Emotional and Behavioral Trajectories of 2 to 9 Years Old Children Born to Opioid-Dependent Mothers.

Maternal opioid use in pregnancy has increased dramatically. Knowledge about children's longer-term emotional and behavioral development after prenatal opioid exposure is scarce. A regional sample of 89 opioid-exposed and 104 non-exposed comparison children were studied prospectively at ages 2, 4.5, and 9 years using the Strengths and Difficulties Questionnaire (SDQ) completed by primary caregivers. Across all childhood assessments, opioid-exposed children obtained significantly higher total difficulties scores than non-exposed comparison children. Growth curve modeling revealed that, relative to their same age peers, opioid-exposed children's emotional and behavioral difficulties significantly worsened over time. Moreover, fixed effects estimates showed that total difficulties trajectories were poorer for children subject to higher prenatal risk (Est = 1.78, 95% CI = [0.46, 3.09]) who were born to mothers with high levels of social adversity (1.11 [0.51, 1.71]), and were then raised in families characterized by high levels of psychosocial risk (1.94 [0.90, 2.98]) and unstable caregiving (1.91 [0.33, 3.48]). A complex set of pre- and postnatal processes contribute to opioid-exposed children's emotional and behavioral development. Efforts to mitigate the long-term consequences of opioid use in pregnancy need to consider both children's and their caregivers' biopsychosocial risks.

Longitudinal Study of Infant Sleep Development: Early Predictors of Sleep Regulation Across the First Year.

BACKGROUND: An important developmental task for infants over their first few years of life is to learn to settle to sleep with a reasonably short latency, maintain sleep through the night and coordinate with family sleeping and waking schedules. A child who can reliably do this is exhibiting self-regulated sleep. Otherwise, children's sleep may have to be other (non-self) regulated to some degree and they may exhibit pediatric sleep disturbances (e.g., extended sleep latency, and/or frequent nightwaking); these are reported by 36-45% of parents of infants between ages four to 12 months. PURPOSE: To answer the question: Can infant and parent factors observed at 1 month of infant age predict which infants will have regulated sleep at 6- and 12-months of age? Prediction from 1 month has not previously been investigated. METHODS: In a prospective longitudinal study, the mothers of 52 typically developing infants completed 6-day sleep diaries at 1, 3, 6, 9 and 12 months from which a composite sleep score (CSS) was derived for each child at each month. Diary reliability was assessed once (for 54% of families) using all-night videosomnography. RESULTS: At 6 months, CSS scores were distributed bi-modally and thus differentiated into two groups by an empirically observed CSS cutoff score, with a majority (56%) of infants classified as self-sleep regulated (S-R) and the rest as non-self sleep-regulated (NS-R). At 12 months, 72% could similarly be classified as S-R, while 28% exhibited some continuing sleep disturbance. Discriminant function analysis investigated the predictors of S-R vs NS-R group membership at 6 and 12 months from parent and child variables recorded at 1 month. Parent presence at sleep onset and less total infant sleep time predicted group membership at 6 months with 94% classification accuracy, and parental presence at sleep onset and frequency of infant night wakings predicted group membership at 12 months with 85% accuracy. At 1 month, parents of infants later classified as NS-R at 6 and 12 months had higher frequencies of all settling activities than parents of those later classified as S-R. CONCLUSION: Variables measured at 1 month that predicted sleep status at 6 and 12 months were parental presence at sleep onset, frequency of infant night waking and total infant sleep time. The overall frequency of parent settling activities at 1 month also clearly differentiated the two sleep groups at the older ages. Parenting behaviours are modifiable factors and thus may have the potential for preventing pediatric sleep disturbances in children.

Quantified biomechanical properties of lower lumbar myofascia in younger adults with chronic idiopathic low back pain and matched healthy controls.

