Neuronal Intranuclear Inclusion Disease Complicated by Acute Middle Cerebral Artery Infarction: A Case Report

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder with no prior reports linking it to acute large-vessel cerebral infarction. A 65-year-old man with progressive limb numbness and acute neuropsychiatric symptoms underwent MRI, skin biopsy, and genetic testing. MRI revealed corticomedullary "ribbon signs" and right middle cerebral artery (MCA) stenosis. Follow - up imaging not only confirmed the occlusion of the MCA accompanied by an infarction in the basal ganglia but also indicated an enlargement of the "ribbon signs". Skin biopsy showed p62-positive intranuclear inclusions; genetic testing identified a NOTCH2NLC GGC expansion (>41 repeats). Despite treatment, the patient died of pneumonia three months post-infarction. This single-case, first-reported observational study of NIID with large-vessel stenosis illustrates a potential vasculopathic link. While robust histopathological validation is pending, the temporal correlation between NIID progression and vascular events warrants further investigation.