Management of anxiety and motor symptoms in Parkinson's disease.

Parkinson's disease (PD) is typically known for its cardinal motor symptoms, but a growing body of literature is recognizing a multitude of important nonmotor symptoms as well. Anxiety is one of the most common nonmotor symptoms of PD; unfortunately, neither the management of anxiety nor its influence on motor symptoms is well understood. While recent literature indicates a correlation between motor symptoms and anxiety in PD, it remains uncertain whether one symptom acts as the underlying cause of the other. This review considers the cyclic interaction between anxiety and motor symptoms in PD, each exacerbating the other when they coexist. It may be critically important to disentangle if one symptom serves as an underlying cause of the other, since this might dictate appropriate treatment. Neuroanatomical substrates as well as the treatments for both motor symptoms and anxiety are discussed in detail to consider the evidence-base for the management of PD.