Background: Despite state-of-the-art therapeutic strategies for pain, some types of chronic pain remain difficult to treat. We evaluated the effectiveness of an innovative neuromodulative approach to the treatment of chronic pain using electrical stimulus integrated with pharmacological support.
Methods: The MC5-A Calmare© is a new device for patient-specific cutaneous electrostimulation which, by "scrambling" pain information with "no pain" information, aims to reduce the perception of pain intensity. We prospectively treated 73 patients with cancer- (40) and non-cancer-related (33) pain whose pain management was unsatisfactory. The primary objective of the study was to assess efficacy and tolerability of the device. Pain intensity was assessed daily with a Numerical Rating Scale (NRS) for the duration of treatment (2 weeks) and then on a weekly basis for the 2 weeks of follow-up.
Results: Mean pain value at T0 (pre-treatment value) was 6.2 [± 2.5 SD (standard deviation)], 1.6 (± 2.0) (p < 0.0001) at T2 (after the 10th day of treatment), and 2.9 (± 2.6) (p < 0.0001) at T4 (after the second week of follow-up, i.e., 1 month after the beginning of treatment). Response after the second week of treatment showed a clear reduction in pain for both cancer (mean absolute delta of the reduction in NRS value = 4.0) and non-cancer (mean delta = 5.2) patients. The pain score had decreased by 74% at T2. On the basis of pre-established response criteria, there were 78% of responders at T2 and 81% at T4. No side effects were reported.
Conclusions: Our preliminary results suggest that cutaneous electrostimulation with the MC5-A Calmare© can be hypothesized as part of a multimodality approach to the treatment of chronic pain. Further studies on larger numbers of patients are needed to assess its efficacy, to quantify the effects of inter-operator variability, and to compare results obtained from the active device versus those from a sham machine.