Auditory neuropathy: clinical characteristics and therapeutic approach

PURPOSE: Auditory neuropathy is characterized by congenital sensorineural hearing loss associated with absent or impaired auditory brainstem evoked responses and preservation of outer hair cell activity. This study describes the recent experience of our tertiary pediatric center with auditory neuropathy (AN). METHODS: The files of all children diagnosed with AN at our center from 2000 to 2005 were reviewed for background data, associated factors, laboratory and audiometry findings, management, and outcome. RESULTS: Mean age at diagnosis was 13 months. Factors known to be associated with AN were found in 18 children, namely, prematurity, hyperbilirubinemia, parental consanguinity, or positive family history. Conception by in vitro fertilization was an additional factor not previously reported. The hearing loss was mostly moderate to severe, and bilateral in all patients but one. Otoacoustic emissions and/or cochlear microphonics were demonstrated in all cases. Hearing improved spontaneously in 4 patients. Management with a hearing aid was successful in 1 of 19 patients. Twelve patients received cochlear implants with good outcome. CONCLUSION: Because neonates with AN have normal otoacoustic emissions and/or cochlear microphonics, screening tests for high-risk neonates should be complemented by auditory brainstem evoked responses to avoid false-negative findings. Because AN is considered a retrocochlear lesion, with normal outer hair cell function, rehabilitation with hearing aids is problematic. Although the level of pathology is apparently at the cochlear nerve, cochlear implantation is often a good solution for failures of conventional rehabilitation. However, our finding of spontaneous improvement in a small subgroup raises questions regarding implantation before age 1 year.     

PSTPIP1‐associated myeloid‐related proteinemia inflammatory syndrome: A rare cause of childhood neutropenia associated with systemic inflammation and hyperzincemia

Neutropenia in pediatric patients can be due to a variety of disorders. We describe two patients who underwent extensive evaluation over many years for arthralgias and moderate neutropenia of unclear etiology. Genetic testing identified a pathogenic variant in PSTPIP1 (proline‐serine‐threonine phosphatase‐interacting protein 1) in both patients. Markedly elevated inflammatory markers and zinc levels confirmed the rare diagnosis of PSTPIP1‐associated myeloid‐related proteinemia inflammatory (PAMI) syndrome, tailoring treatment. Neutropenia is common in patients with PAMI syndrome. Unique mutations seen in PAMI syndrome may account for the specific phenotypic features of this disorder.     

Does antenatal steroids treatment prior to elective cesarean section at 34–37 weeks of gestation reduce neonatal morbidity? Evidence from a case control study

Objective

To determine whether antenatal corticosteroids administration prior to an elective cesarean section (ECS) at 34–37 weeks gestation is associated with improved neonatal outcome.

Materials and methods

A case control study of women with singleton pregnancies who underwent ECS between 34 and 37 weeks of gestation including two groups: (1) study group in which patients were treated with betamethasone prior to ECS (n = 58) and (2) control group matched for gestational age at delivery in which patients did not receive betamethasone (n = 107). Neonatal measures including respiratory distress syndrome (RDS), transient tachypnea of the newborn (TTN), oxygen requirement, admission to the special care unit, hypoglycemia, hyperbilirubinemia and length of hospitalization were determined in both groups. Composite respiratory morbidity was defined as the presence of either RDS, TTN, mechanical ventilation or oxygen requirement.

Results

There was no significant difference in the rate of composite respiratory morbidity nor its components between patients with and without betamethasone treatment (25.9 vs. 25.2%, respectively, p = 0.9).

Conclusion

Antenatal treatment with corticosteroids prior to ECS at 34–37 weeks of gestation did not result in significant reduction in neonatal respiratory morbidity in our cohort of patients.

     

Retest Reliability of Force-Time Variables of Neck Muscles Under Isometric Conditions

Context:

Proper conditioning of the neck muscles may play a role in reducing the risk of neck injury and, possibly, concussions in contact sports. However, the ability to reliably measure the force-time–based variables that might be relevant for this purpose has not been addressed.

