Shared alterations in hippocampal structural covariance in subjective cognitive decline and migraine

Abstract

Introduction: Subjective cognitive decline (SCD) and migraine are often comorbid. Hippocampal structural abnormalities have been observed in individuals with both SCD and migraine. Given the known structural and functional heterogeneity along the long axis (anterior to posterior) of the hippocampus, we aimed to identify altered patterns of structural covariance within hippocampal subdivisions associated with SCD and migraine comorbidities.

Methods: A seed-based structural covariance network analysis was applied to examine large-scale anatomical network changes of the anterior and posterior hippocampus in individuals with SCD, migraine and healthy controls. Conjunction analyses were used to identify shared network-level alterations in the hippocampal subdivisions in individuals with both SCD and migraine.

Results: Altered structural covariance integrity of the anterior and posterior hippocampus was observed in the temporal, frontal, occipital, cingulate, precentral, and postcentral areas in individuals with SCD and migraine compared with healthy controls. Conjunction analysis revealed that, in both SCD and migraine, altered structural covariance integrity was shared between the anterior hippocampus and inferior temporal gyri and between the posterior hippocampus and precentral gyrus. Additionally, the structural covariance integrity of the posterior hippocampus-cerebellum axis was associated with the duration of SCD.

Conclusion: This study highlighted the specific role of hippocampal subdivisions and specific structural covariance alterations within these subdivisions in the pathophysiology of SCD and migraine. These network-level changes in structural covariance may serve as potential imaging signatures for individuals who have both SCD and migraine.

Keywords: gray matter volume; hippocampus; migraine; network; structural covariance (SC); subjective cognitive decline.

FIGURE 1

Spatial pattern of hippocampus structural covariance network (SCN) in each group (HC, SCD, and migraine). (A) Seed regions for the hippocampus: anterior (red) and posterior (blue) division of the hippocampus. (B) Covariance patterns from the anterior hippocampus were mapped in each group. (C) Covariance patterns from the posterior hippocampus were mapped in each group. Hot/cold colors indicate the positive/negative correlation to the seed. Black outlines indicate significant regions at a corrected level for threshold p-values < 0.05. FWE, family wise error; HC, healthy control; MIG, migraine; SCD, subjective cognitive decline; SCN, structural covariance network.

FIGURE 2

Structural covariance (SC) differences in the anterior hippocampus between the control and clinical groups (migraine and SCD). (A) Group-wise differences in SC between patients with migraine and controls. (B) Group-wise differences in SC between individuals with SCD and controls. Red/blue colors indicate decreased/increased SC in SCD and migraine compared with controls. Black outlines indicate significant regions at a corrected level for threshold p-values < 0.05. (C) Conjunction analyses showing SC alterations of the anterior hippocampus common to both clinical groups, located in the bilateral inferior temporal gyrus. FWE, family wise error; HC, healthy control; Lt, left; MIG, migraine; Rt, right; SC, structural covariance; SCD, subjective cognitive decline.

FIGURE 3

Structural covariance differences in the posterior hippocampus between the control and clinical groups (migraine and SCD). (A) Group-wise differences in SC between patients with migraine and controls. (B) Group-wise differences in SC between individuals with SCD and controls. Red/blue colors indicate decreased/increased SC in SCD and migraine compared with controls. Black outlines indicate significant regions at a corrected level for threshold p-values < 0.05. (C) Conjunction analyses showing SC alterations of the posterior hippocampus common to both clinical groups, located in the left precentral gyrus. FWE, family wise error; HC, healthy control; Lt, left; MIG, migraine; Rt, right; SC, structural covariance; SCD, subjective cognitive decline.