Abstract
BackgroundTo date, no functional MRI (fMRI) studies have focused on brain entropy in right temporal lobe epilepsy (rTLE) patients. Here, we characterized brain entropy (BEN) alterations in patients with rTLE using resting‐state functional MRI(rs‐fMRI) and explored the relationship between BEN and alertness.MethodThirty‐one rTLE patients and 33 controls underwent MRI scanning to investigate differences in BEN and resting‐state functional connectivity (rs‐FC) in regions of interest (ROIs) between patients and controls. Correlation analyses were performed to examine relationships between the BEN of each ROI and alertness reaction times (RTs) in rTLE patients.ResultsCompared with controls, the BEN of rTLE patients was significantly increased in the right middle temporal gyrus, inferior temporal gyrus, and other regions of the left hemisphere and significantly decreased in the right middle frontal gyrus and left supplementary motor area (p < .05). The rs‐FCs between the ROIs (at p < .01, with the left superior parietal lobule and right precentral gyrus defined as ROI1 and ROI2, respectively) and the whole brain showed an increasing trend in rTLE patients. In addition, the BEN of ROI2 was associated with the intrinsic alertness and phasic alertness RTs of patients with rTLE.ConclusionsOur findings suggest that BEN is altered in patients with rTLE and that decreased BEN in the right precentral gyrus is positively related to intrinsic and phasic alertness; the abnormal FC in the brain regions with altered entropy suggests a reconstruction of brain functional connectivity. These findings suggest that BEN mapping may provide a useful tool for probing brain mechanisms related to TLE.
Highlights
Temporal lobe epilepsy (TLE) is one of the most common types of epilepsy
We studied changes in brain entropy in patients with right temporal lobe epilepsy (rTLE) based on an rs‐functional MRI (fMRI) time series
Epilepsy was diagnosed in accordance with the diagnostic criteria proposed by the International League Against Epilepsy (ILAE, 2006) (Glauser et al, 2006). rTLE pa‐ tients met the following criteria: (a) the presence of clinical symptoms, including seizures suggesting that the epileptogenic focus was located in the temporal lobe, as well as abnormal emotional symptoms; (b) MRI results showing right hippocampal scle‐ rosis, atrophy, or aberrations in the right temporal lobe; and (c) an ictal or interictal electroencephalogram revealing epileptic discharges in the right temporal lobe
Summary
Temporal lobe epilepsy (TLE) is one of the most common types of epilepsy. The root cause of epileptic seizures is the highly synchro‐ nized abnormal discharge of cerebral neurons. Because of the frequently synchro‐ nous discharge of neurons in epilepsy, and because the entropy ob‐ served from the EEG changed most at the epileptogenic area, we suspect that the BEN determined from an rs‐fMRI time series will be increased in the brains of temporal epileptic patients, especially at the temporal lobe. Conclusions: Our findings suggest that BEN is altered in patients with rTLE and that decreased BEN in the right precentral gyrus is positively related to intrinsic and pha‐ sic alertness; the abnormal FC in the brain regions with altered entropy suggests a reconstruction of brain functional connectivity
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.
