, age 3 to 20 years, and observed myoclonus in 9. Severity of myoclonus did not correlate with that of the other symptoms or with age. Multifocal, arrhythmic, and asynchronous jerks mainly involved distal limbs. Electromyographic bursts lasted 48 +/- 12 msec. Burst-locked electroencephalographic averaging generated a contralateral centroparietal premyoclonus transient preceding the burst by 34 +/- 7.2 msec. Motor evoked potentials showed normal latencies, indicating integrity of the corticospinal pathway. Somatosensory evoked potentials were enlarged. The C-reflex was hyperexcitable and markedly prolonged (62 +/- 4.3 msec), mainly due to increase in cortical relay time (28.4 +/- 4.5 msec). We conclude that RS patients show a distinctive pattern of cortical reflex myoclonus with prolonged intracortical delay of the long-loop reflex.
 ...
PMID:Cortical reflex myoclonus in Rett syndrome. 954 28

The electroencephalogram (EEG) plays an important role in the evaluation of a child with developmental delay. An EEG is often required to classify seizures in children with developmental delay. Equally important is the role of the EEG in the identification of specific electroclinical syndromes in children who may or may not manifest seizures. Specific electroclinical syndromes include the acquired epileptiform aphasia syndrome, Landau-Kleffner syndrome, and electrical status epilepticus during slow wave sleep. Other clinical situations where the EEG offers diagnostic and prognostic information, such as subacute sclerosing encephalitis, progressive myoclonus epilepsies, Rett syndrome, and Lennox Gastaut syndrome are also discussed.
 ...
PMID:Electroencephalogram in developmental delay: specific electroclinical syndromes. 954 41

The author reviews the applications of transcranial magnetic stimulation (TMS) in a series of movement disorders--namely, Parkinson's disease, corticobasal degeneration, multiple system atrophy, progressive supranuclear palsy, essential tremor, dystonia, Huntington's chorea, myoclonus, the ataxias, Tourette's syndrome, restless legs syndrome, Wilson's disease, Rett syndrome, and stiff-person syndrome. Single- and paired-pulse TMS studies have been done mainly for pathophysiologic purposes. Repetitive TMS has been used largely for therapy. Many TMS abnormalities are seen in the different diseases. They concur to show that motor cortical areas and their projections are the main target of the basal ganglia dysfunction typical of movement disorders. Interpretation has not always been clear, and sometimes there were discrepancies and contradictions. Largely, this may be the result of the extreme heterogeneity of the methods used and of the patients studied. It is premature to give repetitive TMS a role in treatment. Overall, however, TMS gives rise to a new, outstanding enthusiasm in the neurophysiology of movement disorders. There is reason to predict that TMS, with its continuous technical refinement, will prove even more helpful in the near future. Then, research achievements are reasonably expected to spill over into clinical practice.
 ...
PMID:Applications of transcranial magnetic stimulation in movement disorders. 1243 85

We report on three patients with MeCP2 mutation and male Rett phenotypes. Two brothers with T158M mutations and normal karyotype had a severe early onset encephalopathy, progressive microcephaly, severe feeding problems, breathing and sleep disturbances. They died at the ages of 1 year and 8 months, and 3 years and 1 month. This mutation has previously been reported in three males. The phenotypes show a strong resemblance, and might in fact represent a clinical-genetic entity of the T158M mutation within the complex of congenital encephalopathies in males with MeCP2 mutations. We also report a 3-year-old boy with a R294X mutation, normal karyotype, and a more protracted course. He was inactive and sucked poorly from start. The head growth decelerated from the age of 6 months and the feeding problems increased requiring gastrostomy. He had a rapid deterioration period at 2 years and lost sitting and hand grasping functions. He had prolonged periods with tremor and epileptic myoclonus, shifting tonus, and dystonic extension of the trunk and legs, bruxism, and irregular breathing. He was clinically stable with preserved visual and emotional contact function by the age of four years. None of the boys had dysmorphic features.
 ...
PMID:Male Rett phenotypes in T158M and R294X MeCP2-mutations. 1723 9

Rett syndrome (RS) is one of the best human models to study movement disorders. Patients evolve from a hyperkinetic to a hypokinetic state, and a large series of abnormal movements may be observed along their lives such as stereotypies, tremor, chorea, myoclonus, ataxia, dystonia, and rigidity. The aim of this work was to analyze movement disorders in RS patients with a detected MECP2 mutation, as well as their correlation with genotype, in a clinically and genetically well-characterized sample of patients, and thus contribute to redefine the clinical profile of this disease. In this study, we included 60 patients with detected MECP2 mutations. These were categorized and grouped for analysis, according to (1) type of change (missense or truncating, including nonsense and frameshift but also large deletions) and (2) location of the mutation. Differences were found concerning the frequency of independent gait, dystonia, type of tremor, and global score severity when comparing the group of patients with missense and truncating mutations. We also found differences in the presence, distribution, severity, or type of movement disorders in the two groups of patients according to the median duration of the disease (less than 60 months; 60 months or more). We conclude that movement disorders seem to reflect the severity and rate of progression of Rett disorder, patients with truncating mutations presenting a higher rate and more severe dystonia and rigid-akinetic syndrome, when comparing groups with similar time of disease evolution.
 ...
PMID:Movement disorders in Rett syndrome: an analysis of 60 patients with detected MECP2 mutation and correlation with mutation type. 1851 55