BACKGROUND: Non-specific chronic low back pain (LBP) is a prevalent condition that is poorly understood with respect to possible altered physical properties. Five biomechanical properties of stiffness, frequency, decrement, creep, and stress relaxation time of the L3-L4 myofascial tissue were quantified using the MyotonPro® in chronic idiopathic LBP and matched normal control subjects. METHODS: Measurements were obtained in the resting prone position on the left and right sides (initially and after 10 min rest) in 25 chronic LBP participants (16 female, 9 male) and 25 age- and sex-matched control subjects. Surface electromyography measurements were simultaneously conducted to ensure a resting state. FINDINGS: Female LBP had significantly greater median decrement (p < 0.001) and stiffness (p < 0.010) than female controls. In female LBP patients, BMI correlated with decrement (p < 0.010) and creep (p < 0.050); creep also correlated with decrement (p < 0.050). Significant male versus female differences were found in all five properties in both LBP and control subgroups, except decrement in control males versus females. INTERPRETATION: This study showed that greater median decrement was found in LBP female subjects suggesting decrease in elasticity in the lumbar myofascia. Most of the biomechanical properties differed significantly by gender. This study further documented that right-handed dominance might correlate with greater right-sided lumbar myofascial stiffness.

Health and Neurodevelopment of Children Born to Opioid-Dependent Mothers at School Entry.

OBJECTIVE: To examine the school readiness of a regional cohort of prenatally methadone-exposed children across 5 domains and to examine factors contributing to impairment risk. METHODS: Data were drawn from a single-center, prospective longitudinal study. One hundred children born to women in methadone maintenance treatment and 110 randomly identified non-methadone-exposed children were studied from birth (2003-2008) to age 4.5 years. At 4.5 years, children underwent comprehensive assessment of their physical/motor development, social-emotional skills, approaches to learning, language development, and cognitive functioning. Predictors of children's overall school readiness were examined, including the extent of prenatal substance exposure (number and quantity of different substances), social risk, maternal mental health, infant clinical factors, and the quality of the home environment at age 18 months Home Observation for Measurement of the Environment (HOME) score. RESULTS: Methadone-exposed children had higher rates of delay/impairment across all outcome domains (odds ratios 4.0-5.3), with 72% impaired in at least 1 domain. Multiple problems were also common, affecting 48% of methadone-exposed children compared with 15% of control children. The mean number of school readiness domains impaired increased, with increasing prenatal substance exposure (rate ratio [RR] = 1.05 [1.01-1.11]), higher social risk (RR = 1.35 [1.20-1.53]), male sex (RR = 1.69 [1.27-2.25]), and lower HOME scores indicating a poorer quality postnatal environment (RR = 0.96 [0.94-0.99]). CONCLUSION: Children born to opioid-dependent mothers are at high risk of impaired school readiness, with multiple domain problems being common. Impaired school readiness was associated with greater maternal prenatal substance use, higher social risk, male sex, and lower-quality caregiving environments.

Neurodevelopmental Outcomes of Children Born to Opioid-Dependent Mothers: A Systematic Review and Meta-Analysis.

BACKGROUND: Children born to opioid-dependent mothers are at risk of adverse neurodevelopment. The magnitude of this risk remains inconclusive. OBJECTIVE: To conduct a meta-analysis of studies that assessed neurodevelopmental outcomes of children aged 0 to 12 years born to opioid-dependent mothers, compared with children born to nonopioid-dependent mothers, across general cognitive, language, motor, and social-emotional domains. DATA SOURCES: PubMed, CINAHL, PsycINFO, and Google Scholar databases. STUDY ELIGIBILITY CRITERIA: English-language publications between January 1993 and November 2018, including prenatally opioid-exposed and nonopioid-exposed comparison children, reporting outcomes data on standardized assessments. STUDY APPRAISAL AND SYNTHESIS METHODS: Two reviewers independently extracted data. Pooled standardized mean differences (SMDs) were analyzed using random effects models. Risk of bias was assessed with the Newcastle-Ottawa Quality Assessment Scale. RESULTS: Across 16 studies, individual domain outcomes data were examined for between 93 to 430 opioid-exposed and 75 to 505 nonopioid-exposed infants/children. Opioid-exposed infants and children performed more poorly than their nonopioid-exposed peers across all outcomes examined, demonstrated by lower infant cognitive (SMD = 0.77) and psychomotor scores (SMD = 0.52), lower general cognition/IQ (SMD = 0.76) and language scores (SMD = 0.65-0.74), and higher parent-rated internalizing (SMD = 0.42), externalizing (SMD = 0.66), and attention problems (SMD = 0.72). LIMITATIONS: Most studies examined early neurodevelopment; only 3 reported school-age outcomes thereby limiting the ability to assess longer-term impacts of prenatal opioid exposures. CONCLUSIONS AND IMPLICATIONS OF FINDINGS: Children born to opioid-dependent mothers are at modest- to high-risk of adverse neurodevelopment at least to middle childhood. Future studies should identify specific clinical and social factors underlying these challenges to improve outcomes.

