Effects of distraction versus spatial discrimination on laser-evoked potentials in migraine.
OBJECTIVE
To evaluate whether migraine patients exhibit less inhibition to painful stimuli when distracted from pain as compared to healthy subjects, testing the spatial discrimination of painful stimuli, the performance during the mental arithmetic task used to contrast the discrimination performance and the behavior of N1 and N2-P2 laser-evoked potentials (LEPs) amplitudes during spatial discrimination and during distraction.


METHODS
Eight migraine patients and 8 healthy controls were examined. During repetitive series of painful laser stimulation of the hand, they had to (1) perform a spatial discrimination task, contrasted by (2) a mental arithmetic task that served as distraction.


RESULTS
Patients made 50% to 100% more mistakes than controls in the spatial discrimination task (P < .001) as well as during mental arithmetic (P < .05). Whereas healthy subjects showed a marked decrease of the LEP vertex potential amplitudes during distraction compared to the discrimination task, no such attenuation of LEPs was seen in migraine patients (group x task interaction, P < .05). N1 amplitude exhibited a left-hemisphere dominance in both groups, significantly smaller amplitude in migraine patients, but no significant task modulation.


CONCLUSIONS
Migraine patients exhibited reduced inhibition by attentional modulation of pain processing, accompanied by impaired spatial discrimination of painful stimuli.
de Tommaso
Marina
M
University of Bari - Neurologic and Psychiatric Sciences, Bari, Italy.
Baumgartner
Ulf
U
Sardaro
Michele
M
Difruscolo
Olimpia
O
Serpino
Claudia
C
Treede
Rolf-Detlef
RD
D000328:Adult; D001288:Attention / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006225:Hand / Q000502:physiology; D006801:Humans; D007834:Lasers; D008297:Male; D008881:Migraine Disorders / Q000503:physiopathology*; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D013028:Space Perception