Untoward effects of fenfluramine in autistic children

Several recent studies have described the benefits of fenfluramine for the symptomatic treatment of infantile autism. No large surveys of side effects of this drug have been reported in autistic children. To evaluate the untoward effects of fenfluramine in children with autism, 12 subjects were systematically studied. Medication was administered in a double-blind, placebo-controlled cross-over study. Parents were trained in monitoring untoward effects. These observations were compiled in detailed daily notes. In addition, four cases describing unusual effects found in a sample of 170 patients treated with fenfluramine are also reported. In the initial 2 weeks of active drug listlessness, food refusal, and stomach upset were frequently seen. A different pattern of untoward effects was seen in the final 14 weeks of treatment. Irritability, agitation, and crying along with continued food refusal were noted. The subjects lost 2.1% of body weight during active drug phase, but there was a rebound weight gain during the subsequent placebo phase. A thorough understanding of fenfluramine's side effects and adverse reactions is necessary so as to differentiate them from the multiple symptoms inherent in the syndrome of autism.

Lower Purkinje cell counts in the cerebella of four autistic subjects: initial findings of the UCLA-NSAC Autopsy Research Report

As part of an autopsy research project, the brains of four autistic subjects were examined and compared with those of three comparison subjects without CNS pathology and one with phenytoin toxicity. The cerebellum was selected for initial investigation because pathognomonic symptoms and neurophysiological measures suggest that pathology may exist in the cerebellar-vestibular axis in certain patients. Total Purkinje cell counts were significantly lower in the cerebellar hemisphere and vermis of each autistic subject than in the comparison subjects.

Evidence for autosomal recessive inheritance in 46 families with multiple incidences of autism

The authors ascertained 46 families with multiple incidences of autism (41 with two and five with three autistic probands). Classical segregation analyses revealed a maximum likelihood estimate of the segregation ratio of p = 0.19 +/- 0.07. This is not significantly less than 0.25, the expected value for autosomal recessive inheritance. However, it is significantly less than 0.50, the expected value for autosomal dominant inheritance. The polygenic threshold model was tested and rejected over a full range of values of heritability and ascertainment probability for these families. These results are most consistent with the hypothesis of autosomal recessive inheritance in this subset of 46 families with multiple incidences of autism.

Concordance for the syndrome of autism in 40 pairs of afflicted twins

The UCLA Registry for Genetic Studies in Autism was established in 1980 to test the hypothesis that genetic factors may be etiologically significant in subsets of patients. To date 61 pairs of twins have enrolled and 40 meet research diagnostic criteria for autism. The authors found a concordance for autism in these 40 pairs of 95.7% in the monozygotic twins (22 of 23) and 23.5% in the dizygotic twins (four of 17).

Study of fenfluramine in outpatients with the syndrome of autism

Fenfluramine was administered to 14 outpatient children with the syndrome of autism to determine whether previously produced decreases in blood serotonin concentrations and clinical improvements could be reinstituted. A double-blind medication-placebo crossover design was used. Each patient received fenfluramine 1.5 mg/kg daily (0.75 mg/kg twice daily) for 8 months, followed by placebo for 2 months. Blood serotonin levels promptly fell approximately 49% regardless of baseline levels. Clinical improvement returned, and on some scales gains after 8 months exceeded those noted after only 4 months of treatment. Significant correlations emerged among the amount of clinical response, initially high verbal IQs, and low blood serotonin concentrations. Compliance was excellent, and no clinically relevant side effects or weight changes occurred. It appears that fenfluramine is effective in ameliorating specific symptoms in certain autistic patients. The extent and mechanism of its action remain to be discovered.

Stimulus overselectivity in autistic and mentally retarded children--a research note

Groups of autistic and mentally retarded children were compared for the degree of stimulus overselectivity manifested during test probes after discrimination learning. Results demonstrated that stimulus overselectivity was a function of diagnostic category when groups were equated for performance IQ and mental age. Procedures used to obtain IQ as well as discrimination learning rate were also shown to be equivalent. Pulse rate response suggested that the test probes may be assessing performance during the early trials of a transfer problem for both groups of children. Implications for 'one-look' models of discrimination learning were discussed.

Parental reproductive problems and gestational hormonal exposure in autistic and schizophrenic children

The incidence of infertility and two or more spontaneous abortions was significantly increased in the parents, compared to that reported for the general population, in this pilot survey of 61 patients evaluated for major childhood psychoses. In addition, 18% of our patients had a history of early gestational exposure to progesterone/estrogen compounds (9 patients) and to cortisone (2 patients). This frequency of gestational hormoné exposure was significantly increased over that in normal infants from three published surveys. However, in 5 of the 11 patients with gestational hormonal exposure, the medication was prescribed because of prior parental reproductive problems or bleeding during the current pregnancy. Therefore, it cannot be concluded that the gestational hormonal exposure was causally related to the psychoses present in these patients. In order to obtain more conclusive data, there will need to be continued monitoring of parental reproductive histories and gestational environmental exposures in autistic and schizophrenic children.

Behavior observation system for autism: analysis of behaviors among autistic, mentally retarded, and normal children

The Behavior Observation Scale is being developed to objectively differentiate autistic, normal, and mentally retarded children of ages 30 to 60 mo. Operational definitions and procedures are described and frequency data from 140 children are reported. Of 59 scale items 26 were significantly different among the subject groups. Further statistical analysis showed that to assess the diagnostic significance of a behavior both the frequency of occurrence per subject and the number of children exhibiting it must be considered concurrently. Methodological problems encountered when attempting to establish objective diagnostic data for the syndrome of autism are discussed.

Behavioral characteristics of high- and low-IQ autistic children

The authors are developing the Behavior Observation Scale to objectively differentiate autistic, normal, and mentally retarded children aged 30--60 months. They describe operational definitions and procedures and report data on the frequency of selected behaviors among 114 children. Prior studies have revealed that to assess the clinical significance of behaviors in autistic children, both frequency of occurrence per subject and the number of children exhibiting the behaviors must be considered concurrently. This study confirms the hypothesis that it is critical to consider the IQ of the child when assessing the clinical significance of individual behaviors and groups of behaviors.

Objectively defined linguistic parameters in children with autism and other developmental disabilities

The language of children with autism and other developmental disabilities was examined systematically according to a set of objectively defined linguistic parameters. These criteria were drawn from clinical observations reported in the literature and from developmental norms of language acquisition. Data analysis identified sets of parameters that were correlated with psychiatrists' clinical diagnoses but failed to isolate individual parameters (such as echolalia or noncommunicativeness) that have been suggested to be pathonomic.

Behavior Observation Scale: perliminary analysis of the similarities and differences between autistic and mentally retarded children

35 autistic and 30 mentally retarded children matched for both mean chronological and mental age were observed in a playroom. The frequencies of occurrence of 67 objectively defined behaviors were coded on the Behavior Observation Scale. Implication for determining the objective diagnosis of autism is discussed.

The effect of environmental stimulation upon the stereotyped behavior of autistic children

Two groups of three autistic children, equated for chronological age but differing in IQ and performance MA, were observed for 20-minute sessions. Total duration of time subjects engaged in stereotyped behavior was recorded for each minute. During minutes 6--15, subjects were provided with either minimal or high environmental stimulation. High environmental stimulation was found to increase the mean duration of time the low-IQ group engaged in stereotyped behavior but to decrease the duration for the high-IQ group. The theoretical implications are discussed.