Educational achievement at age 9.5 years of children born to mothers maintained on methadone during pregnancy.

Recent research shows that preschool children born to opioid-dependent mothers are at increased risk for cognitive, psychomotor, attention, and social-emotional adjustment problems. But very little is known about their school-age functioning, particularly their educational achievement. This analysis examined the educational outcomes of a regional cohort of 100 prenatally methadone-exposed children who were prospectively studied from birth to age 9.5 years alongside a comparison group of 110 randomly identified non-exposed children born between 2003 and 2008. At age 9.5, as part of a comprehensive neurodevelopmental evaluation, children's teachers rated their achievement across the school curriculum, and children completed the Woodcock Johnson-III Tests of Achievement (WJ-III). Detailed information about the birth mother's social background, pregnancy substance use, and mental health was also collected during pregnancy/at term. Infant clinical data were collected after birth. Methadone-exposed children performed less well than non-exposed children across seven school curriculum areas rated by teachers (ps ≤.001), performed less well than non-exposed children on all reading and mathematics subtests of the WJ-III, and had higher rates of any educational delay on the WJ-III (57% vs. 15%), OR = 7.47 (3.71-15.02). Results were similar when children with severe intellectual impairment were excluded. After adjusting for confounding factors, methadone-exposed children had increased odds of educational delay, but this was only marginally significant (OR = 3.62, [1.01-13.01], p = .049). Maternal educational attainment level (OR = 0.69, [0.50-0.89], p = .006), and maternal benzodiazepine use during pregnancy (OR = 2.70 [1.03-7.12], p = .044) were also associated with later educational risk. Findings suggest that children born to opioid-dependent women enrolled in methadone maintenance are at high risk of educational delay by age 9.5 years. Children's academic difficulties appeared to reflect the effects of both adverse prenatal exposures and postnatal social risk.

Biomechanical properties of low back myofascial tissue in younger adult ankylosing spondylitis patients and matched healthy control subjects.

BACKGROUND: Ankylosing spondylitis is a degenerative and inflammatory rheumatologic disorder that primarily affects the spine. Delayed diagnosis leads to debilitating spinal damage. This study examines biomechanical properties of non-contracting (resting) human lower lumbar myofascia in ankylosing spondylitis patients and matched healthy control subjects. METHODS: Biomechanical properties of stiffness, frequency, decrement, stress relaxation time, and creep were quantified from 24 ankylosing spondylitis patients (19 male, 5 female) and 24 age- and sex-matched control subjects in prone position on both sides initially and after 10 min rest. Concurrent surface electromyography measurements were performed to ensure resting state. Statistical analyses were conducted, and significance was set at p < 0.05. FINDINGS: Decreased lumbar muscle elasticity (inverse of decrement) was primarily correlated with disease duration in ankylosing spondylitis subjects, whereas BMI was the primary correlate in control subjects. In ankylosing spondylitis and control groups, significant positive correlations were observed between the linear elastic properties of stiffness and frequency as well as between the viscoelastic parameters of stress relaxation time and creep. The preceding groups also showed significant negative correlations between the linear elastic and viscoelastic properties. INTERPRETATION: Findings indicate that increased disease duration is associated with decreased tissue elasticity or myofascial degradation. Both ankylosing spondylitis and healthy subjects revealed similar correlations between the linear and viscoelastic properties which suggest that the disease does not directly alter their inherent interrelations. The novel results that stiffness is greater in AS than normal subjects, whereas decrement is significantly correlated with AS disease duration deserves further investigation of the biomechanical properties and their underlying mechanisms.

