In an up-to-date review of most of the common neurological disorders in the United States published in the January 30, 2007, issue of Neurology, the scientific journal of the American Academy of Neurology, researchers reviewed studies from nearly 500 articles published between 1990 and 2005 to determine the best available data.
The study found nearly one out of 1,000 people have multiple sclerosis (MS). “Our estimate of MS prevalence is about 50 percent higher than a comprehensive review from 1982. Whether this reflects improvements in diagnosis or whether incidence is actually increasing deserves further study,” said one of the study authors Deborah Hirtz, MD, with the National Institute of Neurological Disorders and Stroke at the National Institutes of Health, and a member of the American Academy of Neurology.
The rate of Alzheimer?s disease was also up substantially from the past estimate, with the study finding 67 out of 1,000 elderly Americans with Alzheimer?s disease. The authors say these findings merit further research. As for the rate of traumatic brain injuries, the study found 101 out of every 100,000 Americans have a traumatic brain injury each year. That?s a 50-percent drop compared to the past estimate. The authors say the decrease likely reflects more restrictive hospital admission criteria, but improvements in motor vehicle safety may have had an effect.
The study found 183 out of every 100,000 people suffer a stroke each year, and one in 100 has had a stroke in the past. In addition, the study found nearly 10 out of 1,000 elderly Americans have Parkinson?s disease, while nearly four out of every 100,000 Americans have ALS (Lou Gehrig?s disease). Nearly five out of every 100,000 have a new onset spinal cord injury each year. As for childhood neurological disorders, the study found nearly six out of every 1,000 children have autism, with two out of every 1,000 children having cerebral palsy.
This review looked at currently available literature, which presented a wide range of estimates for some diseases. For some disorders the best available data was from western Europe, which was extrapolated to the U.S. population. More high-quality studies from the United States are needed.
“Current, accurate estimates of the numbers of people affected by neurological disorders are needed to understand the burden of these conditions on patients, families, and society, to plan and carry out research on their causes and treatment, and to provide adequate services to people who suffer from these illnesses,” said Hirtz, who is also a member of the Quality Standards Subcommittee at the American Academy of Neurology.