Background: Patients who have sustained aneurysmal subarachnoid hemorrhage (aSAH) are thought to have cognitive impairment. However, little is known about the characteristics of functional imaging in patients with aSAH. In this study, we explored whole brain activity patterns in patients with aSAH using amplitude of low-frequency fluctuation (ALFF) and functional connectivity (FC).
Methods: Fifty patients with aSAH and 30 healthy controls were recruited and subjected to a resting-state functional magnetic resonance imaging scan and cognitive tasks. Abnormalities of ALFF and FC in patients with aSAH and the correlations with cognitive tasks were assessed.
Results: The aSAH group exhibited increased ALFF mainly in the left parahippocampal gyrus (PHG), left inferior temporal gyrus (ITG), and left thalamus (THAL). FC and regression analysis showed positive correlations between functional connectivity strength (FCS) and memory performance in several connections in the aSAH group. These included (1) decreased FC between the left PHG and left inferior parietal lobe; (2) decreased FC between the left ITG and bilateral inferior frontal gyrus orbital part (ORBinf), right middle frontal gyrus; and (3) increased FC between the left THAL and right inferior frontal gyrus orbital part (ORBinf), and right inferior frontal gyrus opercular part.
Conclusions: Our findings not only demonstrate the unique abnormal cerebral functional topology of patients with aSAH on both local and network levels, but also confirm the correlation between specific FCS and memory function in these patients. In addition, we have identified several potential imaging biomarkers for predicting cognitive outcomes in patients with aSAH.
Keywords: Amplitude of low-frequency fluctuation; Functional MRI; Functional connectivity; Memory; Subarachnoid hemorrhage.
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