Stiffness of resting lumbar myofascia in healthy young subjects quantified using a handheld myotonometer and concurrently with surface electromyography monitoring.

This study aimed to non-invasively quantify passive stiffness of superficial myofascia at a lower lumbar (L3-L4) anatomical level in young healthy male and female subjects and investigate its possible morphological variation. Resting prone lumbar myofascial measurements were quantified using MyotonPro(®) and statistically analyzed in 20 young healthy individuals over 3-weekly intervals, concurrently with surface electromyography (sEMG). Averaged mean ± SE stiffness (Newton/meter) over three weeks was significantly (p < 0.001) greater in males (247.8 ± 11.3) than females (208.4 ± 11.3), on the right (237.7 ± 12.8) than left sides (218.5 ± 12.3), at 10-min (231.4 ± 9.1) than initial baseline (224.8 ± 9.1) values. A polymorphism of stiffness values in 10 male and 10 female subjects was suggested by box plot analyses of the 3 weekly measurements and greater inter-individual than intra-individual variances. Greater knowledge of lumbar myofascial stiffness can improve understanding of their contributions in health and chronic low back disorders.

Sports Participation in Genotype Positive Children With Long QT Syndrome.

OBJECTIVE: The study sought to examine the prevalence and outcomes of sports participation (both competitive and recreational) in our single-center LQTS genotype positive pediatric population. BACKGROUND: The risks of sports participation in patients with long QT syndrome (LQTS) are not clearly elucidated. METHODS: A retrospective review was performed on genotype positive patients referred for the evaluation and management of LQTS between 1998 and 2013 at the Children's Hospital of Philadelphia. Pediatric patients participating in competitive or recreational sports were included in the analysis and their charts were reviewed for documented LQTS events during follow-up. RESULTS: The cohort of genotype-positive LQTS patients included 212 patients, and 103 patients (49%, female n = 53, average follow-up 7.1 ± 4.0 years, average QTc 468 ± 42 ms) participated in sports. A total of 105 LQTS disease-causing mutations were identified: KCNQ1 n = 60 (58%), KCNH2 n = 36 (35%), SCN5A n = 6 (6%), KCNE1 n = 1 (1%), and KCNE2 n = 2 (2%). All patients were treated with beta-blockade, with noncompliance in 1 patient and intolerance in 1 patient. Twenty-six patients participated in competitive sports (26%, female n = 15, average follow-up 6.9 ± 4.1 years, average QTc 461 ± 35 ms). Seventy-seven patients (75%, female n = 35, average follow-up 7.3 ± 3.9 years, average QTc 470 ± 43 ms) participated in recreational sports. No patients had LQTS symptoms during sports participation. Five appropriate implantable cardioverter-defibrillator shocks occurred in 2 patients, though none were related to sports participation. CONCLUSIONS: In this series no cardiac events and no deaths were observed in treatment-compliant LQTS children while participating in sports in 755 patient-years of follow-up.

Greater Resting Lumbar Extensor Myofascial Stiffness in Younger Ankylosing Spondylitis Patients Than Age-Comparable Healthy Volunteers Quantified by Myotonometry.

