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

Periventricular leukomalacia (PVL) is defined as an ischemic lesion of the brain of the preterm infant, characterized by infarction of the deep white matter surrounding the external angle of the lateral ventricles, a watershed area lacking collateral circulation, representing a typical "border zone" of vascular supply. This lesion is considered the neuroanatomic basis of motor and sensory impairments, as spastic diplegia or quadriplegia, mental retardation, visual and auditory deficits. An early diagnosis and the study of the developmental sequence of PVL, are recently become possible by realtime ultrasound scanning. During a period of one year, from 2/1/1986 to 2/1/1987, 136 newborns hospitalized in the Division of neonatology of the Conegliano General Hospital, have been studied by serial ultrasound scans. The incidence of PVL in the whole group was of 2.9% (4 cases); the incidence increased to 5.6% in infants weighing less than or equal to 2.500 gr (median 1.800 gr), and was 12.5% in the newborns less than or equal to 35 weeks of gestational age (median 31.7 weeks g.e.). Females presented PVL in three cases, with a M/F ratio of 1:3. Cranial real-time ultrasound provided a practical and valuable tool for diagnosis and monitoring of PVL, for its accuracy and safety. The sequence of four stage in the evolution of PVL has been confirmed on ultrasound regular scanning: 1) initial echodensity at the external angle of the lateral ventricles, 2) mild normalisation, 3) gradual cavitation and development of cysts, 4) final development of ventriculomegaly.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Periventricular leukomalacia in the newborn infant. Clinical and echographic diagnosis and follow-up]. 328 50

Hypoxic ischaemic encephalopathy (HIE) is a major cause of motor and mental retardation. There ist no doubt that the haemorrhagic form of HIE can be detected by cerebral sonography, but it is of great interest to recognize non-haemorrhagic HIE as well. We demonstrate the follow-up of three patients with different types of non-haemorrhagic HIE: Periventricular leukomalacia in a critical ill premature infant 35 weeks gestational age, multicystic encephalopathy in a term newborn with severe perinatal asphyxia and circumscript ischaemic leukomalacia in a five month old infant with near miss event for sudden infant death. Correlation between ultrasound and computed tomography proved that non-haemorrhagic HIE produces global or circumscript high echogenicity in the first week after the hypoxic event whereas computed tomography shows pathologic hypodensity in the same areas. Cerebral sonography is a very helpful and harmless method for the difficult diagnosis HIE. In the case of periventricular leukomalacia, CT scan gives no further information and can be avoided. Concerning HIE of term newborns and small infants, CT scan remains necessary, to evaluate the extension of cerebral injury.
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PMID:Hypoxic ischaemic encephalopathy: correlation between ultrasound and computed tomography. 368 8

Periventricular leukomalacia (PVL) usually is manifested as discrete foci of coagulation necrosis of the deep periventricular white matter in the human neonatal brain. During the examination of the brains of 116 infants utilizing an oil red O technic on gelatin-embedded frozen sections, 25 cases of PVL were found with typical foci of coagultion necrosis. Three morphologic varieties of the lesion could be demonstrated. In the first type, rather than being restricted to the periventricular zone, the discrete necrotic foci extended throughout the entire zone of cerebral white matter, even out to just beneath the cortex. The subcortical lesions appeared of short duration, whereas older lesions were always present nearer the ventricle. The second type of lesion presented as linear, some-what serpentine zones of coagulation necrosis radiating into the cerebral white matter. A third type of lesion consisted of a variegated irregular coagulation necrosis which was poorly delineated from more normal tissue. Diffuse pallor of the white matter, the nature of which is still not clear, was associted with the more severe lesions. Although the pathogenesis of PVL is unknown, it is suggested that these new varieties of PVL beyond the discrete periventricular foci of necrosis would be more apt to result in a diffuse loss of white matter and hence mental retardation if the child should survive.
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PMID:Morphologic variations in periventricular leukomalacia. 481 3

We reviewed the neuroimaging studies of 40 patients with classic Sotos syndrome. The studies consisted of CT scans only in 4 patients and one or more MRI scans in 36 patients. The diagnosis of Sotos syndrome was made using well-established clinical criteria. The neuroimaging studies of each patient were evaluated subjectively by visual inspection and the chief findings were tabulated and grouped into five categories: 1) ventricular abnormalities, 2) extracerebral fluid spaces, 3) midline abnormalities, 4) migrational abnormalities, and 5) others. The most common abnormality of the cerebral ventricles was prominence of the trigone (90%), followed by prominence of the occipital horns (75%) and ventriculomegaly (63%). The supratentorial extracerebral fluid spaces were increased for age in 70% of the patients and the fluid spaces in the posterior fossa were increased in 70% also. A variety of midline abnormalities were noted but anomalies of the corpus callosum were almost universal. Gray matter heterotopias occurred in only 3 (8%) of 36 patients. Periventricular leukomalacia, presumably the result of prenatal or perinatal difficulties and unrelated to the basic condition, was the most common of the miscellaneous other abnormalities noted. The neuroimaging findings of Sotos syndrome are distinct enough to allow differentiation of this syndrome from other mental retardation syndromes with macrocephaly.
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PMID:The neuroimaging findings in Sotos syndrome. 1070 67

