Long-term preservation of pharyngeal swallowing function in MM2-cortical-type sporadic Creutzfeldt-Jakob disease

Swallowing function in long-term survivors of Creutzfeldt-Jakob disease (CJD) has not been elucidated. Herein, we report a patient with MM2-cortical-type sporadic CJD (MM2C-type sCJD) with long-term preservation of pharyngeal swallowing function using videofluoroscopic (VF) examination of swallowing. A 55-year-old woman was admitted to hospital because of dyscalculia and memory disturbance 3 years after the onset of these symptoms. Neurological examination revealed dementia, extrapyramidal signs, and delusion. Diffusion-weighted MRI revealed bilateral hyperintensity in the basal ganglia and frontal, temporal, and parietal cortices. No mutation with the methionine homozygote at codon 129 was found on PRNP gene analysis. VF was performed 68 months after the onset. Although bolus transport from the oral cavity to the pharynx worsened, the pharyngeal swallowing function was preserved even 68 months after onset. Serial MRI examinations revealed no apparent atrophy of the brainstem. Single photon emission computed tomography revealed that the regional cerebral blood flow in the brainstem was preserved. These findings suggest that pseudobulbar palsy is the pathophysiology underlying dysphagia in long-term survivors of MM2C-type sCJD, probably owing to preserved brainstem function even in a state of akinetic mutism.