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Aberrant long-range functional connectivity density in generalized tonic-clonic seizures

View Article: PubMed Central - PubMed

ABSTRACT

Studies in generalized tonic-clonic seizures (GTCS) have reported both structural and functional alterations in the brain. However, changes in spontaneous neuronal functional organization in GTCS remain largely unknown.

In this study, 70 patients with idiopathic generalized epilepsy characterized by tonic–clonic seizures and 70 age- and sex-matched healthy controls were recruited. Here, functional connectivity density (FCD) mapping, an ultrafast data-driven method based on functional magnetic resonance imaging (fMRI), was applied for the first time to investigate the changes of spontaneous functional brain activity caused by epilepsy.

The results showed significantly decreased long-range FCD in the middle and inferior temporal, prefrontal, and inferior parietal cortices as well as increased long-range FCD in the cerebellum anterior lobe and sensorimotor areas. Negative correlation between duration of disease and reduced long-range FCD was found. In addition, most regions with reduced long-range FCD showed decreased resting-state functional connectivity (rsFC) within default mode network.

Negative correlation between duration of disease and long-range FCD may reflect an adverse consequence eventually from original. Furthermore, the observed FCD and rsFC alterations have been speculated to be associated with the social–cognitive impairments as well as motor control. Our study provided novel evidences to look into neuro-pathophysiological mechanisms underlying GTCS.

No MeSH data available.


Statistical significance of rsFC patterns for each seed region (middle and inferior temporal gyrus (MTG and ITG), medial prefrontal cortex (MPFC), and superior frontal gyrus (SFG)) with significant group differences in long-range FCD between GTCS and HCs. Each result is displayed on 3 “brains” shown from the right (top left image of each group), from behind (top right image of each group), and from above (bottom left image of each group). Warm and cool colors indicate that rsFC increases and decreases, respectively, in patients with GTCS.
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Figure 3: Statistical significance of rsFC patterns for each seed region (middle and inferior temporal gyrus (MTG and ITG), medial prefrontal cortex (MPFC), and superior frontal gyrus (SFG)) with significant group differences in long-range FCD between GTCS and HCs. Each result is displayed on 3 “brains” shown from the right (top left image of each group), from behind (top right image of each group), and from above (bottom left image of each group). Warm and cool colors indicate that rsFC increases and decreases, respectively, in patients with GTCS.

Mentions: We further examined the seed-based FC in 2 groups of participants. As discussed earlier, a significant change in long-range FCD measurements of GTCS was detected (Table 2). The regions with significant different long-range FCD between 2 groups were defined as seeds for FC analyses. Specifically, the left MPFC and SFG exhibited decreased rsFCs with the left MTG; the left MTG and ITG displayed subdued rsFCs with the left PCu, ANG, and MPFC (Table 3; Fig. 3).


Aberrant long-range functional connectivity density in generalized tonic-clonic seizures
Statistical significance of rsFC patterns for each seed region (middle and inferior temporal gyrus (MTG and ITG), medial prefrontal cortex (MPFC), and superior frontal gyrus (SFG)) with significant group differences in long-range FCD between GTCS and HCs. Each result is displayed on 3 “brains” shown from the right (top left image of each group), from behind (top right image of each group), and from above (bottom left image of each group). Warm and cool colors indicate that rsFC increases and decreases, respectively, in patients with GTCS.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4998471&req=5

Figure 3: Statistical significance of rsFC patterns for each seed region (middle and inferior temporal gyrus (MTG and ITG), medial prefrontal cortex (MPFC), and superior frontal gyrus (SFG)) with significant group differences in long-range FCD between GTCS and HCs. Each result is displayed on 3 “brains” shown from the right (top left image of each group), from behind (top right image of each group), and from above (bottom left image of each group). Warm and cool colors indicate that rsFC increases and decreases, respectively, in patients with GTCS.
Mentions: We further examined the seed-based FC in 2 groups of participants. As discussed earlier, a significant change in long-range FCD measurements of GTCS was detected (Table 2). The regions with significant different long-range FCD between 2 groups were defined as seeds for FC analyses. Specifically, the left MPFC and SFG exhibited decreased rsFCs with the left MTG; the left MTG and ITG displayed subdued rsFCs with the left PCu, ANG, and MPFC (Table 3; Fig. 3).

View Article: PubMed Central - PubMed

ABSTRACT

Studies in generalized tonic-clonic seizures (GTCS) have reported both structural and functional alterations in the brain. However, changes in spontaneous neuronal functional organization in GTCS remain largely unknown.

In this study, 70 patients with idiopathic generalized epilepsy characterized by tonic–clonic seizures and 70 age- and sex-matched healthy controls were recruited. Here, functional connectivity density (FCD) mapping, an ultrafast data-driven method based on functional magnetic resonance imaging (fMRI), was applied for the first time to investigate the changes of spontaneous functional brain activity caused by epilepsy.

The results showed significantly decreased long-range FCD in the middle and inferior temporal, prefrontal, and inferior parietal cortices as well as increased long-range FCD in the cerebellum anterior lobe and sensorimotor areas. Negative correlation between duration of disease and reduced long-range FCD was found. In addition, most regions with reduced long-range FCD showed decreased resting-state functional connectivity (rsFC) within default mode network.

Negative correlation between duration of disease and long-range FCD may reflect an adverse consequence eventually from original. Furthermore, the observed FCD and rsFC alterations have been speculated to be associated with the social–cognitive impairments as well as motor control. Our study provided novel evidences to look into neuro-pathophysiological mechanisms underlying GTCS.

No MeSH data available.