A survey of practice in the anesthetic management of adolescent idiopathic scoliosis spine fusion by the North American Pediatric Spine Anesthesiologists Collaborative.

BACKGROUND: Adolescent Idiopathic Scoliosis (AIS) affects 2%-4% of the general pediatric population. While surgical correction remains one of the most common orthopedic procedures performed in pediatrics, limited consensus exists on the perioperative anesthetic management. AIMS: To examine the current state of anesthetic management of typical AIS spine fusions at institutions which have a dedicated pediatric orthopedic spine surgeon. METHODS: A web-based survey was sent to all members of the North American Pediatric Spine Anesthesiologists (NAPSA) Collaborative. This group included 34 anesthesiologists at 19 different institutions, each of whom has a Harms Study Group surgeon performing spine fusions at their hospital. RESULTS: Thirty-one of 34 (91.2%) anesthesiologists completed the survey, with a missing response rate from 0% to 16.1% depending on the question. Most anesthesia practices (77.4%; 95% confidence interval [CI], 67.7-93.4) do not have patients come for a preoperative visit prior to the day of surgery. Intravenous induction was the preferred method (74.2%; 95% CI 61.3-89.9), with the majority utilizing two peripheral IVs (93.5%; 95% CI 90.3-100) and an arterial line (100%; 95% CI 88.8-100). Paralytic administration for intubation and/or exposure was divided (51.6% rocuronium/vecuronium, 45.2% no paralytic, and 3.2% succinylcholine) amongst respondents. While tranexamic acid was consistently utilized for reducing blood loss, dosing regimens varied. When faced with neuromonitoring signal issues, 67.7% employ a formal protocol. Most anesthesiologists (93.5%; 95% CI 78.6-99.2) extubate immediately postoperatively with patients admitted to an inpatient floor bed (77.4%; 95% CI 67.7-93.3). CONCLUSION: Most anesthesiologists (87.1%; 95% CI 80.6-99.9) report the use of some form of an anesthesia-based protocol for AIS fusions, but our survey results show there is considerable variation in all aspects of perioperative care. Areas of agreement on management comprise the typical vascular access required, utilization of tranexamic acid, immediate extubation, and disposition to a floor bed. By recognizing the diversity of anesthetic care, we can develop areas of research and improve the perioperative management of AIS.

Patient and Process Outcomes among Pediatric Patients Undergoing Appendectomy during the COVID-19 Pandemic: An International Retrospective Cohort Study.

BACKGROUND: COVID-19 forced healthcare systems to make unprecedented changes in clinical care processes. The authors hypothesized that the COVID-19 pandemic adversely impacted timely access to care, perioperative processes, and clinical outcomes for pediatric patients undergoing primary appendectomy. METHODS: A retrospective, international, multicenter study was conducted using matched cohorts within participating centers of the international PEdiatric Anesthesia COVID-19 Collaborative (PEACOC). Patients younger than 18 yr old were matched using age, American Society of Anesthesiologists Physical Status, and sex. The primary outcome was the difference in hospital length of stay of patients undergoing primary appendectomy during a 2-month period early in the COVID-19 pandemic (April to May 2020) compared with prepandemic (April to May 2019). Secondary outcomes included time to appendectomy and the incidence of complicated appendicitis. RESULTS: A total of 3,351 cases from 28 institutions were available with 1,684 cases in the prepandemic cohort matched to 1,618 in the pandemic cohort. Hospital length of stay was statistically significantly different between the two groups: 29 h (interquartile range: 18 to 79) in the pandemic cohort versus 28 h (interquartile range: 18 to 67) in the prepandemic cohort (adjusted coefficient, 1 [95% CI, 0.39 to 1.61]; P < 0.001), but this difference was small. Eight centers demonstrated a statistically significantly longer hospital length of stay in the pandemic period than in the prepandemic period, while 13 were shorter and 7 did not observe a statistically significant difference. During the pandemic period, there was a greater occurrence of complicated appendicitis, prepandemic 313 (18.6%) versus pandemic 389 (24.1%), an absolute difference of 5.5% (adjusted odds ratio, 1.32 [95% CI, 1.1 to 1.59]; P = 0.003). Preoperative SARS-CoV-2 testing was associated with significantly longer time-to-appendectomy, 720 min (interquartile range: 430 to 1,112) with testing versus 414 min (interquartile range: 231 to 770) without testing, adjusted coefficient, 306 min (95% CI, 241 to 371; P < 0.001), and longer hospital length of stay, 31 h (interquartile range: 20 to 83) with testing versus 24 h (interquartile range: 14 to 68) without testing, adjusted coefficient, 7.0 (95% CI, 2.7 to 11.3; P = 0.002). CONCLUSIONS: For children undergoing appendectomy, the COVID-19 pandemic did not significantly impact hospital length of stay.

