Targeting pain with deep brain stimulation: Insights into the thalamus and associated structures

Chronic pain is a major public health issue, and despite advances in understanding its pathophysiology, current treatments remain insufficient, significantly affecting patients' quality of life. Existing therapies, including opioids, antidepressants and non-steroidal anti-inflammatory drugs, target specific mechanisms but fail to address the multifactorial nature of chronic pain, which is often accompanied by comorbidities like depression and anxiety. In cases like neuropathic pain, where pharmacological treatments are ineffective, alternatives such as deep brain stimulation (DBS) have gained attention. Although widely used for movement disorders, particularly in Parkinson's disease, DBS has the potential to treat pain by targeting identified deep brain structures while minimizing side effects. Neuropathic pain is linked to changes in several brain networks making up the so-called pain matrix, which includes the thalamus, the cornerstone of sensory, emotional and cognitive dimensions. This review focuses on the use of DBS of the thalamus and closely associated brain structures, such as the periaqueductal and periventricular gray, anterior cingulate cortex and insula, to treat pain.