Introduction: Intellectual and developmental disabilities (IDD) include conditions associated with physical, learning, language, behavioural, and/or intellectual impairment. Pain is a common and debilitating secondary condition compromising functional abilities and quality of life. Objectives: This article addresses scientific and clinical challenges in pain assessment and management in individuals with severe IDD. Methods: This Clinical Update aligns with the 2019 IASP Global Year Against Pain in the Vulnerable and selectively reviews recurring issues as well as the best available evidence and practice. Results: The past decade of pain research has involved the development of standardized assessment tools appropriate for individuals with severe IDD; however, there is little empirical evidence that pain is being better assessed or managed clinically. There is limited evidence available to inform effective pain management practices; therefore, treatment approaches are largely empiric and highly variable. This is problematic because individuals with IDD are at risk of developing drug-related side effects, and treatment approaches effective for other populations may exacerbate pain in IDD populations. Scientifically, we are especially challenged by biases in self-reported and proxy-reported pain scores, identifying valid outcome measures for treatment trials, being able to adequately power studies due to small sample sizes, and our inability to easily explore the underlying pain mechanisms due to compromised ability to self-report. Conclusion: Despite the critical challenges, new developments in research and knowledge translation activities in pain and IDD continue to emerge, and there are ongoing international collaborations.

Children with CP with greater motor involvement, as indexed by GMFCS level, may be at risk for increased pain (intensity, frequency and duration) that interfers with activities of daily living. The clinical index of suspicion should be raised accordingly when evaluating children with developmental disability who cannot self-report reliably.

Rett syndrome (RTT) is associated with myriad debilitating health issues and significant motor and communicative impairments. Because of the former there is concern about the possibility of recurrent and chronic pain but because of the latter it remains difficult to determine what pain ‘looks like’ in RTT. This study investigated pain experience and expression using multiple complementary subjective and objective approaches among a clinical RTT sample. Following informed consent, 18 participants (all female) with RTT (mean age= 12.8 years, SD= 6.32) were characterized in terms of pain experience and interference, typical pain expression, and elicited pain behavior during a passive range of motion-like examination procedure. Parents completed the Dalhousie Pain Interview (DPI; pain type, frequency, duration, intensity), the Brief Pain Inventory (BPI; pain interference), and the Non-Communicating Children’s Pain Checklist – Revised (NCCPC-R; typical pain expression). A Pain Examination Procedure (PEP) was conducted and scored using the Pain and Discomfort Scale (PADS). The majority of the sample (89%) were reported to experience pain in the previous week which presented as gastrointestinal (n=8), musculoskeletal (n=5), and seizure related pain (n=5) that was intense (scored 0–10; M= 5.67, SD= 3.09) and long in duration (M= 25.22 hours, SD= 53.52). Numerous pain-expressive behaviors were inventoried (e.g., vocal, facial, mood/interaction changes) when parents reported their child’s typical pain behaviors and based on independent direct observation during a reliably coded pain exam. This study provides subjective and objective evidence that individuals with RTT experience recurring and chronic pain for which pain expression appears intact.

Introduction:Cerebral palsy (CP) is the most common cause of physical disability in children and is often associated with secondary musculoskeletal pain. Cerebral palsy is a heterogeneous condition with wide variability in motor and cognitive capacities. Although pain scales exist, there remains a need for a validated chronic pain assessment tool with high clinical utility for use across such a heterogeneous patient population with and without cognitive impairment.Objectives:The purpose of this study was an initial assessment of several psychometric properties of the 12-item modified brief pain inventory (BPI) pain interference subscale as a proxy-report tool in a heterogeneous sample of children with CP with and without cognitive impairment.Methods:Participants (n = 167; 47% male; mean age = 9.1 years) had pain assessments completed through caregiver report in clinic before spasticity treatment (for a subgroup, the modified BPI was repeated after procedure). To measure concurrent validity, we obtained pain intensity ratings (Numeric Rating Scale of pain) and pain intensity, duration, and frequency scores (Dalhousie Pain Interview).Results:Modified BPI scores were internally consistent (Cronbach α = 0.96) and correlated significantly with Numeric Rating Scale intensity scores (rs = 0.67, P < 0.001), Dalhousie Pain Interview pain intensity (rs = 0.65, P < 0.001), pain frequency (rs = 0.56, P = 0.02), and pain duration scores (rs = 0.42, P = 0.006). Modified BPI scores also significantly decreased after spasticity treatment (pretest [scored 0–10; 3.27 ± 2.84], posttest [2.27 ± 2.68]; t (26) = 2.14, 95% confidence interval [0.04–1.95], P = 0.04).Conclusion:Overall, the modified BPI produced scores with strong internal consistency and that had concurrent validity as a proxy-report tool for children with CP.

