The aim of this investigation was to compare olfactory functions of pa
tients suffering from Parkinson's disease (PD) and Alzheimer's disease
(AD). Olfactory threshold, odor identification ability and odor memor
y performance were assessed in 21 non-demented PD patients and in 22 A
D patients. Both patient groups were impaired in relation to an age-ma
tched control group for the measure of odor identification. AD patient
s showed a:higher olfactory threshold and poorer odor memory performan
ce.