It is striking that preterm children may have both a risk of atypical sensory behaviors as well as increased rates of ASD. It is possible that atypical sensory behaviors in very low and extremely low birth weight children may result in false-positive ASD diagnoses.22 On the other hand, atypical sensory behaviors might be important components of the ASD phenotype, at least in some preterm infants. Our team was the first to use a standardized norm-referenced sensory parent questionnaire as an autism-specific screening tool in prematurely born children. The other screening instruments used in this study were broadband screens, the Modified Checklist for Autism in Toddlers (M-CHAT), and the Communication and Symbolic Behavior Scales Developmental Profile Infant-Toddler Checklist (CSBS-DP-ITC). We have already published two articles on this topic. The first article was based on preliminary data and involved first 101 examined preterm children.16 The second article comprised the final sample of 157 preterm children and was focused on ASD prevalence in preterm children, as well as on specific psychometric values of the three tests.17 Our assessment of the screening potential of the ITSP led to skepticism. Its usefulness as a sole test in autism screening seemed to be limited. The ITSP was significantly inferior to the CSBS-DP-ITC (14.3% versus 27.1% of positive screens, P=0.022) and nonsignificantly inferior to the M-CHAT (14.3% versus 17.8%, P=0.522) in our study.17 Although the present study is based on the same final data set, its aim and methods are completely different.
The evidence regarding sensation seeking patterns in children with ASD is the least consistent. Ermer and Dunn35 found that a lower incidence of sensation seeking behavior was one of the main characteristics that differentiated children with ASD from both typically developing children and children with ADHD and suggested that since the Sensory Profile was able to discriminate between the studied groups, the measure might be useful during the screening process for autism, PDD, or ADHD. In contrast, Dunn1 did not find a difference in sensation seeking scores for toddlers with PDD and typically developing children, when using the ITSP. On top of that, the higher incidence of sensation seeking behaviors in children with ASD compared with typically developing children was described by Dunn et al36 and Watling et al.37 Ben-Sasson et al38 suggested that this inconsistency may relate to differences in the age range, which ranged from 3 to 15 years. In the study of Ben-Sasson et al,4 toddlers with ASD were most distinct from typically developing groups in their low frequency of sensation seeking, high frequency of under-responsiveness, and avoidance behaviors. In a meta-analysis by Ben-Sasson et al,4 a lower incidence of sensation seeking in studies of 0- to 3-year olds was the only finding of a lower frequency of any sensory seeking behavior in ASD cases relative to typical groups. Chronological age was found to be the only factor that contributed to the variability in sensation seeking in persons with ASD. Therefore, these findings could be explained that the sensation seeking increases with age. These behaviors in toddlers with ASD may not differ from typically developing toddlers in frequency (as described by the ITSP) but rather in quality.38
Autism is a neurodevelopmental disorder characterized by impairments in social communication and presence of restricted and repetitive patterns of behavior and interests, including abnormal reactions to sensory stimuli. Atypical responses to sensory input are increasingly recognized as a common feature of ASDs. In addition to repetitive patterns of behavior, the inclusion of sensory aspects in the diagnosis of autism in the latest Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is evidence of the prevalence of sensory dysfunctions in this population. There are several tools investigating these areas, mostly rating scales that, far from wishing to replace other methods, allow a better understanding of the alterations presents and help in defining clinical picture and individual trajectory so improving diagnosis and intervention. The purpose of this study was to investigate the relation between sensory and repetitive behavioral characteristics of a sample of 50 preschool children with ASD measured with the Short Sensory Profile and the Repetitive Behavior Scales-Revised. Results are consistent with previous researches describing the co-occurrence of repetitive behaviors and sensory response abnormalities in the ASD population. We found evidence to support that the most frequently dysfunctional sensory areas in ASD children regard tactile hypersensitivity, auditory filtering, hyporeactivity and low energy/weak; while among repetitive behaviors the most common are those stereotyped. Furthermore it emerged that direct assessment with ADOS-2, a gold standard test for ASDs, and indirect assessment with questionnaires converged on the same profiles, so suggesting the usefulness to hold together both ecological and structured observations.
