ABSTRACT
Dementia is a major public health problem, crossing gender, socioeconomic, and ethnic lines. The
incidence of dementia increases with age and prevalence increases every decade after age 65 (1,2).
Alzheimer’s disease (AD), the most common cause of dementia, is covered in detail by Morris in
Chapter 10. The differential diagnosis of dementia includes a wide range of disorders, many of
which are covered by other authors in this volume. The focus of this chapter will be on disorders
where Lewy bodies (LBs) are the predominant distinctive pathology whether or not AD pathologic
lesions [senile plaques (SPs) and neurofibrillary tangles (NFTs)] are also found. In this chapter we
will review three disorders that share common clinical and cognitive features as well as
pathologic lesions.