Frontal lobe dementia is not a variant of prion disease

Frontal lobe dementia (FLD) is a syndromal diagnosis with a variable pathology. It has been argued that FLD is a dementing disorder which should be nosologically and etiologically distinguished from other types of dementia. However, similarities with prior disease and Alzheimer's disease have led to the suggestion that FLD is a variant of one or other of these dementias. We have tested this line of argument by examining the frontal cortex and cerebellum of 14 FLD cases and probing the molecular pathology using well characterized antibodies to prion protein and beta-amyloid protein. No prion protein deposits or significant levels of beta-amyloid protein were detected. FLD is a dementing disorder whose molecular pathology, whilst as yet uncharacterised, can be distinguished from those of other dementing disorders.