Key Inclusion Criteria:  Study candidate is undergoing a temporary SCS trial of commercially approved BSC neurostimulator system, per local directions for use (DFU). Subject signed a valid, EC/IRB-approved informed consent form. Age 18 or above, or above legal age and willing and capable of giving informed consent specific to national law when written informed consent is obtained. In the clinician best judgment, subject is able to distinguishably describe quality and location of sensation and pain.  Key Exclusion Criteria:  Subject meets any contraindication in BSC neurostimulation system local DFU. Investigator-suspected gross lead migration during the SCS trial period which may preclude the study candidate from receiving adequate SCS therapy. Subject is currently diagnosed with cognitive impairment, or exhibits any characteristic, that in the clinician's best judgement would limit study candidate's ability to assess and report sensation information. Subject is currently diagnosed with a physical impairment, or exhibits a condition that would limit study candidate's ability to complete study assessments.