Pain reactivity in children with autistic disorder

Abstract

Abnormal pain reactivity is often reported by the parents of children with autistic disorder (AD). This is an interesting feature because it could be related to some neurochemical findings frequently reported in autism. The aim of the present study is to report the preliminary findings about pain reactivity in children with autism, and to relate them to serotoninemia. We studied 77 subjects with “primary” AD. Reports of each child's pain reactivity were obtained through a structured interview with the child's parent. In 44 of the 77 children, serotonin blood levels were measured. We found an abnormal pain reactivity in children with autistic disorder when compared with non-autistic children, matched for age, sex, and socio-economic level. The pain reactivity showed a significant correlation with the serotoninemia levels. The data obtained by the present study are interesting, although they must be considered with careful attention, both for the sample size and for methodological difficulties. In fact, in studying this disorder, only the parents' insight can be of help

Serotonin transporter gene promoter variants do not explain the hyperserotoninemia in autistic children

“…22,23 Qualitatively and/or quantitatively altered production of these oligopeptides could potentially exert a major influence on platelet 5-HT accumulation. The modest yet positive correlation between urinary peptide excretion rates and 5-HT blood levels found in our sample, and the inverse correlation between 5-HT blood levels and pain reactivity, possibly due to increased activity of endogenous opioid peptides, 24 point in this direction. Second, concomitant alterations of post-translational processing of 5-HTT protein may be required for full phenotypic expression.…”

“…24 Urinary peptide excretion analysis was performed by HPLC on the first morning urine samples of all family members, as described. 19,28 The total area of peaks under the 215 nm absorption curve (AUC) in the peptide region following the hippuric acid peak was calculated and expressed in m 2 .…”

Behavioral Alterations in Rats Prenatally Exposed to Valproic Acid: Animal Model of Autism

“…Indeed, autistic patients express: (1) lowered or even abolished sensitivity to pain (Gillberg and Coleman, 1992;Tordjman et al, 1999;Militerni et al, 2000) and hypersensitivity to some nonpainful stimuli (Ritvo et al, 1968;Ayres and Tickle, 1980;Grandin, 1984), (2) deficits of information processing and attention with impaired sensorimotor gating (Harris et al, 1999;Townsend et al, 2001;Allen and Courchesne, 2001;McAlonan et al, 2002;Ceponiene et al, 2003), (3) hyperactivity with lowered exploratory activity (De MouraSerra, 1990;Pierce and Courchesne, 2001) and motor repetitive/stereotypic behaviors (Golse, 1986;Sauvage et al, 1993;American Psychiatric Association, 1994;Pierce and Courchesne, 2001), as well as (4) social interaction deficits (American Psychiatric Association, 1994). The maturational and developmental data obtained from VPA rats also stay in concordance with prolonged persistence of some reflexes and delayed appearance of others observed in a subgroup of autistic-to-be infants (Teitelbaum et al, 1998(Teitelbaum et al, , 2002.…”

“…Therefore, we selected four behavioral patterns corresponding to those frequently observed in autism for examination under laboratory conditions: (1) nociception, because of the reported changes in endogenous opioids systems in a subgroup of autistic patients (Ross et al, 1987;Cazzullo et al, 1999) and their lowered or even abolished sensitivity to pain (Tordjman et al, 1999;Militerni et al, 2000) and hypersensitivity to some nonpainful stimuli (Ritvo et al, 1968;Ayres and Tickle, 1980;Grandin, 1984); (2) sensorimotor gating measured by acoustic prepulse inhibition, as information processing and attention deficits have been consistently reported in autism (Harris et al, 1999;Townsend et al, 2001;Allen and Courchesne, 2001;Ceponiene et al, 2003), and sensorimotor gating is impaired in autism spectrum disorders (McAlonan et al, 2002); (3) locomotor, exploratory, and repetitive/stereotypic activity, as hyperactivity and lower exploration have been described in autistic patients (De Moura-Serra, 1990;Pierce and Courchesne, 2001), and repetitive/stereotyped behaviors belong to the main symptoms of autism (American Psychiatric Association, 1994); and (4) social behaviors, whose diminution is a hallmark feature of autism (American Psychiatric Association, 1994). In addition, we measured postnatal growth, maturation, and behavioral development.…”

Environmental Enrichment Reverses Behavioral Alterations in Rats Prenatally Exposed to Valproic Acid: Issues for a Therapeutic Approach in Autism

“…We previously presented evidence that administration of VPA on day 12.5 of gestation also has long-term effects on postnatal behaviors in male rats, which include lower sensitivity to pain and higher sensitivity to nonpainful stimuli; diminished acoustic prepulse inhibition; locomotor and repetitive, stereotypic-like hyperactivity combined with lower exploratory activity; decreased number of social behaviors; and increased latency to social behaviors (Schneider et al, 2001;Schneider and Przewlocki, 2005). Similar behavioral abnormalities have been observed in autistic persons (Militerni et al, 2000;Ayres and Tickle, 1980;Allen and Courchesne, 2001;McAlonan et al, 2002;De Moura-Serra, 1990;Pierce and Courchesne, 2001;American Psychiatric Association, 1994). Autistic patients also exhibit enhanced reaction to stress (Tordjman et al, 1997(Tordjman et al, , 1999aMaher et al, 1975;Jansen et al, 2003).…”