Limited-channel bedside electroencephalography combining amplitude-integrated electroencephalography with 2-channel electroencephalography, interpreted by experienced neonatal readers, detected the majority of electrical seizures in at-risk newborn infants.

Bedside EEG measures in term-born encephalopathic infants are related to the severity of cerebral injury as defined by qualitative MRI. A minimum amplitude of <4 microV appears useful in predicting outcome.

Amplitude measurements by the B-aEEG appear more sensitive in detecting cerebral injury in comparison with the S-aEEG, particularly in the setting of unilateral injury.

Amplitude-integrated electroencephalography (aEEG) findings in hypoxic-ischemic encephalopathy characterized by secondary energy failure have been described in detail. In contrast, reports of use of aEEG in patients with encephalopathy due to primary energy failure as seen in inherited metabolic disorders are sparse. We report two cases of lethal mitochondrial encephalopathy due to mitochondrial respiratory chain complex I deficiency. We present clinical course, laboratory evaluations, aEEG, conventional electroencephalography, magnetic resonance imaging and magnetic resonance spectroscopy findings of two cases identified with mitochondrial encephalopathy between 2002 and 2007. Both infants were born at term. Both presented with intractable seizures and mild hypotonia within the first days of life, in the absence of any evidence suggestive of hypoxic-ischemic encephalopathy. Both cases were treated with multiple anticonvulsants and in neither case were seizures fully controlled. Magnetic resonance imaging in both cases revealed a structurally normal brain and case one showed subtle diffuse deep white matter signal abnormality. Magnetic resonance spectroscopy revealed no elevation of lactate. In both cases, aEEG tracings were markedly abnormal, confirmed by electroencephalography. Case one showed status epilepticus on an abnormally high amplitude background and case two presented with a mainly discontinuous background pattern with intermittent burst-suppression pattern activity. Complex I activity in skeletal muscle homogenate was abnormally low in both patients. The use of aEEG as a valuable assessment and monitoring tool in patients with metabolic encephalopathy should be further promoted.

Continuously monitoring brain ftinction at the bedside in the NICU for term infants at risk of brain injury has become part of routine clinical practice in many countries. These monitors offer invaluable information about the sick infant's neurologic status by providing real-time measurements of the brain's electrical activity and identifring or confirming seizure activity. With the increasing availability of bedside electroencephalogram technology, it is essential for neonatal intensive care nursing staff to understand the rationale for its use, as well as the fundamentals of application and interpretation of this new technology.