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Fig. 5 | Journal of Translational Medicine

Fig. 5

From: Transitioning from acute to chronic pain: a simulation study of trajectories of low back pain

Fig. 5

The cortisol trajectory data for a manic-style pain. a A simulated cortisol level of manic-style pain over the 100-day period. This is simulated with a patient who can quickly recover from acute pain with identical parameters as in Fig. 3, when the stress is elevated (K-stress is increased from 10.1 to 30 µg days). The cortisol trajectory can transition from acute pain to a “manic” oscillatory pattern, based on simulated cortisol level data for the HPA model with the new parameter set. The cortisol level is presented here. The nearly periodic patterns have a period around 10, and alternate between high-amplitude oscillations and low-amplitude ones during the 100 days time period. b Pain trajectory calculated from data in a for 100 days of the HPA model simulation. The cortisol level values obtained from HPA model are classified into three different groups, and they present high pain state, low pain state and no pain (healed) state patterns. We take a daily average of cortisol level (24 hourly data points). Subjective thresholds (0.23990 and 0.29980 in this model) of cortisol level are used to separate the first 100 days into three groups: high-pain day (labeled in the high-pain group in the top) for the days when cort  0. 23990, or healed day when 0.23990 > cort  0.23980 (labeled in the healed or no-pain group in the middle), and low-pain for cort < 0.23980 (in the bottom) for trajectory studies. The simulated pain trajectory is representative for a manic-style pain LBP

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