OBJECTIVE: To quantify resting lumbar erector myofascial stiffness in younger patients with ankylosing spondylitis (AS) and age-comparable healthy control subjects using a handheld mechanical impulse-based myotonometric device. DESIGN: A case-control study of 24 patients with AS and 24 age-comparable healthy control subjects. SETTING: University physical therapy department. PARTICIPANTS: Patients with AS (men: n=19; women: n=5; total: N=24) and healthy volunteers (men: n=19; women: n=5; total: N=24) without low back pain (age range, 18-46y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Lumbar myofascial stiffness. RESULTS: At the initial measurements, median stiffness (Nm) of the averaged right- and left-sided values was greater (P=.021) in 24 patients with AS than 24 control subjects (268.9 vs 238.9, respectively). Repeated measurements after a 10-minute prone resting period were also greater (P=.007) in patients with AS than control subjects (281.0 vs 241.4, respectively). The 48 averaged right- and left-sided values from baseline and 10-minute measurements were compared in each subject group. The patients with AS more frequently (P=.012) had stiffness values >250 Nm (35 [72.9%] vs 22 [45.8%] in control subjects). CONCLUSIONS: Lumbar myofascial stiffness was greater in 24 patients with AS than in the control subjects. A hypothesized biomechanical concept of increased resting lumbar myofascial stiffness in AS may be supported by this preliminary controlled study.

Sleeping through the night: a community survey of parents' opinions about and expectations of infant sleep consolidation.

AIM: This study examined parents' expectations of and opinions about infant sleep consolidation, the temporal timing and definitions of sleeping through the night and sources of advice about their infant's sleep. METHODS: Participants were 412 parents (mean age 31 years ±6.8) with a child 2 years or younger recruited at shopping malls and other public places. Parents completed a brief survey on (i) the nocturnal duration they considered an infant should sustain uninterrupted sleep; (ii) a temporal location within the night for a criterion for sleeping through the night; (iii) their agreement or disagreement with Moore and Ucko's (1957) 24:00-05:00 h criterion defining sleeping through the night; and (iv) the sources of advice they had sought about infant's sleep. RESULTS: Parents expected infants to sustain sleep on average for 9.6 ± 3.4 h, with trends indicating the more children in the family (P = 0.02; d = 0.26) and lower family socio-economic status (P = 0.01; d = 0.34) the shorter the durations expected. Sleeping through the night was defined within a temporal location from 20:00 to 06:30 h. Over 80% of parents disagreed that 24:00-05:00 h criterion defined sleeping through the night. Forty-seven per cent of parents had sought advice regarding their infants' sleep, with Child Health Care Nurses the most popular source. CONCLUSIONS: New Zealand parents have realistic expectations of infant capabilities for sleep consolidation that were within contemporary clinical guidelines. A new parent-based definition of sleeping through the night is presented that has social and developmental validity.

Do LQTS gene single nucleotide polymorphisms alter QTc intervals at rest and during exercise stress testing?

BACKGROUND: The impact of harboring, genetic variants or single nucleotide polymorphisms (LQT-PM) on the repolarization response during exercise and recovery is unknown. OBJECTIVE: To assess the QTc interval adaptation during exercise stress testing (EST) in children with LQT polymorphisms compared to a group of age and gender matched normal controls. METHODS: One hundred forty-eight patients were age and gender matched into two groups: LQT-PM and control. Each patient underwent a uniform exercise protocol employing a cycle ergometer followed by a 9 minute recovery phase with continuous 12-lead electrocardiogram (ECG) monitoring. Intervals (RR, QT and QTc) at rest (supine), peak exercise and in recovery (1, 3, 5, 7, and 9 minutes) were measured. RESULTS: Forty-three patients were positive for LQT-PM and the control group consisted of 105 patients. A total of 83 SNPs were identified: SCN5A n = 31 (37%), KCNE1 n = 29 (35%), KCNH2 n = 20 (24%), KCNQ1 n = 2 (2%) and KCNE2 n = 1 (1%). The QTc interval measurements of the LQT-PM were longer at rest, peak exercise and all phases of recovery when compared to the control group. Neither group demonstrated abnormal QTc interval adaptation in response to exercise. Patients with homozygous SNPs had longer resting QTc intervals when compared to patients with only heterozygous SNPs (435 ± 23 ms vs. 415 ± 20 ms, respectively, P value <0.006). CONCLUSIONS: Individuals with LQT-PM may have longer QTc intervals at rest as well as at peak exercise and all phases of the recovery period compared to normal controls. Additionally, subjects with homozygous SNPs had longer resting QTc intervals when compared to those with only heterozygous SNPs.

