Abstract
Background: Recently, there have been many reports about abnormalities regarding structural and functional brain connectivity of the patients with primary insomnia. However, the alterations in functional interaction between the left and right cerebral hemispheres have not been well understood. The resting-state fMRI approach, which reveals spontaneous neural fluctuations in blood-oxygen-level-dependent signals, offers a method to quantify functional interactions between the hemispheres directly.Methods: We compared interhemispheric functional connectivity (FC) between 26 patients with primary insomnia (48.85 ± 12.02 years) and 28 healthy controls (49.07 ± 11.81 years) using a voxel-mirrored homotopic connectivity (VMHC) method. The patients with primary insomnia and healthy controls were matched for age, gender, and education. Brain regions, which had significant differences in VMHC maps between the primary insomnia and healthy control groups, were defined as seed region of interests. A seed-based approach was further used to reveal significant differences of FC between the seeds and the whole contralateral hemisphere.Results: The patients with primary insomnia showed higher VMHC than healthy controls in the anterior cingulate cortex (ACC) bilaterally. The seed-based analyses demonstrated increased FC between the left ACC and right thalamus (and the right ACC and left orbitofrontal cortex) in patients with primary insomnia, revealing abnormal connectivity between the two cerebral hemispheres. The VMHC values in the ACC were positively correlated with the time to fall asleep and Self-Rating Depression Scale scores (SDS).Conclusions: The results demonstrate that there is abnormal interhemispheric resting-state FC in the brain regions of patients with primary insomnia, especially in the ACC. Our finding demonstrates valid evidence that the ACC is an area of interest in the neurobiology of primary insomnia.
Highlights
Insomnia is a remarkably prevalent disorder, which is characterized by difficulty in initiating sleep, maintaining sleep and impaired daytime functioning (Edinger et al, 2004)
Since the ACC exhibited significant Voxel-mirrored homotopic connectivity (VMHC) differences between the PI group and the healthy control group, it was used as a biomarker to separate PI patients from healthy controls
Mean VMHC values were extracted from the left ACC and receiver operating characteristic curves (ROC) analysis was conducted
Summary
Insomnia is a remarkably prevalent disorder, which is characterized by difficulty in initiating sleep, maintaining sleep and impaired daytime functioning (Edinger et al, 2004). Insomnia causes a reduction in the quality of life, work productivity, and impairment in social function (Rosekind and Gregory, 2010). It has been recognized as a major public health issue, associated with increased societal burden and health expense (Staner, 2010). There have been many reports about abnormalities regarding structural and functional brain connectivity of the patients with primary insomnia. The resting-state fMRI approach, which reveals spontaneous neural fluctuations in blood-oxygen-level-dependent signals, offers a method to quantify functional interactions between the hemispheres directly
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
