Eur Child Adolesc Psychiatry (2006) 15:343–351 DOI 10.1007/s00787-006-0540-9
Hugues Desombre Joelle Malvy Sylvie Roux Re´gis de Villard Dominique Sauvage Jean Dalery Pascal Lenoir
Accepted: 2 March 2006 Published online: 13 April 2006 H. Desombre (&) Æ R. de Villard Unite´ de Psychopathologie de l’Enfant et de l’Adolescent De´pt. de Pe´diatrie Hoˆpital Edouard Herriot Place d’Arsonval 69437 Lyon Cedex 03, France E-Mail:
[email protected] H. Desombre Æ J. Dalery Universite´ Claude Bernard – CHS Le Vinatier Equipe d’accueil 3092 CHS Le Vinatier Bron, France J. Malvy Æ D. Sauvage Æ P. Lenoir Service Universitaire de Pe´dopsychiatrie Hoˆpital Bretonneau Centre Hospitalier Re´gional et Universitaire Tours, France S. Roux Service Universitaire d’Explorations Fonctionnelles et de Neurophysiologie en Pe´dopsychiatrie Hoˆpital Bretonneau Centre Hospitalier Re´gional et Universitaire Tours, France
ORIGINAL CONTRIBUTION
Autism and developmental delay A comparative clinical study in very young children using IBSE scale
j Abstract Objective This study
improves the knowledge of early autistic symptomatology and research concerning (i) the significant differences in the behaviors of children with autistic disorder (AD) and children with a developmental delay (DD), and (ii) the influence of the cognitive delay on symptomatology. Method Two groups of 20 young children (7– 42 months) were compared: children with AD, and those with DD. The groups were paired by chronological and developmental age. The comparison was extended to four subgroups composed according to age (younger and older children—24 months) and to the global development quotient (GDQ) (the more and less delayed). Each child was evaluated with the Infant Behavior Summarized Evaluation scale (IBSE). Results For the younger AD children, significant differences affected social com-
Introduction
j Key words autism – developmental delay – early features – pre-school children
very severely delayed child, it may be difficult to differentiate autism plus DD from DD alone [44]. It is crucial that children be identified as early as possible enrolled in appropriate treatment approaches. There are several research strategies that have been employed in attempting to uncover the earliest manifestation of autism. The first strategy was retrospective, based on questionnaires and interviews with parents [18, 32, 36,
ECAP 540
For all clinicians faced with early management of developmental disorders, a major priority is the earlier identification of children with autism. Autism and cognitive delay are most often combined [16, 30, 31], and the germane differential diagnoses in 2- and 3year-old children include general developmental delay (DD) due to mental retardation. In very young and/or
munication and their adaptation to the environment (intolerance to frustration, resistance to change). For the older children (>24 months), this study showed the rapid progression of the number of distinctive signs between AD and DD children according to age and/or developmental level. Conclusions Cognitive delay has an important influence on the symptomatology at the moment of initial recognition of an autistic syndrome. This study is a complement for the fuller understanding of the nature and early diagnosis of disorders specific to autism at the earliest phases of development.
