Childhood Disintegrative Disorder
Childhood Disintegrative Disorder, also known as Heller's Syndrome or Dementia Infantilis is a rare disorder where children lose the skills that they previously learnt, such as speech, motor skills, social skills, etc. It is different from autism with regression, because a child with CDD loses skills much later than a child with regressive autism would. It is also much more severe and obvious.
Symptoms
The main characteristic of Childhood Disintegrative Disorder is that a child loses skills they have already learnt. Some children are aware of this and in 75% of cases, they have a 'prodrome.' This is anxiety and terror that comes before the regression, but it doesn't always happen. The most apparent symptom is that skills are lost.
Symptoms and severity can vary from child to child, but some symptoms include:
- Loss of speech (a child who could say a sentence may suddenly lose their speech, only saying parts of the words and sometimes losing speech altogether)
- Loss of cognitive skills (a child who had good memory may forget things, or they may not be able to understand simple questions that were asked to them)
- Loss of motor skills (a child may lose the ability to grasp things, perform certain movements or even walk)
- Loss of social skills (a child may lose the ability to have a conversation or understand social cues, such as eye contact and responding to others appropriately)
- Loss of play skills (a child may lose the ability to play with other children, use their imagination and pretend, or suddenly engage in repetitive play)
- Loss of self-care skills (a child who could feed themself, bathe, or get dressed on their own may not be able to anymore—this might be because the child has forgot the steps on taking care of themself, or they do not have the motor function to do so)
Some other symptoms to note are:
- Aggression (a child may start hitting, kicking, or biting themself or others)
- Behaviour changes (a child may seem hyperactive or show unusual repetitive behaviours, such as rocking or flapping their hands)
- Special interests (a child may show unusual special interests, similar to autism)
Children usually stop regressing around the age of 10. The symptoms of CDD may come abruptly (quickly) or gradually (over a long period of time).
Causes
Doctors do not know what causes CDD as a whole, but it is thought to be caused by:
- Lipid Storage Diseases (where fats excessively build up in the brain and nervous system)
- Panencephalitis (infection of the brain caused by measles; causes brain inflammation and nerve cell death)
- Tuberous Sclerosis (where non-cancerous tumours grow in the brain)
- Leukodystrophy (where myelin sheaths do not develop correctly, which causes white matter in the brain to not work)
- Encephalitis (inflammation of the brain caused by viral or bacterial infection)
- Genetics (there are many genes linked to autism, such as CHD8, ADNP, ANK2, CTNND2, etc.)
It is linked to epilepsy, because patients with CDD have a higher chance of seizures, but they do not know if it has anything to do with the disorder. A child who has language regression and seizures would fit more with the criteria of Landau-Kleffner Syndrome.
It is important to rule out any other disorders such as mercury poisoning, lead poisoning, hypothyroidism, brain tumours, HIV, childhood schizophrenia, etc.
Treatment
Children diagnosed with CDD have a treatment plan similar to children with autism. They will need speech therapy to regain their speech, occupational therapy to regain life skills and to work on social skills. Sensory integration therapy—therapy that helps with sensory issues—may be used to stabilise the sensory systems. Medicine such as Risperidone, Olanzapine, or Cerebrolysin may be used to help aggression and mental decline.
Educating parents about CDD is also important. Parents with CDD can feel uncertain or anxious about the diagnosis, so it's also important to give parents counselling to help them navigate the disorder.
In 20% of cases, it is possible to regain speech, but very few children regain all their skills.
Prognosis
The prognosis (outcome) for this disorder is not very good. A child that has CDD will need special support all their life. They can still go to school, but they either need a helper or have to go to a separate special school altogether. Children with CDD grow up to need support services such as carers. Life expectancy (how long someone lives) is normal.