A developmental disability is a life-long physical or cognitive impairment that limits daily functioning and restricts participation in activities. A developmental disability may interfere with learning, mobility, working, speaking, understanding the speech of others and being able to live independently. An estimated 15 in 1,000 people have a developmental disability, according to a report by Dr. Sheryl Larson and her colleagues in the April 2000 issue of "MR/DD Data Brief."
Autism
Children with autism usually have difficulty with social interaction, empathy, pretend play, speech and nonverbal communication, such as making eye contact. Many individuals with autism never develop productive speech. Those who learn constructive speech often have difficulty carrying on a conversation or simply repeat what is said by others. Individuals with autism may also engage in ritualistic behaviors, do the same action repeatedly, or have an intense interest in something that seems like an obsession. Symptoms of autism appear before age three. About two out of 1,000 children are estimated to have autism, according to research in the January 30, 2007 issue of "Neurology."
Cerebral Palsy
Cerebral palsy is a group of disorders caused by brain damage that impacts muscle tone and the coordination of body movement. The nervous system controls the muscles for movement, so movement can be difficult if the neural signals from the brain are faulty or lacking. Individuals with cerebral palsy may experience difficulty with engaging in common activities, such as walking, dressing or eating. Development of cerebral palsy occurs during pregnancy, at childbirth or in early childhood. Cerebral palsy affects approximately two of every 1,000 children, as estimated by the study in "Neurology."
Mental Retardation
Mental retardation is a condition that occurs when a person has below-average intelligence and has deficits in communication, social or self-care skills. The average IQ score is 100; a person with mental retardation has a score of 70 or below. Symptoms of mental retardation are diagnosed before the age of 18. According to the report by Dr. Larson, about nine in 1,000 people meet the criteria for mental retardation.
Spina Bifida
Spina bifida is a birth defect that occurs when the brain, spinal cord or protective covering surrounding the brain and spinal cord--called the meninges--does not fully develop. In the United States, about 1 in 2,500 infants are born with spina bifida each year, according to a population-based study published in the November 2006 issue of "Birth Defects Research Part A: Clinical and Molecular Teratology." The three most common types of spina bifida are the occulta, meningocele and myelomeningocele forms, as noted by the March of Dimes.
Individuals with the occulta form of spina bifida usually experience no disabilities and no visible signs, except for a tuft of hair, dimple, or pigmented region on the skin over the defect. Infants with the meningocele form of spina bifida have a bulge that protrudes through the vertebrae and can be seen on the back. The bulge does not contain the spinal cord and may be covered by skin. Some individuals with the meningocele type have few or no symptoms, while others may experience leg pain, cognitive difficulties, some paralysis, or bladder and bowel problems. The myelomeningocele form of spina bifida is the most serious. Infants have a bulge in the back that contains the spinal cord and is often exposed without skin. Paralysis and loss of sensation usually occurs in the areas of the body that are below the level of the spinal cord defect. This type of spina bifida leads to difficulties with bladder and bowel control. Hydrocephalus, or excess fluid in and around the brain, often occurs. Individuals may experience intense pain in the lower back, legs and behind the knees.
References
- "Birth Defects Research Part A: Clinical and Molecular Teratology"; National estimates and race/ethnic-specific variation of selected birth defects in the United States, 1999-2001; Mark Canfield, Margaret Honein, Nataliya Yuskiv, Jian Xing, Cara Mai, Julianne Collins, Owen Devine, Joann Petrini, Tunu Ramadhani, Charlotte Hobbs, and Russell Kirby, for the National Birth Defects Prevention Network; November 2006.
- March of Dimes: Spina Bifida
- "MR/DD Data Brief"; Prevalence of Mental Retardation and/or Developmental Disabilities: Analysis of the 1994/1995 NHIS-D; Sheryl Larson, Charlie Lakin, Lynda Anderson, Nahoon Kwak, Jeoung Hak Lee, and Deborah Anderson; April 2000
- "Neurology"; How Common are the "Common" Neurological Disorders; Deborah Hirtz, David Thurman, Katrina Gwinn-Hardy, Maha Mohamed, Asish Chaudhuri, and R. Zalutsky; January 30, 2007.
