Score for neonatal acute physiology-II and neonatal pain predict corticospinal tract development in premature newborns

Premature infants are at risk for adverse motor outcomes, including cerebral palsy and developmental coordination disorder. The purpose of this study was to examine the relationship of antenatal, perinatal, and postnatal risk factors for abnormal development of the corticospinal tract, the major voluntary motor pathway, during the neonatal period. In a prospective cohort study, 126 premature neonates (24-32 weeks' gestational age) underwent serial brain imaging near birth and at term-equivalent age. With diffusion tensor tractography, mean diffusivity and fractional anisotropy of the corticospinal tract were measured to reflect microstructural development. Generalized estimating equation models examined associations of risk factors on corticospinal tract development. The perinatal risk factor of greater early illness severity (as measured by the Score for Neonatal Acute Physiology-II [SNAP-II]) was associated with a slower rise in fractional anisotropy of the corticospinal tract (P = 0.02), even after correcting for gestational age at birth and postnatal risk factors (P = 0.009). Consistent with previous findings, neonatal pain adjusted for morphine and postnatal infection were also associated with a slower rise in fractional anisotropy of the corticospinal tract (P = 0.03 and 0.02, respectively). Lessening illness severity in the first hours of life might offer potential to improve motor pathway development in premature newborns.

Survival without disability to age 5 years after neonatal caffeine therapy for apnea of prematurity

Very preterm infants are prone to apnea and have an increased risk of death or disability. Caffeine therapy for apnea of prematurity reduces the rates of cerebral palsy and cognitive delay at 18 months of age.

Initial validation of the Behavioral Indicators of Infant Pain (BIIP)

Accurate pain assessment in preterm infants in the neonatal intensive care unit (NICU) is complex. Infants who are born at early gestational ages (GA), and who have had greater early pain exposure, have dampened facial responses which may lead to under-treatment. Since behavioral and physiological responses to pain in infants are often dissociated, using multidimensional scales which combine these indicators into a single score may limit our ability to determine the effects of interventions on each system. Our aim was to design a unidimensional scale which would combine the relatively most specific, individual, behavioral indicators for assessing acute pain in this population. The Behavioral Indicators of Infant Pain (BIIP) combines sleep/wake states, 5 facial actions and 2 hand actions. Ninety-two infants born between 23 and 32 weeks GA were assessed during 3, 1 min Phases of blood collection. Outcome measures included changes in BIIP and in Neonatal Infant Pain Scale (NIPS) scores coded in real time from continuous bedside video recordings; changes in heart rate (HR) were obtained using custom physiological processing software. Scores on the BIIP changed significantly across Phases of blood collection (p

Neonatal procedural pain exposure predicts lower cortisol and behavioral reactivity in preterm infants in the NICU

Data from animal models indicate that neonatal stress or pain can permanently alter subsequent behavioral and/or physiological reactivity to stressors. However, cumulative effects of pain related to acute procedures in the neonatal intensive care unit (NICU) on later stress and/or pain reactivity has received limited attention. The objective of this study is to examine relationships between prior neonatal pain exposure (number of skin breaking procedures), and subsequent stress and pain reactivity in preterm infants in the NICU. Eighty-seven preterm infants were studied at 32 (+/-1 week) postconceptional age (PCA). Infants who received analgesia or sedation in the 72 h prior to each study, or any postnatal dexamethasone, were excluded. Outcomes were infant responses to two different stressors studied on separate days in a repeated measures randomized crossover design: (1) plasma cortisol to stress of a fixed series of nursing procedures; (2) behavioral (Neonatal Facial Coding System; NFCS) and cardiac reactivity to pain of blood collection. Among infants born

Are there developmentally distinct motor indicators of pain in preterm infants?

