Salience Network Dynamics Across Spontaneous Attacks, Interictal Rest and Interictal Pain Imagery in Menstrually Related Migraine

Abstract

The persistent sensitivity to sensory and painful stimuli of people with migraine has been associated with disruption of the salience network (SN). Although migraine is characterized by severe head pain attacks, brain changes have been observed in people with migraine in between attacks (i.e., during the interictal phase). We hypothesized that SN dynamics may be altered in people with migraine during spontaneous attacks as well as an attack imagery task engaging sensory, emotional, and cognitive aspects of pain. To test this, we analysed the SN dynamics in patients with episodic menstrually related migraine without aura across three conditions: at rest during a spontaneous attack; during the interictal phase while performing an imagery task recalling a previous attack and at interictal rest. Healthy controls were studied in matching conditions, including rest and a non-migraine head-pain imagery. We collected functional magnetic resonance imaging (fMRI) data, using a dynamic functional connectivity (dFC) analysis to examine SN temporal features from a total of 26 participants. A significant between-group difference was observed during the pain imagery task, with people with migraine exhibiting a shorter SN dwell time than controls. Such differences were not detected during spontaneous attacks or interictal rest. The between-group difference in SN dynamics observed during the pain imagery condition suggests that this paradigm may be useful for engaging the cognitive and emotional dimensions of pain. However, further work is needed to determine whether this difference is migraine-specific or rather reflects differences in the salience and affective content of the recalled experiences.