20 ASD (17 boys; 3 girls) & 20 TD controls (16 boys; 4 girls). Age range: 8–18 years.
High
Assessing self-report of pain using vignettes and also comparing this to parental reports.
No significant differences in pain intensity ratings between the ASD and controls. No significant differences between the pain ratings of youths with ASD or their parents as compared with a sample of typically developing youths.
8 adults with ASD (clinical diagnoses of either Autistic or Asperger Disorder; all had IQ of at least 70 (7 males & 1 female (mean age 29.3 years, range 20–45). 8 adults without ASD (sex and age matched). (mean age 29.0, range 21–45).
High
To investigate tactile sensitivity in adults with autism using a variety of stimuli, in order to probe different submodalities of somatosensation. Experiment specifically related to present review—thermal pain threshold.
Yes, significant difference—ASD group showed a greater degree of pain sensitivity. For cold pain, there was a main effect of site (, ), and group (, ), with the ASD group displaying average cold pain thresholds of 16.68°C, compared to the control group average of 9.04°C. For heat pain, there was a significant effect of group. The average threshold for the ASD group was 43.66°C, while that of the control group was 46.58°C.
5 children with a documented ASD (between the age 7–11 years).
Does not specify.
A pilot study to investigate pain and distress in children with autism during a dental cleaning procedure.
Children with ASD exhibited greater pain scores (M ) than children without ASD (M ). Greater levels of interfering distress behaviour were exhibited in the children with ASD. Moderate associations between severity of ASD symptoms and pain during the dental cleaning procedure () and interfering distress behaviours (), with increased severity of the child’s symptoms relating to higher levels of pain and distress.
Population-based group of 208 20–54-month-old children, diagnosed with ASD and referred to a specialised habilitation centre for early intervention. Children were sub-grouped (8 in total) based upon degree of ASD symptoms & cognitive level.
Subgroups (i.e., classic autism, nuclear autism)—but does not specify low or high functioning.
To describe sensory abnormalities in preschool children with an ASD, compared to different subgroups within the autism spectrum in terms of the presence of sensory abnormalities, and relate the findings to other clinically relevant symptom domains.
Yes: significant differences in pain sensitivity. Under-reactivity to pain in 40% of the sample. Under-reactivity to cold and heat were reported for 22% and 7%, respectively. Children with self-injurious behaviours had more sensory abnormalities affected (M , SD = 1.5, ) than children with no such behaviours (M , SD = 1.2, ); (206) = 2.791, .
Survey data were collected in Pennsylvania from 969 caregivers of children who had ASD and were younger than 21 years regarding their service experiences.
Does not specify low or high functioning in terms of DSM and so forth.
Early diagnosis of children with ASD is critical but often delayed until school age. This study attempted to identify these factors among a community sample of children with ASD.
Oversensitivity to pain was associated with a 0.6-year increase in the age of diagnosis.
6 ASD individuals (4 boys and 2 girls between 3 and 7 years).
Video clips of children with ASD undergoing venepuncture were obtained from a previous study [62]; see below for details.
To examine the influence of information about the pain experience of children with autism on observers’ judgement of pain intensity in children with ASD and to examine the impact of facial activity on observers’ judgement of pain intensity in children with ASD.
Facial activity had a significant impact on observers’ estimates of pain intensity while pain sensitivity information did not.
16 right-handed men with ASD (aged 28.0 ± 7.2 years) and 20 neurotypical controls (aged 25.3 ± 6.7 years) age, sex, and IQ matched.
Mention levels of severity in terms of score on the AQ.
To explore whether people with AS differ from neurotypical control participants in their empathic corticospinal response to the observation of others’ pain and the modulatory role played by phenomenal experience of observed pain and personality traits.
Participants with AS, compared with control participants, tended to judge the touch as more painful (, 0.08).
21 3-year-old to 7-year-old children with ASD and 22 nonimpaired children.
