Progressive supranuclear palsy presenting with primary progressive aphasia - Clinicopathological report of an autopsy case

We report a Japanese autopsy case of progressive supranuclear palsy (PSP). The male patient was 74 years old at the time of death. At age 64, he developed non-fluent aphasia that progressed slowly over 8 years, eventually associated with behavioral abnormality, postural instability, and dysphagia at 2 years prior to his death. Magnetic resonance imaging of the brain at age 73 demonstrated marked atrophy of the frontal lobes, particularly on the left side. Neuropathological examination revealed the typical pathology of PSP: loss of neurons, gliosis, occurrence of neurofibrillary tangles, oligodendroglial coiled bodies, and tuft-shaped astrocytes in the frontal cortex, associated with argyrophilic threads in the underlying white matter, in the basal ganglia, including the thalamus, globus pallidus, and subthalamic nucleus, and in the brainstem nuclei, including the substantia nigra, pontine nucleus, and inferior olivary nucleus. No astrocytic plaques or ballooned neurons were observed. Protein analysis revealed accumulation of hyperphosphorylated tau of 68 and 64kDa consisting of the four repeat tau isoforms. We conclude that the present case represented PSP with an 8-year history of primary progressive aphasia (PPA). Although focal cortical symptoms in PSP are rare or absent, we should keep in mind the possibility of atypical PSP in which cortical pathology is predominant, particularly in the frontal lobe, and could result in PPA.