Mapping macrostructural and microstructural brain alterations in patients with neuronal intranuclear inclusion...

Area of Science:

• Neuroimaging
• Neurodegenerative Diseases
• Diffusion MRI

Background:

• Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder with diverse radiological manifestations.
• Understanding NIID's structural brain abnormalities is crucial for diagnosis and management.

Purpose of the Study:

• To investigate structural brain abnormalities in adult-onset NIID using multi-shell diffusion MRI.
• To compare diffusion MRI measures between NIID patients and healthy controls.
• To explore associations between MRI findings and clinical variables in NIID.

Main Methods:

• Included 28 adult-onset NIID patients and 32 healthy controls.
• Acquired volumetric and multi-shell diffusion MRI data for six brain structures.
• Analyzed fractional anisotropy (FA), mean diffusivity (MD), intracellular volume fraction (ICVF), orientation dispersion index (ODI), and isotropic volume fraction (ISOVF).

Main Results:

• NIID patients exhibited significant volume loss across all analyzed brain regions.
• Widespread alterations in diffusion metrics were observed, including lower FA in cerebral white matter and higher MD in white matter regions.
• Higher mean diffusivity in cerebellar white matter correlated with lower Montreal Cognitive Assessment (MoCA) scores, indicating cognitive impairment.

Conclusions:

• NIID is characterized by extensive brain atrophy and heterogeneous diffusion tensor imaging (DTI) alterations.
• Cerebellar white matter integrity is compromised in NIID, correlating with cognitive decline.
• Multi-shell diffusion MRI provides a detailed view of structural brain changes in NIID.