A STUDY OF DEMENTIA WITH ARGYROPHILIC GRAINS - POSSIBLE CYTOSKELETAL ABNORMALITY IN DENDROSPINAL PORTION OF NEURONS AND OLIGODENDROGLIA

Two mildly demented patients with emotional disorder presented massive cortical argyrophilic grains (ArG) in the limbic area and coiled bodi es mainly in the white matter. Immunohistochemically, the ArG consiste d of partially ubiquitinated full-length phosphorylated tau. A modifie d Gallyas-Braak method, used after potassium permanganate and oxalic a cid pretreatment, revealed many filiform, knobby or pleomorphic spine- like appendages on the ArG, Double immunohistochemical staining using anti-tau with either anti-microtubule-associated protein 2 or anti-neu rofilament 200K revealed that ArG were intimately associated with dend rites rather than with axons. Electron microscopic studies with tau im munohistochemistry and the Gallyas-Braak method revealed that the ArG were composed of bundles of smooth tubules of 25-nm diameter. The coil ed body-bearing cells had the morphological characteristic of oligoden droglia. These results indicate that the presence of ArG is a cytoskel etal abnormality affecting predominantly the dendrospinal portions of neurons, A survey of diseases with cytoskeletal disorders revealed tha t a small number of similar argyrophilic granular structures are somet imes observed in progressive supranuclear palsy, Pick's disease with P ick bodies and corticobasal degeneration, Dementia with ArG is thought to be a unique cytoskeletal abnormality associated predominantly with the dendrospinal portions of neurons and oligodendroglia.