Postnatal white matter necrosis in preterm infants.

One hundred twenty-seven infants less than 36 weeks of gestation (mean +/- SE = 31 +/- 3.2 weeks) were studied with echoencephalography to determine the incidence and complications associated with white matter necrosis. Ten infants (8%) developed cysts ten or more days after birth, indicating postnatal onset of white matter necrosis. Univariate analysis showed that postnatal white matter necrosis was significantly associated with maternal infection (other than urinary infection), respiratory distress syndrome, and longer requirement of an oxygen concentration greater than 40%. Forward logistic regression analysis showed postnatal white matter necrosis to be associated with maternal infection, chronic placental infarction, congenital pneumonia, and longer requirement of an oxygen concentration greater than 40%. Neurodevelopmental outcome was abnormal during infancy in 4 of the 6 survivors with postnatal white matter necrosis. Severe respiratory disease and maternal and/or fetal infection appear to increase the risk of the immature brain to white matter necrosis, predisposing the infants to subsequent neurodevelopmental delay.

Internal carotid artery blood flow velocities before, during, and after extracorporeal membrane oxygenation.

Blood flow velocities in the internal carotid arteries were studied with pulsed Doppler in 25 neonatal patients (birth weight range, 2600 to 4100 g) who had extracorporeal membrane oxygenation (ECMO). Time averaged mean systolic, mean diastolic, and mean blood flow velocities were calculated. Five infants had right common carotid artery reconstruction. Blood flow velocities measured in 15 healthy full-term infants were used as controls. Findings during ECMO included the following: (1) forward flow in the right internal carotid artery in 50% of the infants; (2) significant increase in the mean diastolic and the mean flow velocities (48% and 128%, respectively) in the left internal carotid artery when compared with pre-ECMO and control infants' values; (3) the elevation in the mean and the mean diastolic velocities was associated with changes in the PaCO2 and with an increase in the diastolic blood pressure; and (4) forward blood velocities in the right internal carotid artery were comparable with blood velocities in the left internal carotid artery and with the blood velocities of control infants. After ECMO, the mean diastolic velocity in the left internal carotid artery decreased significantly, but it remained elevated when compared with pre-ECMO values. Infants with right common carotid reconstruction had blood velocities in the right internal carotid artery comparable with the simultaneous blood velocities in the left internal carotid artery and to the blood velocities of control infants. Twenty-eight percent of the infants had major neuroanatomic lesions. Right or left preponderance was not noted. No association between blood velocity values in the internal carotid arteries or flow direction and the presence or the absence of brain lesions was noted.

Carotid artery reconstruction following neonatal extracorporeal membrane oxygenation.

Although reconstruction of the right common carotid artery (RCCA) in neonatal extracorporeal membrane oxygenation (ECMO) patients is intuitively attractive, there is little known about prolonged arterial cannulation and how it may affect subsequent vascular repair. A histological study of RCCA segments from neonatal ECMO patients was performed, so that cannulation technique and catheter design could be optimized before proceeding with arterial reconstruction. Circumferential transmural necrosis (CTN) was found in 25 of 31 (80%) arteriotomy specimens in comparison with 2 of 9 (20%) more proximal carotid specimens; the remaining specimens in each group demonstrated either focal subintimal or focal transmural necrosis. CTN was more common in patients with longer ECMO runs (96 +/- 5.9 versus 75 +/- 5.6 hours, P = .009; arteriotomy site), but was independent of cannula size, birthweight, and gestational age. Eleven patients have undergone RCCA reconstruction. Doppler flow studies at 4 to 7 months of follow-up in five patients demonstrated slightly higher right-sided versus left-sided peak systolic, end-diastolic, and mean flow velocities. No neurological or developmental problems could be attributed to vascular reconstruction. In conclusion, RCCA reconstruction is technically feasible, but due to the high prevalence of CTN at the arteriotomy site, excision of this segment is recommended at the time of arterial repair.

Neonatal schizencephaly: comparison of brain imaging.

Schizencephaly is a regional disturbance of cerebral hemisphere formation occurring at 3-5 months gestation; neonatal presentation is uncommon. Three neonates with schizencephaly were evaluated with cranial ultrasonography (US), unenhanced computed tomography (CT), and magnetic resonance imaging (MRI) examinations. Common findings in US, CT, and MRI include parasylvian and midline clefts, size asymmetries of the basal ganglia and thalamus, cerebral parenchymal volume loss, ventriculomegaly, ventricular diverticula, and absence of the septum pellucidum. MRI and CT were superior to US in detecting calcification, gyral and sulcal abnormalities, and parasylvian clefts. MRI alone demonstrated homolateral absence of the sylvian vasculature, small medullary pyramids, low position of the fornix, and the thinning of the corpus callosum. Although US appears adequate as a screening test, MRI best defines the precise pathoanatomic findings of neonatal schizencephaly and allows for the prediction of neurologic outcomes in affected newborns.

Ventriculoperitoneal shunts in low birth weight infants with intracranial hemorrhage: neurodevelopmental outcome.

Fifty preterm infants (mean birth weight, 1266 +/- 303 g; mean gestational age, 30 +/- 2 weeks) who required a ventriculoperitoneal (VP) shunt for posthemorrhagic hydrocephalus (92% with Grade III or IV hemorrhage) were followed for neurodevelopmental problems. VP shunts were placed at a median age of 29 days (range, 18 to 87 days) after serial lumbar punctures failed to control progressive and symptomatic ventriculomegaly. A total of 34 infants (68%) required one shunt revision or more, and the overall infection rate per patient was 50%. Seven infants died, 2 from shunt infections. The infants were evaluated with audiological, ophthalmological, and neurodevelopmental examinations. Of the survivors, 11 (28%) have severe visual loss and 10 (24%) have hearing impairment. Of the infants, 21 (49%) have severe motor handicaps and 19 (38%) have seizure disorders. Developmental and motor scores were obtained using the Bayley or Knobloch-Gesell scales. Seven infants (18%) have normal developmental outcomes; 26 (60%) have multiple handicaps. Grade IV hemorrhage or the occurrence of seizures was a predictor of poor neurodevelopmental outcome. We conclude that progressive posthemorrhagic hydrocephalus in low birth weight infants is associated with multiple handicaps despite early VP shunt placement.