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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cerebral palsy is a permanent and non-progressive brain damage due to various causes affecting a child from the intrauterine life up to the first two years of life. Its most common cause is neonatal hypoxic encephalopathy. The cerebral damage is diffuse so that it is commonly associated with epilepsy, mental retardation, dysarthria, hearing loss and oculomotor abnormalities. Strabismus is found in 50% of children with cerebral palsy. This prevalence is significantly different from the 2% incidence of oculomotor abnormalities in the pre-school age, it is noteworthy that strabismus and refractive errors respond to the classical therapeutic measures.
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PMID:[Physiopathology of ocular movements in infantile cerebral paralysis]. 270 64

Cerebellar hypoplasia is found in association with a variety of neurologic and systemic disorders. It is the primary finding in the uncommonly reported condition of autosomal recessive cerebellar hypoplasia. We describe two siblings with cerebellar hypoplasia documented in both by magnetic resonance imaging (MRI) and review the clinical features of previously reported cases of autosomal recessive cerebellar hypoplasia. The most common findings in this disorder are nonprogressive ataxia, strabismus, mental retardation, and speech delay with dysarthria. Previously reported cases have been confirmed by autopsy, pneumoencephalography, or computed tomographic (CT) scans. MRI clearly documents diffuse cerebellar hypoplasia and aids in distinguishing autosomal recessive cerebellar hypoplasia from other disorders. The pathophysiology of this disorder is uncertain, however, studies of the weaver mutant mouse (an animal model of autosomal recessive cerebellar hypoplasia) suggest that an abnormality of the Bergmann glia may lead to the observed granule cell layer deficiency in these patients. This diagnosis should be considered for children with nonprogressive ataxia and families should be made aware of the 25% recurrence risk.
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PMID:Autosomal recessive cerebellar hypoplasia. 200 8

Xeroderma pigmentosum associated with neurological abnormalities is a less familiar neurocutaneous disorder. In this report, 35 patients with group A xeroderma pigmentosum were assessed for neurological complications. Of these, 17 showed microcephaly and 24 mental retardation. Of 25 patients over 7 years of age, 22 had sensorineural deafness and 12 showed spinocerebellar signs such as nystagmus, dysarthria, tremor and ataxia, while none below 7 years of age had such neurological complications. Thirty-five EEG studies were performed on 29 patients, and 15 showed intermittent spindles of grouped theta waves with abnormal slow background activity and a poorly developed alpha rhythm, suggesting immature brain development or a regression from normal brain function in many areas including the diencephalon. Twenty-six patients were examined by cranial CT scan, of whom 20 showed abnormal CT findings such as ventricular dilatation, diffuse cortical atrophy, and marked thickening of the calvarial bones. The incidence of abnormal EEG and CT findings increased with advancing age in accordance with the development of neurological complications in the CNS, thus suggesting a chronic progressive degenerative disease.
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PMID:EEG and CT abnormalities in xeroderma pigmentosum. 281 76

We describe a family with a syndrome of mental retardation, dystonic movements of the hands and dysarthria inherited in an X-linked recessive pattern. DNA marker studies gave a maximum lod score of 2.11 at theta of 0.00 for DXS41 with a likely localization of the gene to Xpter----Xp21.
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PMID:X-linked mental retardation with dystonic movements of the hands. 317 52

Xeroderma pigmentosum is an unusual neurocutaneous disorder. Recent studies have classified patients with xeroderma pigmentosum into 10 groups by somatic cell hybridization methods. In this report we describe 32 patients with Group A xeroderma pigmentosum, including 1 patient with an atypical case, who were assessed for neurological complications. Of these patients, 17 had microcephaly, 13 short stature, and 21 mental retardation. In patients over 7 years of age, sensorineural deafness and spinocerebellar signs such as nystagmus, dysarthria, tremor, and ataxia were frequently observed; no patients below 7 years of age had such neurological complications. Electroencephalographic studies revealed abnormal slow and low voltage background activity. Two patients had focal abnormal discharges, one of whom developed versive seizures. Cranial computed tomographic scans revealed abnormalities, including ventricular dilatation, cerebral atrophy, cerebellar and brainstem atrophy, and cranial bone thickening. A patient with an atypical case of Group A xeroderma pigmentosum had less skin and neurological involvement, and higher levels of postultraviolet colony-forming ability and host cell reactivation than did a typical Group A case. It is possible that these less severe cytological findings are responsible for the less severe skin lesions and neurological complications noted clinically.
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PMID:Neurological manifestations in xeroderma pigmentosum. 374 Aug 15

An unselected series of 116 dyskinetic cerebral palsy cases born 1959-70 was delineated and subgrouped according to neurological criteria into 35 hyperkinetic (30%) and 81 dystonic (70%) cases. Of the hyperkinetics, 80% had a mild motor disability, while 90% of the dystonics had moderate or severe disability. Subordinated spastic signs were found in 9% of the hyperkinetic and in 44% of the dystonic cases. IQ was greater than 90 in 69% of the hyperkinetics and 25% of the dystonics and less than 50 in 11% and 41%, respectively. Two or more additional neurological abnormalities (spasticity, mental retardation, epilepsy, anarthria, dysarthria, hearing deficit) were detected in 46% hyperkinetic and 81% dystonic cases. A heavy multihandicap complex was present predominantly in the dystonic subgroup. The 5-19 year mortality rate was 6% and was confined to the most severely handicapped dystonic cases. The twin rate was 5%. A total of 9% had birth weights less than or equal to 1500 g, and 31% had less than or equal to 2500 g. The weight- and age-specific incidences increased rapidly with decreasing birth weights and gestational ages. The crude incidence of hyperkinetic cerebral palsy was 0.07 and dystonic cerebral palsy 0.17 per thousand live births.
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PMID:Dyskinetic cerebral palsy. I. Clinical categories, associated neurological abnormalities and incidences. 713 69

