Facts about Developmental Disabilities

Developmental Disability constitutes a disability which originates before an individual attains age 18, continues or can be expected to continue indefinitely, and constitutes a substantial handicap for the individual. This term includes the diagnoses of mental retardation, cerebral palsy, epilepsy and autism. This term also includes handicapping conditions found to be closely related to mental retardation or requiring treatment similar to that required for persons with mental retardation, but does not include other handicapping conditions that are solely physical in nature. (Lanterman Act, Welfare and Institutions Code, Section 4512.)

Substantial Handicap means the individual’s needs cannot be adequately met by participating in social, educational, vocational, recreational, medical, or other resources and life activities which generally are expected to be available to other non-handicapped individuals in the community.

Mental Retardation refers to significantly sub average general intellectual functioning existing concurrently with deficits in adaptive behavior and manifested during the developmental period. Generally the regional center interprets this to mean a measured performance on standardized intellectual tests at least two standard deviations below the mean or average, typically an Intelligence Quotient (IQ) less than 70. Mental retardation is usually diagnosed by a psychologist or physician.

Epilepsy is a clinical disorder involving impairment of consciousness, characterized by paroxysmal attacks of loss of consciousness, convulsive movements, or disturbances of feeling or behavior. These transient episodes or seizures are associated with excessive nerve cell discharges occurring diffusely or focally in the brain. The sites of the neuronal discharges determine the clinical manifestations of the seizure. Epilepsy is diagnosed by a physician following a neurological evaluation which may include an electroencephalogram (EEG) to determine the type and degree of brain wave abnormality.

The major types of seizures include:

• Grand mal seizures
• Focal (frontal, parietal, or occipital lobe) seizures
• Temporal lobe (psychomotor) seizures
• Minor (petit mal, myoclonic, akinetic) seizures

The incidence of epilepsy is about 1% of the general population, three-fourths of whom develop it prior to age 21 years. It is estimated that an equal number remain undiagnosed or unrecognized. Appropriate medications will result in good control of seizures for about 80% of those diagnosed and fair control for about 10%. Seizures will be poorly controlled or intractable for the remaining 10%.

Autism is a syndrome which appears early in life, usually prior to age 3, which is characterized by extreme withdrawal, language disturbance, inability to form effective ties, frequent lack of responsiveness to other people, monotonously repetitive motor behaviors, inappropriate response to external stimuli, and an obsessive urge for the maintenance of sameness. Diagnosis is made by a physician based on the developmental history and clinical manifestations, generally between the ages of 2 and 4 years. The incidence of autism is less than 1% of the general population. About 80% of the children will function in the mentally retarded range. About 35 to 40% will eventually develop epilepsy. Cerebral Palsy is a non-progressive pathologic lesion in the developing infant or child’s brain causing permanent motor and/or sensory impairment.

Cerebral palsy is evidenced by delayed gross motor development, abnormal motor performance, alterations of muscle tone, abnormal postures at rest, and abnormal reflexes. The impact may vary from slight to very severe. The four most common types of cerebral palsy are spastic, athetoid, ataxic and mixed. Diagnosis is made by a physician based on history, observation and medical tests. The incidence of cerebral palsy is about .5% of the general population. It is the most common permanent physical disability of childhood. About one-third of the children with cerebral palsy have normal intelligence. About one-half of the children with cerebral palsy have some type of seizure disorder.

Disability Descriptions courtesy of Far Northern Regional Center
visit www.farnorthernrc.org for more information.