Nonmotor symptoms of Parkinson’s disease

Parkinson’s disease is generally thought of first and foremost as a disorder of motor control. The cardinal signs of PD are all motor defects, which generally respond favorably to dopaminergic stimulation. While the most obvious pathological change in PD is degeneration of pigmented neurons in the substantia nigra, many other neuronal pathways not involved in motor function (such as the noradrenergic locus ceruleus, the serotonergic raphe nuclei, and the cholinergic nucleus basalis of Meynert) also degenerate in this disease (1). It is not surprising, therefore, that nonmotor symptoms abound in this patient population (Table 1). In this chapter we will consider the most common and important nonmotor symptoms seen in PD and, where possible, discuss therapeutic options for these problems.