Behroze Vachha

Language Differences in Young Children with Myelomeningocele and Shunted Hydrocephalus

Objective: This comparative cohort study examined language differences in young children (preschool to first grade) with myelomeningocele and shunted hydrocephalus (MM/SH). Method: A well-validated, standardized language test was administered to 17 children with MM/SH (age range 4–6 years) and 16 age-matched, nonaffected children. Results: Standard scores were obtained within lexical/semantic, syntactic, and pragmatic domains. An analysis of performance on individual subtests within the lexical/semantic domain was striking. Children with MM/SH performed significantly worse (p < 0.01) on a test measuring the comprehension of words representing important early learning concepts and on pragmatic tasks that measured their ability to use language functionally in social situations. Conclusions: Words representing basic precepts and concepts are commonly used in instructions to children in early childhood. Difficulty with functional pragmatic language results in suboptimal communication skills. Academic and community implications are discussed.

A Nanoporous, Transparent Microcontainer for Encapsulated Islet Therapy

Present-day islet encapsulation techniques such as polymer microcapsules and microelectromechanical system (MEMS)-based biocapsules have shown promise in insulin replacement therapy, but they each have limitations—the permeability characteristics of existing polymeric capsules cannot be strictly controlled because of tortuosity and the large size of present-day MEMS biocapsules leads to necrotic regions within the encapsulation volume. We report on a new microcontainer to encapsulate and immunoprotect islets/β cells that may be used for allo- or xenotransplantation in cell-based therapy. The microcontainers have membranes containing nanoslots to permit the bidirectional transport of nutrients, secretagogues, and cellular products while immunoprotecting the encapsulated cells. The 300-μm microcontainers were fabricated from an epoxy-based polymer, SU-8, with 50-μm-thick walls. Arrays of 25-nm wide slots were created in the SU-8 microcontainer lid. Isolated mouse islets were encapsulated in the microcontainer, and their physiological response to glucose was studied with fluorescence and two-photon imaging over 48 hours. The physiological response of the encapsulated islets was indistinguishable from controls. An agarose-filled microcontainer was imaged with magnetic resonance imaging to demonstrate the feasibility of future noninvasive, in vivo imaging. The SU-8 microcontainers maintained mechanical integrity upon islet loading and mechanical manipulation. Islet encapsulation, as well as the ability to visualize islet function within these transparent microcontainers, was demonstrated.

Cell encapsulation and oxygenation in nanoporous microcontainers

With strides in stem cell biology, cell engineering and molecular therapy, the transplantation of cells to produce therapeutic molecules endogenously is an attractive and achievable alternative to the use of exogenous drugs. The encapsulation of such cell transplants in semi-permeable, nanoporous constructs is often required to protect them from immune attack and to prevent their proliferation in the host. However, effective graft immunoisolation has been mostly elusive owing to the absence of a high-throughput method to create precisely controlled, high-aspect-ratio nanopores. To address the clinical need for effective cell encapsulation and immunoisolation, we devised a biocompatible cell-encapsulating microcontainer and a method to create highly anisotropic nanopores in the microcontainer’s surface. To evaluate the efficacy of these nanopores in oxygenating the encapsulated cells, we engineered 9L rat glioma cells to bioluminesce under hypoxic conditions. The methods described above should aid in evaluating the long term survival and efficacy of cellular grafts.

Optic nerve and chiasm enlargement in a case of infantile Krabbe disease: quantitative comparison with 26 age-matched controls

Hypertrophy of the optic nerves and optic chiasm is described in a 5-month-old boy with infantile Krabbe disease. Optic nerve and optic chiasm hypertrophy is a rarely described feature of Krabbe disease. The areas of the prechiasmatic optic nerves and optic chiasm were measured and compared with those of 26 age-matched controls. The areas of the prechiasmatic optic nerves and optic chiasm were 132% and 53% greater than normal, respectively.