Association Between Behavioral and Learning Outcomes and Single Exposures to Procedures Requiring General Anesthesia Before Age 3: Secondary Analysis of Data From Olmsted County, MN.

BACKGROUND: Two prior population-based (children born in Olmsted County, MN), retrospective cohort studies both found that multiple exposures to anesthesia before age 3 were associated with a significant increase in the frequency of attention-deficit hyperactivity disorder (ADHD) and learning disabilities (LD) later in life. The primary purpose of this secondary analysis of these data was to test the hypothesis that a single exposure to anesthesia before age 3 was associated with an increased risk of ADHD. We also examined the association of single exposures with LD and the need for individualized educational plans as secondary outcomes. METHODS: This analysis includes 5339 children who were unexposed to general anesthesia before age 3 (4876 born from 1976 to 1982 and 463 born from 1996 to 2000), and 1054 children who had a single exposure to anesthesia before age 3 (481 born from 1976 to 1982 and 573 born from 1996 to 2000). The primary outcome of interest was ADHD. Secondary outcomes included LD (reading, mathematics, and written language) and the need for individualized educational programs (speech/language and emotion/behavior). To compare the incidence of each outcome between those who were unexposed and singly exposed to anesthesia before the age of 3 years, an inverse probability of treatment weighted proportional hazards model was used. RESULTS: For children not exposed to anesthesia, the estimated cumulative frequency (95% confidence interval [CI]) of ADHD at age 18 was 7.3% (95% CI, 6.5-8.1) and 13.0% (95% CI, 10.1-16.8) for the 1976-1982 and 1996-2000 cohorts, respectively. For children exposed to a single anesthetic before age 3, the cumulative frequency of ADHD was 8.1% (95% CI, 5.3-12.4) and 17.6% (95% CI, 14.0-21.9) for the 1976-1982 and 1996-2000 cohorts, respectively. In weighted analyses, single exposures were not significantly associated with an increased frequency of ADHD (hazard ratio [HR], 1.21; 95% CI, 0.91-1.60; P = .184). Single exposures were also not associated with an increased frequency of any LD (HR, 0.98; 95% CI, 0.78-1.23), or the need for individualized education plans. CONCLUSIONS: This analysis did not find evidence that single exposures to procedures requiring general anesthesia, before age 3, are associated with an increased risk of developing ADHD, LD, or the need for individualized educational plans in later life.

Postoperative pain and psychological outcomes following minimally invasive pectus excavatum repair: A report from the Society for Pediatric Anesthesia Improvement Network.

BACKGROUND: Minimally invasive repair of pectus excavatum (MIRPE) is associated with less tissue trauma; however, it may result in increased postoperative pain. Pain experience is a known risk factor for the development of posttraumatic stress symptoms, though there are little data on its relationship with long-term psychological outcomes following major surgery in pediatric patients. AIMS: In this study, we examined the relationship between immediate postoperative pain and psychological outcomes at 2 weeks and three months after discharge in a cohort of pediatric patients who underwent MIRPE. We sought to determine whether immediate postoperative pain levels were associated with ongoing distress related to aspects of surgery at both time points. We were also interested in how psychological symptoms related to persistent pain concerns. METHODS: Data on patients undergoing MIRPE across 14 institutions were collected as part of the Society for Pediatric Anesthesia Improvement Network (SPAIN). Patients were contacted at 2 weeks and three months following discharge to track pain levels and assess psychological distress using a self-report questionnaire. Patients were grouped into cohorts based on self-report of distress related to aspects of surgery, nonsurgical distress, or absence of distress. RESULTS: Analysis revealed that a higher proportion of children reporting ongoing distress related to surgery at both 2 weeks and 3 months experienced higher immediate postoperative pain levels. A subset of patients with complete data sets for 2 weeks and 3 months (N = 76) was further examined. Among the 47 patients who endorsed surgical distress at 2 weeks, 25 (53.2%) continued to endorse surgical distress at 3 months. Additionally, report of surgical distress at 3 months was associated with longer-term postoperative pain. CONCLUSIONS: Our data suggest that, in patients undergoing MIRPE, the presence of distress at 2 weeks and 3 months may be associated with higher immediate postoperative pain levels.

