Spongiform alterations in brain biopsies of presenile dementia.

Spongiform lesions were observed in close association with typical presenile alterations in three of six frontal lobe biopsies taken in presenile demented patients without any familial relationship. These findings are discussed in relation with recent investigations indicating the production of spongiform lesions after inoculation of nervous tissue from an Alzheimer patient to animals and the effects of saline extract of such material on cultured nerve cells.