Daousi and colleagues (2005) assessed the efficacy and complication rate of SCS at least 7 years previously in 8 patients. After a trial period of percutaneous stimulation, 8 male patients had been implanted with a permanent system. Mean age at implantation was years and all patients were insulin-treated with stage 3 severe disabling CPDN of at least 1 year's duration. The stimulator was removed from 1 patient at 4 months because of system failure and 1 patient died 2 months after implantation from a myocardial infarction. Thus, a total of 6 patients were reviewed a mean of years post-implantation. With the stimulator off, McGill pain questionnaire (MPQ) scores (a measure of the quality and severity of pain) were similar to MPQ scores prior to insertion of the stimulator. Visual analog scale (VAS) were measured with the stimulator off and on, respectively: background pain [ (63 to 79) mm versus 25 (17 to 33) mm, median (inter-quartile range), p = ), peak pain (85 (80 to 92) mm versus 19 (11 to 47) mm, p = ]. There were 2 further cardiovascular deaths (these patients had continued pain relief) and the 4 surviving patients were re-assessed at (range of 7 to ) years: background pain [73 (65 to 77) mm versus 33 (28 to 36) mm, median (inter-quartile range)], peak pain [86 (81 to 94) mm versus 42 (31 to 53) mm]. Late complications (greater than 6 months post-insertion) occurred in 2 patients; electrode damage secondary to trauma requiring replacement (n = 1), and skin peeling under the transmitter site (n = 1). One patient had a second electrode implanted in the cervical region which relieved typical neuropathic hand pains. The authors concluded that SCS can continue to provide significant pain relief over a prolonged period of time with little associated morbidity.