In spite of a great deal of study, both histopathologic and histochemical, no agreement has been reached as to the exact origin of the characteristic plaques that occur in the brain in cases of senile dementia. A survey of the extensive literature indicates that the hypotheses concerning the histogenesis of these senile plaques may be briefly listed as follows:
They represent an inclusion of a parasitic fungus in the brain: Fischer1 (1907) and Schönfeld2 (1914).
They consist of disintegrated neuroglial reticulum or of a deposit of some product of abnormal metabolism: Blocq and Marinesco3 (1892), Redlich4 (1898), Miyake5 (1906), Léri6 (1906), Simchowicz7 (1911), Bielschowsky8 (1911), Alzheimer9 (1907), Perusini10 (1909-1911), Ciarla11 (1914), Tumbelaka12 (1920), Bonfiglio13 (1922) and Uyematsu14 (1923).
They are the result of primary thickening of the axis cylinder: Fischer15 (1908) and Fuller16 (1911).
They are derived from nerve cells: Bonfiglio17 (1908), Ansalone18 (1913),
HIROISI S, LEE CC. ORIGIN OF SENILE PLAQUES. Arch NeurPsych. 1936;35(4):827-NP. doi:10.1001/archneurpsyc.1936.02260040135009