title: Parkinson's disease.
abstract: Parkinson's disease is a neurological disorder with evolving layers of complexity. It has long been characterised by the classical motor features of parkinsonism associated with Lewy bodies and loss of dopaminergic neurons in the substantia nigra. However, the symptomatology of Parkinson's disease is now recognised as heterogeneous, with clinically significant non-motor features. Similarly, its pathology involves extensive regions of the nervous system, various neurotransmitters, and protein aggregates other than just Lewy bodies. The cause of Parkinson's disease remains unknown, but risk of developing Parkinson's disease is no longer viewed as primarily due to environmental factors. Instead, Parkinson's disease seems to result from a complicated interplay of genetic and environmental factors affecting numerous fundamental cellular processes. The complexity of Parkinson's disease is accompanied by clinical challenges, including an inability to make a definitive diagnosis at the earliest stages of the disease and difficulties in the management of symptoms at later stages. Furthermore, there are no treatments that slow the neurodegenerative process. In this Seminar, we review these complexities and challenges of Parkinson's disease.
authors.affiliation: Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J Safra Program in Parkinson's Disease, Toronto Western Hospital, Division of Neurology, Department of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: Lorraine V
authors.initials: LV
authors.lastname: Kalia
authors.affiliation: Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J Safra Program in Parkinson's Disease, Toronto Western Hospital, Division of Neurology, Department of Medicine, University of Toronto, Toronto, ON, Canada. Electronic address: lang@uhnres.utoronto.ca.
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Lang
mesh_terms: D001921:Brain / Q000473:pathology; D018450:Disease Progression; D015259:Dopamine Agents / Q000009:adverse effects / Q000627:therapeutic use; D020022:Genetic Predisposition to Disease; D006801:Humans; D010300:Parkinson Disease / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D012307:Risk Factors
chemical_list: D015259:Dopamine Agents