Using the best available data, our survey of a limited number of disorders shows that the burden of neurologic illness affects many millions of people in the United States.

Traumatic brain injury (TBI) is a leading cause of death and disability among persons in the United States. Each year, an estimated 1.5 million Americans sustain a TBI. As a result of these injuries, 50,000 people die, 230,000 people are hospitalized and survive, and an estimated 80,000-90,000 people experience the onset of long-term disability. Rates of TBI-related hospitalization have declined nearly 50% since 1980, a phenomenon that may be attributed, in part, to successes in injury prevention and also to changes in hospital admission practices that shift the care of persons with less severe TBI from inpatient to outpatient settings. The magnitude of TBI in the United States requires public health measures to prevent these injuries and to improve their consequences. State surveillance systems can provide reliable data on injury causes and risk factors, identify trends in TBI incidence, enable the development of cause-specific prevention strategies focused on populations at greatest risk, and monitor the effectiveness of such programs. State follow-up registries, built on surveillance systems, can provide more information regarding the frequency and nature of disabilities associated with TBI. This information can help states and communities to design, implement, and evaluate cost-effective programs for people living with TBI and for their families, addressing acute care, rehabilitation, and vocational, school, and community support.

SUMMARYWorldwide, about 65 million people are estimated to have epilepsy. Epidemiologic studies are necessary to define the full public health burden of epilepsy; to set public health and health care priorities; to provide information needed for prevention, early detection, and treatment; to identify education and service needs; and to promote effective health care and support programs for people with epilepsy. However, different definitions and epidemiologic methods complicate the tasks of these studies and their interpretations and comparisons. The purpose of this document is to promote consistency in definitions and methods in an effort to enhance future population-based epidemiologic studies, facilitate comparison between populations, and encourage the collection of data useful for the promotion of public health. We discuss: (1) conceptual and operational definitions of epilepsy, (2) data resources and recommended data

Objective: To update the 1997 American Academy of Neurology (AAN) practice parameter regarding