Developmental Course of Patients with Asperger's Disorder Followed Objectively from Infancy

Abstract

  This follow-up study evaluated cognitive and language development in Asperger's disorder (AD) patients diagnosed at the age of 5 to 6 years, with initial complaints of delays in motor or language development in infancy. We evaluated 12 patients (10 males and 2 females) using two intelligence tests: Kyoto Scale of Psychological Development 2001 (K-scale) for those under 6 years, and WISC-III for those over 5-6 years. The cognitive-adaptive area (C-A) of the former test was compared to the performance IQ (PIQ) of the latter test, and the language-social area (L-S) of the former to verbal IQ (VIQ) of the latter. The mean age at the first examination was 3.2 years (range: 2.1-4.6 years), and the average age at follow-up was 7.7 years (range: 5.3-12.3 years). The average length of follow-up from the initial visit was 5.6 years (range: 3.3-8.6 years). During follow-up, the PIQ, VIQ and full scale DQ or IQ (F-DQ/IQ) improved with age. Average scores of the 12 patients at the first examination and last follow-up evaluated by K-scale were: C-A: 70.6 (first) and 84.5 (last), L-S: 64.8 (first) and 85.8 (last), and F-DQ: 68.5 (first) and 84.8 (last).
  Compared to those with AD, 12 autistic patients with the Kanner type (10 males and 2 females) who visited our clinic during almost the same period, and belonged to almost the same age group, showed average scores at the first examination and last follow-up of: C-A: 61.9 (first) and 43.3 (last), L-S: 43.0 (first) and 43.4 (last), and F-DQ: 60.2 (first) and 44.5 (last).
  From these observations, it is apparent that AD patients also showed language delay during infancy, but they improved rapidly between the ages of 4-6 years. This developmental spurt was not seen in autistic patients with the Kanner type.