Donna R. Mendez

Prevalence and Predictors of Poor Recovery from Mild Traumatic Brain Injury

Although most patients with mild traumatic brain injury (mTBI) recover within 3 months, a subgroup of patients experience persistent symptoms. Yet, the prevalence and predictors of persistent dysfunction in patients with mTBI remain poorly understood. In a longitudinal study, we evaluated predictors of symptomatic and cognitive dysfunction in adolescents and young adults with mTBI, compared with two control groups-patients with orthopedic injuries and healthy uninjured individuals. Outcomes were assessed at 3 months post-injury. Poor symptomatic outcome was defined as exhibiting a symptom score higher than 90% of the orthopedic control (OC) group, and poor cognitive outcome was defined as exhibiting cognitive performance poorer than 90% of the OC group. At 3 months post-injury, more than half of the patients with mTBI (52%) exhibited persistently elevated symptoms, and more than a third (36.4%) exhibited poor cognitive outcome. The rate of high symptom report in mTBI was markedly greater than that of typically developing (13%) and OC (17%) groups; the proportion of those with poor cognitive performance in the mTBI group exceeded that of typically developing controls (15.8%), but was similar to that of the OC group (34.9%). Older age at injury, female sex, and acute symptom report were predictors of poor symptomatic outcome at 3 months. Socioeconomic status was the only significant predictor of poor cognitive outcome at 3 months.

Social communication in young children with traumatic brain injury: Relations with corpus callosum morphometry

The purpose of the present investigation was to characterize the relations of specific social communication behaviors, including joint attention, gestures, and verbalization, with surface area of midsagittal corpus callosum (CC) subregions in children who sustained traumatic brain injury (TBI) before 7 years of age. Participants sustained mild (n = 10) or moderate–severe (n = 26) noninflicted TBI. The mean age at injury was 33.6 months; mean age at MRI was 44.4 months. The CC was divided into seven subregions. Relative to young children with mild TBI, those with moderate–severe TBI had smaller surface area of the isthmus. A semi‐structured sequence of social interactions between the child and an examiner was videotaped and coded for specific social initiation and response behaviors. Social responses were similar across severity groups. Even though the complexity of their language was similar, children with moderate–severe TBI used more gestures than those with mild TBI to initiate social overtures; this may indicate a developmental lag or deficit as the use of gestural communication typically diminishes after age 2. After controlling for age at scan and for total brain volume, the correlation of social interaction response and initiation scores with the midsagittal surface area of the CC regions was examined. For the total group, responding to a social overture using joint attention was significantly and positively correlated with surface area of all regions, except the rostrum. Initiating joint attention was specifically and negatively correlated with surface area of the anterior midbody. Use of gestures to initiate a social interaction correlated significantly and positively with surface area of the anterior and posterior midbody. Social response and initiation behaviors were selectively related to regional callosal surface areas in young children with TBI. Specific brainbehavior relations indicate early regional specialization of anterior and posterior CC for social communication.

Total and Ionized Plasma Magnesium Concentrations in Children after Traumatic Brain Injury

This study examined 1) whether plasma total Mg (TMg) and ionized Mg (IMg) concentrations in children are reduced by traumatic brain injury (TBI) and 2) whether the extent of reduction correlates with severity of trauma assessed by the Glasgow Coma Scale (GSC) score. This was a prospective cohort study of 98 pediatric patients who had TBI and were admitted through the emergency department. A GCS score was assigned and blood was obtained upon presentation and 24 h later. Plasma was analyzed for TMg and IMg. Patients were grouped into three categories—GCS scores 13–15, 8–12, and <8—to designate mild (n = 21), moderate (n = 37), and severe (n = 40) TBI, respectively. Blood was obtained from 50 healthy children before elective surgery as controls. Control subjects had a TMg and an IMg of 0.94 ± 0.08 and 0.550 ± 0.06 mM. TBI patients had an initial TMg and IMg of 0.83 ± 0.09 and 0.520 ± 0.05 mM, respectively. Initial TMg for mild, moderate, and severe TBI subgroups (0.87 ± 0.16, 0.81 ± 0.15, and 0.83 ± 0.14 mM, respectively) was reduced from control subjects (p < 0.01). IMg was reduced only in the severe TBI subgroup (0.516 ± 0.07 mM; p = 0.016). Twenty-four hours later, TMg remained lower than in control subjects for all subgroups of TBI; however, IMg normalized. TBI in children is associated with a reduction in TMg, whereas IMg decreased only with severe TBI. IMg returned to control values by 24 h despite a continued lower TMg, suggesting mechanisms to maintain IMg. Changes in plasma IMg may serve as a marker for TBI but only over a limited time interval.

Social interaction in young children with inflicted and accidental traumatic brain injury: relations with family resources and social outcomes.

