ABSTRACT
Olfactory dysfunction can arise from a variety of reasons and can profoundly influence a patient’s quality of life. Such problems are not uncommon, being present in at least 1 % of the population under the age of 65 years, and in well over 50% of the population older than 65 years (Doty et al., 1984, 1986; Hoffman et al., 1998; Murphy et al., 2001; Schiffman, 1983). We now know that decrements in olfactory function are among the first clinical signs of Alzheimer’s disease and idiopathic Parkinson’s disease, and are commonly present in epilepsy, multiple sclerosis, and schizophrenia (see Chapter 23). Although some patients initially present with a frank complaint of a smell disturbance, others are unaware of their dysfunction, pointing out the need for routine quantitative olfactory assessment, which is now easily performed in the office (see Chapter 10).