PRO: In the past decade, genotyping has started to help the neurologic practitioner treat patients with three types of epilepsy causing mutations, namely (1) SCN1A, a sodium channel gene mutated in Dravet's sporadic severe myoclonic epilepsy of infancy (SMEI and SMEB); (2) laforin (dual specificity protein phosphatase) and malin (ubiquitin E3 ligase) in Lafora progressive myoclonic epilepsy (PME); and (3) cystatin B in Unverricht-Lundborg type of PME. Laforin, malin, and cystatin B are non-ion channel gene mutations that cause PME. Genotyping ensures accurate diagnosis, helps treatment and genetic counseling, psychological and social help for patients and families, and directs families to organizations devoted to finding cures for specific epilepsy diseases. In SCN1A and cystatin B mutations, treatment with sodium channel blockers (phenytoin, carbamazepine, oxcarbazepine, lamotrigine) should be avoided. Because of early and correct diagnosis by genotyping of SCN1A mutations, the avoidance of sodium channel blockers, and aggressive treatment of prolonged convulsive status, there is hope that Dravet's syndrome may not be as severe as observed in all past reports. Genotyping also identifies nonsense mutations in Lafora PME. Nonsense mutations can be corrected by premature stop codon readthrough drugs such as gentamicin. The community practitioner together with epilepsy specialists in PME can work together and acquire gentamicin (Barton-Davis et al., 1999) for "compassionate use" in Lafora PME, a generalized lysosome multiorgan storage disorder that is invariably fatal. In Unverricht-Lundborg PME, new cohorts with genotyped cystatin B mutations have led to the chronic use of antioxidant N-acetylcysteine and combination valproate clobazam or clonazepam plus antimyoclonic drugs topiramate, zonisamide, piracetam, levetiracetam, or brivaracetam. These cohorts have minimal ataxia and no dementia, questioning whether the syndrome is truly progressive. In conclusion, not only is genotyping a prerequisite in the diagnosis of Dravet's syndrome and the progressive myoclonus epilepsies, but it also helps us choose the correct antiepileptic drugs to treat seizures in Dravet's syndrome and Unverricht-Lundborg PME. Genotyping also portends a brighter future, helping us to reassess the true course, severity, and progressive nature of Dravet's syndrome and Unverricht-Lundborg PME and helping us craft a future curative treatment for Dravet's syndrome and Lafora disease. Without the genotyping diagnosis of epilepsy causing mutations we are stuck with imprecise diagnosis and symptomatic treatment of seizures. CON: Genotyping of epilepsy may help to better understand the genetics of epilepsy, to establish an etiology in a patient with epilepsy, to provide genetic counseling, and to confirm a clinical diagnosis. However, critical analysis reveals that genotyping does not contribute to an improved treatment for the patients. In order to improve treatment, genotyping would have to (1) improve our ability to select the drug of choice for a given epilepsy or epileptic syndrome; (2) improve our ability to predict the individual risk of adverse reactions to certain drugs; (3) improve our ability to avoid unnecessary treatments or treatments that could aggravate seizures. Many example illustrate the lack of impact of genetic information on the treatment outcome: we do not treat Dravet syndrome more successfully since SCN1A testing became available; we do not treat Lafora disease more successfully since testing for laforin and malin became available; we do not need to know the genetic nature of Unverricht-Lundborg disease or test for the cystatin B mutation in order to select or avoid certain drugs; we do not treat Rett syndrome more successfully since MECP2 testing became available; we do not treat JME more successfully since we know its genetic origin; we do not treat autosomal dominant nocturnal frontal lobe epilepsy more successfully since we know its genetic origin and can test for its mutation. The clinical characteristics as well as the response to treatment of these epilepsy syndromes have been well established before genotyping became available. It can not be argued that genotyping is necessary for establishing a diagnosis or ensure accurate diagnosis. Since not all individuals with given syndromes have been shown to have the corresponding mutation, the clinical diagnosis must have been based on well-established clinical criteria. In addition, the presence or absence of the mutation in a given patient has never been shown to specifically predict the response to any form of treatment, positive or negative. Finally, the appropriate psychological and social help in a given patient will not depend on the identification of a mutation. This does not leave any role for genotyping in epilepsy for the sole reason of improving treatment of the patient. Claiming that the result of genotyping predicts optimal treatment in certain epilepsies is equivalent to stating that genotyping for diabetes has become available and that, based on this breakthrough, insulin can now be selected as the treatment of choice in those who test positive.
 ...
PMID:Debate: Does genetic information in humans help us treat patients? PRO--genetic information in humans helps us treat patients. CON--genetic information does not help at all. 1908 13

Myoclonic jerks and myoclonic status (MS) are sometimes difficult to distinguish clinically from movement disorders such as hand stereotypies, tremor, and dystonia in Rett syndrome. We describe a rare and complete video-polygraphic study of a girl with Rett syndrome (MECP2 mutation) and MS misdiagnosed as movement disorders and disclosed after video-polygraphic recordings. Corresponding to closely recurring activity of diffuse spike and polyspikes-wave-type paroxysms, rhythmic and, especially, arrhythmic myoclonias, usually asymmetrical and asynchronous, involving mainly right muscle deltoid and rarely followed by an inhibitory phenomenon, appeared. The MS improved and, most importantly, disappeared after the use of levetiracetam, with an evident antimyoclonic efficacy and a marked improvement of daily life for the patient and her caregivers. The difficulty in differentiating some typical nonepileptic behavioral features and movement disorders of patients with Rett syndrome from seizures was overcome using prolonged video-polygraphic recordings in our case.
 ...
PMID:Myoclonic status misdiagnosed as movement disorders in Rett syndrome: a video-polygraphic study. 1960 60


1 2 Next >>