Magnetic resonance (MR) findings at the cerebral white matter and the thalamus in 44 children with spastic cerebral palsy born at preterm were analysed. Periventricular leukomalacia (PVL) was found in all of the children. Lesions of the thalamus were revealed in 22 children, 19 of which were in the anterior part of the pulvinar and 3 of which were in other areas. Gestational ages and birthweights of the children with a lesion of the pulvinar were significantly greater than those without lesions of the thalamus. Mental retardation and paroxysmal ocular downward deviation were more frequently seen in the children with a lesion of the pulvinar than in those without lesions of the thalamus. The children with thalamic lesions in areas other than the pulvinar showed the most severe motor and mental disabilities.
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PMID:Thalamic lesions revealed by MR associated with periventricular leukomalacia and clinical profiles of subjects. 918 88

Serial EEG recordings beginning immediately after birth are not only of great diagnostic and prognostic value but also useful to elucidate the timing and the mode of brain injuries in the preterm newborn. It is extremely useful to distinguish between acute stage and chronic stage EEG abnormalities. The former is characterized by findings of acute depression such as increased discontinuity, decreased faster frequency activities, and lowered amplitudes. The latter mainly includes dysmature patterns and disorganized patterns. The timing of brain insult can be assessed by considering EEG findings in relation to the time of birth. Different modes of brain injury are associated with different types of EEG abnormalities and different types of neurological outcome. Sudden strong brain insults are usually associated with findings of severe depression followed by disorganized pattern and later cerebral palsy, while persistent mild insults are usually associated with prolonged mild depression followed by dysmature pattern and later mental retardation. Routine serial EEG studies in preterm infants demonstrated that one fourth of cerebral palsies in these infants were of antenatal origin, two thirds of perinatal origin and postnatal injuries played the least role. Periventricular leucomalacia (PVL) manifesting itself on the ultrasound in the late neonatal period and suggesting postnatal origin was often found to be of antenatal origin with an EEG soon after birth. PVL without apparent causes was often associated with abnormal fetal heart rate patterns and early neonatal EEG abnormalities, and considered to have originated in the antepartum period.
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PMID:Neonatal EEG: a powerful tool in the assessment of brain damage in preterm infants. 1048 68

The immature visual system in infants born preterm is vulnerable to adverse events during the perinatal period. Periventricular leukomalacia affecting the optic radiation has now become the principal cause of visual impairment and dysfunction in children born prematurely. Visual dysfunction is characterized by delayed visual maturation, subnormal visual acuity, crowding, visual field defects, and visual perceptual-cognitive problems. Magnetic resonance imaging is the method of choice for diagnosing this brain lesion, which is associated with optic disk abnormalities, strabismus, nystagmus, and deficient visually guided eye movements. Children with periventricular leukomalacia may present to the ophthalmologist within a clinical spectrum from severe cerebral visual impairment in combination with cerebral palsy and mental retardation to only early-onset esotropia, normal intellectual level, and no cerebral palsy. Optimal educational and habilitational strategies need to be developed to meet the needs of this group of visually impaired children.
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PMID:Periventricular leukomalacia: an important cause of visual and ocular motility dysfunction in children. 1094 78

Periventricular leukomalacia is the most common type of brain injury in premature infants. Our aim is to describe the frequency and the features of epilepsy in a single-center population of 137 children with periventricular leukomalacia. Forty-two of the 137 (31%) patients presented epilepsy. Twelve percent of these patients presented West syndrome, whereas 19% showed a pattern of continuous spike-waves during slow sleep syndrome. In the latter group, outcome was frequently unfavorable, with a greater number of seizures and more drug resistance. A significant association was found between epilepsy and neonatal seizures, spastic tetraplegia, and mental retardation. Although less common than in other forms of brain injury, epilepsy is nevertheless a significant complication in children with periventricular leukomalacia. The fairly frequent association with continuous spike-waves during slow sleep syndrome deserves particular attention: electroencephalographic sleep monitoring is important in order to provide early treatment and prevent further neurologic deterioration.
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PMID:Epileptic encephalopathy with continuous spike and wave during sleep associated to periventricular leukomalacia. 2429 9