Myelomeningocele, Temperament Patterns, and Parental Perceptions

Objective. Description of temperament profiles of children has largely been reported in typically developing populations. Children undergo individualized assessments of achievement (developmental/academic) and receive individualized interventions. In contrast, their individual behavioral styles are not evaluated as completely, if at all. For children with developmental disabilities, description of temperament characteristics can provide better understanding of the already complex child. This study describes temperament characteristics in a group of children with myelomeningocele and shunted hydrocephalus (MM/SH). Methods. A consecutive cohort study with historical control group measuring temperament characteristics was conducted at a tertiary-level, university affiliated, interdisciplinary spina bifida program. Analysis includes group comparisons. Primary caregivers of 46 children (age range: 5–12 years) with MM/SH completed age-appropriate Carey Temperament Scales questionnaires as a component of a larger developmental study. The Carey Temperament Scales comprise a series of behavioral rating instruments that assess 9 temperament characteristics: activity, adaptability, approach-withdrawal, mood, intensity, attention/persistence, distractibility, sensory threshold, and rhythmicity/predictability. The Carey questionnaires used in this study were (1) the Behavioral Style Questionnaire for children aged 5 to 7 years and (2) the Middle Childhood Temperament Questionnaire for those aged 8 to 12 years. Both questionnaires assess the same temperament characteristics; the contexts within which items were rated were designed to better reflect developmental levels. Children were excluded when there were comorbid diagnoses of attention-deficit/hyperactivity disorder or mental retardation. Results. One-sample normal tests (Bonferroni corrected) revealed that children within the MM/SH group differed significantly from the standardized population in 5 dimensions: (1) adaptability (less adaptable), (2) approach/withdrawal (poor first approach/greater withdrawal), (3) distractibility (more distractible), (4) attention/persistence (less attentive/persistent), and (5) predictability/rhythm (less predictable). Caregiver perceptions of having a difficult-to-manage child were significantly correlated with negative mood, more intensity of response, and less adaptability. Conclusions. Temperament profiles previously described in typically developing populations (eg, “easy” or “difficult child”) were not prominent profiles in this group of children with MM/SH. A constellation of temperament characteristics not commonly recognized may place these children at risk for being contributors to and recipients of misunderstandings of social cues and have implications for successful learning within academic, home/community, and medical settings.

Incidence of New Onset Metabolic Acidosis Following Enteroplasty for Myelomeningocele

PURPOSEnExtant literature is mixed regarding risk of metabolic acidosis after enteroplasty for myelomeningocele. This study is the first known attempt to describe the pattern of developing metabolic acidosis in a group of children who underwent enteroplasty and served as their own controls. Multiple preoperative and postoperative laboratory measures for each child were obtained for comparison.nnnMATERIALS AND METHODSnThis retrospective cohort study allowed participants to serve as their own controls for pre-intervention and post-intervention analysis. The setting was a tertiary, university affiliated, interdisciplinary spina bifida program. All patients followed in the spina bifida program who had undergone ileal or colonic enteroplasty were included for review (total 113). Strict exclusion criteria were preoperatively diagnosed renal insufficiency, preexisting metabolic acidosis consistent with renal tubular acidosis (pH less than 7.35, bicarbonate 20 mmol/l or less) and history of augmentation using gastric or ureteral tissue. Final analysis included 71 children who met inclusion criteria. Children in our spina bifida program periodically undergo routine laboratory evaluation of electrolytes, blood urea nitrogen, creatinine, blood count, and venous blood gases including pH, bicarbonate and partial pressure of carbon dioxide. Primary outcome measures were comparative shifts in blood gases and electrolytes that would confirm the new onset of metabolic acidosis after enteroplasty. Changes in electrolytes and serum creatinine were secondary outcome measures to identify potential markers for postoperative effects. With each child as his/her own control, analysis included paired t tests.nnnRESULTSnNo statistically significant differences (p <0.05) were found when comparing laboratory values before and after bladder augmentation, including pH, bicarbonate, partial pressure of carbon dioxide and electrolytes. No child had metabolic acidosis based on the aforementioned criteria. Followup ranged from 1 to 138 months after enteroplasty (mean 46.8). Respiratory compensation was considered in the analysis, and no difference in partial pressure of carbon dioxide following surgery was noted (p = 0.65).nnnCONCLUSIONSnTo our knowledge no previous study has examined the matched paired results of before and after development of metabolic acidosis among children (serving as their own controls) with myelomeningocele undergoing ileal or colonic enteroplasty. The negative statistical results in this controlled cohort are clinically significant. If a child with myelomeningocele has metabolic acidosis after enteroplasty, other clinical reasons beyond the effects of surgery warrant careful consideration.

