Olfactory Dysfunction.
Olfactory dysfunction is well documented as an early nonmotor manifestation of Parkinson’s disease (PD). This chapter outlines the anatomy and physiology of the olfactory system and summarizes the pathological changes in the olfactory system in PD. We review the occurrence of olfactory dysfunction in parkinsonian syndromes and familial parkinsonism. Different methods to assess olfactory function a