Fig. 2: Inflammation is associated with increased spinal cord excitability and hyperalgesia during a noxious procedure in neonates.

a (Top) Average electromyography (EMG) traces during a clinically required heel lance for participants in the Neonatal Control Group (blue, n = 36) and Neonatal Inflammation Group (gold, n = 21, CRP > 10 mg/l or presented evidence of infection). (Bottom) Root mean square (RMS) of the reflex withdrawal in the limb ipsilateral to the stimulus site in the two groups. The difference between groups was assessed using a two-sample, one-sided t test, t = 1.74, *p = 0.048 (corrected using Holm’s method). b Relationship between the CRP level at the time of the study and the magnitude of the reflex withdrawal following a clinically required heel lance (n = 57, Pearson correlation r = 0.28, one-sided p = 0.028). c (Top) Group average Woody filtered electroencephalography (EEG) traces in response to the clinically required heel lance; Neonatal Control Group (n = 32) and Neonatal Inflammation Group (n = 19). The template of noxious-evoked brain activity³⁸ is shown overlaid in red. (Bottom) Magnitude of the noxious-evoked brain activity following heel lancing in the two groups. The difference between groups was assessed using a two-sample, one-sided t test, t = 2.4, *p = 0.022 (corrected using Holm’s method). d Relationship between the CRP level at the time of the study and the magnitude of the noxious-evoked brain activity following a clinically required heel lance (n = 51, Pearson correlation r = 0.31, one-sided p = 0.023). a, c dashed lines indicate the point of stimulation, and error bars indicate mean ± standard error, in b and d, solid line indicates the line of best fit. a.u: arbitrary units. Source data are provided as a Source Data file.