Performance on the Operant Test Battery in young children exposed to procedures requiring general anaesthesia: the MASK study.

BACKGROUND: It is not known whether the neurotoxicity produced by anaesthetics administered to young animals can also occur in children. Exposure of infant macaques to ketamine impairs performance in selected domains of the Operant Test Battery (OTB), which can also be administered to children. This study determined whether a similar pattern of results on the OTB is found in children exposed to procedures requiring general anaesthesia before age 3 yr. METHODS: We analysed data from the Mayo Anesthesia Safety in Kids (MASK) study, in which unexposed, singly-exposed, and multiply-exposed children born in Olmsted County, MN, USA, from 1994 to 2007 were sampled using a propensity-guided approach and prospectively underwent OTB testing at ages 8-12 or 15-20 yr, using five tasks that generated 15 OTB test scores. RESULTS: In primary analysis, none of the OTB test scores depended upon anaesthesia exposure status when corrected for multiple comparisons. Cluster analysis identified four clusters of subjects, with cluster membership determined by relative performance on the OTB tasks. There was no evidence of association between exposure status and cluster membership. Exploratory factor analysis showed that the OTB scores loaded onto four factors. The score for one factor was significantly less in multiply-exposed children (mean standardised difference -0.28 [95% confidence interval, -0.55 to -0.01; P=0.04]), but significance did not survive a sensitivity analysis accounting for outlying values. CONCLUSIONS: These findings provide little evidence to support the hypothesis that children exposed to procedures requiring anaesthesia show deficits on OTB tasks that are similar to those observed in non-human primates.

Patterns of neuropsychological changes after general anaesthesia in young children: secondary analysis of the Mayo Anesthesia Safety in Kids study.

BACKGROUND: We hypothesised that exposure to multiple, but not single, procedures requiring general anaesthesia before age 3 yr is associated with a specific pattern of deficits in processing speed and fine motor skills. METHODS: A secondary analysis (using factor and cluster analyses) of data from the Mayo Anesthesia Safety in Kids study was conducted, in which unexposed, singly exposed, and multiply exposed children born in Olmsted County, MN, USA from 1994 to 2007 were sampled using a propensity-guided approach and underwent neuropsychological testing at ages 8-12 or 15-20 yr. RESULTS: In the factor analysis, the data were well fit to a five factor model. For subjects multiply (but not singly) exposed to anaesthesia, a factor reflecting motor skills, visual-motor integration, and processing speed was significantly lower [standardised difference of -0.35 (95% confidence interval {CI} -0.57 to -0.13)] compared with unexposed subjects. No other factor was associated with exposure. Three groups were identified in the cluster analysis, with 106 subjects (10.6%) in Cluster A (lowest performance in most tests), 557 (55.9%) in Cluster B, and 334 (33.5%) in Cluster C (highest performance in most tests). The odds of multiply exposed children belonging to Cluster A was 2.83 (95% CI: 1.49-5.35; P=0.001) compared with belonging to Cluster B; there was no other significant association between exposure status and cluster membership. CONCLUSIONS: Multiple, but not single, exposures to procedures requiring general anaesthesia before age 3 yr are associated with a specific pattern of deficits in neuropsychological tests. Factors predicting which children develop the most pronounced deficits remain unknown.

Perioperative Management and In-Hospital Outcomes After Minimally Invasive Repair of Pectus Excavatum: A Multicenter Registry Report From the Society for Pediatric Anesthesia Improvement Network.

