Papers by Danny Camfferman
International Journal of Psychophysiology, Aug 1, 2013
Sleep disruption in childhood is associated with clearly defined deficits in neurocognition and b... more Sleep disruption in childhood is associated with clearly defined deficits in neurocognition and behaviour. Childhood eczema is also a potent cause of sleep disruption though it is unknown whether it too results in neurocognitive deficits. To test this hypothesis, neurocognitive (WISC-IV), parental-reported sleep quality (Sleep Disturbance Scale of Children (SDSC)) and overnight polysomnographic (PSG) data were collected in 21 children with eczema and 20 healthy controls (age range 6-16 years). Children with eczema had worse sleep quality on both PSG (notably increased nocturnal wakefulness, a higher number of stage shifts and a longer latency to REM onset) and parental report. In addition, they demonstrated significant neurocognitive deficits (especially verbal comprehension, perceptual reasoning and to a lesser extent working memory) with a composite Full Scale IQ 16 points lower than controls. Parental reported sleep problems but not PSG parameters were correlated with reduced neurocognitive performance. However, hierarchical regression analyses revealed that eczema status was predictive while sleep fragmentation (parental or PSG) was not predictive of neurocognitive performance. As this is the first study to systematically examine neurocognitive functioning in children with eczema and given the finding of significant deficits it merits replication especially given the prevalence of the condition. The unanswered question is whether these cognitive deficits normalise with effective eczema treatment and if this is mediated by improvements in sleep architecture.
Sleep Medicine, 2016
Highlights Problems with initiating and maintaining sleep in children with eczema may relate to... more Highlights Problems with initiating and maintaining sleep in children with eczema may relate to impaired thermoregulatory mechanisms which also contribute to itching and scratching. Children with eczema were found to have longer periods of nocturnal wakefulness and lower distal temperatures than controls.
<b>DESCRIPTION</b><br>This repository contains the analysis scripts and supplem... more <b>DESCRIPTION</b><br>This repository contains the analysis scripts and supplementary files for the manuscript <i>Rethinking pain threshold as a zone of uncertainty</i>. The analysis scripts and their outputs are located in pain-threshold.zip. Supplementary files are found in PDF form under the relevant name Suppl-*.pdf. Supplementary figures are found in PDF form under the relevant name SupplFig*.pdf.<br>Please note that participant consent materials did not include consent for public release of data, so data are not made available here. However, we do not wish to restrict access to the data needlessly, so requests for access to the data will be considered on a case-by-case basis and data made available subject to Human Research Ethics Committee approval. Requests can be directed to Tory Madden ([email protected]).<br><b>Repository citation</b><br>Kamerman P, Madden V, Catley M, Bellan V, Russek L, Camfferman D, Moseley L. Analysis scripts and supplementary files: Rethinking pain threshold as a zone of uncertainty. Figshare, 2019. DOI: 10.25375/uct.7577456.<br><br>
Thesis (Ph.D.) -- University of Adelaide, School of Paediatrics and Reproductive Health, 2011
Cortex; a journal devoted to the study of the nervous system and behavior, Aug 1, 2016
The magnitude of the hand-blink reflex (HBR), a subcortical defensive reflex elicited by the elec... more The magnitude of the hand-blink reflex (HBR), a subcortical defensive reflex elicited by the electrical stimulation of the median nerve, is increased when the stimulated hand is close to the face ('far-near effect'). This enhancement occurs through a cortico-bulbar facilitation of the polysynaptic medullary pathways subserving the reflex. Here, in two experiments, we investigated the temporal characteristics of this facilitation, and its adjustment during voluntary movement of the stimulated hand. Given that individuals navigate in a fast changing environment, one would expect the cortico-bulbar modulation of this response to adjust rapidly, and as a function of the predicted spatial position of external threats. We observed two main results. First, the HBR modulation occurs without a temporal delay between when the hand has reached the stimulation position and when the stimulus happens (Experiments 1 and 2). Second, the voluntary movement of the hand interacts with the '...
