title: Coexistence of pupillary and heart sympathergic asymmetries in cluster headache.
abstract: Ten cluster headache patients and 10 healthy controls were subjected to electrocardiographic and pupillometric procedures in a search for cardiac and pupillary sympathergic asymmetry. Sympathergic stimulation was provoked by hyperventilation and by instilling tyramine into both eyes. In the control group, hyperventilation changed neither the T-wave form and polarity nor the QTc. Tyramine provoked an equal mydriasis on the two sides. In cluster headache sufferers, hyperventilation produced changes in the T-wave form and polarity as well as an increase of the QTc due to a disproportionate shortening of the R-R and Q-T intervals. An unequal mydriasis was noted after tyramine instillation due to less marked response on the symptomatic side. The observed electrocardiographic abnormalities are considered an expression of an asynchronous repolarization attributed to a sympathergic asymmetry. It is postulated that both the cardiac and pupillary sympathetic imbalance associated with cluster headache are central in origin.
mesh_terms: D000293:Adolescent; D000328:Adult; D003027:Cluster Headache / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D007839:Functional Laterality; D006321:Heart / Q000294:innervation*; D006801:Humans; D006985:Hyperventilation / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011680:Pupil / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D014439:Tyramine; D014653:Vascular Headaches / Q000503:physiopathology*
chemical_list: D014439:Tyramine