| Popis: |
Background Migraine is a cyclic, neurosensory disorder characterized by recurrent headaches and altered sensory processing. In particular, hypersensitivity to visual stimuli, measured with questionnaires and sensory thresholds, as well as abnormal cortical excitability, and a lack of habituation, assessed with visual evoked potentials elicited by pattern-reversal stimulation, have been reported. Here, the goal was to assess sensory sensitivity, cortical excitability, and habituation using two experiments and determine whether factors such as age and/or disease severity may exert a modulatory influence on them. Methods Two similar experiments were carried out, the first comparing 24 young, episodic migraine patients and 28 healthy age- and gender-matched controls and the second 36 middle-aged, episodic migraine patients and 30 healthy age- and gender-matched controls. A neurologist confirmed the diagnoses. Migraine phases were obtained using eDiaries. Sensory sensitivity was assessed with the Sensory Perception Quotient and group comparisons were carried out. We obtained pattern-reversal visual evoked potentials and calculated the N1-P1 Peak-to-Peak amplitude. Two linear mixed-effects models were fitted to this data. The first model had Block (first block, last block) and Group as fixed factors, whereas the second model had Trial (all trials) and Group as fixed factors. Participant was included as a random factor in both. N1-P1 first block amplitude was used to assess cortical excitability and habituation was defined as a decrease of N1-P1 amplitude across Blocks/Trials. Both experiments were performed interictally. Results The final samples consisted of 18 patients with episodic migraine and 27 headache-free controls (first experiment) and 19 patients and 29 controls (second experiment). In both experiments, patients reported increased visual hypersensitivity on the Sensory Perception Quotient as compared to controls. Regarding N1-P1 peak-to-peak data, there was no main effect of Group, indicating no differences in cortical excitability between groups. Finally, significant main effects of both Block and Trial were found indicating normal habituation in both groups, regardless of age and headache frequency. Conclusions The results of this study yielded significant hypersensitivity in patients but similar habituation and cortical excitability, as compared to headache-free controls. Therefore, the mechanisms of sensory-attentional processing in response to PR stimulation may be mostly intact. |
