Abstract: A flexible, conformable, sensor assembly is provided, including an electrode array especially adapted for stable, long-term recording of EEG signals from a pre-term or neonatal infant in intensive care. A kit or sterile pack includes guidance for placement of the electrodes over a designated area of the infant's brain, an area likely to be injured. The sensor assembly includes a left-side and a right-side flexible strip bearing at least electrodes and optional temperature, motion, and optical sensors provide for the monitoring of an extended range of parameters including aspects of cerebral perfusion and metabolism. Optional impedance measurements provide an indication of neuronal swelling. Stable performance over from three days to about a week is intended so that progress, effects of treatment, and outcome can be considered.