Other Special Education Disabilities

Confused young man when do her task

The Individuals with Disabilities Education Act (IDEA) was signed into law in 2004 as a way to provide a free and appropriate general education to all children who need special education services. IDEA has defined what qualifies as a disability under the act; we’ve provided a clearer explanation of some of the disorders that fall under IDEA and how they are defined.

Mental Retardation

This term is used generally to identify people who have limitations in mental skills and daily function, which can cause developmental delays and children to learn at a slower pace than their peers.

IDEA provides this definition of mental retardation: “…significantly sub-average general intellectual functioning, existing concurrently with deficits in adaptive behavior, existing concurrently with defects in adaptive behavior and manifested during the developmental period, that adversely affects a child’s educational performance.” Children who are afflicted by mental retardation often take longer to speak, walk and take care of their personal needs, the self-care portion of living.

Mild Mental Retardation (MIMR)Standard measures of testing intelligence show that the child is performing below average for students of the same age by 2 to 3 deviations.

Moderate Mental Retardation (MOMR) – The child is diagnosed with MMR when they show 3 to 4 deviations from the standard performance testing of children in their peer group.

Severe Mental Retardation (SMR) – Performance testing shows more than 4 deviations from what is normal for children in that age range.

Speech and Language Impairments (SLI)

These occur when there is a problem with oral motor function and communication. The American Speech-Language-Hearing Association defines SLI as “when a person is unable to produce speech sounds correctly or fluently, or has problems with his or her voice, then he or she has a speech disorder.” Problems like stuttering and articulation are considered to be speech disorders, and can be caused by injury, mental retardation, hearing loss or neurological disorders.

Autism (ASD) or Pervasive Development Disorder (PDD)

These two disorders share many of the same symptoms, but with slight differences to each. These conditions become obvious by the age of three and are neurological syndromes that affect a child’s ability to understand language correctly, communicate properly and play appropriately. A professional diagnosis of Autism Spectrum Disorder (ASD) occurs when a child displays 6 to 12 signs of the condition across three key areas: social interaction, communication and behavior. If a child doesn’t qualify for ASD, a diagnosis of PPD might be in order.

Deafness and Hearing Impairment (HI)

IDEA specifies that both deafness and hearing impairments qualify children with special needs to receive special education services through traditional schooling avenues. Although the term “hearing impairment” is often used to describe hearing loss and even deafness, the two are separated in IDEA for better clarification. Hearing impairment becomes “an impairment in hearing, whether permanent or fluctuating, that adversely affects a child’s educational performance,” whereas deafness is defined as “a hearing impairment that is so severe that the child is impaired in processing linguistic information through hearing, with or without amplification.”

There are four types of hearing loss:

  • Conductive Hearing Loss – Caused by disease or obstruction in the outer or middle ear and affects all frequencies evenly. Loss is usually not severe and can be remedied with a hearing aid or minor surgery
  • Sensorineural Hearing Loss – When damage occurs to the delicate sensory hairs in the inner ear, or the nerves that supply it, this type of loss might happen and can range from mild to severe. This affects a person’s ability to hear certain frequencies more than other; even with proper amplification techniques an affected person might hear distorted sounds, which means a hearing aid will bring no relief
  • Mixed Hearing Loss – This is a combination of conductive and sensorineural hearing loss, which means there is a problem with both the outer or middle ear and the inner ear
  • Central Hearing Loss – Impairment of damage to the nuclei or nerves of the central nervous system either in the brain itself of the pathways to the brain

Blindness And Visual Impairment (VI)

Visual impairment is the consequence of a functional loss of vision, rather than the eye disorder itself. There are 4 classified types of visual impairments in relation to special education:

  • Partially Sighted – This refers to a visual impairment of some sort that has resulted in a child requiring special education services
  • Low Vision – This typically refers to children who have a severe visual disorder and isn’t limited to distance viewing alone. A diagnosis is given to an individual when they cannot read a newspaper at a normal viewing distance, even with corrective technology. These children rely on their other senses to get through life, and might even benefit from learning Braille.
  • Legally Blind – A person must have less than 20/200 vision in the better eye or a very limited field of vision, typically 20 degrees at its widest point.
  • Totally Blind – There is no sight whatsoever. Students who have no sight often learn through Braille or other non-visual media techniques.

