Case of Neuronal Intranuclear Inclusion Disease With Dynamic Perfusion Changes Lacking Typical Signs on Diffusion-Weighted Imaging.

Neuronal intranuclear inclusion disease (NIID) is a slowly progressive neurodegenerative disorder with a wide range of clinical manifestations, including dementia and peripheral neuropathy.1 NIID is pathologically characterized by eosinophilic hyaline intranuclear inclusions found in the central and peripheral nervous systems and various organs, including the skin,1,2 which enables the confirmation of a diagnosis by skin biopsy.2 High-intensity signals along the corticomedullary junction on diffusion-weighted imaging (DWI) and bilateral leukoencephalopathy are also specific features of NIID1 and extend as the disease progresses.1,3 However, the clinical and pathophysiologic significance of cerebral blood flow remains undetermined. In this study, we present the case of a patient with NIID exhibiting dynamic perfusion changes on arterial spin labeling (ASL) before typical subcortical DWI signals. The patient's clinical manifestations and radiologic changes are very unique and remarkable for NIID. Her diagnosis was confirmed by skin biopsy and genomic analysis.