Attention! Keep away from pain - neuropsychological changes in a case of pathological pain

People with unilateral pathological pain can show inattention to the affected side of the body and space, reminiscent of hemispatial neglect following brain injury. However, in pathological pain this distortion is usually subtle and it is unclear which aspects of spatial processing are affected. I will present a case-study of one 65-year old, right-handed woman who presented to our lab with Complex Regional Pain Syndrome (CRPS) affecting her left arm and pronounced inattention. We assessed clinical symptoms, body representation and attention to body-, reaching-, far- and imagined space. The patient’s data were compared to cut-off scores for standard neuropsychological tests, and to data from 12 matched controls for experimental measures. We found that the patient had a distorted cognitive representation of her affected limb. Neurological assessment revealed visual and tactile neglect and extinction on the affected side. Experimental measures also indicated a visual attention bias away from the painful limb. Spatial attention deficits manifested in body- and reaching space, thus extended beyond the CRPS-affected limb, but were not observed in far- or imagined space. Finally, no impairments were found on neuropsychological tests of neglect, suggesting that more sensitive measures should be considered in CRPS.