Creutzfeldt-Jakob disease with Alzheimer-type A beta-reactive amyloid plaques.

Creutzfeldt-Jakob disease and Gerstmann-Sträussler-Scheinker syndrome are classified as transmissible cerebral amyloidoses, in contrast to the non-transmissible amyloidoses of Alzheimer's disease type. While the aetiologies of Creutzfeldt-Jakob disease and Alzheimer's disease and the molecular composition of their amyloids are different, similar basic pathogenetic mechanisms operate in both diseases through synthesis and processing of amyloid precursor proteins, to produce an accumulation of amyloid deposits. We report here a case of Creutzfeldt-Jakob disease exhibiting numerous diffuse A beta immunoreactive plaques, thus presenting features of both Creutzfeldt-Jakob disease and Alzheimer's disease. The existence of such cases underlines the existence of a 'grey' area between the two types of amyloidoses.