BACKGROUND: There are few comparative data on the analgesic options used to manage patients undergoing minimally invasive repair of pectus excavatum (MIRPE). The Society for Pediatric Anesthesia Improvement Network was established to investigate outcomes for procedures where there is significant management variability. For our first study, we established a multicenter observational database to characterize the analgesic strategies used to manage pediatric patients undergoing MIRPE. Outcome data from the participating centers were used to assess the association between analgesic strategy and pain outcomes. METHODS: Fourteen institutions enrolled patients from June 2014 through August 2015. Network members agreed to an observational methodology where each institution managed patients based on their institutional standards and protocols. There was no requirement to standardize care. Patients were categorized based on analgesic strategy: epidural catheter (EC), paravertebral catheter (PVC), wound catheter (WC), no regional (NR) analgesia, and intrathecal morphine techniques. Primary outcomes, pain score and opioid consumption by postoperative day (POD), for each technique were compared while adjusting for confounders using multivariable modeling that included 5 covariates: age, sex, number of bars, Haller index, and use of preoperative pain medication. Pain scores were analyzed using repeated-measures analysis of variance with Bonferroni correction. Opioid consumption was analyzed using a multivariable quantile regression. RESULTS: Data were collected on 348 patients and categorized based on primary analgesic strategy: EC (122), PVC (57), WC (41), NR (120), and intrathecal morphine (8). Compared to EC, daily median pain scores were higher in patients managed with PVC (POD 0), WC (POD 0, 1, 2, 3), and NR (POD 0, 1, 2), respectively (P < .001-.024 depending on group). Daily opioid requirements were higher in patients managed with PVC (POD 0, 1), WC (POD 0, 1, 2), and NR (POD 0, 1, 2) when compared to patients managed with EC (P < .001). CONCLUSIONS: Our data indicate variation in pain management strategies for patients undergoing MIRPE within our network. The results indicate that most patients have mild-to-moderate pain postoperatively regardless of analgesic management. Patients managed with EC had lower pain scores and opioid consumption in the early recovery period compared to other treatment strategies.

The Society for Pediatric Anesthesia recommendations for the use of opioids in children during the perioperative period.

Opioids have long held a prominent role in the management of perioperative pain in adults and children. Published reports concerning the appropriate, and inappropriate, use of these medications in pediatric patients have appeared in various publications over the last 50 years. For this document, the Society for Pediatric Anesthesia appointed a taskforce to evaluate the available literature and formulate recommendations with respect to the most salient aspects of perioperative opioid administration in children. The recommendations are graded based on the strength of the available evidence, with consensus of the experts applied for those issues where evidence is not available. The goal of the recommendations was to address the most important issues concerning opioid administration to children after surgery, including appropriate assessment of pain, monitoring of patients on opioid therapy, opioid dosing considerations, side effects of opioid treatment, strategies for opioid delivery, and assessment of analgesic efficacy. Regular updates are planned with a re-release of guidelines every 2 years.

Neuropsychological and Behavioral Outcomes after Exposure of Young Children to Procedures Requiring General Anesthesia: The Mayo Anesthesia Safety in Kids (MASK) Study.

BACKGROUND: Few studies of how exposure of children to anesthesia may affect neurodevelopment employ comprehensive neuropsychological assessments. This study tested the hypothesis that exposure to multiple, but not single, procedures requiring anesthesia before age 3 yr is associated with adverse neurodevelopmental outcomes. METHODS: Unexposed, singly exposed, and multiply exposed children born in Olmsted County, Minnesota, from 1994 to 2007 were sampled using a propensity-guided approach and underwent neuropsychological testing at ages 8 to 12 or 15 to 20 yr. The primary outcome was the Full-Scale intelligence quotient standard score of the Wechsler Abbreviated Scale of Intelligence. Secondary outcomes included individual domains from a comprehensive neuropsychological assessment and parent reports. RESULTS: In total, 997 children completed testing (411, 380, and 206 unexposed, singly exposed, and multiply exposed, respectively). The primary outcome of intelligence quotient did not differ significantly according to exposure status; multiply exposed and singly exposed children scoring 1.3 points (95% CI, -3.8 to 1.2; P = 0.32) and 0.5 points (95% CI, -2.8 to 1.9; P = 0.70) lower than unexposed children, respectively. For secondary outcomes, processing speed and fine motor abilities were decreased in multiply but not singly exposed children; other domains did not differ. The parents of multiply exposed children reported increased problems related to executive function, behavior, and reading. CONCLUSIONS: Anesthesia exposure before age 3 yr was not associated with deficits in the primary outcome of general intelligence. Although secondary outcomes must be interpreted cautiously, they suggest the hypothesis that multiple, but not single, exposures are associated with a pattern of changes in specific neuropsychological domains that is associated with behavioral and learning difficulties.

