Neuroepidemiology of Porencephaly, Schizencephaly, and Hydranencephaly in Miyagi Prefecture, Japan.

BACKGROUND: No population-based surveys of porencephaly, schizencephaly, and hydranencephaly have been conducted in Japan or other Asian countries. We performed a neuroepidemiologic analysis to elucidate the incidence of porencephaly, schizencephaly, and hydranencephaly in Miyagi prefecture, Japan, during 2007-2011. METHODS: We sent inquiry forms in February 2012 to three neonatal intensive care units, 25 divisions of orthopedic surgery in municipal hospitals, 33 divisions of pediatrics including one university hospital, municipal hospitals, pediatric practitioners, and institutions for physically handicapped children located in Miyagi prefecture. These covered all clinics related to pediatric neurology and orthopedic surgery in Miyagi prefecture. In the inquiry, diagnostic criteria for porencephaly, schizencephaly, and hydranencephaly were described and representative images of magnetic resonance imaging were shown. We obtained an 82% (27 of 33) response rate from the divisions of pediatrics, a 100% (3 of 3) response rate from the neonatal intensive care units, and a 68% (17 of 25) response rate from orthopedic surgery clinics. The magnetic resonance imaging scans of each patient were retrieved and inspected. RESULTS: Five, one, and two individuals developed porencephaly, schizencephaly, and hydranencephaly, respectively. The estimated incidence rates of porencephaly, schizencephaly, and hydranencephaly were 5.2 (95% confidence interval [CI], 0.6-9.8), 1.0 (95% CI, 0.0-3.1), and 2.1 (95% CI, 0.0-5.0) per 100,000 live births, respectively. CONCLUSIONS: The prevalence rates of porencephaly, schizencephaly, and hydranencephaly at birth reported herein are compatible with results reported previously in the United States and European countries. The overall prevalence rate of these three diseases was 8.3 (95% CI, 2.6-14.1) per 100,000 live births.

Dynamic characteristics of the middle ear in neonates.

OBJECTIVE: Early diagnosis and treatment of hearing disorders in neonates is highly effective for realization of linguistic competence and intellectual development. To objectively and quickly evaluate the dynamic characteristics of the middle ear, a sweep frequency impedance (SFI) meter was developed, which allowed the diagnosis of middle-ear dysfunctions in adults and children. However, this SFI meter was not applicable to neonates since the size of the measurement probe was too large. In the present study, therefore, the SFI meter was improved, i.e., the diameter of the probe was reduced to that of the neonatal external ear canal. By using this newly designed SFI meter, SFI tests were performed in healthy neonates. METHODS: A sound of the sweeping sinusoidal frequency between 0.1 kHz and 2.0 kHz in 0.02-kHz step intervals is presented to the ear canal by an SFI probe while the static pressure of the ear canal is kept constant. During this procedure, the sound pressure level (SPL) is measured. The measurements are performed at 50-daPa intervals of static pressure from 200 daPa to -200 daPa. RESULTS: Measurements were conducted in 10 ears of 9 neonates. The SPL showed two variations at 0.26 ± 0.03 kHz and 1.13 ± 0.12 kHz. Since the SPL is known to show a variation at frequencies from 1.0 kHz to 1.6 kHz due to the resonance of the middle ear in adults and children with normal hearing, the second variation is probably related to such resonance in neonates. The measurement of gel models, which mimics the neonatal external ear canal, showed a variation in SPL at around 0.5 kHz. This implies that the source of the first variation may possibly be related to the resonance of the external ear canal wall. CONCLUSIONS: SFI tests revealed that there were two variations in the SPL curve in neonates, one at 0.26 ± 0.03 kHz and the other at 1.13 ± 0.12 kHz, the former and the latter being possibly related to the resonance of the external ear canal wall and that of the middle ear, respectively. This result suggests that the dynamic characteristics of the middle ear in neonates are different from those in adults.

Severe postnatal cytomegalovirus infection in a very premature infant.

Several studies have reported that postnatally acquired cytomegalovirus (CMV) infection can cause sepsis-like syndrome in premature infants. We here report a 622-gram birth weight male infant of 23 weeks' gestation who had sepsis-like syndrome and pneumonia. Substantial CMV loads were detected in peripheral blood cells, plasma, and urine when the patient was in crisis, but was decreased in parallel to clinical improvement without using ganciclovir. CMV DNA was not detected from his umbilical cord or Guthrie card, even by highly sensitive real-time PCR. Molecular profiles were indistinguishable between the CMV strain isolated from his urine and that from maternal breast milk, indicating postnatal acquisition of CMV through breast milk. Although he had transient hearing impairment, his neurodevelopmental outcome of 30 months of corrected age was normal. Further accumulation of clinical and virological data in postnatal CMV infection is necessary for evaluating the severity and selecting patients requiring antiviral therapy.

Risk factors for cerebral palsy in preterm infants.

OBJECTIVE: To identify crucial factors that precipitate cerebral palsy by controlling confounding factors in logistic regression analyses. DESIGN AND PATIENTS: We retrospectively investigated a cohort of all 922 infants with gestational ages of less than 34 weeks (22-33 weeks), who were admitted to our neonatal intensive care unit between 1990 and 1998. Thirty (3.7%) were diagnosed to have cerebral palsy. We analyzed the prenatal and postnatal clinical variables of the cerebral palsy cases and compared them with 150 randomly selected controls. RESULTS: Risk factors for cerebral palsy identified in univariate analysis were: twin pregnancy, long-term ritodrine tocolysis, respiratory distress syndrome, air leak, surfactant administration, intermittent mandatory ventilation, high frequency oscillation, lowest PaCO2 levels, prolonged hypocarbia during the first 72 h of life, and postnatal steroid therapy. In a conditional multiple logistic model, long-term ritodrine tocolysis, prolonged hypocarbia and postnatal steroid therapy remained associated with an increased risk of cerebral palsy after adjustment for other antenatal and postnatal variables (OR [Odds Ratio] = 8.62, 95% CI [Confidence Interval], 2.18-33.97; OR = 7.81, 95% CI, 1.42-42.92; OR = 21.37, 95% CI, 2.01-227.29, respectively). CONCLUSIONS: Our results suggest that long-term ritodrine tocolysis underlines the development of cerebral palsy. Further assessments of the effect of ritodrine on fetal circulation and nervous system are required. Moreover, possible alternatives to systemic postnatal steroids are needed, and carbon dioxide levels should be more strictly controlled.

Pulmonary hypoplasia with an unusual prenatal history.

We describe a monochorionic, diamniotic twin with renal agenesis who received amniotic fluid from his normal co-twin by spontaneous rupture of the amniotic septum between them. By 16 weeks of gestation the presence of severe oligohydramnios in one twin had resulted in renal agenesis, but not in the other twin, who did not have oligohydramnios. By 20 weeks of gestation, the two amniotic fluid volumes had become the same in both twins. At 33 weeks, the twins were delivered by cesarean section. Despite intensive respiratory care, the twin with renal agenesis died from severe pneumomediastinum on day 3. At autopsy, pulmonary hypoplasia was demonstrated in that twin. This experiment of nature demonstrates that oligohydramnios during the early canalicular stage of pulmonary development (gestational age, 16-20 weeks) may be pathogenically important in pulmonary hypoplasia.