A Case of Neuronal Intranuclear Inclusion Disease Presenting Predominantly with Stroke-like Episodes and Literature Review

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder. Some NIID patients may present with paroxysmal neurological symptoms, posing challenges for clinical diagnosis. Thisarticle reports a 68-year-old male NIID patient presenting predominantly with stroke-like episodes. The patient was admitted with sudden-onset right-sided limb weakness, and had a prior history of cognitive decline and bradykinesia. Brain magnetic resonance imaging revealed severe subcortical white-matter hyperintensities in bilateral cerebral hemispheres on fluid-attenuated inversion recovery sequences, as well as characteristic "ribbon sign" at the corticomedullary junction on diffusion-weighted imaging. Genetic testing identified an abnormal GGC repeat expansion of 112 times in the NOTCH2NLC gene, confirming the diagnosis of NIID. In addition, we reviewed previously reported NIID cases with stroke-like episodes as the predominant clinical manifestation, aiming to provide references for the clinical diagnosis and treatment of this disease.