Abstract
We report the case of a 32-year-old woman presenting with dementia after diplopia and unsteadiness. She gradually developed dementia, psychiatric symptoms, ataxia, and weight loss after divergence palsy. Brain magnetic resonance imaging (MRI) revealed progressive brain atrophy and cortical hyperintensities on fluid attenuated IR (FLAIR) and diffusion-weighted imaging (DWI) within 2 years after symptom onset. Single photon emission computed tomography (SPECT) revealed loss of blood flow to the frontal and temporal lobes. Clinical course and examinations suggested prion disease, but electroencephalography revealed only slow waves. Prion protein gene analysis found codon 129 was Met/Met, and no genetic mutations were identified. Cerebrospinal fluid levels of tau and 14-3-3 protein were below cut-off values. Patients with slowly progressive diplopia, unsteadiness and dementia as in this case require long-term follow-up with MRI, including DWI.
https://ror.org/038dg9e86 
