Abstract
BackgroundMigraine is a primary neurological disorder associated with complex brain activity. Recently, mounting evidence has suggested that migraine is underpinned by aberrant dynamic brain activity characterized by linear and non-linear changes across a variety of time scales. However, the abnormal dynamic brain activity at different time scales is still unknown in patients with migraine without aura (MWoA). This study aimed to assess the altered patterns of brain activity dynamics over different time scales and the potential pathophysiological mechanisms of alterations in patients with MWoA.MethodsMultiscale entropy in 50 patients and 20 healthy controls (HCs) was calculated to investigate the patterns and altered brain complexity (BC) across five different time scales. Spearman rank correlation analysis between BC in regions showing significant intergroup differences and clinical scores (i.e., frequency of migraine attacks, duration, headache impact test) was conducted in patients with MWoA.ResultsThe spatial distribution of BC varied across different time scales. At time scale1, BC was higher in the posterior default mode network (DMN) across participants. Compared with HCs, patients with MWoA had higher BC in the DMN and sensorimotor network. At time scale2, BC was mainly higher in the anterior DMN across participants. Patients with MWoA had higher BC in the sensorimotor network. At time scale3, BC was mainly higher in the frontoparietal network across participants. Patients with MWoA had increased BC in the parietal gyrus. At time scale4, BC is mainly higher in the sensorimotor network. Patients with MWoA had higher BC in the postcentral gyrus. At time scale5, BC was mainly higher in the DMN. Patients with MWoA had lower BC in the posterior DMN. In particular, BC values in the precuneus and paracentral lobule significantly correlated with clinical symptoms.ConclusionMigraine is associated with alterations in dynamic brain activity in the sensorimotor network and DMN over multiple time scales. Time-varying BC within these regions could be linked to instability in pain transmission and modulation. Our findings provide new evidence for the hypothesis of abnormal dynamic brain activity in migraine.
Highlights
Migraine is a debilitating neurological disorder associated with brain excitability dysfunction characterized by attacks of moderate or severe unilateral throbbing and pulsating headache (Ashina, 2020)
Existing studies have focused on exploring the brain mechanisms of migraine using functional magnetic resonance imaging
In time scale2, brain complexity (BC) was mainly higher in the medial orbitofrontal, temporal gyrus, and parietal gyrus across subjects
Summary
Migraine is a debilitating neurological disorder associated with brain excitability dysfunction characterized by attacks of moderate or severe unilateral throbbing and pulsating headache (Ashina, 2020). It is essential to clarify functional brain abnormalities present over different time scales in migraine and how they are associated with migraine attack severity. Accumulating evidence indicates that the pathophysiology of migraine is based on abnormal brain dynamics (Liu et al, 2017; Tu et al, 2019, 2020; Yiheng et al, 2021). Mounting evidence has suggested that migraine is underpinned by aberrant dynamic brain activity characterized by linear and non-linear changes across a variety of time scales. The abnormal dynamic brain activity at different time scales is still unknown in patients with migraine without aura (MWoA).
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