Core social interaction behaviors were examined in young children 0-36 months of age who were hospitalized for accidental (n = 61) or inflicted (n = 64) traumatic brain injury (TBI) in comparison to typically developing children (n = 60). Responding to and initiating gaze and joint attention (JA) were evaluated during a semi-structured sequence of social interactions between the child and an examiner at 2 and 12 months after injury. The accidental TBI group established gaze less often and had an initial deficit initiating JA that resolved by the follow-up. Contrary to expectation, children with inflicted TBI did not have lower rates of social engagement than other groups. Responding to JA was more strongly related than initiating JA to measures of injury severity and to later cognitive and social outcomes. Compared to complicated-mild/moderate TBI, severe TBI in young children was associated with less responsiveness in social interactions and less favorable caregiver ratings of communication and social behavior. JA response, family resources, and group interacted to predict outcomes. Children with inflicted TBI who were less socially responsive and had lower levels of family resources had the least favorable outcomes. Low social responsiveness after TBI may be an early marker for later cognitive and adaptive behavior difficulties.

The diagnostic accuracy of an abdominal radiograph with signs and symptoms of intussusception

OBJECTIVE The objective of this study was to compare the diagnostic accuracy of an abdominal ultrasound to that of a highly suggestive abdominal radiograph combined with signs and symptoms of intussusception. DESIGN This was a retrospective cross-sectional study of children 3 years or younger with signs and symptoms of intussusceptions who presented to a pediatric emergency department (ED). Univariate analysis, multivariate analysis, and diagnostic accuracy of clinical characteristics and radiographic findings were derived. RESULTS A highly suggestive abdominal radiograph (14.80; 5.85-37.45), right upper quadrant mass (8.90; 1.14-69.47), vomiting (2.54; 1.36-4.76), and abdominal pain (2.45; 1.36-4.40) were found to be significantly associated with intussusception by univariate analysis. Vomiting (2.80; 1.34-5.85), abdominal pain (2.75; 1.33-5.69), and bloody stools (2.70; 1.07-6.81) were independently associated with intussusceptions by multivariate analysis. Bloody stools were time dependent. Bloody stools occurred in those patients with intussusception at a median time of 24 hours, from the time the patient started with signs and symptoms to the time of presentation to the ED, vs those without bloody stools presenting at a median time of 11 hours. The combination of a highly suggestive abdominal radiograph, abdominal pain, lethargy, and vomiting was highly specific (95%) for intussusception, comparable to that of an ultrasound (93%). In patients with this combination, all were found to have intussusception by enema or surgery. CONCLUSIONS Ultrasound is not needed before an enema for the diagnosis of intussusception for those with a highly suggestive abdominal radiograph, abdominal pain, lethargy, and vomiting.

Laser Doppler flow and brain tissue PO2 after cortical impact injury complicated by secondary ischemia in rats treated with arginine.

BACKGROUND Traumatic brain injury (TBI) makes the brain susceptible to secondary insults such as ischemia. This study tested the hypothesis that L-arginine would increase regional CBF (rCBF) and brain tissue PO2 (PbtO2) at the injury site. METHODS A secondary insult model was employed in rodents. rCBF was measured with laser doppler flowmetry (LDF) and PbtO2 with a PO2 catheter at the impact site. Animals were randomized to receive L-arginine, D-arginine or saline intravenously, 5 minutes after impact. RESULTS In animals who received L-arginine, the percentage rCBF from baseline (%CBF) was higher at the impact site after impact (p < 0.001), during bilateral carotid occulation (BCO) (p = 0.001) and during reperfusion (p = 0.032). In contrast, PbtO2 was not significantly increased throughout the experiment for the L-arginine group. CONCLUSIONS Administration of L-arginine increased rCBF in the injured brain tissue, and resulted in better preservation of CBF during BCO than D-arginine and saline.

Updating Memory after Mild Traumatic Brain Injury and Orthopedic Injuries

Few studies have examined the trajectory of recovery of executive function (EF) after mild TBI (mTBI). Therefore, consensus has not been reached on the incidence and extent of EF impairment after mTBI. The present study investigated trajectory of change in executive memory over 3 months after mTBI on 59 right-handed participants with mTBI, as defined by Centers for Disease Control criteria, ages 14-30 years, recruited within 96 hours post-injury and tested <1 week (baseline), 1 month, and 3 months after injury. Also included were 58 participants with orthopedic injury (OI) and 27 typically developing (TD) non-injured participants with similar age, socioeconomic status, sex, and ethnicity. MRI data were acquired at baseline and 3 months. Although criteria included a normal CT scan, lesions were detected by MRI in 19 mTBI patients. Participants completed the KeepTrack task, a verbal recall task placing demands on goal maintenance, semantic memory, and memory updating. Scores reflected items recalled and semantic categories maintained. The mTBI group was divided into two groups: high (score ≥12) or low (score <12) symptoms based on the Rivermead Post-Concussion Symptoms Questionnaire (RPQ). Mixed model analyses revealed the trajectory of change in mTBI patients (high and low RPQ), OI patients, and TD subjects were similar over time (although the TD group differed from other groups at baseline), suggesting no recovery from mTBI up to 90 days. For categories maintained, differences in trajectory of recovery were discovered, with the OI comparison group surprisingly performing similar to those in the mTBI group with high RPQ symptoms, and different from low RPQ and the TD groups, bringing up questions about utility of OIs as a comparison group for mTBI. Patients with frontal lesions (on MRI) were also found to perform worse than those without lesions, a pattern that became more pronounced with time.

