This population study of eight California birth cohorts (1987-1994) examined the degree to which improvements in detection and changes in diagnosis contribute to the observed increase in autism prevalence from 5.8 to 14.9 per 10,000. A decreasing prevalence of mental retardation without autism suggests that improvements in detection and changes in…

This study of 102 individuals with autism found that the brainstem and cerebellum increased in size with age but were significantly smaller in autistic patients than in controls. Analysis of the speed of development suggests that brainstem and vermian abnormalities in autism were due to an early insult and hypoplasia rather than to progressive…

Cluster analysis of data from 166 children with autistic spectrum disorders revealed 4 subtypes with differences in behavioral and cognitive areas. The four subtypes include a typically autistic group, a low-functioning group, a high-functioning group (Asperger syndrome/schizoid), and a hard-to-diagnose group with mild/moderate retardation and a…

This study found that motor impairment levels of 12 Asperger syndrome children and 9 high functioning autistic children (ages 7-17) did not differ. Intelligence level was negatively correlated with motor impairment. Fifty percent of Asperger children and 67% of children with autism showed a clinically significant level of motor impairment.…

Two studies evaluated the 10-question Nylander questionnaire as a screening test for autism among adults in British psychiatric hospitals. Both studies found high inter-rater reliability and no false negatives, but the studies resulted in an unacceptably high rate of false positives. (Contains 3 references.) (DB)

In a study by Toshiaki Hashimoto and colleagues (EC 611 142), 10 infants with developmental delay, poor eye contact, and poor facial expression underwent magnetic resonance brain imaging and were later diagnosed with autism. This offered direct evidence of abnormality of the cerebellar vermis and the brainstem at the beginning stages of behavioral…

Examination of 53 children with autism supported the validity of the subtypes "aloof" and "active-but-odd" as predictors of behavior across language/communication, reciprocal social interaction, and stereotyped behavior/restricted interest domains. Partial support for an intermediate, "passive" subtype was garnered. (Author/JDD)

This study examined the validity and internal and interrater reliability of the Wing Subgroups Questionnaire, an assessment that classifies children with autism into subtypes. Subjects were 42 students (ages 5 to 22) enrolled in multihandicapped special education classrooms. Findings support the reliability and validity of the questionnaire for…