Objective:

To assess the between-days reliability of discrete force-time–based variables of neck muscles during maximal voluntary isometric contractions in 5 directions.

Design:

Cohort study.

Setting:

University research center.

Patients or Other Participants:

Twenty-six highly physically active men (age  =  21.6 ± 2.1 years, height  =  1.85 ± 0.09 m, mass  =  81.6 ± 9.9 kg, head circumference  =  0.58 ± 0.01 m, neck circumference  =  0.39 ± 0.02 m).

Intervention(s):

We used a custom-built testing apparatus to measure maximal voluntary isometric contractions of the neck muscles in 5 directions (extension, flexion, protraction, left lateral bending, and right lateral bending) on 2 separate occasions separated by 7 to 8 days.

Main Outcome Measure(s):

Variables measured were peak force (PF), rate of force development (RFD), and time to 50% of PF (T₅₀PF). Reliability indices calculated for each variable comprised the difference in scores between the testing sessions, with corresponding 95% confidence intervals, the coefficient of variation of the typical error of measurement (CV_TE), and intraclass correlation coefficients (ICC [3,3]).

Results:

No evidence of systematic bias was detected for the dependent measures across any movement direction; retest differences in measurements were between 1.8% and 2.7%, with corresponding 95% confidence interval ranges of less than 10% and overlapping zero. The CV_TE was lowest for PF (range, 2.4%–6.3%) across all testing directions, followed by RFD (range, 4.8%–9.0%) and T₅₀PF (range, 7.1%–9.3%). The ICC score range for all dependent measures was 0.90 to 0.99.

Conclusions:

Discrete variables representative of the force-generating capacity of neck muscles under isometric conditions can be measured with an acceptable degree of reliability. This finding has possible applications for investigating the role of neck muscle strength-training programs in reducing the risk of injuries in sport settings.     

The role of CPK isoenzymes in predicting extrauterine early pregnancy

Objective

To evaluate the ability of Creatine phosphokinase (CPK) levels and CPK-MB proportion to differentiate between extra and intrauterine of very early gestations with unknown location.

Materials and methods

The study is case?Ccontrol. CPK levels and CPK-MB proportion in 51 women with extrauterine pregnancies were compared to those in 28 women with early intrauterine pregnancies.

Results

No significant difference was found between women with extrauterine pregnancies and early intrauterine pregnancies in the levels of CPK (80.9?±?62.1 vs. 74.9?±?51.5; p?=?0.66) and CPK-MB proportion (16.2?±?10.1% vs. 15.1?±?11.1%; p?=?0.86).

Conclusion

CPK and CPK-MB proportion determinations do not contribute to the clinical differentiation between early intra and extrauterine pregnancies.     

Risk factors for neonatal brachial plexus paralysis

Purpose

The study was aimed to identify risk factors for neonatal brachial plexus paralysis.

Methods

A retrospective case?Ccontrol study was designed. A comparison was performed between cases of brachial plexus paralysis, with all consecutive deliveries during the same 5 months period, without brachial plexus paralysis. Statistical analysis was performed using the SPSS package.

Results

The prevalence of brachial plexus paralysis was 1.62/1,000 (9/5,525) vaginal births. Independent risk factors for brachial plexus paralysis were shoulder dystocia (OR?=?525; 95% CI 51?C4,977, P?P?4,000?g; OR?=?16.3; 95% CI 3.7?C70.2, P?P?P?=?0.032).

Conclusions

In our population, shoulder dystocia, macrosomia, labor dystocia, vacuum delivery and vaginal breech deliveries were significant risk factors for neonatal brachial plexus paralysis, while maternal characteristics such as obesity and diabetes were not. Despite our growing knowledge concerning the risk factors associated with brachial plexus paralysis, unfortunately, this condition cannot be predicted or prevented.     

Acute antepartum pyelonephritis in pregnancy: a critical analysis of risk factors and outcomes

Objective

To test the incidence and sonographic parameters of pyelonephritis during pregnancy, and to examine risk factors and pregnancy outcomes of women with acute antepartum pyelonephritis.