Speckle-tracking sonographic assessment of longitudinal motion of the flexor tendon and subsynovial tissue in carpal tunnel syndrome.

OBJECTIVES: The aim of this study was to image both tendon and subsynovial connective tissue movement in patients with carpal tunnel syndrome and healthy control volunteers, using sonography with speckle tracking. To estimate accuracy of this tracking method, we used in vivo measurements during surgery to validate the motion estimated with sonography. METHODS: We recruited 22 healthy volunteers and 18 patients with carpal tunnel syndrome. Longitudinal sonograms of the middle finger flexor digitorum superficialis tendon and subsynovial connective tissue were obtained during finger flexion and extension. The images were analyzed with a speckle-tracking algorithm. The ratio of the subsynovial connective tissue velocity to tendon velocity was calculated as the maximum velocity ratio, and the shear index, the ratio of tendon to subsynovial connective tissue motion, was calculated. For validation, we recorded flexor digitorum superficialis tendon motion during open carpal tunnel release. RESULTS: The shear index was higher in patients than controls (P < .05), whereas the maximum velocity ratio in extension was lower in patients than controls (P < .05). We found good intraclass correlation coefficients (>0.08) for shear index and maximum velocity ratio measurements between speckle-tracking and in vivo measurements. Bland-Altman analyses showed that all measurements remained within the limits of agreement. CONCLUSIONS: Speckle tracking is a potentially useful method to assess the biomechanics within the carpal tunnel and to distinguish between healthy individuals and patients with carpal tunnel syndrome. This method, however, needs to be further developed for clinical use, with the shear index and maximum velocity ratio as possible differentiating parameters between patients with carpal tunnel syndrome and healthy individuals.

Transverse plane tendon and median nerve motion in the carpal tunnel: ultrasound comparison of carpal tunnel syndrome patients and healthy volunteers.

BACKGROUND: The median nerve and flexor tendons are known to translate transversely in the carpal tunnel. The purpose of this study was to investigate these motions in differential finger motion using ultrasound, and to compare them in healthy people and carpal tunnel syndrome patients. METHODS: Transverse ultrasounds clips were taken during fist, index finger, middle finger and thumb flexion in 29 healthy normal subjects and 29 CTS patients. Displacement in palmar-dorsal and radial-ulnar direction was calculated using Analyze software. Additionally, the distance between the median nerve and the tendons was calculated. RESULTS: We found a changed motion pattern of the median nerve in middle finger, index finger and thumb motion between normal subjects and CTS patients (p<0.05). Also, we found a changed motion direction in CTS patients of the FDS III tendon in fist and middle finger motion, and of the FDS II and flexor pollicis longus tendon in index finger and thumb motion, respectively (p<0.05). The distance between the median nerve and the FDS II or FPL tendon is significantly greater in patients than in healthy volunteers for index finger and thumb motion, respectively (p<0.05). CONCLUSION: Our results suggest a changed motion pattern of the median nerve and several tendons in carpal tunnel syndrome patients compared to normal subjects. Such motion patterns may be useful in distinguishing affected from unaffected individuals, and in studies of the pathomechanics of carpal tunnel syndrome.

Sonographic measurements of subsynovial connective tissue thickness in patients with carpal tunnel syndrome.

