An 85-year-old man developed l-dopa responsive parkinsonism indistinguishable from Parkinson's disease and subsequent dementia, followed by supranuclear ophthalmoplegia and neck dorsiflexion at the terminal stage. Midbrain tegmentum and medial temporal lobe were atrophic on magnetic resonance imaging, while decreased blood flow was predominant in frontotemporal lobes, detected by 3D-SSP of 123I- IMP SPECT. Alzheimer-type pathology without Lewy body pathology was confirmed at autopsy. Substantia nigra showed mild degeneration and several neurofibrillary tangles without Lewy body pathology or progressive supranuclear palsy cytopathology. L-dopa responsive parkinsonism could be an initial manifestation of Alzheimer's disease, which should be included in the differential diagnosis.
Keywords: 3-iodobenzylguanidine; Alzheimer's disease; Lewy bodies; Parkinsonian disorders; Tegmentum mesencephali; levodopa; progressive supranuclear palsy.