Topography of cerebral white-matter disease of prematurity studied prospectively in 1607 very-low-birthweight infants.

The objective of this study was to evaluate to what extent (1) the characteristics of localization, distribution, and size of echodense and echolucent abnormalities enable individuals to be designated as having either periventricular hemorrhagic infarction or periventricular leukomalacia and (2) the characteristics of periventricular hemorrhagic infarction and periventricular leukomalacia are independent occurrences. The population for this study consisted of 1607 infants with birthweights of 500 to 1500 g, born between January 1991 and December 1993, who had at least one cranial ultrasound scan read independently by at least two ultrasonographers. The ultrasound data collection form diagrammed six standard coronal views. The cerebrum was divided into 17 zones in each hemisphere. All abnormalities were described as being echodense or echolucent and were classified on the basis of their size, laterality, location, and evolution. Eight percent (134/1607) of infants had at least one white-matter abnormality. The prevalence of white-matter disease decreased with increasing gestational age. Most abnormalities were small or medium sized and unilateral; only large echodensities tended to be bilateral and asymmetric. Large abnormalities, whether echodense or echolucent, were more likely than smaller abnormalities to be widespread, and the extent of cerebral involvement was independent of whether abnormalities were unilateral or bilateral. Large abnormalities were relatively more likely than small abnormalities to involve anterior planes. Small abnormalities, whether echodense or echolucent, or whether unilateral or bilateral, preferentially occurred near the trigone. Using the characteristics of location, size, and laterality/symmetry, we were able to allocate only 53% of infants with white-matter abnormalities to periventricular hemorrhagic infarction or periventricular leukomalacia. Assuming that periventricular leukomalacia and periventricular hemorrhagic infarction are independent and do not share risk factors, and that each occurs in approximately 5% of infants, we would have expected 0.25%, or about 4 individuals, to have abnormalities with characteristics of both periventricular leukomalacia and periventricular hemorrhagic infarction, whereas we found 63 such infants. Most infants with white-matter disease could not be clearly designated as having periventricular hemorrhagic infarction or periventricular leukomalacia only. Periventricular hemorrhagic infarction contributes to the risk of periventricular leukomalacia occurrence, or the two sorts of abnormalities share common risk antecedent factors. The descriptive term echodense or echolucent and the generic term white-matter disease of prematurity should be used instead of periventricular leukomalacia or periventricular hemorrhagic infarction when referring to sonographically defined white-matter abnormalities.

Maternal infection, fetal inflammatory response, and brain damage in very low birth weight infants. Developmental Epidemiology Network Investigators.

Echolucent images (EL) of cerebral white matter, seen on cranial ultrasonographic scans of very low birth weight newborns, predict motor and cognitive limitations. We tested the hypothesis that markers of maternal and feto-placental infection were associated with risks of both early (diagnosed at a median age of 7 d) and late (median age = 21 d) EL in a multi-center cohort of 1078 infants <1500 x g. Maternal infection was indicated by fever, leukocytosis, and receipt of antibiotic; fetoplacental inflammation was indicated by the presence of fetal vasculitis (i.e. of the placental chorionic plate or the umbilical cord). The effect of membrane inflammation was also assessed. All analyses were performed separately in infants born within 1 h of membrane rupture (n = 537), or after a longer interval (n = 541), to determine whether infection markers have different effects in infants who are unlikely to have experienced ascending amniotic sac infection as a consequence of membrane rupture. Placental membrane inflammation by itself was not associated with risk of EL at any time. The risks of both early and late EL were substantially increased in infants with fetal vasculitis, but the association with early EL was found only in infants born > or =1 after membrane rupture and who had membrane inflammation (adjusted OR not calculable), whereas the association of fetal vasculitis with late EL was seen only in infants born <1 h after membrane rupture (OR = 10.8; p = 0.05). Maternal receipt of antibiotic in the 24 h just before delivery was associated with late EL only if delivery occurred <1 h after membrane rupture (OR = 6.9; p = 0.01). Indicators of maternal infection and of a fetal inflammatory response are strongly and independently associated with EL, particularly late EL.

