Afterimage duration differs for migraine with or without aura.

Abstract

Background: It is controversial to what extent afterimages, as distinct visual phenomena, are altered in patients with migraine and whether they have a specific role in migraine pathophysiology.

Objective: The aim of this cross-sectional study was to investigate the duration of afterimages in patients with migraine, migraine with aura (MwA), and migraine without aura (MwoA), compared to healthy controls (HCs).

Methods: Adults with migraine, MwA, and MwoA, diagnosed according to The International Classification of Headache Disorders, third edition criteria and HCs without relevant headache history were included. Initially, factors affecting the experimental setting of testing afterimage latency were determined. Then, afterimage duration was measured in the two study groups (MwA and MwoA) and the HC group. Patient characteristics, intraocular pressure, and relevant comorbid conditions, as well as scales on depressive symptoms (nine-item Patient Health Questionnaire) and headache-specific psychosocial impairment (six-item Headache Impact Test) were recorded. Lastly, the role of different stimulus colors, as well as habituation effects after repeated stimulation, were investigated.

Results: The main study included 174 participants (40 with MwA, 53 with MwoA, and 81 HCs). The duration of the afterimage in patients with MwA was significantly longer than in HCs, at a mean (standard error of the mean [SEM]) of 12.6 (2.6) versus 5.5 ( 0.3) s (p = 0.035), while there was no significant difference between patients with MwoA (mean [SEM] 7.7 [1.6] s; p = 0.510) and HCs. There was also no significant effect of stimulus color on afterimage latency (mean [SEM] red: 8.9 [1.2] s and black: 8.4 [1.2] s).

Conclusion: We found significantly longer afterimage duration in patients with MwA compared to both HCs and patients with MwoA. Furthermore, partially selective stimulation of retinal rods and cones by different stimulus colors had no effect on afterimage duration suggesting a relevant subcortical and/or cortical modulation in migraine aura with increased excitability.