Full Answer Section

Key characteristics often include:

1. Significant Cognitive Impairment:
   • Description: This is often the primary defining characteristic, indicating substantial limitations in intellectual functioning and adaptive behavior. Students may have difficulty with abstract thinking, problem-solving, memory, and generalization of skills. Their learning rate is significantly slower than that of their typically developing peers.
   • Impact: Requires highly individualized instruction, concrete examples, repeated practice, and a focus on functional life skills rather than abstract academic concepts.
2. Communication Challenges:
   • Description: Many students with severe disabilities have limited or no verbal communication. They may use gestures, vocalizations, eye gaze, or augmentative and alternative communication (AAC) systems. Understanding and expressing needs, wants, and ideas can be significantly impaired.
   • Impact: Requires teachers to be highly skilled in interpreting non-verbal cues, using visual supports, and teaching various communication methods. Social interaction can be challenging.
3. Physical and Motor Difficulties:
   • Description: Often co-occurs with cognitive impairments, presenting as challenges with gross motor skills (e.g., walking, sitting independently), fine motor skills (e.g., grasping objects, writing), coordination, and balance. Some may require wheelchairs or other assistive devices for mobility.
   • Impact: Necessitates adaptations to the physical environment, specialized equipment (e.g., adaptive seating), and integration of physical therapy goals into daily routines. It can affect participation in classroom activities.
4. Sensory Impairments:
   • Description: Students may have visual impairments (low vision, blindness), hearing impairments (deafness, hard of hearing), or sensory processing disorders (e.g., hypersensitivity to light, sound, touch, or hyposensitivity).
   • Impact: Requires sensory-friendly environments, use of tactile materials, auditory aids, visual schedules, and strategies to minimize sensory overload or provide appropriate sensory input.
5. Adaptive Behavior Deficits:
   • Description: Difficulties in practical, social, and conceptual skills needed for everyday life. This includes self-care (e.g., dressing, hygiene), social skills (e.g., understanding social cues, building relationships), and daily living skills (e.g., managing money, using public transport).
   • Impact: Requires explicit instruction in functional life skills, often integrated into the curriculum, with opportunities for practice in natural settings.
6. Behavioral Challenges:
   • Description: Some students may exhibit challenging behaviors (e.g., self-injurious behavior, aggression, repetitive behaviors) often stemming from communication difficulties, frustration, sensory overload, or unmet needs.
   • Impact: Requires a strong focus on positive behavior support, functional behavior assessments, and creating a highly structured and predictable environment.

Causes of Severe Disabilities

The causes of severe disabilities are diverse and can be attributed to genetic, prenatal, perinatal, or postnatal factors:

• Genetic Factors: Chromosomal abnormalities (e.g., Down syndrome, fragile X syndrome), single gene disorders (e.g., Hurler syndrome, Tay-Sachs disease).
• Prenatal Factors (during pregnancy): Maternal infections (e.g., rubella, Zika virus), exposure to toxins (e.g., alcohol via Fetal Alcohol Spectrum Disorders), certain medications, complications like severe pre-eclampsia, or malnutrition.
• Perinatal Factors (during birth): Birth trauma, oxygen deprivation (anoxia), premature birth, very low birth weight.
• Postnatal Factors (after birth): Severe head injuries, infections (e.g., meningitis, encephalitis), prolonged seizures, exposure to lead or other environmental toxins, severe malnutrition in early childhood.