Komatsu T, Kimura T, Yagishita A, Takahashi K, Koide R A case of reversible cerebral vasoconstriction syndrome presenting with recurrent neurological deficits: Evaluation using noninvasive arterial spin labeling MRI. Clin Neurol Neurosurg. 2014 Nov;126:96-8. doi: 10.1016/j.clineuro.2014.08.023. Epub 2014 Aug 30.
Lee R, Ramadan H, Bamford J Reversible cerebral vasoconstriction syndrome. J R Coll Physicians Edinb. 2013;43(3):225-8. doi: 10.4997/JRCPE.2013.307. Review.
Miller TR, Shivashankar R, Mossa-Basha M, Gandhi D Reversible Cerebral Vasoconstriction Syndrome, Part 1: Epidemiology, Pathogenesis, and Clinical Course. AJNR Am J Neuroradiol. 2015 Aug;36(8):1392-9. doi: 10.3174/ajnr.A4214. Epub 2015 Jan 15. Review.
Miller TR, Shivashankar R, Mossa-Basha M, Gandhi D Reversible Cerebral Vasoconstriction Syndrome, Part 2: Diagnostic Work-Up, Imaging Evaluation, and Differential Diagnosis. AJNR Am J Neuroradiol. 2015 Sep;36(9):1580-8. doi: 10.3174/ajnr.A4215. Epub 2015 Jan 22. Review.
Mortimer AM, Bradley MD, Stoodley NG, Renowden SA Thunderclap headache: diagnostic considerations and neuroimaging features. Clin Radiol. 2013 Mar;68(3):e101-13. doi: 10.1016/j.crad.2012.08.032. Epub 2012 Dec 11. Review.
Rosenbloom MH, Singhal AB CT angiography and diffusion-perfusion MR imaging in a patient with ipsilateral reversible cerebral vasoconstriction after carotid endarterectomy. AJNR Am J Neuroradiol. 2007 May;28(5):920-2.
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.
