Optimizing Therapeutic Effects in Patients with Comorbidities: Drug-Resistant Tremor, Autonomic Dysfunction, Psychiatric Disorders, and Cognitive Impairment

Parkinsonism is a syndrome characterized by a combination of cardinal features including resting tremor, bradykinesia, rigidity, and loss of postural reflexes. The most common presentation of parkinsonism is the idiopathic variety first described by James Parkinson in 1817 now known as Parkinson's disease (PD). This article focuses on identifying the different subtypes of PD, with the recognition that treatment approaches may differ depending on the initial presenting feature. It also addresses issues related to the recognition and treatment of nonmotor comorbidities of PD, such as autonomic dysfunction and neuropsychiatric problems including depression and dementia.