OBJECTIVES: A major pathologic finding in patients with idiopathic carpal tunnel syndrome is noninflammatory fibrosis and thickening of the subsynovial connective tissue. The objective of this study was to determine the ability of sonography to depict this thickening by comparing subsynovial connective tissue thickness in patients with carpal tunnel syndrome and healthy control participants. METHODS: Longitudinal sonograms of the middle finger superficial flexor tendon and subsynovial connective tissue were obtained at 3 levels: at the wrist crease (proximal tunnel), at the hook of the hamate (mid tunnel), and at the distal edge of the transverse carpal ligament (distal tunnel). The thickness of the subsynovial connective tissue perpendicular to the direction of the tendon and the diameter of the flexor digitorum superficialis tendon at the same level were measured. Then, a thickness ratio was created. RESULTS: At all 3 levels, the subsynovial connective tissue was thicker in patients than in controls (P < .0001) with a thickness ranging from 0.60 to 0.63 mm in patients and 0.46 to 0.50 mm in controls. The thickness ratio was significantly greater in patients at the hamate and distal levels (P = .018 and .013, respectively). CONCLUSIONS: With this study, we have shown that it is possible to measure subsynovial connective tissue thickness with sonography, and the tissue is thicker in patients with carpal tunnel syndrome than in healthy controls.

Median nerve deformation in differential finger motions: ultrasonographic comparison of carpal tunnel syndrome patients and healthy controls.

We investigated the median nerve deformation in the carpal tunnel in patients with carpal tunnel syndrome and controls during thumb, index finger, middle finger, and a four finger motion, using ultrasound. Both wrists of 29 asymptomatic volunteers and 29 patients with idiopathic carpal tunnel syndrome were evaluated by ultrasound. Cross-sectional images during motion from full extension to flexion were recorded. Median nerve cross-sectional area, perimeter, aspect ratio of the minimal enclosing rectangle, and circularity in extension and flexion positions were calculated. Additionally, a deformation index was calculated. We also calculated the intra-rater reliability. In both controls and patients, the median nerve cross-sectional area became significantly smaller from extension to flexion in all finger motions (p < 0.05). In flexion and extension, regardless of the specific finger motion, the median nerve deformation, circularity and the change in perimeter were all significantly greater in CTS patients than in controls (p < 0.05). We found excellent intra-rater reliability for all measurements (ICC > 0.84). With this study we have shown that it is possible to assess the deformation of the median nerve in carpal tunnel syndrome with ultrasonography and that there is more deformation of the median nerve in carpal tunnel syndrome patients during active finger motion. These parameters might be useful in the evaluation of kinematics within the carpal tunnel, and in furthering our understanding of the biomechanics of carpal tunnel syndrome in the future.

Genotype- and mutation site-specific QT adaptation during exercise, recovery, and postural changes in children with long-QT syndrome.

BACKGROUND: Exercise stress testing has shown diagnostic utility in adult patients with long-QT syndrome (LQTS); however, the QT interval adaptation in response to exercise in pediatric patients with LQTS has received little attention. METHODS AND RESULTS: One-hundred fifty-eight patients were divided into 3 groups: Those with LQTS type 1 (LQT1) or LQTS type 2 (LQT2) and normal control subjects without cardiovascular disease. Each patient underwent a uniform exercise protocol with a cycle ergometer followed by a 9-minute recovery phase with continuous 12-lead ECG monitoring. Each patient underwent a baseline ECG while resting in the supine position and in a standstill position during continuous ECG recording to determine changes in the QT and RR intervals. Fifty patients were gene-positive for LQTS (n=29 for LQT1 and n=21 for LQT2), and the control group consisted of 108 patients. QT interval adaptation was abnormal in the LQT1 patients compared with LQT2 and control patients (P<0.001). A corrected QT interval (QTc) >460 ms in the late recovery phase at 7 minutes predicted LQT1 or LQT2 versus control subjects with 96% specificity, 86% sensitivity, and a 91% positive predictive value. A recovery ΔQTc((7 min-1 min)) >30 ms predicted LQT2 versus LQT1 with 75% sensitivity, 82% specificity, and a 75% positive predictive value. The postural ΔQT was significantly different between LQTS and control groups (P=0.005). CONCLUSIONS: Genotype-specific changes in repolarization response to exercise and recovery exist in the pediatric population and are of diagnostic utility in LQTS. An extended recovery phase is preferable to assess the repolarization response after exercise in the pediatric population.

