Visual dysfunction between migraine events.

PURPOSE

To evaluate interictal visual dysfunction in persons with migraine in terms of spatiotemporal selectivity and location within the visual pathways.

METHODS

The vision of a group of 15 persons who had experienced migraine with aura was compared with that of 15 normal age-matched control subjects. A range of thresholds was measured to evaluate precortical (background modulation, contrast thresholds for static, and moving stimuli), area V1 (orientation discrimination and motion discrimination thresholds), and higher order (global dot motion thresholds) visual processes. Testing was performed centrally and at 10 degrees in the superior visual field. For each of the tests, the spatial and temporal parameters of the stimuli were selected to bias detection toward either parvocellular or magnocellular visual mechanisms.

RESULTS

No defects were found for parvocellular processes. Significant (P: < 0.05) losses were apparent with the temporal background modulation method (16 Hz), orientation discrimination (0.5 cyc/deg), and global dot motion tasks.

CONCLUSIONS

Both cortical and precortical visual dysfunction were identified in migraine group 7 days after the headache. This loss was selective for targets with temporal modulation of approximately 16 Hz.