Clinical Neuroepidemiology

Neuroepidemiology, the study of neurologic diseases in populations,¹⁻³addresses important issues of disease frequency, causation, and prevention. But often it is of limited use to the clinician or investigator trying to determine the best way to diagnose and treat patients with neurologic problems. The discipline of clinical epidemiology applies the principles of classic epidemiology to questions of clinical care; the powerful techniques used to study populations are used to address questions for individual patients. Several books and articles recently have been written on clinical epidemiology,⁴⁻⁷demonstrating how it is a "... numerate approach to the conduct of clinical research and clinical decision making,"⁸and is "... the study of determinants and effects of clinical decisions."⁹These works have mostly addressed an audience of general internists. The present article and two subsequent ones introduce the neurologist to some concepts of clinical epidemiology, using examples that are relevant to