Definition
Childhood disintegrative disorder (CDD) is a developmental disorder that resembles autism. It is characterized by at least two years of normal development, followed by loss of language, social skills, and motor skills before age ten. Other names for childhood disintegrative disorder are Heller’s syndrome, dementia infantilis, and disintegrative psychosis.
Description
Thomas Heller, an Austrian educator, first described childhood disintegrative disorder in 1908. It is a complex disorder that affects many different areas of the child’s development. It is grouped with the pervasive developmental disorders(PDDs) and is related to the better known and more common disorder of autism.
Initially CDD was considered strictly a medical disorder and was believed to have identifiable medical causes. After researchers reviewed the reported cases of CDD, however, no specific medical or neurological cause was found to account for all occurrences of the disorder. For that reason, CDD was included in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-IV, in 1994. The Diagnostic and Statistical Manualis the standard reference work consulted by mental health professionals in the United States and Canada.
Causes and symptoms
Causes
The cause of childhood disintegrative disorder is unknown. Research findings suggest, however, that it may arise in the neurobiology of the brain. About half the children diagnosed with CDD have an abnormal electroencephalogram (EEG). EEGs measure the electrical activity in the brain generated by nerve transmission (brain waves). CDD is also sometimes associated with seizures, another indication that the neurobiology of the brain may be involved. CDD is occasionally associated with such diagnosed medical disorders of the brain as leukodystrophy and Schilder’s disease; but no one disease, brain defect, disorder, or condition can account for all symptoms and all cases. Research is hampered by the rarity of this disorder.
Symptoms
Children with CDD have at least two years of normal development in all areas—language understanding, speech, skill in the use of large and small muscles, and social development. After this period of normal growth, the child begins to lose the skills he or she has acquired. This loss usually takes place between ages three and four, but it can happen any time up to age ten.
The loss of skills may be gradual, but more often occurs rapidly over a period of six to nine months. The transition may begin with unexplained changes in behavior, such as anxiety, unprovoked anger, or agitation. Behavioral changes are followed by loss of communication, social, and motor skills. Children may stop speaking or revert to single words. They often lose bowel or bladder control and withdraw into themselves, rejecting social interaction with adults or other children. They may perform repetitious activities and often have trouble moving from one activity to the next.
In this way CDD resembles autism. In autism, however, previously acquired skills are not usually lost. According to the Handbook of Autism and Pervasive Developmental Disorders, virtually all children with CDD lose speech and social skills. About 90% lose self-help skills (the ability to feed, wash, and toilet themselves); and about the same number develop non-specific overactivity. After a time, the regression stops, but the child does not usually regain the skills that were lost.
Demographics
CDD is a rare disease, much less common than autism. About 1 in 100,000 children are thought to have CDD. It is possible, however, that the disorder is under-diagnosed. For a long time, it was thought that CDD occurred equally among boys and girls. Newer research suggests that it is about four times more common in boys, and that many girls who were diagnosed with CDD actually had Rett’s disorder, a disorder that shares many of the symptoms of CDD but occurs almost always in girls.
Diagnosis
CDD is most commonly diagnosed when the parents of the affected child consult the pediatrician about the child’sloss of previously acquired skills. The doctor will first give the child a medical examination to rule out epilepsy or other medical conditions. The child’shead may also be x rayed to rule out head trauma or a brain tumor. Following the medical examinations and tests, the child will be referred to a psychiatrist who specializes in treating children and adolescents. The psychiatrist will then make the differential diagnosis of CDD.
To be diagnosed with CDD, a child must show loss or regression in at least two of the areas listed below. Usually regression occurs in more than two areas. These are:
- receptive language skills (language understanding)
- expressive language skills (spoken language)
- social or self-help skills
- play with peers
- motor skills
- bowel or bladder control, if previously established
Children with CDD are unable to start conversations with other people and often do not communicate with nonverbal signals (smiles, gestures, nodding the head, etc.) either. They also lose interest in playing games and in relationships with other people. They may engage in strange repetitive behavior, such as bobbing the head up and down, or other repeated movements. These changes must not be caused by a general medical condition or another diagnosed mental disorder.
CDD must be differentiated from autism and such other specific pervasive developmental disorders as Rett’s disease. It also must be differentiated from schizophrenia. One of the differences between CDD and other PDDs is that to be diagnosed with CDD, a child must develop normally for at least two years before loss of skills occurs, and the loss must occur before age ten. Parents’ reports of the child’s development, records in baby books, medical records kept by the child’s pediatrician, and home movies are often used to document normal development through the first two years of life.
Treatments
Treatment for CDD is very similar to treatment for autism. The emphasis falls on early and intense educational interventions. Most treatment is behavior-based and highly structured. Educating the parents so that they can support the child’streatments at home is usually part of the overall treatment plan. Speech and language therapy, occupational therapy, social skills development, and sensory integration therapy may all be used according to the needs of the individual child
Families with a child who has CDD often find themselves highly stressed. Practical demands on caregivers are high, and CDD takes an emotional toll on family members. Finding appropriate providers with experience delivering services for a child with CDD is sometimes difficult, especially outside large cities. Support groups for families can help reduce their isolation and frustration. Because CDD is rare, autism support groups and organizations include families of children with CDD in their services.
Prognosis
The prognosis for children with CDD is very poor; it is worse than the prognosis for children with autism. Once skills are lost, they are not usually regained. Only about 20% of children diagnosed with the disorder reacquire the ability to speak in sentences. Most adults with CDD remain dependent on full-time caregivers or are institutionalized.
Prevention
Since the causes of CDD are unknown, there are no known ways to prevent this disorder.