Pain medicine (Malden, Mass.), Jan 13, 2017
Spectral power analyses of EEG recordings are reported to distinguish the cortical activity of in... more Spectral power analyses of EEG recordings are reported to distinguish the cortical activity of individuals with chronic pain from those of controls. Further study of these spectral patterns may provide a greater understanding of the processes associated with chronic pain, in addition to providing potential biometric markers of chronic pain for use in both clinical and research settings. However, sleep deprived groups have demonstrated similar characteristics in their spectral power characteristics, particularly in alpha bandwidth power activity. 103 individuals with chronic pain provided resting awake EEG data in addition to ratings of pain and sleep quality. Two Principal Axis Factor analyses using Promax rotation produced one pain and one sleep factor from relevant questionnaire data provided by participants. These factors were then used to test hypothesized relationships with alpha and theta bandwidth power at the frontal and parietal areas of the cortex. Our findings suggest tha...
Psychophysiology, Jun 7, 2016
Learning to initiate defenses in response to specific signals of danger is adaptive. Some chronic... more Learning to initiate defenses in response to specific signals of danger is adaptive. Some chronic pain conditions, however, are characterized by widespread anxiety, avoidance, and pain consistent with a loss of defensive response specificity. Response specificity depends on ability to discriminate between safe and threatening stimuli; therefore, specificity might depend on sensory precision. This would help explain the high prevalence of chronic pain in body areas of low tactile acuity, such as the lower back, and clarify why improving sensory precision may reduce chronic pain. We compared the acquisition and generalization of fear of pain-associated vibrotactile stimuli delivered to either the hand (high tactile acuity) or the back (low tactile acuity). During acquisition, tactile stimulation at one location (CS+) predicted the noxious electrocutaneous stimulation (US), while tactile stimulation at another location (CS-) did not. Responses to three stimuli with decreasing spatial p...
Sleep Medicine Reviews, 2010
Sleep Medicine Reviews, 2008
Prader Willi Syndrome (PWS) is a rare genetic disorder characterized by a range of physical, psyc... more Prader Willi Syndrome (PWS) is a rare genetic disorder characterized by a range of physical, psychological and physiological abnormalities. PWS patients may also demonstrate a range of abnormalities of sleep architecture and of breathing during sleep, and excessive daytime sleepiness (EDS). In the general population EDS is associated with Obstructive Sleep Apnea Syndrome (OSAS). In PWS, by contrast, OSAS is unlikely to fully explain EDS and other factors, including hypothalamic dysfunction are likely to contribute. The present review examines OSAS and hypothalamic dysfunction and other contributing factors to EDS in PWS.
Neuropsychology Review, 2006
Prader-Willi Syndrome (PWS) is a rare genetic disorder characterized by a range of physical, psyc... more Prader-Willi Syndrome (PWS) is a rare genetic disorder characterized by a range of physical, psychological, and physiological abnormalities. It is also distinguished by the high prevalence of obstructive sleep apnea syndrome (OSAS), i.e., repetitive upper airway collapse during sleep resulting in hypoxia and sleep fragmentation. In non-PWS populations, OSAS is associated with a range of neurocognitive and psychosocial deficits. Importantly, these deficits are at least partly reversible following treatment. Given the findings in non-PWS populations, it is possible that OSAS may contribute to neurocognitive and psychosocial deficits in PWS. The present review examines this possibility. While acknowledging a primary contribution from the primary genetic abnormality to central neural dysfunction in PWS, we conclude that OSAS may be an important secondary contributing factor to reduced neurocognitive and psychosocial performance. Treatment of OSAS may have potential benefits in improving neurocognitive perfor
The Journal of Pediatrics, 2005
European Respiratory Journal, 2005
The journal of pain : official journal of the American Pain Society, Oct 21, 2016
A classical conditioning framework is often used for clinical reasoning about pain that persists ... more A classical conditioning framework is often used for clinical reasoning about pain that persists after tissue healing. However, experimental studies demonstrating classically conditioned pain in humans are lacking. The current study tested whether non-nociceptive somatosensory stimuli can come to modulate pain threshold after being paired with painful nociceptive stimuli in healthy humans. We used a differential simultaneous conditioning paradigm in which one non-painful vibrotactile conditioned stimulus (CS+) was simultaneously paired with an unconditioned painful laser stimulus (US), while another vibrotactile stimulus (CS-) was paired with a non-painful laser stimulus. After acquisition, at-pain-threshold laser stimuli were delivered simultaneously with a CS+ or CS- vibrotactile stimulus. The primary outcome was the percentage of at-threshold laser stimuli that were reported as painful. The results were as expected: after conditioning, at-threshold laser trials paired with the CS...
