Diffusional Kurtosis along the Corticospinal Tract in Adult Normal Pressure Hydrocephalus

Area of Science:

• Neuroimaging
• White Matter Integrity
• Diffusion MRI

Background:

• Normal Pressure Hydrocephalus (NPH) is a reversible dementia linked to enlarged ventricles.
• Ventricular enlargement can distort white matter fibers, particularly the corticospinal tract.
• Understanding white matter changes is crucial for diagnosing and managing NPH.

Purpose of the Study:

• To investigate diffusion and kurtosis parameter variations along the corticospinal tract in NPH patients.
• To pinpoint the location of microstructural compromise within the corticospinal tract.
• To assess if diffusion MRI can differentiate NPH from Alzheimer disease and healthy controls.

Main Methods:

• Developed a novel method for analyzing diffusion parameters at discrete points along neural tracts.
• Utilized diffusion MRI data from NPH patients, Alzheimer disease patients, and healthy controls.
• Compared diffusion parameters of the corticospinal tract across the three groups.

Main Results:

• Diffusion parameters successfully differentiated NPH patients from Alzheimer disease patients and healthy controls.
• Significant differences in axial diffusion, axial kurtosis, and axonal water fraction were observed (P < .05).
• These differences were localized to the superior internal capsule and corona radiata region, near the ventricles.

Conclusions:

• Diffusion MRI parameters can serve as biomarkers for NPH.
• Axial kurtosis and axonal water fraction changes suggest axonal compression and reduced density in NPH.
• Findings highlight the potential of diffusion MRI for early detection and understanding of NPH pathophysiology.