Brain magnetic resonance imaging of infants with bacterial meningitis.

OBJECTIVES: To describe the results of brain magnetic resonance imaging (MRI) of infants with bacterial meningitis and how the findings affected clinical management. STUDY DESIGN: This retrospective study included all infants <12 months of age who were hospitalized at Children's Medical Center, Dallas and had culture-confirmed bacterial meningitis and a brain MRI from January 1, 2001 to December 1, 2011. Infants were identified by review of all positive bacterial cultures of cerebrospinal fluid (CSF) from the Children's Medical Center Microbiology Laboratory. Demographic, clinical, laboratory, and neuroimaging data were reviewed. Infants with ventriculoperitoneal shunt or whose CSF culture yielded skin commensals were excluded. A neuroradiologist blinded to clinical information reviewed all MRI studies. RESULTS: Of the 440 infants who had a positive CSF culture result, 111 (25%) had a pathogen isolated from CSF and were enrolled in the study. Of these, 68% (75/111) had a brain MRI performed during the hospitalization; abnormalities included leptomeningeal enhancement (57%), cerebral infarct (43%), subdural empyema (52%), cerebritis (26%), hydrocephalus (20%), and abscess (11%). By multiple logistic regression analysis, infants with late seizures and an abnormal neurologic examination were more likely to have an abnormal MRI (P < .05). MRI results led to neurosurgical intervention in 23% of infants; a positive bacterial culture of CSF obtained >48 hours after initiation of antibiotic therapy was associated with neurosurgical intervention (P = .01). Fourteen (19%) infants with bacterial meningitis had a normal brain MRI. CONCLUSIONS: Brain MRIs were performed frequently and often were abnormal in infants with bacterial meningitis, leading to changes in clinical management.

Short-term outcomes of newborns with perinatal acidemia who are not eligible for systemic hypothermia therapy.

OBJECTIVE: To determine short-term outcomes of infants who had perinatal acidemia and were evaluated for hypothermia therapy but did not qualify based on a standardized neurologic examination. STUDY DESIGN: Retrospective, single-site cohort study of inborn infants of ≥ 36 weeks gestation who had perinatal acidemia from October 2005-September 2008 and had a standardized neurologic examination performed by a certified neonatologist to assess eligibility for hypothermia therapy. An abnormal short-term nursery outcome was defined as death, seizures, brain magnetic resonance imaging consistent with hypoxic-ischemic encephalopathy, abnormal neurologic examination at discharge, gastrostomy tube feeding, or inability to nipple all feeds beyond the first week of age. RESULTS: One hundred forty-four (0.3%) of 46 887 newborns with perinatal acidemia had a neurologic examination performed that was either normal (n = 29) or consistent with mild encephalopathy (1 or 2 abnormal categories; n = 60). Of the latter infants classified as having mild encephalopathy, 12 (20%) experienced an abnormal short-term outcome (feeding difficulties, n = 8; abnormal neurologic examination at discharge, n = 7; abnormal brain magnetic resonance imaging, n = 6; seizures, n = 5; gastrostomy, n = 1; or death, n = 1). CONCLUSIONS: Twenty percent of newborns with perinatal acidemia and a neurologic examination that revealed only mild encephalopathy had abnormal short-term outcomes that could be attributed to the encephalopathy. Adjunctive tools or biomarkers for optimal assessment of infants with fetal acidemia for hypothermia therapy are needed.

Perinatal acidosis and hypoxic-ischemic encephalopathy in preterm infants of 33 to 35 weeks' gestation.

OBJECTIVES: To determine the frequency of hypoxic-ischemic encephalopathy (HIE) in preterm infants of 33 to 35 weeks' gestational age on the basis of physiological screening for perinatal acidosis and neurological assessment of encephalopathy and to correlate neurodevelopmental outcomes with brain magnetic resonance imaging findings. STUDY DESIGN: This retrospective cohort study included all inborn infants of 33 to 35 weeks' gestation admitted to the neonatal intensive care unit at Parkland Memorial Hospital with perinatal acidosis from October 2005 to September 2008. Their medical records were reviewed, and pertinent data were recorded. RESULTS: Of 1305 newborns, 2.5% (n=33) had perinatal acidosis, and 27% (n=9) of these had HIE (2, mild; 4, moderate; 3, severe). Persistence of metabolic acidosis on the first arterial blood gas obtained in the first hour of age was significantly associated with HIE (P<.005). Magnetic resonance imaging results were abnormal in 3 of 4 infants with moderate HIE and in both survivors with severe HIE. Death or disability occurred in no infants with mild or moderate HIE, but in all infants with severe HIE. CONCLUSION: Screening criteria for HIE that use biochemical and neurological assessments as performed in term newborns can be applied to preterm infants of 33 to 35 weeks' gestation.