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37, 39]. Volkmar et al. [42], and Gillberg [16] indicated that rather than the age of onset of the disorders, it was the age at which signs were recognized that was assessed. This implied the existence of subjective variables such as parental experience, denial of the disorders, knowledge of the symptomatology, specificity of the disorders and more. The second way was the use of home videos. This strategy, collecting and coding the videotapes made by parents of infants who were diagnosed with autism later in life was used for the first time by Henry Massie [28]. A literature search uncovered 11 studies using this method: Lo¨ sche, 1990 [21]; Adrien et al., 1992 [2]; Osterling and Dawson, 1994 [33]; Bernabei et al., 1998 [8]; Mars et al., 1998 [27]; Baranek, 1999 [4]; Maestro et al., 1999 [22]; Werner et al., 2000 [43]; Osterling et al., 2002 [34]; Receveur et al., 2005 [35]; Maestro et al., 2005 [25]. They suggest that young children with autism can be distinguished from children undergoing normal development in terms of motility, sensory modulation and attention [2], orientation to social stimuli [33], sensory-motor deficit, social responsiveness [4], failure to orient to names [23, 43], and social attention deficit [24]. These studies confirmed the importance of characteristic signs that are very illusive early on, but highly useful in pediatrics, i.e., the appearance of deafness, anomalies of eye contact, a paucity of mimicry, indifference and prelanguage deficits. One limitation of these studies is the use of typically developing but not developmentally disabled comparison groups. During the last years several new studies have addressed this issue. In the first, Baranek [4], compared three groups including 11 children with autism, 10 with developmental disabilities, and 11 typically developing children, and found that abnormalities in orientation to visual stimuli, aversion to touch and delayed response to name all characterized autism (but not DD) as early as 9 months of age. The second study [5] showed a similar level of engagement with objects and no significant differences in duration of exploratory play. The results of a study by Osterling [34], comparing 20 infants later diagnosed with autism spectrum disorder, 14 infants later diagnosed with mental retardation (without autism), and 20 typically developing infants, suggest that impairments in looking at others and orienting to a name may have higher specificity as a marker of autism at 1 year of age. The third way is a strategy involving screening large numbers of children for deficits that children with autism often show at later ages. Thus in 1992, a study conducted by Baron-Cohen [6], showed that autism could be detected at the age of 18 months, in particular by revealing behavioral disorders involving
symbolic play, joint attention, pointing gestures, social involvement and social play. This was confirmed by a prospective total population study of 16,000 children [7]. The fourth way is a clinical approach starting from the clinical population, using a methodology by comparison of groups of infants to observe and analyze their development. The majority of studies compared infants with autism spectrum disorder and infant with typical development; few compared to DD (without autism). Charman [11] comparing 10 children 20-months old with autism, 9 children with DD (without autism) and 19 children with typical development, found that children with autism were specifically impaired on some aspects of empathy, joint attention, and imitation. Scambler [38], comparing 26 children with autism and 18 children with other DD, found the Checklist for Autism in Toddlers (CHAT) can identify more mature children with autism from those with DD (QDG=70). Wetherby [44], comparing three groups of 18 children (one group with autism spectrum disorder—ASD, one group with developmental delay—DD, one group with typical development—TD) found that lack of showing and repetitive movements did differentiate children in the ASD and DD groups.
j Hypotheses and objectives With the same objective in mind, we conducted a comparative study of very young children and infants clinically diagnosed as having autism or DD. The aims of this study were (i) to describe the existence of signs of autism enabling it to be differentiated from another developmental disorder, e.g., DD, (ii) to measure the influence of the developmental level on symptomatology of AD. This work was conducted according to the hypothesis of some signs distinguishing the youngest children with autism and children with DD, this distinction being nevertheless more clear-cut as age and/ or development level increase. AD features (i) involve communication and socialization disorders, and are associated with disorders in sensorimotor control, particularly concerning attention, perceptions, tactility and motility; (ii) these adaptation and sensorimotor control disorders may even precede those of contact and socialization that will subsequently be in the front line of symptomatology; (iii) they are partially different in children with DD without autism. In other words, children with AD have ‘‘behavioral neuropsychological’’ disorders of a certain specificity, involving adaptation to the surroundings, whereas the difficulties in retarded (and multi-handicapped) children are more suggestive of other neurological deficiencies
H. Desombre et al. Autism and developmental delay
such as hypotonia, cerebral palsy or motor retardation.
