Pathological background of subcortical hyperintensities on diffusion-weighted images in a case of neuronal intranuclear inclusion disease.

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder with eosinophilic intranuclear inclusion bodies. The variable symptoms of NIID increase the difficulty in an antemortem diagnosis. NIID shows leukoencephalopathy on brain magnetic resonance imaging MRI, but the significance of the radiological findings have not been clarified.