<b>DESCRIPTION</b><b><br></b>This repository contains analysis scri... more <b>DESCRIPTION</b><b><br></b>This repository contains analysis scripts (with outputs), figures from the manuscript, and supplementary files for two studies on the properties of the Sensation and Pain Rating Scale (SPARS). All analysis scripts (and their outputs -- <i>/outputs</i> subdirectory) are found in <i>SPARS.zip</i>, while PDF copies of the analysis outputs that are cited in the manuscript as supplementary material are found in the relevant <i>supplement_*.pdf. </i><b><br></b><b>Note: </b>Participant consent did not provide for the publication of their data, and hence neither the original nor cleaned data have been made available. However, we do not wish to bar access to the data unnecessarily and we will judge requests to access the data on a case-by-case basis. Examples of potential use cases include independent assessments of our analyses, and secondary data analyses. Please contact Peter Kamerman ([email protected]), Dr Tory Madden ([email protected], or open an issue on the GitHub repo (https://github.com/kamermanpr/SPARS/issues).<b><br></b><b>BIBLIOGRAPHIC INFORMATION</b><b><br></b><b>Repository citation</b>Kamerman P, Madden V, Bellan V, Catley M, Russek L, Camfferman D, Moseley L. Analysis scripts and supplementary files: Was that painful or non-painful? The Sensation and Pain Rating Scale (SPARS) performs well in the experimental context. Figshare, 2018. DOI: 10.6084/m9.figshare.6561743.<b><br></b><b>Manuscript citation</b>Madden V, Kamerman P, Bellan V, Catley M, Russek L, Camfferman D, Moseley L. The Sensation and Pain Rating Scale (SPARS) performs well in the experimental context. <i>Journal of Pain </i>[in press].<br><b>Manuscript abstract</b>In experiments on pain perception, participants are frequently exposed to non-painful and painful stimuli, yet the conventional pain-rating scales lack a non-painful range and a clear point of transition from non-painful to painful events. The Sensation and Pain Rating Scale (SPARS) is a 0-100 scale that assesses the full stimulus intensity rang [...]
Objectives: To examine the efficacy of self-report and parental report of adolescent sleep proble... more Objectives: To examine the efficacy of self-report and parental report of adolescent sleep problems and compare these findings to the incidence of adolescents who fulfill clinical criteria for a sleep problem. Sleep and daytime functioning factors that predict adolescents ’ self-identification of a sleep problem will also be examined. Method: 308 adolescents (aged 13–17 years) from eight socioeconomically diverse South Australian high schools participated in this study. Participants completed a survey battery during class time, followed by a 7-day Sleep Diary and the Flinders Fatigue Scale completed on the final day of the study. Parents completed a Sleep, Medical, Education and Family History Survey. Results: The percentage of adolescents fulfilling one or more of the criteria for a sleep problem was inordinately high at 66%. Adolescent self-reporting a sleep problem was significantly lower than the adolescents who had one or more of the clinical criteria for a sleep problem (23.1 ...
Examination of the sleep of Australian Indigenous children presents some unique challenges, parti... more Examination of the sleep of Australian Indigenous children presents some unique challenges, particularly in terms of community input, study design and in the collection of relevant data. Abstract Objectives: Research on Indigenous children’s sleep quality is likely to play a significant part in ‘Closing the Gap’ between Indigenous and non-Indigenous children’s health, academic performance and social outcomes. However, examination of the sleep of Australian Indigenous children presents some unique challenges, particularly in terms of community input, study design and in the collection of relevant data. Methods: The current literature on Indigenous sleep research is reviewed and includes factors such as mental and physical health, socioeconomic disadvantage, and their relationships to sleep. Challenges encountered in researching Indigenous sleep and strategies for best practice are explored. Conclusion: Many challenges exist in researching sleep in Indigenous children, but the imperat...
British Journal of Anaesthesia
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Papers by Danny Camfferman