Fig. 1.
Design and chronology of the study. AEs, adverse events; BS, blood sample; DM/Pl, dextromethorphan or placebo administration; HPT, heat pain thresholds; MPT, mechanical pain thresholds; Pup, pupillometry; RTI, reaction time Cambridge Neuropsychological Test Automated Battery test; t1h, 1 h after baseline; t2h, 2 h after baseline; t3h, 3 h after baseline; t5h, 5 h after baseline; t10h, 10 h after baseline; t14h30, 14.5 h after baseline; t22h30, 22.5 h after baseline; Z0, healthy skin; Z1, primary hyperalgesia; Z2, secondary hyperalgesia; Z2 area, secondary hyperalgesia surface measurement.