Neonatal encephalopathy explained
Synonyms: | Hypoxic and ischemic brain injury in the newborn, perinatal asphyxia, neonatal hypoxic and ischemic brain injury |
Neonatal encephalopathy |
Neonatal encephalopathy (NE), previously known as neonatal hypoxic-ischemic encephalopathy (neonatal HIE or NHIE), is defined as a encephalopathy syndrome with signs and symptoms of abnormal neurological function, in the first few days of life in an infant born after 35 weeks of gestation. [1] [2] In this condition there is difficulty initiating and maintaining respirations, a subnormal level of consciousness, and associated depression of tone, reflexes, and possibly seizures.[3] Hypoxia refers to deficiency of oxygen, Ischemia refers to restriction in blood flow to the brain. The result is “encephalopathy” which refers to damaged brain cells. Encephalopathy is a nonspecific response of the brain to injury which may occur via multiple methods, but is commonly caused by birth asphyxia, leading to cerebral hypoxia. [2]
Signs and symptoms
In neonates born at or beyond 35 weeks, neonatal encephalopathy may present itself as the following symptoms:[4] [5]
- Reduced level of consciousness
- Seizures (which peak at 48 hours)
- Difficulty initiating and maintaining respiration
- Depression of tone and reflexes[6]
Diagnosis
Cord blood gas analysis can be used to determine if there is perinatal hypoxia/asphyxia, which are potential causes of hypoxic-ischemic encephalopathy or cerebral palsy, and give insight into causes of intrapartum fetal distress.[7] Cord blood gas analysis is indicated for high-risk pregnancies, in cases where C-sections occurred due to fetal compromise, if there were abnormal fetal heart rate patterns, Apgar scores of 3 or lower, intrapartum fever, or multifetal gestation.[8]
Evidence of brain injury related to the hypoxic-ischemic events that cause neonatal encephalopathy can be seen with brain MRIs, CTs, magnetic resonance spectroscopy imaging or ultrasounds.[9] [10] Neonatal encephalopathy may be assessed using Sarnat staging.[11] Brain MRI is usually performed within eight days of life.[12] Features that can be seen on MRI brain are: periventricular leukomalacia, basal ganglia and thalamus lesions, and multicystic encephalopathy.[13] Besides that, diffusion MRI would show low apparent diffusion coefficient (ADC) values in the first seven days of life. This is followed by pseudonormalisation of ADC values (normalisation of ADC values despite having persistent underlying brain injuries) which can persists up to two weeks.[14]
Treatment
See main article: Hypothermia therapy for neonatal encephalopathy. In the past, treatment options were limited to supportive medical therapy.[15] Currently, neonatal encephalopathy is treated using hypothermia therapy.[16] This has been shown to reduce brain damage, reduce future disability, and improve survival.[17] Hypothermia therapy is also sometimes termed hypothermic neural rescue therapy. Clinical trials are taking place to investigate the effectiveness of stem cell-based interventions, which are thought to have the potential to reduce mortality and improve the long-term development of newborn infants with neonatal encephalopathy.[18]
Prognosis
HIE is a major predictor of neurodevelopmental disability in term infants. 25 percent have permanent neurological deficits.[19]
Epidemiology
Overall, the relative incidence of neonatal encephalopathy is estimated to be between 2 and 9 per 1000 term births. 40% to 60% of affected infants die by 2 years old or have severe disabilities. In 2013 it was estimated to have resulted in 644,000 deaths down from 874,000 deaths in 1990.[20]
Notes and References
- Book: Neonatal Encephalopathy and Neurologic Outcome . 2017-04-17 . American Academy of Pediatrics . 978-1-934984-30-7 . Second . 1518 . 10.1542/9781610020862-part06-neonatal_encephalopathy . 243921388.
- Web site: Neonatal Encephalopathy. adhb.govt.nz. 7 March 2015.
- Book: Neurology. 2008. Saunders/Elsevier. Perlman JM, Polin RA . 9781416031574. Philadelphia. 489075193.
- Hortigüela . María Montesclaros . Martínez-Biarge . Miriam . Conejo . David . Vega-del-Val . Cristina . Arnaez . Juan . 2024-02-01 . Motor, cognitive and behavioural outcomes after neonatal hypoxic-ischaemic encephalopathy . Anales de Pediatría (English Edition) . 100 . 2 . 104–114 . 10.1016/j.anpede.2024.01.009 . 2341-2879. free .
- Park . Joonsik . Park . Sook Hyun . Kim . Chloe . Yoon . So Jin . Lim . Joo Hee . Han . Jung Ho . Shin . Jeong Eun . Eun . Ho Seon . Park . Min Soo . Lee . Soon Min . 2023-12-28 . Growth and developmental outcomes of infants with hypoxic ischemic encephalopathy . Scientific Reports . en . 13 . 1 . 23100 . 10.1038/s41598-023-50187-0 . 2045-2322. 10754824 .
