The international incidence and prevalence of neurologic conditions

In an effort to better understand the global burden of neurologic conditions, the Public Health Agency of Canada launched the National Population Health Study of Neurological Conditions (NPHSNC) in 2009.1 One of the many aims of the NPHSNC was to examine the epidemiology, including the incidence and prevalence, of 15 neurologic conditions: Alzheimer disease (AD) and related dementia, amyotrophic lateral sclerosis (ALS), brain tumors, cerebral palsy, dystonia, epilepsy, Huntington disease (HD), hydrocephalus, multiple sclerosis, muscular dystrophy, Parkinson disease (PD), spina bifida, spinal cord injury (SCI), Tourette syndrome, and traumatic brain injury (TBI). In addition to performing systematic reviews on the worldwide incidence and prevalence of these neurologic conditions, we examined issues arising as a result of heterogeneity in the conduct of international epidemiologic studies in neurology.