Eye disorders that can lead to a diagnosis of a visual impairment include:

  • Infection
  • Congenital disorders
  • Glaucoma
  • Cataracts
  • Retinal degeneration
  • Albinism
  • Diabetic retinopathy
  • Corneal disorders
  • Muscular problems


We turn to IDEA for this definition once more: “simultaneous hearing and visual impairments, the combination of which causes such severe communication and other developmental and educational needs that they cannot be accommodated in special education programs solely for children with deafness or children with blindness.” Deaf-blindness can cause severe communication issues, as well as developmental or educational needs, which is why it’s of utmost importance these children receive special education services.

Orthopedic Impairment (OI)

IDEA defines an OI as “a severe orthopedic impairment that adversely affects a child’s educational performance.” This could be caused by a genetic anomaly, disease or other circumstances such as disease or injury.

Traumatic Brain Injury (TBI)

The term refers to either open- or closed-head injuries that have affected the brain’s normal operation and function, resulting in a total or partial disability or social impairment of some sort. IDEA describes TBI as “an acquired injury to the brain caused by an external physical force, resulting in total or partial functional disability or psychosocial impairment, or both, that adversely affects a child’s educational performance.” It does not, however, apply to congenital defects or degenerative brain injuries.

For a diagnosis of TBI, a child must exhibit trouble in one or more of these areas:

  • Language
  • Cognition
  • Speech
  • Attention
  • Memory
  • Reasoning
  • Problem solving
  • Abstract thinking
  • Judgment
  • Sensory abilities
  • Perceptual abilities
  • Motor abilities

Other Health Impairment (OHI)

OHI, as defined by IDEA in regards to special education, “means having limited strength, vitality, or alertness, including a heightened alertness to environmental stimuli, that results in limited alertness with respect to the educational environment, that (a) is due to chronic or acute health problems such as asthma, diabetes, ADHD, ADD, epilepsy, a heart condition, hemophilia, lead poisoning, leukemia, nephritis, rheumatic fever, sickle cell anemia, and Tourette syndrome; and (b) adversely affects a child’s educational performance.”

Multiple Disabilities (MD)

This is when several disabilities are affecting a child at the same time, such as mental retardation and blindness, or deafness and orthopedic impairment, and in a manner that implies that will not be able to successfully learn without the assistance of special education and related services. MD does not apply to deaf-blindness.

Multiple Disabilities With Severe Sensory Impairment (MD-SSI)

Multiple disabilities refers to a visual impairment or hearing impairment, with another severe disability or a severe visual impairment and severe hearing impairment. This diagnosis qualifies a child to receive special education services.

Preschool Moderate Delay (PMD)

A child has more than three standard deviations from what is the accepted standard in one or more of these areas:

  • Motor
  • Communication
  • Cognitive
  • Adaptive development
  • Social development
  • Emotional development

Preschool Sever Delay (PSD)

This means the child has at least 1.5 but no more than 3 standard deviations from standard performance testing in at least two of the following:

  • Motor
  • Cognitive
  • Communication
  • Social development
  • Adaptive development
  • Emotional development

Developmental Delay (DD)

This term refers to a delay in children age 3 to 9 in one or more of the following areas:

  • Communication
  • Cognitive development
  • Physical development
  • Behavioral development
  • Social development
  • Emotional development

In the world of special education, knowledge is power. When it comes to your child with special needs, the more information you have, the better equipped you will be to advocate the best possible education for them.

Picture of Luke Dalien

Luke Dalien

Author Luke Dalienhttps://specialedresource.com/author/lukedalien/ has spent his life dedicated to helping others break the chains of normal so that they may live fulfilled lives. When he’s not busy creating books aimed to bring a smile to the faces of children, he and his amazing wife, Suzie, work tirelessly on their joint passion; helping children with special needs reach their excellence. Together, they founded an online tutoring and resource company, SpecialEdResource.com. Poetry, which had been a personal endeavor of Luke’s for the better part of two decades, was mainly reserved for his beautiful wife, and their two amazing children, Lily and Alex. With several “subtle nudges” from his family, Luke finally decided to share his true passion in creativity with the world through his first children’s book series, “The Adventures Of The Silly Little Beaver."

One comment

  1. My child has been recommended for a life skills self contained classroom for kindergarten and we dispute this. What are our options?

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