[An autopsy case of Alzheimer's disease presenting with corticobasal syndrome]

A right-handed Japanese man developed memory loss at 51 years of age. The right side clumsiness developed from 52 years of age and then progressively worsened. Temporal/parietal lobe atrophy was observed predominantly on the left side upon MR imaging. Subsequently, limb-kinetic apraxia and parkinsonism became apparent predominantly on the right side. These symptoms became aggravated along with dementia, ultimately leading to an apallic state. The patient eventually died at the age of 59 due to aspiration pneumonia. An autopsy was carried out and cerebral atrophy was observed predominantly on the left side. Senile plaques were observed on the entire cerebral cortex at a high frequency, along with many cotton wool plaques. Anti-phosphorylated tau-positive neurofibrillary tangles and several neuropil threads were observed upon immunostaining. The tau-positive structures were also positive for both RD3 and RD4 antibodies. The findings of tauopathy of the glia were poor, and the tau lesion of the brainstem was milder than that of the cerebral cortex. These results suggest the possibility that the corticobasal syndrome clinically developed in some type of Alzheimer's disease and a definite diagnosis was made only by pathological examination.