Spatial attention to thermal pain stimuli in subjects with visual spatial hemi-neglect: extinction, mislocalization and misidentification of stimulus modality.
One approach to the study of disordered spatial attention is to carry out tests of extinction, in which stimuli are detected on the left when they are presented on the left alone, but not when both sides are stimulated simultaneously in a dual simultaneous stimulation (DSS) protocol. Extinction has been documented for multiple sensory modalities, but not for thermal pain stimuli, to our knowledge. We now test the hypothesis that subjects with visual spatial neglect (hemi-neglect) will have alterations in thermal pain sensation which are related to abnormal spatial attention. The results demonstrate that thermal pain extinction of hot and cold pain stimuli occurs in a proportion of subjects with hemi-neglect. In the subjects with visual spatial hemi-neglect but without thermal pain extinction, the sensation of the thermal pain stimulus on the affected (left) side was not extinguished but was often localized to the unaffected (right) side, and the submodality of the stimulus (cold or hot) was often misidentified. Ratios indicating the magnitude of extinction, mislocalization and misidentification were significantly larger on the left side of subjects with visual spatial neglect than in healthy controls or in controls with stroke but without hemineglect. The proportion of subjects with thermal pain extinction, mislocalization, or misidentification was significantly higher in subjects with hemi-neglect than those in either control group. These results demonstrate that disordered attention exerts a powerful effect upon the perception of both the location and the quality of thermal pain stimuli.
Neurosurgery Dept., Johns Hopkins Hospital, Baltimore, MD, USA Division of Perioperative Care and Emergency Medicine, Rudolf Magus Institute of Neuroscience, Pain Clinic, University Medical Center Utrecht, Utrecht, The Netherlands Department of Neural and Pain Sciences, University of Maryland Dental School, Program in Neuroscience, Baltimore, USA.
C C
CC
Liu
D S
DS
Veldhuijzen
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S
Ohara
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J
Winberry
J D
JD
Greenspan
F A
FA
Lenz
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D005108:Extinction, Psychological / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D006930:Hyperalgesia / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000503:physiopathology*; D010775:Photic Stimulation / Q000009:adverse effects; D013028:Space Perception / Q000502:physiology*