Implications of family environment and language development: comparing typically developing children to those with spina bifida

INTRODUCTIONnThis study examines the effect of family environment on language performance in children with myelomeningocele compared with age- and education-matched controls selected from the same geographic region.nnnMETHODSnSeventy-five monolingual (English) speaking children with myelomeningocele [males: 30; ages: 7-16 years; mean age: 10 years 1 month, standard deviation (SD) 2 years 7 months] and 35 typically developing children (males: 16; ages 7-16 years; mean age: 10 years 9 months, SD 2 years 6 months) participated in the study. The Comprehensive Assessment of Spoken Language (CASL) and the Wechsler tests of intelligence were administered individually to all participants. The CASL measures four subsystems: lexical, syntactic, supralinguistic and pragmatic. Parents completed the Family Environment Scale (FES) questionnaire and provided background demographic information. Standard independent sample t-tests, chi-squared and Fishers exact tests were used to make simple comparisons between groups for age, socio-economic status, gender and ethnicity. Spearman correlation coefficients were used to detect associations between language and FES data. Group differences for the language and FES scores were analysed with a multivariate analysis of variance at a P-value of 0.05.nnnRESULTSnFor the myelomeningocele group, both Spearman correlation and partial correlation analyses revealed statistically significant positive relationships for the FES intellectual-cultural orientation (ICO) variable and language performance in all subsystems (P < 0.01). For controls, positive associations were seen between: (1) ICO and lexical/semantic and syntactic subsystems; and (2) FES independence and lexical/semantic and supralinguistic tasks.nnnCONCLUSIONSnThe relationship between language performance and family environment appears statistically and intuitively sound. As in our previous study, the positive link between family focus on intellectually and culturally enhancing activities and language performance among children with myelomeningocele and shunted hydrocephalus remains robust. Knowledge of this relationship should assist parents and professionals in supporting language development through activities within the natural learning environment.

Losing Your Voice: Etiologies and Imaging Features of Vocal Fold Paralysis

Neurogenic compromise of vocal fold function exists along a continuum encompassing vocal cord hypomobility (paresis) to vocal fold immobility (paralysis) with varying degrees and patterns of reinnervation. Vocal fold paralysis (VFP) may result from injury to the vagus or the recurrent laryngeal nerves anywhere along their course from the brainstem to the larynx. In this article, we review the anatomy of the vagus and recurrent laryngeal nerves and examine the various etiologies of VFP. Selected cases are presented with discussion of key imaging features of VFP including radiologic findings specific to central vagal neuropathy and peripheral recurrent nerve paralysis.

A temperament for learning: The limbic system and myelomeningocele

This article was the winner of the triennial Casey Holter Memorial Prize awarded by the Society for Research into Hydrocephalus and Spina Bifida, 2004.AbstractThis essay explores the link between the limbic/hypothalamic systems within the complex conditions of hydrocephalus and myelomeningocele. Acknowledging the neuroanatomical and neuroendocrine risks inherent in the developing brains of these individuals, we focus on the converging components of temperament, cognition, and language.

MRI of the petromastoid canal in children

To characterize the MRI features of the petromastoid canal in children with sensorineural hearing loss (SNHL) and in normal infants.