White matter disorders of prematurity: association with intraventricular hemorrhage and ventriculomegaly. The Developmental Epidemiology Network.

OBJECTIVES: Because intraventricular hemorrhage (IVH) often precedes the development of sonographically defined white matter damage (WMD) in very preterm infants, we sought to identify the IVH characteristics that predict WMD. HYPOTHESES: We evaluated variations on the null hypothesis that infants with IVH are no more likely than infants without IVH to have WMD. These variations dealt with characteristics of the IVH (presence or absence of ventriculomegaly) or characteristics of the WMD (size, localization, and laterality). METHODS: A total of 1605 infants weighing 500 to 1500 g at birth between January 1991 and December 1993 underwent standardized cranial ultrasound studies with 6 standard coronal and 5 sagittal views at postnatal days 1 to 3, 7 to 10, and at 3 to 8 weeks. RESULTS: A total of 129 (8%) infants had WMD, either an echodensity alone (n = 59), an echolucency alone (n = 18), or both (n = 52). In analyses that controlled for gestational age, IVH was associated with a fivefold to ninefold increased risk of WMD regardless of size, laterality, or extent of lesions (P

Spontaneous resolution of antenatally diagnosed adrenal masses.

Four infants had adrenal masses detected prenatally, through ultrasonography, between 18 and 30 weeks' gestation. Two were predominantly cystic, and two were solid. The sizes ranged from 0.8 to 1.5 cm. There were no associated prenatal maternal complications or stress factors. The urine vanillylmandelic acid levels at birth were normal in three infants. Two infants had a documented decrease in mass size at birth (compared with the last intrauterine study). All masses had a progressive decrease in size after birth, and ultrasound results were normal at 6 to 12 weeks of age. All four patients are well, with normal study results, at 2 to 5 years of age.

Ultrasonic detection of osteomyelitis. Pathologic correlation in an animal model.

The authors correlated sonographic findings with histologic findings in a rabbit model of osteomyelitis. Staphylococcus aureus osteomyelitis was induced in the femora of 11 New Zealand white rabbits. The opposite leg was used as a control. Sonographic findings showed fluid adjacent to the bone in 11 cases. The fluid was believed to be an inflammatory exudate, and its presence suggested osteomyelitis. Pathologic analysis showed extraperiosteal purulent fluid adjacent to the cortex as well as histopathologic changes of osteomyelitis in the 11 rabbits. There was one false-positive sonographic diagnosis of osteomyelitis in a rabbit that had a soft tissue abscess adjacent to the cortex.

Osteomyelitis: detection with US.

To evaluate the role of ultrasound (US) in the detection of osteomyelitis, the authors prospectively studied 48 patients clinically suspected of having osteomyelitis. A sonographic diagnosis was made if fluid was seen directly in contact with bone, without intervening soft tissues. Twelve of the 48 patients were subsequently found to have osteomyelitis. In 10 of them, US demonstrated abnormal fluid adjacent to the bone. This fluid was thought to represent an inflammatory exudate dissecting in a subperiosteal and/or extraperiosteal location. Eight of the 48 patients had soft-tissue fluid collections. The rest of the patients either had no abnormalities or had cellulitis. The authors conclude that US can be useful in the detection of osteomyelitis.

Sequential development of multiple aortic aneurysms in a neonate post umbilical arterial catheter insertion.

A neonate in whom multiple aortic aneurysms developed as a result of umbilical arterial catheterization is presented. Initially a single aneurysm was diagnosed by ultrasound. Serial sonographic examinations showed enlargement of the first as well as formation and subsequent enlargement of additional aneurysms.

Osteomyelitis: detection with US. Work in progress.

