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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.


Spatial distribution of long-range FCD in patients with GTCS and HCs and the statistical differences between the 2 groups. The statistical significance of group differences was corrected by AlphaSim (P < 0.05, a combined threshold of P < 0.01 with a minimum cluster size of 224 voxels). The left hemisphere is on the left.
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Figure 2: Spatial distribution of long-range FCD in patients with GTCS and HCs and the statistical differences between the 2 groups. The statistical significance of group differences was corrected by AlphaSim (P < 0.05, a combined threshold of P < 0.01 with a minimum cluster size of 224 voxels). The left hemisphere is on the left.

Mentions: The high long-range FCD hubs were also bilaterally distributed in both groups, including the bilateral PCC/PCu, precentral gyri (PreCG), temporal gyrus, and frontal gyrus, which were shown in Fig. 2A and B. Regions with high FCD values indicate that they might play important roles in brain networks, namely hubs. The FCD hubs found in our study are consistent with previous studies.[24,25]


Aberrant long-range functional connectivity density in generalized tonic-clonic seizures
Spatial distribution of long-range FCD in patients with GTCS and HCs and the statistical differences between the 2 groups. The statistical significance of group differences was corrected by AlphaSim (P < 0.05, a combined threshold of P < 0.01 with a minimum cluster size of 224 voxels). The left hemisphere is on the left.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 2: Spatial distribution of long-range FCD in patients with GTCS and HCs and the statistical differences between the 2 groups. The statistical significance of group differences was corrected by AlphaSim (P < 0.05, a combined threshold of P < 0.01 with a minimum cluster size of 224 voxels). The left hemisphere is on the left.
Mentions: The high long-range FCD hubs were also bilaterally distributed in both groups, including the bilateral PCC/PCu, precentral gyri (PreCG), temporal gyrus, and frontal gyrus, which were shown in Fig. 2A and B. Regions with high FCD values indicate that they might play important roles in brain networks, namely hubs. The FCD hubs found in our study are consistent with previous studies.[24,25]

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&ndash;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&ndash;cognitive impairments as well as motor control. Our study provided novel evidences to look into neuro-pathophysiological mechanisms underlying GTCS.

No MeSH data available.