Brain injury in term infants with neonatal asphyxia and seizures was evaluated by MRI and MRS at the University of California, San Francisco. Seizure severity was scored by seizure frequency and duration, EEG, and anticonvulsant therapy. Impairment of cerebral metabolism and neuronal integrity in the intervascular boundary zone and basal nuclei were measured by lactate/choline and N-acetyl aspartate/choline. Clinical seizures occurred in 37% of 90 infants studied. At 6 days of age (range, 1-13 days), seizure severity was associated with increased lactate/choline in both brain locations tested, and a diminished N-acetylaspartate/choline in the intervascular boundary zone but not in basal ganglia. The severity of seizures was independently associated with chemical evidence of brain injury and was not limited to the structural brain damage detected by MRI. [1]

COMMENT. Seizure severity in term newborns with perinatal asphyxia can be associated with cerebral metabolic dysfunction and neuronal injury, independent of the structural damage detected by MRI. Previous studies using proton magnetic resonance spectroscopy have demonstrated that abnormalities of lactate and N-acetylaspartate in newborns with perinatal asphyxia are risk factors for abnormal neurodevelopmental outcome. [2]

Brain damage markers. The release of glial protein S-100B from astrocytes into the peripheral circulation, due to abnormal membrane integrity, is used as a measure of brain damage. In patients with head trauma, the higher the S-100B serum concentration, the more severe the outcome and neurologic impairment. Other proteins used as markers of brain damage include glial fibrillary acidic protein (GFAP) and neuron-specific enolase (NSE). In the past, most of the studies involved measurement of serum S-100 after pediatric cardiac operations. Leviton A and Dammann O [3] advocate the use of these protein markers in addition to serum inflammatory cytokines in the evaluation of newborns at risk for brain damage. Blood lactate as a measure of tissue anoxia in neonates has limitations. [4]