Parkinson's Disease: An update on Pathophysiology, Epidemiology, Diagnosis and Management Part 3 : Diagnosis, Symptoms, and Prognosis of Parkinson's Disease

Parkinson disease is a clinical diagnosis. For the condition, there are no laboratory biomarkers, and findings on routine magnetic resonance imaging and computed tomography scans are unremarkable. Medical diagnosis involves 2 of 3 cardinal signs: Resting tremor Bradykinesia and Rigidity. Parkinson's disease often has a multitude of nonmotor symptoms; some may precede the diagnosis, while others may occur early or late after the diagnosis is made, depending on motor features. Careful attention to the history is needed in patients with Parkinsonism to exclude secondary causes such as medication, toxins, or trauma. Medicines that block receptors of striatal dopamine, such as metoclopramide and neuroleptics, can cause druginduced parkinsonism. Parkinsonism can also be caused by other chemicals, such as MPTP (1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine) and manganese (at high exposure). Practical laboratory testing for PD is not available; the diagnosis is based on the clinical characteristics or excluding other causes of parkinsonism. However there are some promising developments in radiology.