White matter alteration in idiopathic normal pressure hydrocephalus: tract-based spatial statistics study

Area of Science:

• Neuroimaging
• Neurology
• White Matter Diseases

Background:

• White matter alterations in idiopathic normal pressure hydrocephalus (iNPH) remain under-investigated.
• Diffusion Tensor Imaging (DTI) provides insights into white matter integrity.
• Tract-Based Spatial Statistics (TBSS) is a voxelwise analysis method for DTI data.

Purpose of the Study:

• To investigate cerebral white matter alterations in iNPH patients using DTI.
• To evaluate the accuracy of TBSS analysis in detecting these changes.

Main Methods:

• DTI data acquired from 20 iNPH patients and 20 controls.
• Fractional Anisotropy (FA) values analyzed using TBSS, region-of-interest (ROI), and tract-specific analysis.
• TBSS accuracy assessed via back-projection and comparison with ROI/tract-specific methods.

Main Results:

• TBSS demonstrated accurate whole-brain registration, with minor exceptions.
• TBSS results aligned with ROI and tract-specific analyses.
• iNPH patients showed decreased FA in corpus callosum, periventricular, and juxtacortical white matter.
• Increased FA observed in the internal capsule and centrum semiovale of iNPH patients.

Conclusions:

• iNPH is associated with diverse white matter damage patterns.
• TBSS is a promising tool for voxelwise analysis of iNPH white matter alterations.
• TBSS accuracy is high, though some areas require careful interpretation.