The Brain in Chronic CRPS Pain: Abnormal Gray-White Matter Interactions in Emotional and Autonomic Regions.Geha PY, Baliki MN, Harden RN, Bauer WR, Parrish TB, Apkarian AV. Neuron. 2008 Nov 26;60(4):570-81.

Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA.

Chronic complex regional pain syndrome (CRPS) is a debilitating pain condition accompanied by autonomic abnormalities. We investigated gray matter morphometry and white matter anisotropy in CRPS patients and matched controls. Patients exhibited a disrupted relationship between white matter anisotropy and whole-brain gray matter volume; gray matter atrophy in a single cluster encompassing right insula, right ventromedial prefrontal cortex (VMPFC), and right nucleus accumbens; and a decrease in fractional anisotropy in the left cingulum-callosal bundle. Reorganization of white matter connectivity in these regions was characterized by branching pattern alterations, as well as increased (VMPFC to insula) and decreased (VMPFC to basal ganglion) connectivity. While regional atrophy differentially related to pain intensity and duration, the strength of connectivity between specific atrophied regions related to anxiety. These abnormalities encompass emotional, autonomic, and pain perception regions, implying that they likely play a critical role in the global clinical picture of CRPS.

"This is the first evidence of brain abnormality in these patients," said the study's lead investigator, Vania Apkarian, a professor of physiology at Northwestern University's Feinberg School of Medicine in Chicago.

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"The new anatomical findings could provide targets for potential drug treatments . . ."