Centralizing the Knowledge and Interpretation of Pain in Chemotherapy-Induced Peripheral Neuropathy: A Paradigm Shift towards Brain-Centric Approaches.

Chemotherapy-induced peripheral neuropathy (CIPN) is a side effect of cancer treatment, often linked with pain complaints. Patients report mechanical and thermal hypersensitivity that may emerge during chemotherapy treatment and may persist after cancer remission. Whereas the latter situation disturbs the quality of life, life itself may be endangered by the appearance of CIPN during cancer treatment. The causes of CIPN have almost entirely been ascribed to the neurotoxicity of chemotherapeutic drugs in the peripheral nervous system. However, the central consequences of peripheral neuropathy are starting to be unraveled, namely in the supraspinal pain modulatory system. Based on our interests and experience in the field, we undertook a review of the brain-centered alterations that may underpin pain in CIPN. The changes in the descending pain modulation in CIPN models along with the functional and connectivity abnormalities in the brain of CIPN patients are analyzed. A translational analysis of preclinical findings about descending pain regulation during CIPN is reviewed considering the main neurochemical systems (serotoninergic and noradrenergic) targeted in CIPN management in patients, namely by antidepressants. In conclusion, this review highlights the importance of studying supraspinal areas involved in descending pain modulation to understand the pathophysiology of CIPN, which will probably allow a more personalized and effective CIPN treatment in the future.