Abnormal heart rate characteristics are associated with abnormal neuroimaging and outcomes in extremely low birth weight infants.

OBJECTIVE: Brain injury in preterm infants may lead to an inflammatory response and central nervous system dysfunction reflected by abnormal heart rate characteristics (HRC). We hypothesized that a continuously monitored HRC index reflecting reduced HR variability and decelerations correlates with abnormal neuroimaging and outcomes in extremely low birth weight infants (ELBW). STUDY DESIGN: We analyzed the average HRC index within 28 days after birth (aHRC28) and head ultrasound (HUS) in 384 ELBW infants. In 50 infants with brain magnetic resonance imaging (MRI) and 70 infants with Bayley neurodevelopmental testing at 1 year of age, we analyzed the relationship between aHRC28, MRI abnormalities and low Bayley scores. RESULT: aHRC28 was higher in infants with severe HUS abnormalities (2.65±1.27 for Grade III-IV intraventricular hemorrhage (IVH) or cystic periventricular leukomalacia (cPVL) versus 1.72±0.95 for normal or Grade I-II IVH, P<0.001). Higher aHRC28 was also associated with white matter damage on MRI and death or Bayley motor or mental developmental index <70. Associations persisted after adjusting for gestational age, birth weight and septicemia. For every one point increase in aHRC28, the odds ratio of death or Bayley score <70 was 2.45 (95% CI 1.46, 4.05, P<0.001). CONCLUSION: A continuously monitored HRC index provides an objective, noninvasive measure associated with abnormal brain imaging and adverse neurologic outcomes in ELBW infants.

Reversible diffusion restriction of the middle cerebellar peduncles and dentate nucleus in acute respiratory syncytial virus cerebellitis: a case report.

Acute cerebellitis is a postinfectious or postvaccinal disorder that predominantly affects children. The typical magnetic resonance imaging appearance has been previously described as cerebellar hemispheric cortical edema. Here, we report a rare case of respiratory syncytial virus-related cerebellitis with transient diffusion restriction of cerebellar peduncles and dentate nucleus. Differential diagnoses are also discussed.

Dorsal thoracic arachnoid web and the "scalpel sign": a distinct clinical-radiologic entity.

Arachnoid webs are intradural extramedullary bands of arachnoid tissue that can extend to the pial surface of the spinal cord, causing a focal dorsal indentation of the cord. These webs tend to occur in the upper thoracic spine and may produce a characteristic deformity of the cord that we term the "scalpel sign." We describe 14 patients whose imaging studies demonstrated the scalpel sign. Ten of 13 patients who underwent MR imaging demonstrated T2WI cord signal-intensity changes, and 7 of these patients also demonstrated syringomyelia adjacent to the level of indentation. Seven patients underwent surgery, with 5 demonstrating an arachnoid web as the cause of the dorsal indentation demonstrated on preoperative imaging. Although the webs themselves are rarely demonstrated on imaging, we propose that the scalpel sign is a reliable indicator of their presence and should prompt consideration of surgical lysis, which is potentially curative.

Implementation of a 'Hypothermia for HIE' program: 2-year experience in a single NICU.

Hypothermia has been shown to be neuroprotective in some newborns with moderate-to-severe perinatal hypoxic-ischemic encephalopathy (HIE). In 2006, the American Academy of Pediatrics recommended that institutions that choose to use therapeutic hypothermia do so in the context of a rigorous protocol, with systematic collection of patient data including neurodevelopmental follow-up. In this report, we describe our experience with implementation of a 'Hypothermia for HIE' program in a single tertiary care Neonatal Intensive Care Unit (NICU). Important components of the program include detailed protocols, staff and outreach education, early initiation of cooling in both inborn and outborn patients, maintaining stable hypothermia during neonatal transport, and comprehensive neurologic evaluation including serial EEGs, brain MRI and neurodevelopmental follow-up. In the first 2 years of the program, we have used hypothermia therapy in 21 patients, 18 with perinatal and 3 with early postnatal events leading to HIE. Eleven of fifteen outborn patients were cooled prior to and during transport, resulting in initiation of therapy 3 h sooner than if therapy had been delayed until arrival at our center. While lowering the body temperature of encephalopathic newborns is not difficult, addressing the complex medical problems of this vulnerable group of patients requires an experienced multidisciplinary team in regional referral centers.

Posterior fossa hemorrhage after supratentorial surgery.

PURPOSE: To evaluate the imaging findings, possible pathogenesis, and frequency of hemorrhage near the tentorial surface of the cerebellum after supratentorial surgery. METHODS: Over a 5-year period, 13 patients with posterior fossa hemorrhage after supratentorial surgery were identified with postoperative CT studies, which were obtained in all patients after craniotomy. Four of the 13 patients also had postoperative MR examinations. Preoperative and postoperative radiologic studies and medical records were reviewed. RESULTS: All hemorrhages were located along the superior aspect of the cerebellum transversely oriented along the cerebellar fossa and fissures. None of the patients had coagulopathy or radiologic evidence of posterior fossa tumor or vascular malformation. None of the hemorrhages had an appearance typical of hypertensive hemorrhage. Ten patients (77%) had lumbar drains placed before surgery and all had epidural drains placed at the conclusion of surgery. One patient had surgery for a meningioma, and 12 had surgery for aneurysms. The frequency of hemorrhage after aneurysmal surgery was 3.5%. No neurologic deficits developed referable to the cerebellum. CONCLUSIONS: Hemorrhage should be viewed as a potentially benign sequela of surgery rather than as an indication of hypertension, aneurysm, or previously unrecognized vascular malformation or neoplasm.

Hen's eggs with retarded gas exchange. I. Chorioallantoic capillary growth.

The diffusing capacity of the hen's egg for carbon monoxide (D tau co) increases during incubation, reflecting the development of the chorioallantoic circulation. Previous work showed that the increase in D tau co could be diminished by incubating eggs in a 60% oxygen environment. The present work explored the effects of impeding gas exchange on the development of D tau co. Half the shell area was covered during incubation by a removable neoprene membrane which limited D tau co by approximately 20%. No difference could be detected between the D tau co values (measured with the membrane removed) of these eggs and control eggs incubated in the same 21% oxygen environment without a neoprene membrane. We conclude that the development of the chorioallantoic circulation is at its maximum under normal conditions of incubation and cannot be accelerated by restricting gas exchange.

Oxygen consumption at rest and during exercise in pregnancy.

The oxygen consumption (Vo2) of 12 normal women was measured at monthly intervals during pregnancy and 2, 6 and 12 weeks and 6 months postpartum. At each study session measurements were made sitting at rest, during standard steady-state exercise on a bicycle ergometer, and for 10 minutes of recovery. A significant increase in exercise Vo2 was observed in late pregnancy when compared to paired postpartum values. The oxygen debt incurred by standard exercise was also greater in late pregnancy than 12-14 weeks postpartum.