The aims of this study were to examine preterm infant reactions to pain in detail over prolonged time periods using multiple measures, and to assess the value of including specific body movements of the Neonatal Individualized Developmental Care and Assessment Program (NIDCAP) system to evaluate pain. Ten preterm infants born at 31 weeks mean gestational age (GA) and mean birth weight 1676 g were studied during a routine blood collection in a Level III neonatal intensive care unit (NICU). At 32-week post-conceptional age, computerized physiologic and video recordings were obtained continuously for 60 min (prior to, during and after lance). Motor and facial behaviors were coded independently, using the NIDCAP and the NFCS (Neonatal Facial Coding System), respectively, and compared with heart rate (HR) and oxygen saturation responses. Of the movements hypothesized to be stress cues in the NIDCAP model, extension of arms and legs (80%) and finger splay (70%) were the most common following lance. Contrary to the model, most infants (70%) had lower incidence of twitches and startles post-lance compared to baseline. Whereas all infants showed some NFCS response to lance, for three infants, the magnitude was low. HR increased and oxygen saturation decreased post-lance. Infants with more prior pain exposure, lower Apgar, and lower GA at birth, displayed more motor stress cues but less facial activity post-lance. Extension of extremities and finger splay, but not twitches and startles, from the NIDCAP, appear to be stress cues and show promise as clinical pain indicators to supplement facial and physiological pain measures in preterm infants.

Children's judgements about pain at age 8-10 years:do extremely low birthweight (<or = 1000 g) children differ from full birthweight peers?

Children's judgements about pain at age 8-10 years were examined comparing two groups of children who had experienced different exposure to nociceptive procedures in the neonatal period: extremely low birthweight (ELBW) <or = 1000 g (N = 47) and full birthweight (FBW) > or = 2500 g (N = 37). The 24 pictures that comprise the Pediatric Pain Inventory, depicting events in four settings: medical, recreational, daily living, and psychosocial, were used as the pain stimuli. The subjects rated pain intensity using the Color Analog Scale and pain affect using the Facial Affective Scale. Child IQ and maternal education were statistically adjusted in group comparisons. Pain intensity and pain affect related to activities of daily living and recreation were significantly higher than psychosocial and medically related pain on both scales in both groups of children. Although the two groups of children did not differ overall in their perceptions of pain intensity or affect, the ELBW children rated medical pain intensity significantly higher than psychosocial pain, unlike the FBW group. Also, duration of neonatal intensive care unit stay for the ELBW children was related to increased pain affect ratings in recreational and daily living settings. Despite altered response to pain in the early years reported by parents, on the whole at 8-10 years of age ELBW children judged pain in pictures similarly to their term peers. However, differences were evident, which suggests that studies are needed of biobehavioural reactivity to pain beyond infancy, as well as research into beliefs, attitudes, and perceptions about pain during the course of childhood in formerly ELBW children.

Judging pain in infants:behavioural, contextual, and developmental determinants

Caretakers intuitively use various sources of evidence when judging infant pain, but the relative importance of salient cues has received little attention. This investigation examined the predictive significance for judgements of painful discomfort in preterm and full-term neonates of behavioural (facial activity and body movement), contextual (invasiveness of the procedure), and developmental (gestational age) information. Judges viewed videotapes showing infants varying in the foregoing characteristics undergoing heel incisions for routine blood sampling purposes. Findings indicated all but the contextual information contributed uniquely to judgements of pain, with facial activity accounting for the most unique variance (35%), followed by bodily activity and gestational age, each accounting for 3% and 1% of the judgmental variance, respectively. Generally, 71% of the variance in ratings of pain could be predicted using facial activity alone, compared to 30% of the variance using bodily activity alone, 19% by relying on context alone, and 8% by referring to gestational age alone. Noteworthy was the tendency to judge early preterm infants to be experiencing less pain even though they were subjected to the same invasive procedure as the older infants. This finding also runs counter to evidence from developmental neurobiology which indicates that preterm newborns may be hypersensitive to invasive procedures.

Pain in the preterm neonate:behavioural and physiological indices

The impact of invasive procedures on preterm neonates has received little systematic attention. We examined facial activity, body movements, and physiological measures in 56 preterm and full-term newborns in response to heel lancing, along with comparison preparatory and recovery intervals. The measures were recorded in special care and full-term nurseries during routine blood sampling. Data analyses indicated that in all measurement categories reactions of greatest magnitude were to the lancing procedure. Neonates with gestational ages as short as 25-27 weeks displayed physiological responsivity to the heel lance, but only in the heart rate measure did this vary with gestational age. Bodily activity was diminished in preterm neonates in general, relative to full-term newborns. Facial activity increased with the gestational age of the infant. Specificity of the response to the heel lance was greatest on the facial activity measure. Identification of pain requires attention to gestational age in the preterm neonate.

