Rationale: Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease identified with diffusion-weighted imaging (DWI) high-intensity signal in magnetic resonance imaging (MRI). The disappearance of the abnormal signal is extremely rare.
Patient concerns: We present the 2 cases of patients, both of them were suffering from heterogeneous symptoms. We followed up one of them for 7 years with MRI, the other accepted comprehensive MRI inspections.
Diagnoses: DWI high-intensity signal were observed along the corticomedullary junction in MRI plan scan of heads of 2 patients. For patient 1, the hyperintensities in DWI and fluid-attenuated inversion recovery (FLAIR) images in the occipital lobe disappeared 5 years after onset. Based on the biopsy, patient 1 and 2 were diagnosed as NIID.
Interventions: There have not effective medication and prevention for NIID. Patient 1 and 2 received symptomatic treatment.
Outcomes: Up until now, the patients are alive but the disease is progressing.
Lessons: DWI high-intensity signal is a strong clue for the diagnosis of NIID, but the rare case of the disappearance of it may lead to misdiagnosis.