Brain alkaline intracellular pH after neonatal encephalopathy

Authors

  • Nicola J. Robertson MRCP,

    Corresponding author
    1. Department of Paediatrics, Division of Paediatrics, Obstetrics and Gynaecology Imperial College of Science, Technology and Medicine, Hammersmith Hospital Campus, London, United Kingdom
    2. Robert Steiner Magnetic Resonance Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College of Science, Technology and Medicine, Hammersmith Hospital Campus, London, United Kingdom
    • Department of Paediatrics, Division of Paediatrics, Obstetrics and Gynaecology, Faculty of Medicine, Imperial College School of Science, Technology and Medicine, Hammersmith Hospital Campus, DuCane Road, London W12 ONN, UK
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  • Frances M. Cowan PhD,

    1. Department of Paediatrics, Division of Paediatrics, Obstetrics and Gynaecology Imperial College of Science, Technology and Medicine, Hammersmith Hospital Campus, London, United Kingdom
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  • I. Jane Cox PhD,

    1. Robert Steiner Magnetic Resonance Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College of Science, Technology and Medicine, Hammersmith Hospital Campus, London, United Kingdom
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  • A. David Edwards FRCP

    1. Department of Paediatrics, Division of Paediatrics, Obstetrics and Gynaecology Imperial College of Science, Technology and Medicine, Hammersmith Hospital Campus, London, United Kingdom
    2. Robert Steiner Magnetic Resonance Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College of Science, Technology and Medicine, Hammersmith Hospital Campus, London, United Kingdom
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Abstract

Experimental studies demonstrate an alkaline shift in brain intracellular pH (pHi) after hypoxia-ischemia (HI). In infants with neonatal encephalopathy after HI, our aims were to assess (1) brain pHi during the first 2 weeks after birth in infants categorized according to magnetic resonance imaging (MRI) during the first 2 weeks after birth and at more than 3 months of age, and neurodevelopmental outcome at 1 year; (2) the relationship between brain pHi and lactate/creatine; and (3) duration of alkaline brain pHi. Seventy-eight term infants with neonatal encephalopathy were studied using MR techniques. One hundred and fifty-one studies were performed throughout the first year including 56 studies of 50 infants during the first 2 weeks after birth. pHi was calculated using phosphorus-31 MR spectroscopy and lactate/creatine was measured using proton MRS. The mean (standard deviation [SD]) brain pHi during the first 2 weeks after birth in infants with severely abnormal versus normal MRI was 7.24 (SD, 0.17) versus 7.04 (SD, 0.05; p < 0.001); in infants who subsequently developed cerebral atrophy versus those who did not: 7.23 (SD, 0.17) versus 7.06 (SD, 0.06; p < 0.05); in infants who died or had a severe neurodevelopmental impairment versus normal outcome: 7.28 (SD, 0.15) versus 7.11 (SD, 0.09; p < 0.05). Brain alkalosis was associated with increased brain lactate/creatine (p < 0.001). pHi remained more alkaline in the severe outcome group up to 20 weeks after birth (p < 0.05). Ann Neurol 2002;52:000–000

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