Objective Assessing and treating pain in nonverbal children with developmental disabilities are a clinical challenge. Current assessment approaches rely on clinical impression and behavioral rating scales completed by proxy report. Given the growing health relevance of the salivary metabolome, we undertook a translational-oriented feasibility study using proton nuclear magnetic resonance (NMR) spectroscopy and neuropeptide/cytokine/hormone detection to compare a set of salivary biomarkers relevant to nociception. Design Within-group observational design. Setting Tertiary pediatric rehabilitation hospital. Subjects Ten nonverbal pediatric patients with cerebral palsy with and without pain. Methods Unstimulated (passively collected) saliva was collected using oral swabs followed by perchloric acid extraction and analyzed on a Bruker Avance 700 MHz NMR spectrometer. We also measured salivary levels of several cytokines, chemokines, hormones, and neuropeptides. Results Partial least squares discriminant analysis showed separation of those children with/without pain for a number of different biomarkers. The majority of the salivary metabolite, neuropeptide, cytokine, and hormone levels were higher in children with pain vs no pain. Conclusions The ease of collection and noninvasive manner in which the samples were collected and analyzed support the possibility of the regular predictive use of this novel biomarker-monitoring method in clinical practice.

Objectives This case-control study explored pain experience and expression among individuals with Neuronal Ceroid Lipofuscinosis (NCL) through parental report, tactile-sensory testing, and infrared thermography (IRT). Methods Individuals with NCL (n=8; M age= 14.8 years) and their unaffected siblings (n=8;M age 23.5 years) were characterized in terms of pain response to a brief tactile sensory test (light touch, Von Frey monofilament). During sensory testing, behavioral expression was measured using the Battens Observational Pain Scale (BOPS) and infrared thermography (IRT) was used to quantify changes in skin/eye temperature. Results Individuals with NCL experienced pain frequently and from multiple sources that negatively impacted their lives. Individuals with NCL were reactive to the sensory testing as indexed by significant increased IRT temperature change (p<.001). Across combined sensory conditions, individuals with NCL were significantly more reactive (BOPS total score) to sensory testing compared to siblings (p< .05). Similarly, IRT difference scores between sensory conditions revealed a significant increase in temperature for individuals with NCL compared to siblings (p<.001). Discussion Ongoing reported pain was a problem for the individuals with NCL in this sample. Increased pain expression during the repeated Von Frey filament suggests that the pathophysiology of the ongoing pain may be centrally mediated.

Purpose We aimed to evaluate the feasibility of using a portable infrared thermal camera (IRTC) to quantify the degree of thermal dysregulation (cold hands/feet) and test for naturally occurring within-patient skin temperature asymmetry in Rett syndrome. Procedures Infrared thermal images were acquired passively from 15 patients (mean age = 13.7 years, range 4 – 47) with clinical diagnoses of Rett. Images were acquired using a FLIR T400 IRTC (still images recorded at 5hz, resolution of 320x240 pixels, thermal sensitivity=.05° C; capture session lasted approximately 3 min). The IRTC was orthogonal to the body part (hands, feet) and positioned approximately 1 m from the skin’s surface. Main Findings There were large intra-individual left/right differences in temperature. Seven (47%) and eight (53%) patients had statistically significant (p < 0.05) left/right asymmetries between hands (M diff = 0.87°C, sd = 1.21) and feet (M diff = 1.73°C, sd = 3.03), respectively. Coders were reliable (intra-class correlations 0.97–0.99) on temperatures and selection of anatomical regions of interest. Conclusions The degree of thermal asymmetry may reflect prolonged activity of the sympathetic nervous system and individual differences in sympathetic regulation. As clinical trials emerge and endpoints are considered, portable IRTC may provide one non-invasive means of evaluating changes in sympathetic regulation.

Assessing tactile function among children with intellectual, motor, and communication impairments remains a clinical challenge. A case control design was used to test whether children with global developmental delays (GDD; n = 20) would be more/less reactive to a modified quantitative sensory test (mQST) compared to controls (n = 20). Reactivity was indexed by blinded behavioral coding across vocal, facial, and gross motor responses during the mQST. On average the children with GDD were significantly more reactive than controls to most tactile sensory modalities including light touch (p = .034), pin prick (p = .008), cool (p = .039), pressure (p = .037), and repeated von Frey (p = .003). The results suggest the mQST approach was feasible and highlights the GDD sample was more reactive than controls to a range of stimuli.