Association between Exposure of Young Children to Procedures Requiring General Anesthesia and Learning and Behavioral Outcomes in a Population-based Birth Cohort.

BACKGROUND: Exposure of young animals to general anesthesia causes neurodegeneration and lasting behavioral abnormalities; whether these findings translate to children remains unclear. This study used a population-based birth cohort to test the hypothesis that multiple, but not single, exposures to procedures requiring general anesthesia before age 3 yr are associated with adverse neurodevelopmental outcomes. METHODS: A retrospective study cohort was assembled from children born in Olmsted County, Minnesota, from 1996 to 2000 (inclusive). Propensity matching selected children exposed and not exposed to general anesthesia before age 3 yr. Outcomes ascertained via medical and school records included learning disabilities, attention-deficit/hyperactivity disorder, and group-administered ability and achievement tests. Analysis methods included proportional hazard regression models and mixed linear models. RESULTS: For the 116 multiply exposed, 457 singly exposed, and 463 unexposed children analyzed, multiple, but not single, exposures were associated with an increased frequency of both learning disabilities and attention-deficit/hyperactivity disorder (hazard ratio for learning disabilities = 2.17 [95% CI, 1.32 to 3.59], unexposed as reference). Multiple exposures were associated with decreases in both cognitive ability and academic achievement. Single exposures were associated with modest decreases in reading and language achievement but not cognitive ability. CONCLUSIONS: These findings in children anesthetized with modern techniques largely confirm those found in an older birth cohort and provide additional evidence that children with multiple exposures are more likely to develop adverse outcomes related to learning and attention. Although a robust association was observed, these data do not determine whether anesthesia per se is causal.

An automated real-time method for the detection of patients at risk for malignant hyperthermia.

BACKGROUND: Malignant hyperthermia (MH) is a rare anesthetic pharmacogenetic disorder that can be difficult to detect in its earliest phases. Prompt treatment is known to improve outcomes. The modern anesthesia information management systems (AIMS) collect enormous amounts of data. However, data lack context and are not able to provide real-time guidance. Utilizing our AIMS, we developed the capacity to incorporate decision support. AIMS: We describe the creation and evaluation of a real-time detection tool for MH. METHODS: Cases of MH from 2003 to 2013 were retrospectively reviewed to confirm the diagnosis of MH and to calculate a MH clinical grading scale score. The index cases were utilized to develop four electronic data Rules, based on endtidal CO2 (ETCO2 ) and temperature criteria. The Rules were then applied retrospectively to the index cases and to a full cohort of general operating room (OR) patients from January 2012 to June 2012. If criteria for possible MH was met, the detection tool generated an alert on the monitor at the patient's bedside. RESULTS: We identified seven patients with confirmed MH with MH Scores ranging from 28 to 70. Using four data Rules, all of our seven index cases were captured and generated an appropriate alert. Median time from MH computer alert time to dantrolene administration time among our index cases was 23 min (IQR 17-77). There were 938 false-positive alerts for possible MH (1.8%) when the Rules were applied to a general OR cohort of 51 579 total cases from January 2012 to June 2012. CONCLUSIONS: We demonstrated a real-time MH detection tool based on established physiologic criteria that is sensitive enough to capture cases suspicious for MH, while limiting false positives to prevent alarm fatigue. This has the potential to notify the provider of possible MH such that treatment may be rapidly initiated.

One-year Results of Minimally Invasive Sutured Fixation of the Slipped Ribs in the Pediatric Population.

