April 21, 2009 -- Nearly 5.6 million people in the U.S. -- about 2% of the population -- are paralyzed, according to a new survey.
The survey, which comes from the Christopher and Dana Reeve Foundation and included more than 33,000 U.S. adults, defines paralysis as having "difficulty or inability" in moving the upper and lower extremities because of a condition affecting their central nervous system (brain or spinal cord).
That definition is in line with the World Health Organization's definition of disability, notes Joseph Canose, vice president for Quality of Life at the Christopher and Dana Reeve Foundation.
Top Causes of Paralysis
Stroke is the top cause of paralysis, affecting an estimated 1.6 million people in the U.S., according to the survey.
Spinal cord injury is the No. 2 cause of paralysis, affecting nearly 1.3 million people, the survey shows.
That's much higher than previous estimates of about 250,000 people paralyzed by spinal cord injury, Canose notes.
The late Christopher Reeve "never believed that the numbers that were estimated were right," Canose tells WebMD. "Chris would guesstimate that there must be 400,000 people [paralyzed by to spinal cord injury], when in fact now we find 1.275 million."
Multiple sclerosis is the third most common cause of paralysis, affecting 939,000 people.
The survey was conducted between May and August 2008.
Range of Severity
Survey participants who reported paralysis also noted how difficult it was for them to move their upper or lower extremities at the time of the survey. Here are those results
- Completely unable to move extremities: 16%
- A lot of difficulty: 36%
- Some difficulty: 29%
- A little difficulty: 17%
- No difficulty: 2%
"Not everyone is completely unable to move," Canose says. People who reported "no difficulty" in moving at the time of the survey may have conditions like multiple sclerosis, which can include phases of greater or lesser impairment.
Race, Income Gaps
Native Americans and African-Americans make up a disproportionately high percentage of the paralyzed population, the survey shows.
Native Americans make up 0.8% of the U.S. population but account for 3.7% of the paralyzed population. African-Americans account for 12.4% of the U.S. population but make up about 17% of the paralyzed population, according to the survey.
Household incomes were far lower for paralyzed participants than for other people.
Nearly a quarter of paralyzed participants -- 24% -- reported that their annual household income was less than $10,000, compared to 7% of the U.S. population.
The extent of the racial and income gaps was surprising, says Canose, who says more research is needed to find out why those gaps exist and how they should be addressed.