Foreign scholarship Medical University Innsbruck 2008

Aim of the project

Evaluation of the cerebral function monitoring (CFM/aEEG) as diagnostic instrument to determine maturation state and damage of the brain in preterm infants. The project is leaded in Innsbruck by Dr. Matthias Keller and is performed in cooperation with Dr. Lena Hellström-Westas (Uppsala, Sweden).

The scolarship of the Medical University Innsbruck offered Dr. Elke Griesmaier a stay abroad with an expert in the field of neonatal CFM, Dr. Lena Hellström-Westas in Sweden.

Background

Preterm infants are at high risk of brain damage and subsequent neurological sequelae. Depending on the birth weight 20% to 50% of these infants suffer from severe motor disabilities and cognitive deficits. Furthermore more than 20% of preterm infants show severe cognitive deficits in the age of 8 years and more than 50% need special support/promotion in school. 20% of children are in special schools and 15% must repeat a class in primary school.This means a severe burden to the child and the parents.

The use of a neuroprotective therapy in preterm born babies requires prediction of existence, severity and prognosis of brain injury at an early stage. In addition the method of diagnosis must be gentle and practiable to be used on neonatal intensive care units. These points state for now the greatest diagnostic challenge in neonatology.

One methode to evaluate severity of brain injury in term newborn babies ist the amplitude-integrated electroencephalogramm (aEEG). The aEEG is a method for continuous monitoring of brain function of the newborn infant on the intensive care unit. In term infants an acute hypoxic insult results with increased discontinuity and decrease of background activity in the aEEG, already in the first hours after birth. The recovery rate of this background activity in term infants in the aEEG is a sensitive prognostic marker. For this the aEEG is used already as inclusion criteria in various hypothermia studies, as it is at the University hospital Innsbruck.

In preterm infants hypoxic-ischemic brain injury is associated with development of germinal matrix resp. intraventricular bleedings, as with damage of white matter brain substance (PVL). The aEEG could also have a diagnostic importance in these diseases. Thus some clinical studies have shown, that an increase of background discontinuity in the aEEG during the first week of life is associated with severe intracerebral bleeding. Another study has shown, that recovery of background activity measured by the maximal number of bursts per hour predicts neurological outcome of preterms with severe intracranial bleeding during the first two days of life and thus could be of important for therapeutic strategies and survival of the baby.

Hypothesis and aim of the study

The aim of the study is to evaluate the aEEG for identification of infants, in special preterm babies with high risk of brain injury. This pilot study is the base for implementation of a clinical therapeutic study to reduce brain injury in newborn infants.

Literature

• Toet MC, Hellström-Westas L, Groenendaal F, Eken P, de Vries LS. Amplitude integrated EEG 3 and 6 hours after birth in full term neonates with hypoxic-ischaemic encephalopathy. Arch Dis Child 1999; 81: F19-F23
• Hellström-Westas L, Klette H, Thorngren-Jerneck K, Rosén I. Early prediction of outcome with aEEG in premature infants with large IVH. Neuropediatrics 2001; 32:319-24
  Gluckman PD, Wyatt JS, Azzopardi D, Ballard R, Edwards AD, Ferriero DM, Polin RA, Robertson CM, Thoresen M, Whitelaw A, Gunn AJ. Selective head cooling with mild systemic hypothermia after neonatal encephalopathy: multicentre randomised trial. Lancet 2005; 365: 663-70
• Inder T, Buckland L, Williams CE, Spencer C, Gunning MI, Darlow BA, Volpe JJ, Gluckman PD. Lowered encephalographic spectral edge frequency predicts the presence of cerebral white matter injury in premature infants. Pediatrics 2003; 111: 27-33
• Wikström S, Rosén I, Ley D, Pupp I, Hellström-Westas L. High interburst interval in early aEEG is associated with brain injury but not with postnatal cytokines in extremely preterm infants. PAS 2005; 57:3342