PURPOSE: Costal cartilage resection with or without rib resection is the gold standard surgery for slipping rib syndrome. Minimally invasive restoration of normal anatomy via nonabsorbable sutures has been described in the adult population with encouraging results. We sought to assess the efficacy of minimally invasive sutured fixation of the hypermobile rib in the pediatric population. METHODS: A retrospective review was performed at Mayo Clinic involving 31 pediatric patients diagnosed with slipped rib syndrome. Minimally invasive sutured open reduction internal fixation was performed between 2020 and 2022. The standardized Örebro Musculoskeletal Pain Screening Questionnaire was given at dedicated time points pre- and post-operatively to assess efficacy. Significance was determined via the Wilcoxon rank sum test. RESULTS: SRS was diagnosed clinically in 31 patients (24 females, 7 males, 1220 years-old). Symptoms were present for an average of 18.9 months and patients had seen an average of 4.7 specialists. Traumatic causes were identified in three patients and eight patients had hypermobility. At one month follow up, there were no surgical complications and patients reported significantly less pain (p < 0.001). Preoperative analgesics reduced by 80%. Ultimately, seven patients underwent a second operation; three patients underwent a third operation; one patient underwent five total operations. Recurrent pain was reported in six patients. Only nine patients followed-up at 1-year post-operation. CONCLUSION: Pediatric patients with SRS demonstrated an early positive response to suture fixation without costal cartilage excision. Reoperation and recurrent pain, however, remain significant in this population. LEVEL OF EVIDENCE: Level IV. TYPE OF STUDY: Case series with no comparison group.

Neuraxial labor analgesia for vaginal delivery and its effects on childhood learning disabilities.

BACKGROUND: In prior work, children born to mothers who received neuraxial anesthesia for cesarean delivery had a lower incidence of subsequent learning disabilities compared with vaginal delivery. The authors speculated that neuraxial anesthesia may reduce stress responses to delivery, which could affect subsequent neurodevelopmental outcomes. To further explore this possibility, we examined the association between the use of neuraxial labor analgesia and development of childhood learning disabilities in a population-based birth cohort of children delivered vaginally. METHODS: The educational and medical records of all children born to mothers residing in the area of 5 townships of Olmsted County, Minnesota from 1976 to 1982 and remaining in the community at age 5 years were reviewed to identify those with learning disabilities. Cox proportional hazards regression was used to compare the incidence of learning disabilities between children delivered vaginally with and without neuraxial labor analgesia, including analyses adjusted for factors of either potential clinical relevance or that differed between the 2 groups in univariate analysis. RESULTS: Of the study cohort, 4684 mothers delivered children vaginally, with 1495 receiving neuraxial labor analgesia. The presence of childhood learning disabilities in the cohort was not associated with use of labor neuraxial analgesia (adjusted hazard ratio, 1.05; 95%confidence interval, 0.85-1.31; P = 0.63). CONCLUSION: The use of neuraxial analgesia during labor and vaginal delivery was not independently associated with learning disabilities diagnosed before age 19 years. Future studies are needed to evaluate potential mechanisms of the previous finding indicating that the incidence of learning disabilities is lower in children born to mothers via cesarean delivery under neuraxial anesthesia compared with vaginal delivery.

Is there any relationship between long-term behavior disturbance and early exposure to anesthesia?

PURPOSE OF REVIEW: There is now more than a decade of mounting animal data that anesthetic drugs can cause apoptosis during a critical period of brain development and that this correlates with later behavioral disturbances. Initial articles examining the effects of early anesthesia on human infants have recently been published. Prospective studies are underway. RECENT FINDINGS: Several retrospective studies in humans have been published over the last year using different methodologies. Although most raise some concern that anesthetic use in infants and young children may be problematic, all have inherent limitations in methodology that prevent clinicians from drawing firm conclusions regarding the risk of anesthesia on brain development in humans. SUMMARY: Although the evidence from animal studies is clear and continuing to mount that anesthetic drugs given at the right time and in sufficiently high and prolonged doses do cause increased neuronal apoptosis and later problems with learning, evidence in humans that this is of clinical concern is both weak and mixed. Additional studies are ongoing to try to better define the risk.

Opacity, Transparency, and Morphological Priming: A Study of Prefixed Verbs in Dutch.

