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Updated: Apr 23, 2026
Network Analysis of the Default Mode Network Using Functional Connectivity MRI in Temporal Lobe Epilepsy
Published on: August 5, 2014
Whole-brain connectome analysis for elucidating specific structural neural networks in idiopathic normal-pressure
Shinya Hasegawa1,2, Daisuke Yoshimaru3,4,5, Norio Hayashi6
1Department of Radiology, Chiba Saiseikai Narashino Hospital, 1-1-1 Izumicho, Narashino City, Chiba, 275-8580, Japan. hase8000.415@gmail.com.
Objective:
To test the hypothesis that idiopathic normal-pressure hydrocephalus (iNPH) is also associated with reproducible whole-brain structural connectivity reductions detectable by diffusion MRI connectomics, beyond the established clinical triad of gait disturbance, cognitive impairment, and urinary incontinence.
Materials And Methods:
Twenty patients with iNPH (71-84 years; Evans index 32.1-43.5) diagnosed according to the Japanese guidelines and 20 age-matched healthy controls (70-88 years) underwent 3.0-T MRI. Distortion-corrected diffusion-weighted imaging (b = 2000s/mm2, 32 directions) was analyzed using constrained spherical deconvolution and anatomically constrained probabilistic tractography. Connectivity matrices were constructed for 84 regions (Desikan-Killiany atlas), yielding 3486 unique edges. Group differences were tested edge wise using the Mann-Whitney U test with Bonferroni-adjusted p-values; statistical significance was defined as adjusted p < 0.01, and effect sizes were quantified using the rank-biserial correlation (large effect: r > 0.5).
Results:
iNPH showed significantly reduced connectivity predominantly in interhemispheric edges (adjusted p < 0.01; r = 0.89-0.98). The paracentral lobule exhibited the greatest number of decreased connections (11 edges), followed by the posterior cingulate gyrus (9 edges) and the superior frontal gyrus (8 edges).
Conclusions:
iNPH is associated with robust interhemispheric disconnection and prominent involvement of motor- and midline-related networks, supporting connectome-derived markers for further validation.
