Tervo, Raymond C.

Abstract 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.

The relation between somatosensory mechanisms and self-injury among children with neurologic impairments associated with developmental delay is not well understood. We evaluated the feasibility of procuring skin biopsies to examine epidermal nerve fiber density and reported self-injury. Following informed parental consent, epidermal skin biopsies were obtained from a distal leg site with no pre-existing skin damage from 11 children with global developmental delay (55% male; mean age = 36.8 months, 17-63 months). Visual microscopic examination and quantitative analyses showed extremely high epidermal nerve fiber density values for some children. Children with reported self-injury (5/11) had significantly ( P < .02) greater density values (138.8, standard deviation = 45.5) than children without self-injury (80.5, standard deviation = 17.5). Results from this novel immunohistologic analysis of skin in very young children with neurodevelopmental delays suggest it may be a useful tool to study peripheral innervation as a possible sensory risk factor for self-injury.

The aim of this preliminary case study series was to investigate epidermal innervation in pediatric patients with significant neurological impairment and self‐injurious behavior. We enrolled four pediatric patients with self‐injury (two males, two females; mean age 12y, range 9–14y) and used archival specimens from healthy, age‐matched children with typical development for comparison purposes. Epidermal nerve fiber density, peptide content, and mast cell degranulation patterns from non‐damaged skin were tested between the patients and the comparison group. The male patients with self‐injury had significantly increased epidermal nerve fiber densities, increased substance P positive fiber count and extensive mast cell degranulation compared with sex‐ and age‐matched individuals with typical development. Our case series shows for the first time altered peripheral innervation from non‐damaged tissue in children with significant self‐injury and developmental disability compared with a healthy comparison group. Establishing the role of peripheral nociceptive and immune modulatory neural pathways may offer new treatment avenues for this devastating neurobehavioral disorder.