Methods j Participants The study population was composed of 40 children. They were selected in the cohort of the Autism resource Center over the course of the past several years to be included in two groups: children with autism (AD), and those with developmental delay (DD) paired by chronological age and global development. Age at the first consultation was between 7 and 42 months (a videotape was recorded during this consultation). The diagnosis (AD or DD) was performed independently after the fourth year of life of children by two senior child and adolescent psychiatrists using a checklist of symptoms according to the DSM IV [3]. Each child was subjected to an extensive evaluation including a detailed developmental history, psychiatric assessment and pediatric, psychological and neurological examinations. It was made during a multidimensional assessment outpatient period (encompassing behavioral observation, psychological testing, and bioclinical examinations) [17, 29]. Each child had been assessed, after the age of 4, with the Brunet-Lezine Scales [9], a French adaptation of the Gesell Scales [15], to calculate the global developmental quotient (GDQ). ADI questionnaire was not included, according to other studies in very young children [10, 25, 26, 35, 46]. In order to define the influence of chronological age and development level on symptomatology, subgroups were then formed (younger and older children; more and less retarded) (Table 1). The population (Table 1) of each group (AD, DD) was composed of 20 children. The mean chronological age of the 20 children with AD was 26 months, with a
Table 1 Characteristics of study population
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mean global development quotient (GDQ) of 49. The mean chronological age of the 20 children with DD was 26 months, with a mean GDQ of 47. AD and DD children groups were composed so as to constitute two sub-groups of 10 children: – according to chronological age: 10 children younger than 26 months; 10 children older than 26 months, – according to the severity of the mental retardation (GDQ): 10 children presenting a moderate, severe or very severe retardation, (GDQ less than 50), 10 children presenting moderate or slight retardation (GDQ more than or equal to 50). The comparison of the AD and DD populations with a t-test, revealed no significant difference for chronological age and for GDQ (Table 1).
j The IBSE scale (Table 2) and scoring method Signs of autism were assessed with the Infant Behavioral Summarized Evaluation (IBSE) scale. It contains 33 items and a glossary defining each item. The items are scored from 1 to 5 according to the intensity of the disorders: 1 if the disorder is never observed, 2 occasionally, 3 often, 4 very often, and 5, if the sign is observed continually. The inter-rater reliability study and the glossary explaining the significance of each item are available in a previous study [1]. Good psychometric properties were confirmed in other studies [10, 25, 26, 35, 46]. The above validation study [1] involving a principal component analysis and a varimax rotation demonstrated that among the 33 IBSE items, there was a factor including 19 items considered as most representative of autistic symptomatology: so-call autism Factor I (Table 3). The 33 items of the scale were scored after a clinical review including a presentation of the first consultation, and that of the child’s development in the
Group
N
Sex-ratio (boys/girls)
AGE (month) mean (SEM)
GDQ mean (SEM)
Mental age (month)
AD DD AD DD AD DD AD DD AD DD
20 20 10 10 10 10 10 10 10 10
13/7 12/8 7/3 4/6 6/4 8/2 6/4 6/4 8/2 6/4
26 26 17 16 35 36 28 28 24 23
49.8 47.4 60.6 48.1 39.1 46.7 34.8 30.4 64.9 64.4
12.9 12.3 10.3 7.7 13.7 16.8 9.8 8.4 15.36 14.72
26 months with GDQ 50
(0.44) (0.44) (0.31) (0.31) (0.63) (0.31) (1.26) (1.26) (0.94) (0.63)
AD, Children with autism; DD, Children with devlopmental delay; AGE, Chronological age
(0.96) (0.96) (1.77) (2.24) (1.45) (1.67) (0.75) (1.01) (1.51) (0.69)
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Table 2 Infant behavioral summarized evaluation scale (IBSE)
Table 3 Items constituting factor I labeled ‘‘Autism’’
No
Item
Abbreviation
No
Item
Abbreviation
1* 2* 3* 4* 5* 6* 7* 8* 9*