Ten patients with clinically suspected osteomyelitis were studied with ultrasound (US). Five patients had abnormalities detectable on sonograms. An abnormal fluid collection was demonstrated adjacent to the bone in three of these five. US-guided aspiration of the fluid in two of the three patients revealed purulent or infected fluid that was thought to represent an inflammatory exudate dissecting in a subperiosteal or extraperiosteal location. Findings from subsequent radiographic and scintigraphic studies confirmed the diagnosis of osteomyelitis in these three patients. The other two patients with abnormal sonographic results had collections of fluid that were separated from the bone by a variable amount of soft tissue. These collections were confined to the soft tissue and did not appear to arise from the bone. Aspiration revealed a soft-tissue abscess in one patient and a seroma in the second. Findings in this preliminary study suggest that fluid around the bone seen on sonograms may indicate acute osteomyelitis.

An unusual anatomic location of pancreatic masses.

By use of accepted criteria, all masses anterior to the splenic vein are thought to arise from the pancreas, whereas all masses posterior to the vein are attributed to other retroperitoneal organs. Three patients with pancreatic masses are presented. Since the mass was posterior to the splenic vein in these cases, a pancreatic origin did not originally suggest itself.

Ultrasound in the diagnosis of systemic candidiasis (renal and cranial) in very low birth weight premature infants.

Premature infants, (in whom prolonged hyperalimentation long term indwelling catheters are used), serve as the ideal hosts for overwhelming Candida sepsis. Two cases of disseminated Candidiasis were studied. Case 1 had sonographically enlarged and highly echogenic kidneys. Case 2 had diffusely enlarged echogenic kidneys with actual fungus balls in the collecting system. This infant also developed hydrocephalus with debris in the ventricular system and abnormal brain parenchymal echogenicity.

The role of ultrasonography in the detection of extrapulmonary tuberculosis in patients with acquired immunodeficiency syndrome (AIDS).

Three cases of extrapulmonary tuberculosis are presented. Retroperitoneal and periportal adenopathy were the major manifestation of the disease detected by ultrasonography in all three cases. All of the patients were subsequently diagnosed as having acquired immunodeficiency syndrome (AIDS). The lymphohematogenous dissemination of the disease and the diagnostic role of ultrasonography are discussed.

Reversal of guanethidine blockade of sympathetic nerve terminals by tetraethylammonium and 4-aminopyridine.

1 The effect of tetraethylammonium (TEA) and 4-aminopyridine (4-AP) on the inhibitory effect of guanethidine on noradrenaline (NA) release was investigated in the perfused spleen of the cat. 2 Guanethidine blocked the release of NA evoked by nerve stimulation. TEA and 4-AP readily reversed this inhibitory effect, and the NA output was nearly doubled after repeated stimulation of the nerves. On subsequent perfusion with Krebs solution without TEA or 4-AP, the inhibitory effect of guanethidine reappeared. 3 The reversal of guanethidine blockade of sympathetic nerves by TEA and 4-AP is discussed.

Effect of 4-aminopyridine on release of noradrenaline from the perfused cat spleen by nerve stimulation.

1. 4-aminopyridine (4-AP, 1 mM) increased noradrenaline (NA) output from the perfused cat spleen at 5 Hz by about fivefold. Enhancement of NA release by 4-AP was reversible. Output of NA induced by potassium was not affected. 2. NA output was doubled at low concentrations (0.1--0.3 mM) of 4-AP, but maximal effect was obtained at 1--3 mM. At 10 mM, it induced spontaneous release of NA which was insensitive to calcium. 3. Insignificant outputs obtained at 5 Hz in 0.1 and 0.3 mM calcium-Krebs solution were markedly enhanced by 4-AP. 4-AP enhanced release at all calcium concentrations up to 5 mM, but maximum output was obtained at 2.5 mM. 4. 4-AP at pH 8.5 was more effective in enhancing NA release than at pH 7.4. 5. 4-AP increased the recovery of intra-arterially infused NA from the control 26 to 47%. 6. 4-AP did not affect release of catecholamines (CA) from the perfused cat adrenal gland by acetylcholine (ACh). 7. It is suggested that 4-AP inactivates potassium current in sympathetic nerves and prolongs the duration of the action potential, thereby allowing a greater influx of calcium ions into the neurone to enhance release of NA.