Diagnosis of typical cases is mainly based on symptoms, with motor symptoms being the chief complaint. Tests such as neuroimaging (MRI or imaging to look at dopamine neuronal dysfunction known as DaT scan) can be used to help rule out other diseases.[1][2] Parkinson's disease typically occurs in people over the age of 60, of whom about one percent are affected.[1][3] Males are more often affected than females at a ratio of around 3:2.[4] When it is seen in people before the age of 50, it is called early-onset PD.[15] By 2015, PD affected 6.2 million people and resulted in about 117,400 deaths globally.[7][8] The average life expectancy following diagnosis is between 7 and 15 years.[8]