Fig. 1From: Benefits in pain perception, ability function and health-related quality of life in patients with failed back surgery syndrome undergoing spinal cord stimulation in a clinical practice settingSchematic definition and duration of the observational period. Schematic representation of the observational period. All the patients were enrolled at T− 1, completed the questionnaires about the previous 12 months, and underwent a simulation test period (STP), named preSCS period. At T0, those who responded positively to the STP were implanted with implantable pulse generator (postSCS period) and completed again the questionnaires at that time and at T6, T12, T18 and T24Back to article page