Long-term outcome after neonatal hypoxic-ischaemic encephalopathy

Abstract

Outcome of full-term infants with neonatal encephalopathy of hypoxic-ischemic origin is often assessed in infancy or early childhood and data on outcome in childhood and adolescence is limited. MRI performed in the neonatal period has made a huge contribution to recognition of different patterns of injury. These different patterns of injury are related to the severity of later motor and cognitive disabilities.Long-term follow-up shows that cognitive and memory diffi culties may follow even in children without motor defi cits. It is therefore recommended to perform follow-up assessment into childhood in children with and without adverse neurological outcome in early infancy.Neonatal encephalopathy (NE) occurs in 1-6/1000 live full-term births and carries a high risk for subsequent neurodevelopmental disabilities. 1 Longterm outcome is known to depend on the severity of the neonatal condition. 2 3 The term NE is now more often used than perinatal asphyxia (PA). This is because PA is diffi cult to defi ne and in order to be reliable, needs access to several markers which are not always available, such as fetal heart rate tracings, umbilical cord gases and reliable Apgar scores. Individually, these markers have been shown to not correlate very well with subsequent outcome. 4 5 NE is 'a clinically defi ned syndrome of disturbed neurological function in the earliest days of life in the full-term infant, manifested by diffi culty with initiating and maintaining respiration, depression of tone and refl exes, subnormal level of consciousness and often seizures'. The widely used three-level grading system of mild, moderate and severe encephalopathy, based on clinical symptoms and EEG, was developed by Sarnat and Sarnat. 6 They based their encephalopathy score on an assessment in only 21 infants. The development of encephalopathy in full-term infants within hours to days after birth is now considered essential in order to be confi dent about an underlying perinatal insult, and NE is almost invariably associated with several of the markers mentioned above. 7 NE can develop for reasons other than hypoxic-ischaemia, for example, metabolic disorders, therefore a combination of markers suggestive of the presence of PA as well as the development of NE is obligatory.Most studies reported so far have focused on early neurodevelopmental outcome at 18-24 months, looking mainly at development of cerebral palsy (CP) or severe cognitive defi cits. 8 Outcome of infants with mild NE have been reported to be comparable to non-affected full-term infants, 2 9 while those with severe NE will either die or

Long-Term Neurodevelopmental Outcome with Hypoxic-Ischemic Encephalopathy

“…Our findings are in line with previous studies demonstrating that the outcome after HIE is not limited to CP and/or severe cognitive impairment, but can be associated with cognitive deficits (3, 4, 23) as well as with impaired motor skills in the absence of CP. (3,7,24) Robertson et al were the first to examine school-age neurodevelopmental outcome in children after HIE. They found that non-disabled survivors after moderate HIE showed marked delays in reading, spelling and arithmetic and were more likely to be at least one grade behind controls or those with mild HIE.…”

“…The basalganglia/thalamus pattern has been associated with severely impaired motor and cognitive outcomes (2, 7) and the watershed-predominant pattern with cognitive impairments that often occur in the absence of functional motor deficits. (2,3) More recently, a correlation of watershedpredominant pattern of injury with verbal IQ has been demonstrated for children at the age of four years. (13) Little is known on the association between neonatal MRI injury pattern and longterm neurodevelopmental outcome in children without major disability.…”

“…(1, 2) Long-term neurodevelopmental outcome depends on the severity of HIE,(2) with adverse outcomes being rare in children with mild HIE, more common in children with moderate HIE and invariably present in children with severe HIE. (3) Many outcome studies of children with HIE focus on major adverse outcomes such as death, cerebral palsy (CP) or severe cognitive impairment. However, deficits in the absence of CP or major disability may include intellectual impairments, specific memory and verbal problems, difficulties in executive functions, behavior, and social competence (4,5) and some studies have also reported motor problems in children with only mild HIE.…”

Lactate as an early predictor of psychomotor development in neonates with asphyxia receiving therapeutic hypothermia

“…Several factors are currently being investigated for making HIE prognosis: clinical examination, CNS imaging and amplitude EEG (aEEG) (ref. [6][7][8] ). 1.…”

The effect of whole-body cooling on brain metabolism following perinatal hypoxic–ischemic injury

“…Recent reviews have shown that the majority of variables used to predict outcome are limited in their accuracy (5,6). Increasingly, MRI is used to assess the severity in newborns suffering many types of injuries, including hypoxia-ischemia.…”