[Impact of transcranial magnetic stimulation on depressive symptoms relief in patients with chronic neuropathic pain and comorbid depression: A narrative literature review].

Abstract

Neuropathic pain results from an injury or a dysfunction of the somatosensory system. Management of this disease is complex due to a restricted therapeutic arsenal and limited efficacy of currently available treatments. Because of its chronic and disabling nature, neuropathic pain is strongly associated with depressive disorders. New neuromodulatory approaches such as repetitive transcranial magnetic stimulation (rTMS) represent an innovative therapeutic option with documented efficacy in the treatment of neuropathic pain and major depressive disorder respectively. Despite the frequent comorbidity between neuropathic pain and depressive disorder, there is no accurate data in the literature concerning the place of rTMS in the combined treatment of these two diseases. This narrative literature review was conducted to assess the impact of antalgic rTMS protocols on the improvement of depressive symptoms in patients with chronic neuropathic pain. An analysis of 20 trials showed that motor cortex rTMS protocols with optimised parameters (frequency of at least 10 Hz, at least 2000 pulses per session and at least 10 stimulation sessions) could improve depressive symptoms in patients with chronic neuropathic pain. Other cortical target protocols including dorsolateral prefrontal cortex, anterior cingulate cortex and secondary somatosensory cortex did not seem to be effective in relieving depressive symptoms in these patients. Available data indicates a strong heterogeneity and must be confirmed by large sample size randomized trials.