Mean CARS score for the ASD group was 39.10 (SD = 4.98, range 30.5–47), which put the average for the group into the severely autistic range (CARS score >37). 9 fell into the mildly-moderately ASD range (CARS score 30–37), and 12 fell into the severely ASD range.
Aims of the study were to (1) characterise the behavioural response of children with ASD experiencing a venepuncture using objective observational measures of pain and distress, (2) examine parents’ assessments of pain behaviour in children with and without autism, including comparison of the relationship of parental reports with behavioural measures, and (3) compare the behavioural reactions and parental assessments of children with ASD with children without ASD undergoing venepuncture.
In contrast with many of the other studies reported in this review, this study found evidence which indicates that individuals with ASD do not have an insensitivity to pain as manifested by a lack of behavioural response—children with ASD display a significant behavioural reaction in response to a painful stimulus. Using FPS scores as a measure of parental assessment of pain response following the venepuncture, parents of children with ASD reported observing more pain in their children during the venepuncture (M , SD = 1.45) compared with parents of the children without autism (M , SD = 1.90; (41) = 2.97, ). Using the NCCPC as a retrospective measure of parental assessment of typical pain reactivity in their children, scores did not differ between the autism group (M = 60.33, SD = 13.50) and comparison group (M , SD = 14.19; (41) = 0.46, ). Parent reports of pain temperament in children with ASD (M , SD = 1.32) were similar to parent reports of pain temperament in the children without ASD (M , SD = 1.30; (38) = −0.23, ).
19 Japanese children (17 boys, 2 girls, mean age 4.23 ± 1.18 years, range 2.00–6.42) with typical infantile autism. 23 controls—age-matched Japanese children (18 boys, 5 girls, mean age 3.78 ± 3.37 years, range 0–10.75). 3 patients with Rett syndrome (3 girls, ages 10–14 years).
Does not specify.
To clarify whether P-endorphin plays an important role in infantile autism, we determined the cerebrospinal fluid (CSF) levels of p-endorphin and evaluated the correlation between these levels and ASD symptoms.
Finding do not support the opioid hypothesis to explain pain sensitivity in ASD. No significant correlation between CSF levels and clinical symptoms, including self-injurious behaviour, pain insensitivity, and stereotyped movement. However, CSF levels of p-endorphin were significantly higher in the patients with Rett syndrome than in the control (). Data suggest that neurons containing p-endorphin may not be involved in patients with infantile autism.
73 children and adolescents with ASD and 115 control matched for age, sex and pubertal stage. (ASD group 49 males and 24 females. ASD group total age 11.7 plus or minus 4.5; comparison group 75 males and 40 females. Total age 12.7 + or −5.9).
Individuals with ‘‘severe’’ ASD (). Individuals with ‘‘mild’’ to ‘‘moderate’’ ASD (). Normal controls ().
To examine behavioural and physiological pain responses, plasma b-endorphin levels, and their relationship in a large group of individuals with ASD.
No: individuals with ASD do not have decreased sensitivity to pain. A high proportion of individuals with ASD displayed absent or reduced behavioural pain reactivity at home (68.6%), at day care (34.2%), and during venepuncture (55.6%). Despite their high rate of absent behavioural pain reactivity during venepuncture (41.3 versus 8.7% of controls, ), individuals with ASD displayed a significantly increased heart rate in response to venepuncture () which was significantly greater than for controls (mean 6 SEM; 6.462.5 versus 1.360.8 beats/min, ). Plasma b-endorphin levels were higher in the ASD group () and were positively associated with ASD severity () and heart rate before or after venepuncture (), but not with behavioural pain reactivity.
Key: AQ: Autism Spectrum Quotient [90]. CARS: The Childhood Autism Rating Scale [92]. CFS: Cerebralspinal fluid. CNS: Central Nervous System. PDD-NOS: Pervasive Developmental Disorder Not-Otherwise Specified. TD: Typically developing.