Prospective Pilot Derivation of a Decision Tool for Children at Low Risk for Testicular Torsion

OBJECTIVE The purpose of this study was to derive a pilot clinical decision tool with 100% negative predictive value for testicular torsion based on prospectively collected data in children with acute scrotal pain. METHODS This was a prospective cohort study of a convenience sample of newborn to 21-year-old males evaluated for acute (72 hours or less) scrotal pain at an urban childrens hospital emergency department (ED). A pediatric emergency medicine fellow or attending physician documented history and examination findings on a standardized data collection form. The study investigators used ultrasound (US), operative reports, or clinical follow-up to identify patients who had testicular torsion. Pearsons chi-square test and odds ratios (OR) were used to identify factors associated with the diagnosis of testicular torsion. The authors also used a recursive partitioning model to create a low-risk decision tool for testicular torsion. RESULTS Of the 450 eligible patients, 228 (51%) were enrolled, with a mean (± SD) age of 9.9 (± 4.1) years, including 21 (9.2%, 95% confidence interval [CI] = 5.8% to 13.7%) with testicular torsion. The derived clinical decision tool consisted of three variables: horizontal or inguinal testicular lie (OR = 18.17, 95% CI = 6.2 to 53.2), nausea or vomiting (OR = 5.63, 95% CI = 2.08 to 15.22), and age 11 to 21 years (OR = 3.9, 95% CI = 1.27 to 11.97). These variables had a sensitivity of 100% (95% CI = 98% to 100%) and negative predictive value of 100% (95% CI = 98% to 100%) for the diagnosis of testicular torsion. CONCLUSIONS Based on a decision tool derived with recursive partitioning, study patients with all of the following characteristics had no risk of testicular torsion: normal testicular lie, lack of nausea or vomiting, and age 0 to 10 years. Future research should focus on externally validating this tool to optimize emergent evaluation when testicular torsion is likely, while minimizing routine sonographic evaluation when patients are unlikely to have a serious condition requiring immediate management.

At the intersection of toxicology, psychiatry, and genetics: a diagnosis of ornithine transcarbamylase deficiency

Ornithine transcarbamylase (OTC) deficiency is a genetic disorder involving a mutation of the ornithine transcarbamylase gene, located on the short arm of the X chromosome (Xp21.1). This makes the expression of the gene most common in homozygous males, but heterozygous females can also be affected and may be more likely to suffer from serious morbidity. Most males present early in the neonatal period with more devastating outcomes than their female counterparts. Up to 34% will present in the first 30 days of life (J Pediatr 2001;138:S30). Females often have partially functioning mitochondria due to uneven distribution of the mutant gene secondary to lyonization (“X-chromosome Inactivation”. Genetics Home Reference, 2012). Occasionally, symptomatic females may not even present until they are placed under metabolic stress such as a severe illness, fasting, pregnancy, or new medication (Roth KS, Steiner RD. “Ornithine Transcarbamylase Deficiency”. EMedicine, 2012). The urea cycle is the bodys primary tool for the disposal of excess nitrogen, which is generated by the routine metabolism of proteins and amino acids. Mitochondrial dysfunction impairs urea production and result in hyperammonemia (Semin Neonatol 2002;7:27). The sine qua non among all degrees of OTC deficiency at presentation is hyperammonemia. As in adults, children will have similar symptoms of encephalopathy, but this may be expressed differently depending on the childs developmental level. We present an unusual case of OTC deficiency in an older child with undifferentiated symptoms of an anticholinergic toxidrome, liver failure, iron overdose, and mushroom poisoning.

Safety and efficacy of rocuronium for controlled intubation with paralytics in the pediatric emergency department

Background Controlled intubation in the pediatric emergency department (ED) requires a paralytic agent that is safe, efficacious, and of rapid onset. The safety of succinylcholine has been challenged, leading some clinicians to use vecuronium as an alternative. Rocuronium’s onset is similar to that of succinylcholine. Objective To evaluate the safety and efficacy of rocuronium for controlled intubation with paralysis (CIP) in the pediatric ED. Methods A retrospective, observational study reviewed the records of patients less than 15 years of age, who received controlled intubation with paralytics at two Dallas EDs. The patients received either vecuronium or rocuronium. Results The study included 84 patients (vecuronium 19, rocuronium 65). Complications were similar between the two groups. Rocuronium had a shorter time from administration to intubation when compared to vecuronium (P < 0.05). Conclusion Rocuronium is as safe and efficacious as vecuronium for CIP in the pediatric ED.