Developmental changes in pain expression in premature, full-term, two- and four-month-old infants

The purpose of this study was to examine the behavioural responses of infants to pain stimuli across different developmental ages. Eighty infants were included in this cross-sectional design. Four subsamples of 20 infants each included: (1) premature infants between 32 and 34 weeks gestational age undergoing heel-stick procedure; (2) full-term infants receiving intramuscular vitamin K injection; (3) 2-month-old infants receiving subcutaneous injection for immunisation against DPT; and (4) 4-month-old infants receiving subcutaneous injection for immunisation against DPT. Audio and video recordings were made for 15 sec from stimulus. Cry analysis was conducted on the first full expiratory cry by FFT with time and frequency measures. Facial action was coded using the Neonatal Facial Action Coding System (NFCS). Results from multivariate analysis showed that premature infants were different from older infants, that full-term newborns were different from others, but that 2- and 4-month-olds were similar. The specific variables contributing to the significance were higher pitched cries and more horizontal mouth stretch in the premature group and more taut tongue in the full-term newborns. The results imply that the premature infant has the basis for communicating pain via facial actions but that these are not well developed. The full-term newborn is better equipped to interact with his caretakers and express his distress through specific facial actions. The cries of the premature infant, however, have more of the characteristics that are arousing to the listener which serve to alert the caregiver of the state of distress from pain.

Robust Multimodal Person Identification With Limited Training Data

This paper presents a novel method of audio-visual feature-level fusion for person identification where both the speech and facial modalities may be corrupted, and there is a lack of prior knowledge about the corruption. Furthermore, we assume there are limited amount of training data for each modality (e.g., a short training speech segment and a single training facial image for each person). A new multimodal feature representation and a modified cosine similarity are introduced to combine and compare bimodal features with limited training data, as well as vastly differing data rates and feature sizes. Optimal feature selection and multicondition training are used to reduce the mismatch between training and testing, thereby making the system robust to unknown bimodal corruption. Experiments have been carried out on a bimodal dataset created from the SPIDRE speaker recognition database and AR face recognition database with variable noise corruption of speech and occlusion in the face images. The system's speaker identification performance on the SPIDRE database, and facial identification performance on the AR database, is comparable with the literature. Combining both modalities using the new method of multimodal fusion leads to significantly improved accuracy over the unimodal systems, even when both modalities have been corrupted. The new method also shows improved identification accuracy compared with the bimodal systems based on multicondition model training or missing-feature decoding alone.

Modeling continuous self-report measures of perceived emotion using generalized additive mixed models

Emotion research has long been dominated by the “standard method” of displaying posed or acted static images of facial expressions of emotion. While this method has been useful it is unable to investigate the dynamic nature of emotion expression. Although continuous self-report traces have enabled the measurement of dynamic expressions of emotion, a consensus has not been reached on the correct statistical techniques that permit inferences to be made with such measures. We propose Generalized Additive Models and Generalized Additive Mixed Models as techniques that can account for the dynamic nature of such continuous measures. These models allow us to hold constant shared components of responses that are due to perceived emotion across time, while enabling inference concerning linear differences between groups. The mixed model GAMM approach is preferred as it can account for autocorrelation in time series data and allows emotion decoding participants to be modelled as random effects. To increase confidence in linear differences we assess the methods that address interactions between categorical variables and dynamic changes over time. In addition we provide comments on the use of Generalized Additive Models to assess the effect size of shared perceived emotion and discuss sample sizes. Finally we address additional uses, the inference of feature detection, continuous variable interactions, and measurement of ambiguity.

Validation of a passive stereophotogrammetry system for imaging of the breast: A geometric analysis

The overall aim of this study was to assess the accuracy, reproducibility and stability of a high resolution passive stereophotogrammetry system to image a female mannequin torso, to validate measurements made on the textured virtual surface compared with those obtained using manual techniques and to develop an approach to make objective measurements of the female breast. 3D surface imaging was carried out on a textured female torso and measurements made in accordance with the system of mammometrics. Linear errors in measurements were less than 0.5 mm, system calibration produced errors of less than 1.0 mm over 94% over the surface and intra-rater reliability measured by ICC = 0.999. The mean difference between manual and digital curved surface distances was 1.36 mm with maximum and minimum differences of 3.15 mm and 0.02 mm, respectively. The stereophotogrammetry system has been demonstrated to perform accurately and reliably with specific reference to breast assessment. (C) 2011 IPEM. Published by Elsevier Ltd. All rights reserved.