Ependymal changes in sudden infant death syndrome

Neonatal respiratory inhibition

OBJECTIVE

To present information on neonatal respiratory inhibition (NRI) to the medical staff caring for infants.

METHODS

The author reviewed investigations of the above conditions. NRI is defined as severe hypoxemia accompanied by clinical manifestations of central cyanosis and a decrease in SpO₂ to less than 70%. Neonatal respiratory inhibition consists of respiratory inhibition after crying (RIAC), feeding hypoxemia, and respiratory inhibition after gastroesophageal reflux (RIGER). The infants were monitored continuously via pulse oximetry from birth until discharge. To identify the details of NRI, we analyzed detailed notes taken by both parents and medical staff during monitoring using specific software designed to interpret pulse oximetry measurements.

RESULTS

Among infants who weighed at least 2000 g and who were born at a gestational age of at least 36 weeks, NRI was observed in ∼50% of infants, including RIAC in ∼25%, feeding hypoxemia in 40%, and RIGER in 2 ∼ 4%, respectively. Among the infants with NRI, ∼40% experienced one or more episodes of prolonged cyanosis for at least 60 s. RIAC, feeding hypoxemia, and RIGER is significantly associated with each other. Among perinatal factors, NRI was related to maternal diabetes mellitus, twin pregnancy, asymmetric intrauterine growth restriction, threatened premature labor, cesarean section, shorter gestational periods, and abnormal ultrasound findings, including increased echogenicity in the ganglionic eminence (GE), a cyst in the GE, a subependymal cyst, and slight lateral ventricular enlargement. Almost all infants with RIAC and RIGER, even those with severe cases, recovered until discharge around day 5. Despite the provision of nursing guidance in feeding control, ∼60% of infants experienced feeding hypoxemia continuously. The more frequently the infants experienced feeding hypoxemia, the more severe the degree of feeding hypoxemia became. Breastfeeding reduced the frequency and degree of feeding hypoxemia compared to bottle feeding. Approximately 40% of infants with feeding hypoxemia required additional feeding control after being discharged.

CONCLUSIONS

NRI is very common and occurs in many infants worldwide. The infants with NRI experienced repeated severe hypoxemia due to RIAC, feeding hypoxemia, and RIGER after birth. Breastfeeding and careful feeding control should be recommended to mothers of infants with repeated feeding hypoxemia. Spreading knowledge about NRI worldwide is very important.

Respiratory inhibition after crying or gastroesophageal reflux and feeding hypoxemia in infants

OBJECTIVE

The objective of this study is to present information on respiratory inhibition after crying (RIAC), feeding hypoxemia, and respiratory inhibition after gastroesophageal reflux (RIGER) to medical staff caring for infants.

METHODS

The author reviewed investigations of these conditions.

RESULTS

These conditions have been observed in full-term healthy infants, and they are accompanied clinically by central cyanosis and a decrease in SpO2 to less than 70%. These conditions are easily diagnosed using pulse oximetry. Among Japanese infants with a gestational age of 36 weeks or older, the incidence of RIAC and feeding hypoxemia is 24% and 32%, respectively. The incidence of RIGER is approximately 4%. Feeding hypoxemia occurs significantly more often during bottle-feeding than during breastfeeding. RIAC, feeding hypoxemia, and RIGER are significantly associated with each other. The risk factors are maternal smoking during pregnancy, threatened premature labor, twin gestation, asymmetric intrauterine growth restriction, and abnormal cranial ultrasound findings. Almost all infants recover from RIAC by day 7 after birth. Some infants with feeding hypoxemia require additional assistance and monitoring by nursing staff until the day of discharge.

CONCLUSIONS

Medical staff caring for infants should note the presence of RIAC, feeding hypoxemia, and RIGER.

Analysis of ependymal abnormalities in subjects with schizophrenia, bipolar disorder, and depression

Abnormalities of the ependyma can serve as a marker of early brain insults. The presence of ependymal abnormalities was determined in sections containing ependyma of the temporal horn obtained from the Stanley Neuropathology Consortium: 15 subjects with schizophrenia, 15 with bipolar illness, 15 with major depression and 15 normal controls. There were no significant differences in numbers of subjects with ependymal discontinuities or subventricular rosettes. Subjects with schizophrenia had significantly less nodular gliosis than normal subjects (p=0.02); there was a trend for subjects with depression to have less nodular gliosis than normal subjects (p=0.06). Control subjects had unexpectedly high rates of ependymal abnormalities, indicating that ependymal abnormalities may not be a useful marker of pre- or perinatal events associated with schizophrenia and other psychiatric disorders in adult postmortem tissue.