Ultrasound assessment of the motion patterns of human flexor digitorum superficialis and profundus tendons with speckle tracking.

The purposes of our study were to correlate ultrasonographically measured and joint angle estimated excursions of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons of the hand and to estimate the relative motion of FDS and FDP while gripping cylinders of standard diameter in normal human subjects. Thirty wrists from 15 human subjects were imaged with an ultrasound scanner. Speckle tracking was used to measure the excursion of the FDS and FDP tendons. The tendon excursions necessary to grip three differently sized acrylic tubes were measured and correlated with the corresponding finger joint angles. The FDP/FDS excursion ratio was calculated. The Pearson's correlation coefficient between the FDS excursion and MP + PIP joint angle was 0.61. The Pearson's correlation coefficient between the FDP + FDS excursion and the DIP + PIP + MP joint angle was 0.67. The FDP/FDS excursion ratio was smaller for larger excursions (gripping a smaller diameter tube) and larger for small excursions (gripping a larger diameter tube, P < 0.01). These data suggest that speckle tracking may be a useful method to discriminate the relative motion of flexor tendons, which in turn may be relevant in evaluating tendon function, for example after tendon injury.

Finite element model of subsynovial connective tissue deformation due to tendon excursion in the human carpal tunnel.

Carpal tunnel syndrome (CTS) is a nerve entrapment disease, which has been extensively studied by the engineering and medical community. Although the direct cause is unknown, in vivo and in vitro medical research has shown that tendon excursion creates microtears in the subsynovial connective tissue (SSCT) surrounding the tendon in the carpal tunnel. One proposed mechanism for the SSCT injury is shearing, which is believed to cause fibrosis of the SSCT. Few studies have reported quantitative observations of SSCT response to mechanical loading. Our proposed model is a 2-D section that consists of an FDS tendon, interstitial SSCT and adjacent stationary tendons. We believe that developing this model will allow the most complete quantitative observations of SSCT response to mechanical loading reported thus far. Boundary conditions were applied to the FEA model to simulate single finger flexion. A velocity was applied to the FDS tendon in the model to match loading conditions of the documented cadaver wrist kinematics studies. The cadaveric and FEA displacement results were compared to investigate the magnitude of stiffness required for the SSCT section of the model. The relative motions between the model and cadavers matched more closely than the absolute displacements. Since cadaveric models do not allow identification of the SSCT layers, an FEA model will help determine the displacement and stress experienced by each SSCT layer. Thus, we believe this conceptual model is a first step in understanding how the SSCT layers are recruited during tendon excursion.

The consolidation of infants' nocturnal sleep across the first year of life.

This review investigates development in the durations of infants' capabilities for sustained sleep across their first year, a matter of interest to clinicians, parents and researchers. It describes three aspects of sleep development: longest sustained sleep period (sleep sustained without awakening), longest self-regulated sleep period (behavioural quietude including sleep and quiet awakenings), and sleeping through the night (a predetermined nocturnal period). Clear trends were evident despite methodological differences making comparison between studies difficult. The most marked changes were across the first 4 months, particularly ages 1 and 2 months. Minimal changes followed through to 9 months and a small increase in all but the longest sustained sleep period, until age 12 months. Moore and Ucko's early, yet influential definition for sleeping through the night (24:00-05:00 h) may have underestimated infants' capacities for uninterrupted sleep. Infants do meet more stringent criteria and most can sleep 8 h by age 6 months and 9 or more hours thereafter. These findings have implications for clinicians addressing parental concerns around developmentally appropriate expectations of infant sleep. Researchers now have sufficient evidence to identify developmentally sensitive timing for preventive interventions for infant sleep disturbance.