Four motor symptoms are considered cardinal signs in PD: slowness of movement (bradykinesia), tremor, rigidity, and postural instability.[1] Typical for PD is an initial asymmetric distribution of these symptoms, where in the course of the disease, a gradual progression to bilateral symptoms develops, although some asymmetry usually persists. Other motor symptoms include gait and posture disturbances such as decreased arm swing, a forward-flexed posture, and the use of small steps when walking; speech and swallowing disturbances; and other symptoms such as a mask-like facial expression or small handwriting are examples of the range of common motor problems that can appear.[1]