- Web site: Clinical features, diagnosis, and treatment of neonatal encephalopathy. www.uptodate.com. 2016-03-24.
- Armstrong L, Stenson BJ . Use of umbilical cord blood gas analysis in the assessment of the newborn . Archives of Disease in Childhood. Fetal and Neonatal Edition . 92 . 6 . F430–F434 . November 2007 . 17951550 . 2675384 . 10.1136/adc.2006.099846 .
- Yilmaz . Aslan . Kaya . Nesrin . Gonen . Ilker . Uygur . Abdulkerim . Perk . Yildiz . Vural . Mehmet . 2023-09-08 . Evaluating of neonatal early onset sepsis through lactate and base excess monitoring . Scientific Reports . en . 13 . 1 . 14837 . 10.1038/s41598-023-41776-0 . 2045-2322. 10491792 .
- American Academy of Pediatrics. 2014-05-01. Neonatal Encephalopathy and Neurologic Outcome, Second EditionReport of the American College of Obstetricians and Gynecologists' Task Force on Neonatal Encephalopathy. Pediatrics. en. 133. 5. e1482–e1488. 10.1542/peds.2014-0724. 0031-4005. free.
- News: Identifying HIE: Diagnostic Tests and Medical Evaluations. HIE Help Center. 2017-11-16. en-US.
- Agut T, León M, Rebollo M, Muchart J, Arca G, Garcia-Alix A . Early identification of brain injury in infants with hypoxic ischemic encephalopathy at high risk for severe impairments: accuracy of MRI performed in the first days of life . BMC Pediatrics . 14 . 1 . 177 . July 2014 . 25005267 . 4113122 . 10.1186/1471-2431-14-177 . free .
- Li Y, Wisnowski JL, Chalak L, Mathur AM, McKinstry RC, Licona G, Mayock DE, Chang T, Van Meurs KP, Wu TW, Ahmad KA, Cornet MC, Rao R, Scheffler A, Wu YW . 6 . Mild hypoxic-ischemic encephalopathy (HIE): timing and pattern of MRI brain injury . Pediatric Research . March 2022 . 92 . 6 . 1731–1736 . 35354930 . 10.1038/s41390-022-02026-7 . 9771796 . 247781397 .
- Cabaj A, Bekiesińska-Figatowska M, Mądzik J . MRI patterns of hypoxic-ischemic brain injury in preterm and full term infants - classical and less common MR findings . Polish Journal of Radiology . 77 . 3 . 71–76 . July 2012 . 23049586 . 3447438 . 10.12659/PJR.883379 .
- Winter JD, Lee DS, Hung RM, Levin SD, Rogers JM, Thompson RT, Gelman N . Apparent diffusion coefficient pseudonormalization time in neonatal hypoxic-ischemic encephalopathy . Pediatric Neurology . 37 . 4 . 255–62 . October 2007 . 17903669 . 10.1016/j.pediatrneurol.2007.06.005 .
- Allen KA, Brandon DH . Hypoxic Ischemic Encephalopathy: Pathophysiology and Experimental Treatments . Newborn and Infant Nursing Reviews . 11 . 3 . 125–133 . September 2011 . 21927583 . 3171747 . 10.1053/j.nainr.2011.07.004 . Neuroprotective Strategies .
- Web site: Encephalopathy in neonates: Neonatal ehandbook . Department of Health and Human Services, Victoria, Australia . en. 2016-03-24.
- Jacobs SE, Berg M, Hunt R, Tarnow-Mordi WO, Inder TE, Davis PG . Cooling for newborns with hypoxic ischaemic encephalopathy . The Cochrane Database of Systematic Reviews . 1 . CD003311 . January 2013 . 2013 . 23440789 . 7003568 . 10.1002/14651858.CD003311.pub3 .
- Bruschettini M, Romantsik O, Moreira A, Ley D, Thébaud B . Stem cell-based interventions for the prevention of morbidity and mortality following hypoxic-ischaemic encephalopathy in newborn infants . The Cochrane Database of Systematic Reviews . 2020 . CD013202 . August 2020 . 8 . 32813884 . 7438027 . 10.1002/14651858.CD013202.pub2 .
- Graham EM, Ruis KA, Hartman AL, Northington FJ, Fox HE . A systematic review of the role of intrapartum hypoxia-ischemia in the causation of neonatal encephalopathy . American Journal of Obstetrics and Gynecology . 199 . 6 . 587–595 . December 2008 . 19084096 . 10.1016/j.ajog.2008.06.094 .
- Naghavi M, Wang H, Lozano R, Davis A, Liang X, Zhou M, etal . GBD 2013 Mortality and Causes of Death Collaborators . Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013 . Lancet . 385 . 9963 . 117–171 . January 2015 . 25530442 . 4340604 . 10.1016/S0140-6736(14)61682-2 .