Deafferentation in Pain Medicine: A Narrative Review of Mechanisms and Management.

Deafferentation is an umbrella term that includes several clinical conditions. The exact mechanism is not yet known, and the different clinical conditions do not necessarily share common pathophysiology. It includes both non-painful and painful conditions, including cancer pain conditions. Clinical presentation can be immediate or delayed, sometimes years after the causative lesion. Patients experience neuropathic pain symptoms in an area of abnormal or absent sensation. Laboratory tests show denervation and loss of function. Pain management strategies can be directed toward alleviating symptoms rather than eradication. The site of origin of the pain can help decide the treatment modalities to be tried. Gabapentinoids, antidepressants, and sodium channel blockers can be used. This type of pain is typically opioid-nonresponsive, but some patients may benefit. Neuronal destructive procedures are indicated for brachial plexus avulsion injuries. Spinal cord stimulation, dorsal root entry zone rhizotomy, deep brain thalamic stimulation, and motor cortex stimulation have been suggested for the management of the complex clinical conditions under the umbrella of deafferentation.