Early loss of previously acquired abilities and CDC

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The fourth panel addressed the question how does developmental regression (and particularly Childhood Disintegrative Disorder) fit into the autism spectrum? In her introduction, Sarah J. Spence, M.D., Ph.D., (Bethesda, MD) raised a number of questions about the construct of regression in ASD, including what is it and how commonly does it occur? Does regression represent true loss of skills versus just a plateau, and which skills should define a regression? Does it require normal development to precede it? When does it happen? What causes it? How important are medical factors? s it specific to ASDs? Regression is currently only included in the diagnostic criteria in Childhood Disintegrative Disorder (CDD), where it is required. Clinically it is commonly seen in Rett Syndrome but not included in the criteria, and is not even mentioned in Autistic Disorder, Asperger’s Disorder, or PDD-NOS, although it is known to occur fairly frequently. Childhood Disintegrative Disorder was first mentioned by Heller in 1908 and was first included in the DSM starting with DSM-IV. The available literature on CDD consists of case reports and a few case series. The paucity of reports is confirmation that CDD is a rare condition, with prevalence thought to be 1.1 to 6.4 per 100,000. It was once assumed that various presentations of CDD have a common medical etiopathogenesis, but a cause is not identified in most cases. Dr. Spence summarized some of the challenges in defining the role of regression in CDD and other ASDs as follows: 1) determining the validity of the age requirement (24 months-10 years); 2) operationalizing the definition of regression; 3) close examination of pathogenesis and clarification of the role of co-morbid medical diagnoses; and 4) determining its impact on prognosis and response to intervention. In his presentation, Hiroshi Kurita, M.D., (Tokyo, Japan) argued that although CDD is quite rare and research on CDD very scarce, there is no convincing evidence to abolish or merge it with autistic disorder, and that it should be preserved as an independent disorder. He made a number of specific suggestions to improve the CDD criteria set, including: 1) changing the requirement in criterion A for the regression history from “apparently normal development” to “no clinically significant delay or abnormality in development”; 2) deleting motor skills regression from the areas of regression in criterion B because of scarcity; and 3) in criterion D, having the diagnosis of CDD pre-empt a diagnosis of autistic disorder so that CDD with onset before age 3 is not diagnosed as autistic disorder (one-third to one-half of CDD patients show their regression between ages 2 and 3). Compared with autistic disorder, CDD has no significant difference in clinical symptomatology apart from its higher incidences of epilepsy and EEG abnormalities. Dr. Kurita concluded by noting that given the rarity of CDD, a standard format of evaluating a possible CDD case or a case with a history of regression is needed to facilitate early detection and research of CDD and other PDD with regression. Pauline A. Filipek, M.D., (Irvine, CA) showed prospective video clips of an infant aged 13 months through 26 months that illustrated apparently normal development at age 13 months, with gestures and 6 to 7 spontaneous words. One month later, he presented to the clinic with a loss of response to name, followed by loss of his 6 to 7 words, onset of highly repetitive play and loss of eye contact, which progressed to frank autistic disorder by age 24 months. This sequence raised questions about what separates autistic regression from CDD -- how often does regression occur in autistic disorder? Is CDD simply autistic regression that occurs later, after age 24 months? During the ensuing discussion, it was pointed out that regression may be a more common feature of autism than was previously thought with some prospective studies indicating that a loss of skills is the rule rather than the exception. In regressive autism, the skills are lost in the second year of life, while in “early onset” autism, skills are lost in the first year of life. There was general agreement that symptom onset is on a continuum between regression and non-regression and that defining the borders between the two can be difficult. Diagnostic certainty is particularly problematic because most parents are not going to pick up a regression of acquired skills unless the child has acquired language which then is lost.

Where did you get the idea that most autistics regress?

(II) Delays or abnormal functioning in at least one of the following areas, with onset prior to age 3 years:

(A) social interaction
(B) language as used in social communication
(C) symbolic or imaginative play

(III) The disturbance is not better accounted for by Rett's Disorder or Childhood Disintegrative Disorder