A Mayo Clinic report indicates: "Comprehensive medical and neurological examinations in children diagnosed with childhood disintegrative disorder seldom uncover an underlying medical or neurological cause. Although the occurrence of epilepsy is higher in children with childhood disintegrative disorder, experts dont know whether epilepsy plays a role in causing the disorder. "CDD, especially in cases of later age of onset, has also been associated with certain other conditions, particularly the following:
Lipid storage diseases: In this condition, a toxic buildup of excess fats (lipids) takes place in the brain and nervous system. Subacute sclerosing panencephalitis: Chronic infection of the brain by a form of the measles virus causes subacute sclerosing panencephalitis. This condition leads to brain inflammation and the death of nerve cells. Tuberous sclerosis (TSC): TSC is a genetic disorder. In this disorder, tumors may grow in the brain and other vital organs like kidneys, heart, eyes, lungs, and skin. In this condition, noncancerous (benign) tumors, hamartomas, grow in the brain. Leukodystrophy: In this condition, the myelin sheath does not develop in a normal way, causing white matter in the brain to eventually fail and disintegrate. Treatment
Loss of language and skills related to social interaction and self-care are serious. The affected children face ongoing disabilities in certain areas and require long-term care. Treatment of CDD involves both behavior therapy, environmental therapy and medications. Behavior therapy: Applied Behavior Analysis (ABA) is considered to be the most effective form of treatment for Autism spectrum disorders by the American Academy of Pediatrics.
The primary goal of ABA is to improve quality of life, and independence by teaching adaptive behaviors to children with autism, and to diminish problematic behaviors like running away from home, or self-injury by using positive or negative reinforcement to encourage or discourage behaviors over time. Environmental Therapy: Sensory Enrichment Therapy uses enrichment of the sensory experience to improve symptoms in autism, many of which are common to CDD. Medications: There are no medications available to directly treat CDD. Antipsychotic medications are used to treat severe behavior problems like aggressive stance and repetitive behavior patterns. Anticonvulsant medications are used to control seizures. References
Further reading
Maurice, Catherine (1993). Let me hear your voice: a familys triumph over autism. New York: Knopf. ISBN 978-0-679-40863-5. OCLC 26633221. Westphal A, Schelinski S, Volkmar F, Pelphrey K (February 2013). "Revisiting regression in autism: Hellers dementia infantilis. Includes a translation of Über Dementia Infantilis". J Autism Dev Disord. 43 (2): 265–71. doi:10.1007/s10803-012-1559-z. PMID 22677931. S2CID 3924122. Dobbs, David (2016). "The most terrifying childhood condition youve never heard of." Spectrum 6 July 2016, accessed 6 May 2017 at en:Childhood_disintegrative_disorder?action=edit,   oldid 778841596&wteswitched=1

External links
NIH/Medline