[Neuroimaging in epileptic encephalopathies in infants]. / Neuroimagen en las encefalopatias epilepticas del lactante.

Magnetic resonance plays a vital role in the aetiological diagnosis of epileptic encephalopathies, since it is capable of identifying specific aetiological patterns or patterns which are suggestive of different conditions. We review the main magnetic resonance findings that are observed in symptomatic epileptic encephalopathies.

TITLE: Neuroimagen en las encefalopatias epilepticas del lactante.La resonancia magnetica desempeña un papel crucial en el diagnostico etiologico de las encefalopatias epilepticas, al poder identificar patrones etiologicamente especificos o sugestivos de diferentes entidades. Se revisan los principales hallazgos por resonancia magnetica que se objetivan en las encefalopatias epilepticas sintomaticas.

Prenatal multicystic encephalomalacia due to anomaly of the aortic arch.

Multicystic encephalomalacia (ME) usually results from severe hypoxic-ischemic brain damage occurring during the late third trimester of gestation and birth. We report on a case of congenital ME due to a congenital anomaly of the aortic origin of brachiocephalic vessels resulting in subclavian steal syndrome. A 5-day-old term neonate presented with microcephaly and overlapping cranial sutures. Both arms were developed normally. Magnetic resonance imaging of the brain showed extensive bilateral supratentorial ME. Color duplex sonography of the aortic arch and the intracranial and extracranial vessels revealed a stenosis at the origin of the left common carotid artery and atresia of the origin of the left subclavian artery resulting in left-sided subclavian steal syndrome and retrograde perfusion of the basilar artery. Total cerebral blood flow volume was reduced to 22 mL/min. Severely reduced cerebral blood flow volume resulted from left carotid artery stenosis and atresia of the origin of the left subclavian artery with consecutive subclavian steal. Infratentorial brain structures and the left arm remained intact, but supratentorial brain structures were severely affected with ME.

Role of excessive maternal iron in the pathogenesis of congenital leukoencephalomalacia in captive black rhinoceroses (Diceros bicornis).

OBJECTIVE: To investigate the possibility that excessive maternal iron (overload) may contribute to development of congenital leukoencephalomalacia in captive black rhinoceroses. SAMPLE POPULATION: Tissue specimens and serum samples from 18 rhinoceroses in 2 kindreds harboring 4 (possibly 5) affected female calves. PROCEDURE: Fresh and archival sera and necropsy tissue specimens were evaluated to determine the nature and extent of iron overload in captive and wild black rhinoceroses as well as other rhinoceros species. RESULTS: Quantitative serum and tissue assays of iron and iron analytes, corroborated by histopathologic findings, indicated that these kindreds carried the greatest body burdens of iron yet found among captive black rhinoceroses. Fourteen of 18 rhinoceroses had the highest serum ferritin concentrations measured among 64 black rhinoceroses in captivity in the United States. Dams of affected calves had serum ferritin concentrations 2 orders of magnitude higher than clinically normal humans, equids, or free-ranging rhinoceroses. A neonatal serum sample from 1 affected female calf had a high ferritin concentration (approx 100-fold increase), but a male sibling of another affected female did not, suggesting a possible sex disparity in fetal response to maternal iron overload. Morphologic hallmarks of hemochromatosis were prominent in dams and grandams of affected calves. CONCLUSIONS AND CLINICAL RELEVANCE: Excessive maternal iron may affect female fetuses more than males, possibly inducing leukoencephalomalacia by catalyzing production of highly toxic hydroxyl free radicals during crucial periods of in utero development. Reduction of maternal iron overload may decrease the probability of developing leukoencephalomalacia and some other disorders commonly affecting rhinoceroses in captivity.

Computerized electroencephalographic assessment of congenital brain infarction.

We studied 12 children (8 female and 4 male) aged 2.2-14.3 years, whose computed tomographic (CT) examination had shown evidence of malacic and/or porencephalic outcomes of early vascular brain infarction. Topographic spectral electroencephalographic (EEG) analysis was performed in all patients in the awake state. The following spectral EEG variables were studied: topography, absolute and relative power of delta, theta, alpha, beta bands, overall power, and peak alpha frequency asymmetries. The results of topographic spectral EEG analysis were compared with the localization and nature of lesions as detected by CT scans. Depending on the nature of the lesions, we were able to identify two different spectral patterns. Porencephalic cysts were characterized by an increase in delta and theta bands in the areas surrounding the lesion sites, as identified by CT. Spectral EEG patterns of malacic outcomes resulted in a focal increase in theta and delta band power, corresponding to the topography of lesions. Moreover, in 9/12 subjects an asymmetry of alpha rhythm in occipital leads was found homolaterally to the lesion sites, associated with a decrease in power, without any CT evidence of an occipital lesion.

[Multicystic encephalomalacia in twin pregnancies]. / Encefalomalacia multiquística en gestaciones gemelares.

Multicystic encephalomalacia (ME) is a rare entity in the pediatric age. In ME brain tissue in substituted by cavities of variable size. ME has different etiologies being asphyxia and circulatory alterations the most important factors. In monozygotic twins there is an increased incidence of structural anomalies than dizygotic twins. We present four twin patients with ME. Three of them had a prenatal dead sibling. The fourth pair of twins had a twin-twin transfusion. We want to stress the utility of brain echography in early diagnosis of ME.

[Diagnoses to consider in newborn infants with inactive EEG tracings]. / Diagnostic à évoquer devant un tracé inactif du nouveau-né.

Thirty-one neonates without any electroencephalographic activity detectable on the first EEG before day 5 were studied. In the first group (20 neonates) the first EEG was performed on day 0. Signs of foetal and/or perinatal anoxia were observed. In the second group (11 neonates), the first EEG was performed between day 1 and day 4. In 7 cases, the neonate was considered normal during a period varying between a few hours and a few days. Various aetiologies other than foetal or perinatal anoxia were found: cardiac arrest, metabolic disease, polycystic encephalomalacia.

Multiple cystic and focal encephalomalacia in infancy and childhood with brain stem damage.

Two cases are described in which damage to the brain stem was associated with extensive necrosis of the cerebral hemisphere. In the first case--a monochorionic twin--there was clear evidence that injury of an ischaemic or hypoxic type had occurred during fetal life and some evidence that an inadequate share of the placental circulation was an important aetiological factor. In the second case death occurred 4 yr after an asphyxial episode at birth. The lesions in the hemispheres and brain stem were extensive, although less than in the first example. The lesions are discussed in the context of our knowledge of the anatomy and physiology of the developing nervous system. Although they cannot as yet be fitted into the concepts of "critical periods" and "vulnerable periods" of development, this is perhaps because observations on human cases are scanty in comparison with the extensive animal studies which have been reported. The lesions are contrasted and compared with those seen in animals.

Morphologic variations in periventricular leukomalacia.

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.