MD Glossary of Terms

Common terms used within Multiple Disabilities.

AFO (Ankle-foot orthosis)
A brace, usually made of plastic, which is worn on the lower leg and foot to support the ankle, hold the foot and ankle in the correct position and correct foot drop. The physical therapist fits it and is the specialist to contact with questions and concerns.

Angelman Syndrome
Angelman Syndrome occurs in approximately 1 in 12,000 people and is caused by a chromosomal abnormality. (Angelman Foundation 2006) People with Angelman Syndrome often display characteristics such as an unsteady gait or jerky body movements, impaired or limited speech, motor delays, cognitive delays, difficulty eating, limited attention spans, and usually appear to be smiling or laughing. In many cases people with Angelman Syndrome also have a coexisting seizure disorder. Though people with Angelman Syndrome sometimes display aggression, they are typically very social people and enjoy interacting with others.
Please refer to the U.S. National Library of Medicine for more details regarding AS.
Cerebral Palsy (CP)
CP is caused by injuries or abnormalities of the brain and usually occurs before birth, but can happen any time up to two years old. Because it is a condition involving the brain, many functions of the body can be affected such as movement, learning, seeing, hearing, and thinking. The symptoms range from mild to severe.
Please refer to the U.S. National Library of Medicine for more details regarding CP.

CI - Cognitive impairment: based on the DSM-VI
A developmental condition that is characterized by significantly lower then average level of general intellectual functioning. CI is a failure to develop cognitive abilities and achieve an intelligence level that would be appropriate for their age group.

There are varying levels of impairment.
*Mild Cognitive Impairment (IQ level 50-55 up to about 70) About 85% of persons that are cognitively Impaired fall into this group.
*Moderate Cognitive Impairment (IQ level 35-40 to 50-55) About 10% of persons that are cognitively Impaired fall into this group.
*Severe Cognitive Impairment (IQ level 20-25 to 35-40) About 3% to 4% of persons that are cognitively Impaired fall into this group.
*Profound Mental Retardation (IQ level below 20 or 25 ) About 1% to 2% of persons that are cognitively Impaired fall into this group.
Cortical Visual Impairment (CVI)
CVI is a condition where an individual has low vision, or is blind due to a problem with the occipital lobe of the brain. The eyes may be perfectly healthy, but the individual still has a problem with vision. CVI can occur at or during birth or from any event that causes less oxygen from getting to the brain.
Please refer to the American Printing House for the blind for more details regarding CVI.
Down syndrome (DS) or Down’s syndrome
DS, also known as trisomy 21, is a congenital disease, or a disease that an individual is born with. A person with Down syndrome is born with 47 chromosomes instead of 46. The extra chromosome affects the development of cognitive ability (most have intellectual disabilities) and physical growth. Symptoms range from mild to severe.
Please refer to the U.S. National Library of Medicine for more details regarding DS.
Early Childhood Developmental Delay (ECDD)
To qualify for special education and related services under the heading of ECDD a child must be between the ages of 3 and 8. The child must function at least 2 standard deviations below the national norm or be 25% delayed in at least one of the following areas:

  • Cognitive Development

  • Physical Development (fine or gross motor skills)

  • Speech or Language Development (expressive, receptive, fluency, articulation and voice)

  • Social/Emotional Development

  • Adaptive functioning/Self-help skills


Alternately, if a student is 20% delayed in at least 2 of the above areas, s/he can qualify as a student with ECDD.
For more information, please see the Alaska State Special Education Handbook Part III- Evaluation and Eligibility.
Fetal Alcohol Syndrome (FAS)/Fetal Alcohol Spectrum Disorder (FASD)
FAS/FASD is a pattern of mental and physical defects that can develop in a baby when the mother consumes alcohol during pregnancy. The affects of FAS/FASD can vary from individual to individual. The main affect of FAS/FASD is permanent damage to the central nervous system, specifically the brain. The damage can cause mental retardation, physical growth abnormalities, memory and attention problems and behavior problems.
Please refer to the U.S. National Library of Medicine for more information regarding FAS/FASD.
Fragile X Syndrome
Fragile X Syndrome is a genetically linked syndrome caused by a chromosomal abnormality on the X chromosome. Approximately 1 in 3,600 males and 1 in 4,000 to 1 in 6,000 females are diagnosed with the syndrome. (National Fragile X Foundation, 2006) People with Fragile X Syndrome tend to have similar physical characteristics including a long, narrow face, protruding ears, and hyperextensible joints. People with Fragile X Syndrome tend to often have speech delays, cognitive impairments, and difficulty with auditory processing. Some behaviors typically displayed by people with Fragile X Syndrome include inattention, lack of eye contact, perseverative speech, and hyperactivity. Individuals with Fragile X often have a wonderful sense of humor and enjoy sharing it with others.
Please refer to the U.S. National Library of Medicine for more information regarding Fragile X Syndrome.
G-Tube (Gastronomy Tube)
A gastronomy (g-tube) is a tube inserted through the abdomen that delivers nutrients directly to the stomach. A gastronomy tube is used with children and adults that have medical problems that prevent them from being able to take adequate nutrition by mouth.
Leukodystrophy
Leukodystrophy is a group of rare genetic disorders (the leukodystrophies) that affect the central nervous system by disrupting the growth or maintenance of the myelin sheath that insulates the nerve cells in the brain. The disorders are progressive, meaning they get worse throughout the life of the patient. The affects of the leukodystrophies are cognitive as well as physical.
For more information about specific types of leukodystrophy and general information about leukodystrophies please see the United Leukodystrophy Foundation.
Multiple Disabilities (MD)
MD is a disability category where a student qualifies for special education and related services under two or more of the qualifying impairments (autism, specific learning disability, speech/language, hearing impairment, visual impairment, duel sensory impairment, cognitive impairment, orthopedic impairment, other health impairment) where the combination causes severe education problems.
For more information, please see the Alaska State Special Education Handbook Part III- Evaluation and Eligibility.
Other Health Impaired (OHI)
To qualify as a student receiving services for OHI, there must be a diagnosis by a physician. In addition, the student must exhibit limited strength, vitality or alertness due to a chronic or acute condition (ex. asthma, Tourette Syndrome, epilepsy, leukemia); or heightened alertness to environmental stimuli due to chronic or acute health problems (ex. ADD, ADHD). The condition must adversely affect the educational performance of the student to receive special education and related services as a result of the health impairment.
For more information, please see the Alaska State Special Education Handbook Part III- Evaluation and Eligibility.
Traumatic Brain Injury (TBI)
A TBI is caused by a head injury, most typically a concussion, that is so severe that it affects the brain’s normal functioning. According to the CDC, each year approximately 1.7 million people sustain a TBI. The effects of a TBI can range from mild to severe. A brief loss of conscientiousness would be considered a mild form of a TBI, while the effects of a severe TBI may last a lifetime.
Please refer to the U.S. National Library of Medicine for more information regarding Traumatic Brain Injury.