"Ataxia" refers to both the neurologic syndrome of motor coordination and to a large and diverse group of diseases that have motor coordination impairment as their main clinical feature. The brain structure most consistently affected is the cerebellum. Although many different brain diseases may manifest with ataxia, the vast majority of slowly progressive ataxias are genetic diseases. Indeed, genetic molecular analysis has become the cornerstone of both diagnosis and classification of this complex group of conditions. In this overview, the basics of the clinical features and the classification of these diseases, as well as common conditions, and recently defined novel forms of ataxia are discussed.

This chapter provides an overview of the three most common disorders likely to be encountered by geriatric providers. Together, tremors, parkinsonism, and gait disorders are common enough that nearly one in three patients in a geriatrics clinic may be affected by at least one of these disorders. Each section begins with definitions of each of the conditions, clinical phenomenology, and features, followed by practical treatment approaches and algorithms. In addition, when there is overlap between conditions (i.e., atypical parkinsonism), hallmarks and red flags of each condition will be highlighted to help to compare and contrast.