A high incidence of sensory processing difficulties exists in children with ASD who have more sensory-related behavioral symptoms than typically developing controls. Atypical behavioral and physiologic responses to sensory stimuli are reported in various groups with clinical diagnoses, such as Fragile X Syndrome or Attention-Deficit Hyperactivity Disorder [3-5], but few studies compare sensory symptoms across clinical conditions. A better understanding of the similarities and differences in sensory functioning between clinical disorders would be crucial to differential diagnosis and could have a profound impact on treatment planning . According to previous studies, a wide range of sensory disturbances were reported in children with ASD [7-10]. Evidence suggested the profile of atypical sensoryrelated behaviors in children with ASD was different than children with other developmental disorders [11,12]. Rogers, et al. , for example, using parent questionnaires, found that toddlers with autism had more deficits in tactile sensitivity, auditory filtering and taste/smell sensitivity, as measured by the Short Sensory Profile, than those with other developmental delays. A specific search of sensory selfstimulation could also be present, as reported by some parents who reported their children need to get under the mattress, roll up in blankets or squeeze into very tight places .
Parents and professionals who treat people with ASD frequently reported abnormalities in their sensory profile. In fact, sensory deficits, along with communication and social difficulties, become highly pervasive in their lives. The difficulties of ASD people in entering the world could therefore be ascribed to hyper or hypostimulation of the various sensory systems (e.g., a weak sound heard with particular intensity or a touch experienced as a strong pressure).
Since the 70s, many researches revealed the presence of sensory disorders in 70-80% of people with autism [16-18]. A more recent study  about rating scales for assessment of sensory profiles  showed very high percentage (95%) of ASD preschool children with sensory processing disorders. Specifically, the most affected areas appeared to be: the tactile and taste/smell sensitivity, the auditory filtering and the sensory seeking . Furthermore, several significant relationships were found between these impairments and social, emotional and behavioral function .
The aims of this study were to identify a characteristic sensory profile of ASD children, and to verify the relation between repetitive behaviors and sensory profile. In addition, we was interested to explore the personal variables (age, ADOS-2 score, IQ, therapy duration) that were correlated with the sensory profile and with the repetitive behaviors of ASD children.
Findings from the SSP collected in the current study show a sensory profile that is common to more than 60% of children and that respond to some of the main features of the disorder such as tactile and auditory hypersensitivity, under-responsivity with low energy and sensation seeking. These sensory features translate into those behaviors so commonly observed in children with ASD such as: avoidance of physical contact, difficulties in carrying out activities of daily living related to personal care, low tolerance for some materials and clothing textures, avoidance or extreme reactions to noise; with respect to hyporeactivity, are also typical the lack of responses to name and commands in absence of hearing loss, the predilection for noisy activities (especially in the early years of life), the reduced perception of danger. The situation described is strongly limiting with respect to experiences and, dealing with a neurobiological component of altered perception/sensory integration, these considerations should always accompany the assessment and therapy of people with ASD. Primarily working on the body, on uni/multi-modal sense-perception and on emotion-related feelings/atypical reactions, as evidenced by another research conducted at the Institute , it is possible to change many of the dysfunctional behaviors.
Findings from the RBS-R demonstrated that restricted and repetitive behaviors certainly constitute a key feature of ASDs, in fact they are included in diagnostic algorithms of the ADOS-2 and in DSM-5. Our results maintain coherence between what clinically observed, what found with the ADOS and with the RBS-R. The age group we analyzed did not revealed self-injurious behaviors, even in children with lower nonverbal IQ and ADOS-2 scores; these are behaviors that, in clinical practice, more often belong to severe intellectual disabilities and organic syndromes. Ritualistic and compulsive behaviors, they too very rare in our sample regardless of ADOS-2 and nonverbal IQ scores, represent an unc