Cognitive processing of cluster headache patients: evidence from event-related potentials

Background: The peripheral and central origins of pain in cluster headache (CH) have been a matter of much debate. The development and application of functional imaging techniques have provided more evidence supporting the hypothesis that CH is not a disorder exclusively peripheral in origin, and in fact central regions might be more important. Event-related potentials confer advantages in the functional evaluation of the cortex, but few studies thus far have employed this method in cluster headache. Methods: Seventeen cluster patients (15 males; mean age = 35.4 years) and 15 age-matched healthy participants (13 males; mean age = 34.6 years) were recruited. A visual oddball paradigm was employed to analyze target processing using event-related potentials. We investigated the P3/P3d components in the experiment. Results: P3/P3d amplitudes were decreased in CH patients (P3, 3.82 mu V; P3d, 5.8 mu V) compared with controls (P3, 7.28 mu V; P3d, 8.95 mu V), F(1,30) = 4.919, p < 0.05, eta 2 = 0.141 for P3 and F(1,30) = 8.514, p < 0.05, eta 2 = 0.221 for P3d, respectively). Moreover, the amplitudes of P3/P3d were no significantl difference in the side of pain as compared to contralateral one (p > 0.05). Conclusions: These results provide evidence of dysfunction in the cognitive processing of CH patients, which may also contribute to the pathophysiology of CH.