کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6015672 | 1186075 | 2014 | 8 صفحه PDF | دانلود رایگان |
- We examine frequency-dependent amplitude alterations in IGE patients.
- Full frequency analysis can provide high frequency information.
- We demonstrate the topology of the maximally altered amplitude over full frequency.
- We find the specific frequency range with the maximally altered amplitude.
- Full frequency amplitude analysis may help to select specific frequency for detecting IGE-related activity.
SummaryPurposeAmplitude of low-frequency fluctuation (ALFF) of blood-oxygenation level-dependent (BOLD) has proven a promising way to detect disease-related local brain activity. However, routine approach employs an arbitrary frequency band of 0.01-0.08Â Hz, which lacks frequency specificity and blinds to the information contained in other frequency bands. This study investigated the amplitude of fluctuations in full BOLD frequency bands, and addressed how amplitudes of fluctuations change in each specific frequency range in idiopathic generalized epilepsy (IGE).MethodsThirty-four IGE patients with generalized tonic-clonic seizure and the same number of age- and sex-matched healthy controls were included. Functional MRI data were acquired using a 2Â s repetition time. Routine amplitude of low-frequency fluctuation analysis was first performed. The regions showing group difference were set as Region-of-interest for analysis of amplitudes of full-frequency. The amplitudes of BOLD fluctuations were consecutively performed at each frequency bin of 0.002Â Hz, and specific frequency amplitude analyses were performed in five different frequency ranges (0-0.01Â Hz, 0.01-0.027Â Hz, 0.027-0.073Â Hz, 0.073-0.198Â Hz, and 0.198-0.25Â Hz).Key findingsThe thalamus and prefrontal cortex showed significant group differences in routine amplitude analysis. For amplitude of full-frequency analysis, a reverse pattern was found in the dynamic changes between the thalamus and prefrontal cortex in IGE. Moreover, the prefrontal cortex showed amplitude difference in the 0.01-0.027Â Hz band, while the thalamus showed amplitude difference in the 0.027-0.073Â Hz band. Both these two regions showed amplitude differences in 0.198-0.25Â Hz band.SignificanceWe demonstrated the characteristic alterations of amplitude of BOLD fluctuations in IGE in frequency domain. The amplitude analysis of full frequency may potentially help to select specific frequency range for detecting epilepsy-related brain activity, and provide insights into the pathophysiological mechanism of IGE.
Journal: Epilepsy Research - Volume 108, Issue 5, July 2014, Pages 853-860