A basic question for the study of the mental lexicon is whether there are morphological representations and processes that are independent of phonology and semantics. According to a prominent tradition, morphological relatedness requires semantic transparency: semantically transparent words are related in meaning to their stems, while semantically opaque words are not. This study examines the question of morphological relatedness using intra-modal auditory priming by Dutch prefixed verbs. The key conditions involve semantically transparent prefixed primes (e.g., aanbieden 'offer', with the stem bieden, also 'offer') and opaque primes (e.g., verbieden 'forbid'). Results show robust facilitation for both transparent and opaque pairs; phonological (Experiment 1) and semantic (Experiment 2) controls rule out the possibility that these other types of relatedness are responsible for the observed priming effects. The finding of facilitation with opaque primes suggests that morphological processing is independent of semantic and phonological representations. Accordingly, the results are incompatible with theories that make semantic overlap a necessary condition for relatedness, and favor theories in which words may be related in ways that do not require shared meaning. The general discussion considers several specific proposals along these lines, and compares and contrasts questions about morphological relatedness of the type found here with the different but related question of whether there is morphological decomposition of complex forms or not.

Symptomatic Oppenheimer ossicle: a rare mimic of pars interarticularis fracture.

We report a case of symptomatic Oppenheimer ossicle in an 18-year-old male who presented with back pain. L5 pars interarticularis defect was suspected on initial lumbar spine radiographs. A subsequent technetium99m-methylene diphosphonate (Tc99m-MDP) bone scintigraphy with single-photon emission computed tomography/computed tomography (SPECT/CT) revealed focal radiotracer uptake in an Oppenheimer ossicle in L2 vertebra. CT was negative for pars defect. Oppenheimer ossicle is a developmental variant resulting from an unfused accessory ossification center at the tip of the articular process. It is important to recognize this entity as a rare cause of low back pain. Focal tracer uptake can mimic changes from pars interarticularis defect on planar and SPECT images. SPECT/CT helps to resolve both entities. To our knowledge, this is also the first report in English literature describing a symptomatic Oppenheimer ossicle on a bone scan.

Early exposure to anesthesia and learning disabilities in a population-based birth cohort.

BACKGROUND: Anesthetic drugs administered to immature animals may cause neurohistopathologic changes and alterations in behavior. The authors studied association between anesthetic exposure before age 4 yr and the development of reading, written language, and math learning disabilities (LD). METHODS: This was a population-based, retrospective birth cohort study. The educational and medical records of all children born to mothers residing in five townships of Olmsted County, Minnesota, from 1976 to 1982 and who remained in the community at 5 yr of age were reviewed to identify children with LD. Cox proportional hazards regression was used to calculate hazard ratios for anesthetic exposure as a predictor of LD, adjusting for gestational age at birth, sex, and birth weight. RESULTS: Of the 5,357 children in this cohort, 593 received general anesthesia before age 4 yr. Compared with those not receiving anesthesia (n = 4,764), a single exposure to anesthesia (n = 449) was not associated with an increased risk of LD (hazard ratio = 1.0; 95% confidence interval, 0.79-1.27). However, children receiving two anesthetics (n = 100) or three or more anesthetics (n = 44) were at increased risk for LD (hazard ratio = 1.59; 95% confidence interval, 1.06-2.37, and hazard ratio = 2.60; 95% confidence interval, 1.60-4.24, respectively). The risk for LD increased with longer cumulative duration of anesthesia exposure (expressed as a continuous variable) (P = 0.016). CONCLUSION: Exposure to anesthesia was a significant risk factor for the later development of LD in children receiving multiple, but not single anesthetics. These data cannot reveal whether anesthesia itself may contribute to LD or whether the need for anesthesia is a marker for other unidentified factors that contribute to LD.

Anesthesia for cesarean delivery and learning disabilities in a population-based birth cohort.