Primary degeneration of the granular layer of the cerebellum is an autosomal recessive disorder exhibiting characteristic clinical features: hypotonia, strabismus, delayed motor development, nonprogressive ataxia, delayed language development with dysarthria and mental retardation. We studied fourteen children, seven of each gender. Neuroimaging tests including pneumoencephalography, computed tomography (CT) and magnetic resonance imaging (MRI) showed severe cerebellar atrophy in all. MRI best demonstrated the cerebellar lesion, revealing great uniformity amongst the cases. Vertebrobasilar angiography was performed in two cases and showed marked hypoplasia of the cerebellar arteries, predominantly the posterior inferior cerebellar artery (PICA) and its branches. Necropsy was performed in three cases; cerebellar atrophy with loss of granular cells and diverse abnormalities of the Purkinje cells was found in two. The third, the sister of one of the other two cases, had a similar but shorter clinical course and died at three months of age. Her sister, who died at 5 years of age, presented a severe cerebellar atrophy with typical changes in the granular cell layer and Purkinje cells. In the third patient, who lived three months, only focal cerebellar folial atrophy with no microscopic changes in the granular cell layers was present. Though this case cannot objectively be included in the cerebellar atrophy syndrome with granular cell loss, her family history and clinical picture suggest the same disease. The findings observed in our series and the study of cases described in the literature, suggest that there are several forms of this disease which differ mainly in severity and neurological evolution. The cerebellar lesion seems to be a progressive atrophic process with the most severe changes during the early years of life.
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PMID:Primary degeneration of the granular layer of the cerebellum. A study of 14 patients and review of the literature. 782 90

The advent of MRI technique has enabled the diagnosis of neuronal migration disorders(NMD) and made it possible to make "in vivo" diagnosis. Congenital bilateral perisylvian syndrome(CBPS) is a recently described disease identify characterized by pseudobulbar palsy, epilepsy, mental retardation, and migration disorders in the bilateral perisylvian area. We have identified four CBPS patients based on neuroimaging and dysarthria patterns among the candidates for epilepsy surgery. All the patients had orofacial diplegia and variable degrees of mental retardation. In the spectrographic analysis of dysarthria, the loss of specific characteristics of formants of vowels and increment of noise in the high frequency formants were observed. Epilepsy was present in all, but only one patient showed intractable seizure requiring surgical intervention. MRI was most helpful in identifying NMD and polymicrogyria in both centroparietal areas in this context. Great alertness is needed to identify this disorder to determine the etiology of epilepsy and dysarthria of uncertain origin.
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PMID:Congenital bilateral perisylvian syndrome: analysis of the first four reported Korean patients. 784 82

A family with a syndrome of mental retardation, dystonic movements of the hands, and dysarthria (MIM no. 309510) was described and mapped to Xp22 by Partington et al. (Am J Med Genet 1988; 30:251-262). The original localization encompassed the distal half of the short arm of the X chromosome, with a peak lod score of 2.1 at the DXS41 locus. The gene localization for this disorder (PRTS) has now been refined using recently characterized dinucleotide repeat markers. The PRTS gene maps between DXS365 and DXS28, an interval estimated to be less than 15 cM. A peak lod score of 3.01 at a recombination fraction of zero was generated by 2-point linkage analysis with the marker DXS989. Dystonic movements may be progressive and could be overlooked in children. Clinical assessments of affected men who are mentally retarded should be critically evaluated for this manifestation, where they belong to families in which the gene localization overlaps with PRTS.
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PMID:X-linked mental retardation with dystonic movements of the hands (PRTS): revisited. 794 40

Two half-brothers and their mother had symptomatic pyruvate dehydrogenase complex deficiency. The infants had severe congenital lactic acidosis, seizures, and apneic spells and died at the ages 3 and 4 months. The mother was less symptomatic with mental retardation, truncal ataxia, and dysarthria. The residual pyruvate dehydrogenase activities in cultured skin fibroblasts from the 2 infants and their mother were 7, 15, and 10% of control values. Immunoblot analysis showed negligible amounts of E1 alpha and E1 beta subunits of the complex. Northern blot analysis for the E1 alpha subunit showed normal results. In the 2 sons, complementary DNA sequence analysis revealed a cytosine to thymine mutation in exon 4, resulting in a change of arginine 127 to tryptophan in the E1 alpha subunit. Restriction enzyme analysis of the polymerase chain reaction product representing exon 4 of the E1 alpha gene revealed that the mother was a heterozygotes. Complementary DNA restriction analysis and methylation analysis of the X chromosome DXS255 loci revealed skewed activation of the mutant allele, consistent with the deficient pyruvate dehydrogenase activity in the mother's fibroblasts. The milder maternal phenotype is consistent with variable X-inactivation patterns in different organs of female heterozygotes.
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PMID:Pyruvate dehydrogenase deficiency: molecular basis for intrafamilial heterogeneity. 802 67


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