Gibb WR, Lees AJ The relevance of the Lewy body to the pathogenesis of idiopathic Parkinson's disease. J Neurol Neurosurg Psychiatry. 1988 Jun;51(6):745-52. Review.
Jordan J, Biaggioni I Diagnosis and treatment of supine hypertension in autonomic failure patients with orthostatic hypotension. J Clin Hypertens (Greenwich). 2002 Mar-Apr;4(2):139-45.
Karrasch M, Laatu S, Martikainen K, Marttila R CERAD test performance and cognitive impairment in Parkinson's disease. Acta Neurol Scand. 2013 Dec;128(6):409-13. doi: 10.1111/ane.12138. Epub 2013 May 14.
O'Sullivan JD, Said CM, Dillon LC, Hoffman M, Hughes AJ Gait analysis in patients with Parkinson's disease and motor fluctuations: influence of levodopa and comparison with other measures of motor function. Mov Disord. 1998 Nov;13(6):900-6.
Woodford H, Walker R Emergency hospital admissions in idiopathic Parkinson's disease. Mov Disord. 2005 Sep;20(9):1104-8.
Technology-Based Objective Measures for Gait and Postural Assessment in Parkinson Disease Patients With Orthostatic Hypotension: Feasibility and Effect-Size Finding Study
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
