What is central neuropathic pain?
Central neuropathic pain is pain caused by a lesion of the CNS—typically the brain or spinal cord. Examples are pain following stroke, pain associated with disease of the CNS such as multiple sclerosis or Parkinson’s disease, plexus avulsion, or pain associated with spinal cord injury (SCI). The pain may develop concurrent with the initial injury or over time. While the injury that starts the process is in the CNS, peripheral input may modify the pain, either making it worse or better.
Deafferentation pain (including phantom pain, plexus avulsion, and SCI) is a type of central neuropathic pain. Research shows that “central sensitization” has a prominent role in deafferentation syndromes. Central sensitization is a complex process involving functional and structural changes in the CNS pathways involved in nociception. This is an area of continued research, but one mechanism involves the interaction of excitatory amino acids like glutamate with the N -methyl- d -aspartate receptor (NMDA), producing sensitization of the nociceptive neurons in the dorsal horn of the spinal cord. Central neuropathic pain may also involve changes in cortical pain processing that may be seen with positron emission tomography (PET) scans or functional MRI scanning.