Developmental impairment of compound action potential in the optic nerve of myelin mutant taiep rats

The taiep rat is a myelin mutant with an initial hypomyelination, followed by a progressive demyelination of the CNS. The neurological correlates start with tremor, followed by ataxia, immobility episodes, epilepsy and paralysis. The optic nerve, an easily-isolable central tract fully myelinated by oligodendrocytes, is a suitable preparation to evaluate the developmental impairment of central myelin. We examined the ontogenic development of optic nerve compound action potentials (CAP) throughout the first 6 months of life of control and taiep rats. Control optic nerves (ON) develop CAPs characterized by three waves. Along the first month, the CAPs of taiep rats showed a delayed maturation, with lower amplitudes and longer latencies than controls; at P30, the conduction velocity has only a third of the normal value. Later, as demyelination proceeds, the conduction velocity of taiep ONs begins to decrease and CAPs undergo a gradual temporal dispersion. CAPs of control and taiep showed differences in their pharmacological sensitivity to TEA and 4-AP, two voltage dependent K+ channel-blockers. As compared with TEA, 4-AP induced a significant increase of the amplitudes and a remarkable broadening of CAPs. After P20, unlike controls, the greater sensitivity to 4-AP exhibited by taiep ONs correlates with the detachment and retraction of paranodal loops suggesting that potassium conductances could regulate the excitability as demyelination of CNS axons progresses. It is concluded that the taiep rat, a long-lived mutant, provides a useful model to study the consequences of partial demyelination and the mechanisms by which glial cells regulate the molecular organization and excitability of axonal membranes during development and disease.     

Chronic rumination reduction in a severely developmentally disabled adult following combined use of positive and negative contingencies

The use of combined positive and negative contingencies markedly reduced ruminative behavior in a severely mentally retarded, blind 20-year-old male residing in a residential treatment facility. A 95.4% decrease in rumination events occurred from baseline to follow-up. This procedure is offered as an effective and convenient treatment for chronic rumination.     

Confirmation of chromosomal microarray as a first-tier clinical diagnostic test for individuals with developmental delay,intellectual disability,autism spectrum disorders and dysmorphic features

Background and objectivesSubmicroscopic chromosomal rearrangements are the most common identifiable causes of intellectual disability and autism spectrum disorders associated with dysmorphic features. Chromosomal microarray (CMA) can detect copy number variants <1 Mb and identifies size and presence of known genes. The aim of this study was to demonstrate the usefulness of CMA, as a first-tier tool in detecting the etiology of unexplained intellectual disability/autism spectrum disorders (ID/ASDs) associated with dysmorphic features in a large cohort of pediatric patients.Patients and methodsWe studied 349 individuals; 223 males, 126 females, aged 5 months-19 years. Blood samples were analyzed with CMA at a resolution ranging from 1 Mb to 40 Kb. The imbalance was confirmed by FISH or qPCR. We considered copy number variants (CNVs) causative if the variant was responsible for a known syndrome, encompassed gene/s of known function, occurred de novo or, if inherited, the parent was variably affected, and/or the involved gene/s had been reported in association with ID/ASDs in dedicated databases.Results91 CNVs were detected in 77 (22.06%) patients: 5 (6.49%) of those presenting with borderline cognitive impairment, 54 (70.13%) with a variable degree of DD/ID, and 18/77 (23.38%) with ID of variable degree and ASDs. 16/77 (20.8%) patients had two different rearrangements. Deletions exceeded duplications (58 versus 33); 45.05% (41/91) of the detected CNVs were de novo, 45.05% (41/91) inherited, and 9.9% (9/91) unknown. The CNVs caused the phenotype in 57/77 (74%) patients; 12/57 (21.05%) had ASDs/ID, and 45/57 (78.95%) had DD/ID.ConclusionsOur study provides further evidence of the high diagnostic yield of CMA for genetic testing in children with unexplained ID/ASDs who had dysmorphic features. We confirm the value of CMA as the first-tier tool in the assessment of those conditions in the pediatric setting.     

The effect of pre-operative developmental delays on the speech perception of children with cochlear implants

Objective

The objective of this study was to evaluate the relationship between developmental delays and speech perception in pre-lingually deafened cochlear implant recipients.