Study design

A retrospective population-based study comparing all singleton pregnancies of patients with and without acute antepartum pyelonephritis was performed. Patients lacking prenatal care as well as multiple gestations were excluded from the study. Multiple logistic regression models were used to control for confounders.

Results

Out of 219,612 singleton deliveries in 1988–2010, 165 women (0.07%) suffered from acute antepartum pyelonephritis. Abnormal sonographic findings were found in 85.7% of the patients with pyelonephritis. Pyelonephritis was significantly associated with nulliparity (46.1% vs. 24.4%, p < 0.001), younger maternal age (26.3 ± 6.0 vs. 28.6 ± 5.8 years, p < 0.001), intrauterine growth restriction (IUGR) (6.7% vs. 2.1%, p < 0.001), placental abruption (3.6% vs. 0.7%, p < 0.001), low 1 min Apgar scores (10.3% vs. 6.0%, p < 0.05), urinary tract infection (UTI) (4.2% vs. 0.4%, p < 0.001) and preterm delivery (less than 37 weeks gestation; 20.0% vs. 7.8%; p < 0.001). Using a multivariable analysis, independent risk factors for acute antepartum pyelonephritis were nulliparity (OR 2.0; 95% C.I 1.4–2.9; p < 0.001), UTI (OR 10.3; 95% C.I 4.8–22.1; p < 0.001) and younger maternal age (OR 0.96; 95% C.I 0.93–0.99; p = 0.009). Using another multivariable analysis, with preterm delivery as the outcome variable, acute antepartum pyelonephritis was found as an independent risk factor for preterm delivery (OR 2.6; 95% C.I 1.7–3.9; p < 0.001).

Conclusion

Acute antepartum pyelonephritis is associated with adverse perinatal outcomes and specifically is an independent risk factor for preterm delivery.     

Children with medical complexity in Canada

The burden of chronic disease is placing pressure on the Canadian health care system. A small but important chronic disease population is children with medical complexity, defined as individuals with: high family-identified needs; complex chronic disease necessitating specialized care; functional disability; and high health care utilization. These patients present a challenge to community providers who are expected to provide holistic care and manage complex issues, often with a paucity of services and supports. Alternative models of care may address the complex needs of this population. In addition, strategies can be implemented in community practices that may assist with the care of children with medical complexity such as collaborative care, engagement of key workers, focus on goal-directed care and use of care plans. The paediatric community should engage in health care reform discussions focused on chronic disease to ensure that the complex needs of these children are met.     

Early Activation of Metalloproteinases after Experimental Myocardial Infarction Occurs in Infarct and Non-infarct Zones

The collagen matrix of the heart forms a network linking muscle fibers, muscle bundles, and intramyocardial blood vessels. Collagen turnover in the heart is normally a dynamic process that involves both collagen synthesis and degradation. Collagen breakdown generally involves its chemical digestion by matrix metalloproteinases (MMPs) which are activated in tissue repair, wound healing, and myocardial ischemia. We studied activation of MMPs by zymography in infarct (anterolateral wall) and non-infarct (septum) zones of rat hearts following coranary artery ligation, as well as in sham operated rats. Rats were sacrificed at 30 minutes, 1 hour, 2 hours, 4 hours, and 24 hours post infarction (six hearts for each time period). MMP activity was detected at different molecular weights, with bands at 54 kDa (MMP-1), 62 kDa (MMP-2), and 92 kDa (MMP-9) being the most prominent. MMP activities were indexed by densitometer optical reading. Activity was detected as early as 1 hour post infarct in the MI and remote zones at the 54 kDa (MMP-1) ( p < 0.01) and 62 kDa bands (MMP-2) ( p < 0.001), and at 2 hours post infarct in the infarct zone only at 92 kDa (MMP-9) ( p < 0.05). MMPs are activated early after infarction both in the infarct and importantly, non-infarct zones. This may contribute to collagen breakdown, infarct expansion, and left ventricular remodeling, known to occur early after infarction in experimental and clinical settings.