BACKGROUND: Anesthetics administered to immature brains may cause histopathological changes and long-term behavioral abnormalities. The association between perinatal exposure to anesthetics during Cesarean delivery (CD) and development of learning disabilities (LD) was determined in a population-based birth cohort. METHODS: The educational and medical records of all children born to mothers residing in five townships of Olmsted County, Minnesota from 1976-1982 and remaining in the community at age 5 were reviewed to identify those with LDs. Cox proportional hazards regression was used to compare rates of LD between children delivered vaginally and via CD (with general or regional anesthesia). RESULTS: Of the 5,320 children in this cohort, 497 were delivered via CD (under general anesthesia n = 193, and regional anesthesia n = 304). The incidence of LD depended on mode of delivery (P = 0.050, adjusted for sex, birth weight, gestational age, exposure to anesthesia before age 4 yr, and maternal education). LD risk was similar in children delivered by vagina or CD with general anesthesia, but was reduced in children receiving CD with regional anesthesia (hazard ratio = 0.64, 95% confidence interval 0.44 to 0.92; P = 0.017 for comparison of CD under regional anesthesia compared to vaginal delivery). CONCLUSION: Children exposed to general or regional anesthesia during CD are not more likely to develop LD compared to children delivered vaginally, suggesting that brief perinatal exposure to anesthetic drugs does not adversely affect long-term neurodevelopmental outcomes. The risk of LD may be lower in children delivered by CD whose mothers received regional anesthesia.

Differences in static and dynamic measures in evaluation of talonavicular mobility in gait.

STUDY DESIGN: Controlled laboratory study using a cross-sectional design. OBJECTIVES: To compare the measurements of navicular drop during walking and running to those made clinically during a static position in a group of healthy young adults. BACKGROUND: The navicular drop test is a common clinical measure of foot structure and, more specifically, of talonavicular joint function. Previous work has focused on static measurement to establish the relationship between navicular drop and various overuse injuries. However, loads on foot structure are dramatically increased during gait. Examining navicular drop dynamically is more reflective of the functional demands of the foot when walking and running. METHODS: The navicular drop of 72 healthy runners was evaluated using 2 static methods. Results were used to classify individuals into groups and compared to dynamic measures of navicular drop made during walking and running. Three-dimensional motion capture and an instrumented treadmill were used to assess dynamic navicular mobility. A repeated-measures analysis of variance (ANOVA) was performed to examine differences between measurement conditions. Between-group differences were assessed with independent-samples t test (P<.05). RESULTS: Static measures of navicular drop were not found to be uniformly predictive of dynamic function during walking or running. Functional navicular drop measurements underestimated the dynamic measures in all foot types, while subtalar neutral drop overestimated dynamic measures for individuals with neutral and hypermobile foot types. No differences in navicular drop were found between foot types during walking, and small differences were found in running only between the hypomobile and hypermobile foot types. Maximum foot deformation during gait occurs at the time of maximum ground reaction force. Significant differences in navicular drop between foot type groups measured statically become muted when looking at group differences while walking and running. CONCLUSIONS: Differences in navicular mobility between foot type groups during walking and running indicate that factors other than static alignment affect dynamic foot mobility. Dynamic assessment of navicular mobility may be an effective tool to examine the interplay of how the extrinsic force demands of gait and intrinsic structure and neuromuscular control affect foot function in walking and running.

Differences between morphological and repetition priming in auditory lexical decision: Implications for decompositional models.

A natural way of probing the effects of morphology on lexical processing is to directly compare morphological priming, for which primes and targets share a stem but are mismatched in morphological structure (e.g., frogs â†’ frog), with outright repetition priming (e.g., frog â†’ frog). However, work making this comparison has reported no difference between these two types of priming. Importantly, the reported non-differences have been found in the visual domain. Here, we investigate morphological (Morph) versus repetition (Rep) priming in two auditory primed lexical decision experiments. Using the English plural suffix -/z/, we compare Rep priming with Morph priming for both singular and plural target conditions (e.g., frog/frogs â†’ frog, frog/frogs â†’ frogs). Overall, we find robust priming in both Rep and Morph conditions. However, for both singular and plural targets, there is consistent evidence that Rep priming is greater than Morph priming at early lags of 0 and 1 intervening items. This facilitation decreases with an increasing number of intervening items. Comparisons with phonological and semantic controls demonstrate that this pattern cannot be attributed solely to shared form or meaning. We interpret these findings in a decompositional model of morphological processing. The robust facilitation in Morph and Rep conditions is attributed to the activation of a shared stem representation. The convergence of Morph and Rep is attributed to a diminishing episodic trace related to morphological recombination.