Objective: To investigate the clinical features of neuronal intranuclear inclusion disease(NIID).

Methods: The clinical data of a NllD patient presenting with essential tremor, including head PET-MRl, skin biopsy, and genetic testing, were reported in conjunction with the relevant literature.

Results: The patient presented with essential tremor of the left hand as the main clinical symptom, without cognitive impairment and autonomic neuropathy. The cranial PET-MRl showed multiple intracranial white matter degeneration (PVH grade 3, DWMH grade 3),and skin biopsy showed no inclusion bodies within the sweat gland duct epithelial nuclei of skin tissue stained with light microscopy H&E, and immunohistochemistry showed no p62-positive inclusion bodies within the sweat gland duct epithelial nuclei, and the detectable gene NOTCH2NLC showed 22 repeats of one allele of GGC and 115 repeats ofthe other allele of GGC, which could theoretically be pathogenic.

Conclusion: Clinical manifestations of NIID vary from each other, the brain MRl and skin biopsy and genetic testing can assist in diagnosis, but there is no specific treatment method currently.