Methods

This study was a retrospective review of patient charts conducted at a tertiary referral center. Thirty-five pre-lingually deafened children underwent multichannel cochlear implantation and habilitation at the Kyoto University Hospital Department of Otolaryngology-Head and Neck Surgery. A pre-operative cognitive–adaptive developmental quotient was evaluated using the Kyoto scale of psychological development. Post-operative speech performance was evaluated with speech perception tests two years after cochlear implantation. We computed partial correlation coefficients (controlled for age at the time of implantation and the average pre-operative aided hearing level) between the cognitive–adaptive developmental quotient and speech performance.

Results

A developmental delay in the cognitive–adaptive area was weakly correlated with speech perception (partial correlation coefficients for consonant–vowel syllables and phrases were 0.38 and 0.36, respectively).

Conclusion

A pre-operative developmental delay was only weakly associated with poor post-operative speech perception in pre-lingually deafened cochlear implant recipients.     

Ecosystemic Needs Assessment for Children with Developmental Coordination Disorder in Elementary School: Multiple Case Studies

ABSTRACT

This study explored the needs of children with developmental coordination disorder (DCD) from an ecosystemic viewpoint as part of a theory-driven program evaluation process. A multiple case study needs assessment was conducted. Participants included ten children with DCD, their parents (n = 12), teachers (n = 9), and service providers (n = 6). Data collection involved semi-structured interviews, validated questionnaires, and a review of the children's records. The results support the relevance of using an ecosystemic model to assess the needs of children with DCD in their life and social contexts. More specifically, the results highlight the need to provide additional services at school, such as occupational therapy and special education, as well as information and training regarding DCD for parents and teachers. The results also point to the relevant variables to consider in an intervention program based on theory-driven evaluations. This study shows how employing an ecosystemic frame of reference provides a better understanding of the needs of children with DCD. Future research should document the ecosystemic profiles and evolution of the needs of children with DCD with a larger sample from diverse socioeconomic backgrounds using a longitudinal study design.     

AN EARLY INTERVENTION PROGRAM FOR HIGH-RISK CHILDREN IN A HEALTH CARE SETTING

Early intervention programs are designed to provide detection, treatment, and prevention of handicaps, developmental delays, and environmental deprivation as early in a child's life as possible. Health care facilities, especially community health centers, are in a unique position to provide intervention services. The social work and nursing staffs of the Dimock Community Health Center in Roxbury, Massachusetts designed an early intervention program (P.E.C.S.-Parent Education and Child Stimulation) for high-risk families. The program addresses the effects of developmental delays and environmental deprivation prevalent in the birth to three-year-old population of the Center. This paper describes the organization and methodology of the program and indicates ways in which the program can be replicated.     

Validity of the school setting interview: an assessment of the student–environment fit

The School Setting Interview (SSI) is an internationally used client-centred interview assessment that specifically investigates the student–environment fit for students with physical disabilities. In this study the Rasch measurement model was used to examine validity of the SSI; specifically, whether or not the SSI measures a unidimensional construct. Data for analysis included SSI assessments of 87 Swedish students with physical disabilities aged between 8 and 19 years of age. The results of the Rasch analysis revealed that all items had acceptable infit MnSq and z values supporting evidence of construct validity of the SSI. The established order of the difficulty of the items was also shown to be in acceptable congruence with the theoretical basis for item development. In addition, the analysis revealed aspects of the SSI that need improvements, such as the need for more challenging items and refinements of the manual. Further investigations of validity in different cultural contexts are recommended.     

Developmental disturbances of permanent teeth following trauma to the primary dentition

The topographic relationship of the apices of the primary teeth to the permanent tooth germs explains the potential for possible developmental disturbances of the permanent teeth after injuries to their predecessors. The anatomical, histologic and clinical aspects of permanent tooth malformation following trauma to the primary teeth are described. One hundred and fourteen children with originally 255 traumatized primary teeth have been re-examined (with an average period of 5.1 years after the trauma) to assess any developmental disturbances of the corresponding permanent teeth. Twenty-three per cent of partially or completely erupted permanent teeth showed developmental disturbances. The most frequent malformation was enamel hypoplasia including enamel discoloration and/or enamel defects. The highest prevalence of developmental disturbances of permanent teeth was found after intrusive injuries of primary teeth.