Ignores people Prefers aloneness Poor social interaction No social smile No eye contact Abnormal eye contact Lack of vocal communication Lack of appropriate facial expressions Lack of appropriate gesture and/or expressive postures No or poor imitation of gestures or voice of others Too calm Overly excited Inappropriate use of objects Stereotyped behavior Hypoactivity Hyperactivity Hypotonia Unusual postures Autoaggressiveness Heteroaggressiveness Does not differentiate people No expression of emotions Unmotived fits of crying or laughing Intolerance to frustration, anger Resistance to change Eating problems Sleeping problems Does not like to be touched Interested only in body contact Unstable attention, easily distracted No reaction to auditory stimuli Bizarre responses to auditory stimuli Behavior variability
IGN ALO SOC SMI VIS GAZ VOI EXP GES
1* 2* 3* 4* 5* 6* 7* 8* 9*
IGN ALO SOC SMI VIS GAZ VOI EXP GES
IMI
10*
CAL EXC OBJ STE ACT AGI TON POS AGR HGR DIF EMO MOO FRU SAM EAT SLE TOU BOD ATT SOU AUD VAR
13* 14* 18* 21* 22* 30* 31* 32* 33*
Ignores people Prefers aloneness Poor social interaction No social smile No eye contact Abnormal eye contact Lack of vocal communication Lack of appropriate facial expressions Lack of appropriate gesture and/or expressive postures No or poor imitation of gestures or voice of others Inappropriate use of objects Stereotyped behavior Unusual postures Does not differentiate people No expression of emotions Unstable attention, easily distracted No reaction to auditory stimuli Bizarre responses to auditory stimuli Behavior variability
10* 11 12 13* 14* 15 16 17 18* 19 20 21* 22* 23 24 25 26 27 28 29 30* 31* 32* 33*
*Items constituting Factor I labeled ‘‘Autism’’
first months of his life, followed by screening a video taken during the first pedopsychiatric consultation and the psychological examination. All videotapes were coded by two researchers who were not acquainted with the definitive diagnosis. They were experts in the assessment of child development and were different from those individuals who made the clinical diagnoses. Each video recording lasted about 20 min and included a number of interaction sequences. First, they were ‘‘structured’’ between the examiner and the child (playing ball; singing, vocal, verbal and gestural imitation; mimicry play; and several standardized activities from tests suited to the developmental age of the child: cubes, drawing, puzzles, naming images). This was followed by a ‘‘free’’ period during which the child could handle objects as he desired, move around the examination room or spontaneously interact with the examiner. These items can be clustered by developmental domains (Table 4).
IMI OBJ STE POS DIF EMO ATT SOU AUD VAR
Table 4 Developmental domaines of Infant behavioral summarized evaluation scale Developmental domaines
Items
Perception Intention Motor function Emotion Instinct Contact Communication Adaptation to environment
Items Items Items Items Items Items Items Items
Abbreviation 6, 19, 28, 29, 31, 32 15, 16 14, 18 20, 22, 23 11, 12, 13, 21, 26, 27 1, 2, 3, 4, 5 7, 8, 9 24, 25
PER(d) INT(d) MOT(d) EMO(d) INS(d) CON(d) COM(d) ENV(d)
j Statistical analysis Taking into account the relatively small populations of the groups and sub-groups and the semi-quantitative nature of the data, the statistical tests used were non-parametric. Each group and sub-group was analyzed based on the IBSE scores: first the factor I score (F1S), then the score of items taken individually, and finally items clustered in developmental domains. Initially and for each analysis, the comparison between groups and between sub-groups was carried out with the Kruskal–Wallis test at the risk of 5%. After this, a Mann–Whitney test was used to compare groups two-by-two and sub-groups two-by-two for the items having a score that was significantly different with the Kruskal–Wallis test. The risk chosen was 1.7% (5%/number of comparisons) after the Bonferonni correction as recommended by Krauth [20].
H. Desombre et al. Autism and developmental delay Table 5 Statistical results for the comparison between groups and subgroups for items and developmental domains
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AD/DD GDQ AGE POP 1* IGN 2* ALO 3* SOC 4* SMI 5* VIS 6* GAZ 7* VOI 8* EXP 9* GES 10* IMI 11 CAL 12 EXC 13* OBJ 14* STE 15 ACT 16 AGI 17 TON 18* POS 19 AGR 20 HGR 21* DIF 22* EMO 23 MOO 24 FRU 25 SAM 26 EAT 27 SLE 28 TOU 29 BOD 30* ATT 31* SOU 32* AUD 33* VAR Perception Intention Motor function Emotion Instinct Contact Communication Adapt. to envir.
50/48 26/26 Global
39/47 35/36 >26 M.
35/30 28/28 GDQ 50
A4 A4 A3 A3 A4 A3
A4 A4 A3 A3 A4 A3
A3
A3 A3 A3
A3
A3 A3 A3 A2 A3 A1 A1 A1 A1 A2
A3 A3
A3 A3
A3
A3 A3
A4 A4
60/48 17/16
