Neuronal Intranuclear Inclusion Disease with Abnormal Peripheral Nerve Conduction

A 70-year-old female presented with progressive gait disturbance. Neurologic examination revealed sensory impairment, hyporeflexia, and sensory ataxia. Nerve conduction study demonstrated mildly decreased velocity in motor nerves. Brain magnetic resonance imaging showed high signal intensities in the corticomedullary junction on diffusion weighted imaging. Neurocognitive function test implied mild cognitive impairment. Based on eosinophilic intranuclear inclusions in pathology, neuronal intranuclear inclusion disease was confirmed. Neuronal intranuclear inclusion needs to be considered when abnormal nerve conduction studies are consistent with abnormal brain imaging findings.