Language lateralisation and early right ear deafness: was Wernicke right?
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The effects of early right ear deafness on lateralisation of auditory language functions are not fully known. A 36 year old right handed man, with a history of perinatal right ear deafness and undergoing evaluation for surgical treatment of seizures that began at age 10 years was studied. Language lateralisation testing by intracarotid sodium amobarbital injection showed receptive and expressive language functions to be strongly lateralised to the left hemisphere. Results with intracarotid sodium amobarbital injection further suggested that transmission of auditory input to the patient's left hemisphere was partially dependent on ipsilateral left ear pathways. Cortical language mapping through implanted subdural electrodes localised auditory language functions to traditional left posterior perisylvian language areas. These results suggest that early right ear deafness does not impede left hemisphere lateralisation and localisation of auditory language functions. Moreover, transmission of auditory information to the patient's left hemisphere seems to be accomplished, in part, by recruitment of ipsilateral left ear pathways. (+info)
Randomised controlled trial of community based speech and language therapy in preschool children.
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OBJECTIVE: To compare routine speech and language therapy in preschool children with delayed speech and language against 12 months of "watchful waiting." DESIGN: Pragmatic randomised controlled trial. SETTING: 16 community clinics in Bristol. PARTICIPANTS: 159 preschool children with appreciable speech or language difficulties who fulfilled criteria for admission to speech and language therapy. MAIN OUTCOME MEASURES: Four quantitative measures of speech and language, assessed at 6 and 12 months; a binary variable indicating improvement, by 12 months, on the trial entry criterion. RESULTS: Improvement in auditory comprehension was significant in favour of therapy (adjusted difference in means 4.1, 95% confidence interval 0.5 to 7.6; P=0.025). No significant differences were observed for expressive language (1.4, -2.1 to 4.8; P=0.44); phonology error rate (-4.4, -12.0 to 3.3; P=0.26); language development (0.1, -0.4 to 0.6; P=0.73); or improvement on entry criterion (odds ratio 1.3, 0.67 to 2.4; P=0.46). At the end of the trial, 70% of all children still had substantial speech and language deficits. CONCLUSIONS: This study provides little evidence for the effectiveness of speech and language therapy compared with watchful waiting over 12 months. Providers of speech and language therapy should reconsider the appropriateness, timing, nature, and intensity of such therapy in preschool children. Continued research into more specific provision to subgroups of children is also needed to identify better treatment methods. The lack of resolution of difficulties for most of the children suggests that further research is needed to identify effective ways of helping this population of children. (+info)
Language development in profoundly deaf children with cochlear implants.
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Although cochlear implants improve the ability of profoundly deaf children to understand speech, critics claim that the published literature does not document even a single case of a child who has developed a linguistic system based on input from an implant. Thus, it is of clinical and scientific importance to determine whether cochlear implants facilitate the development of English language skills. The English language skills of prelingually deaf children with cochlear implants were measured before and after implantation. We found that the rate of language development after implantation exceeded that expected from unimplanted deaf children (p < .001) and was similar to that of children with normal hearing. Despite a large amount of individual variability, the best performers in the implanted group seem to be developing an oral linguistic system based largely on auditory input obtained from a cochlear implant. (+info)
Evidence for a susceptibility gene for autism on chromosome 2 and for genetic heterogeneity.
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Although there is considerable evidence for a strong genetic component to idiopathic autism, several genomewide screens for susceptibility genes have been performed with limited concordance of linked loci, reflecting either numerous genes of weak effect and/or sample heterogeneity. Because decreasing sample heterogeneity would increase the power to identify genes, the effect on evidence for linkage of restricting a sample of autism-affected relative pairs to those with delayed onset (at age >36 mo) of phrase speech (PSD, for phrase speech delay) was studied. In the second stage of a two-stage genome screen for susceptibility loci involving 95 families with two or more individuals with autism or related disorders, a maximal multipoint heterogeneity LOD score (HLOD) of 1.96 and a maximal multipoint nonparametric linkage (NPL) score of 2.39 was seen on chromosome 2q. Restricting the analysis to the subset of families (n=49) with two or more individuals having a narrow diagnosis of autism and PSD generated a maximal multipoint HLOD score of 2.99 and an NPL score of 3.32. The increased scores in the restricted sample, together with evidence for heterogeneity in the entire sample, indicate that the restricted sample comprises a population that is more genetically homogeneous, which could therefore increase the likelihood of positional cloning of susceptibility loci. (+info)
Disruption of the ProSAP2 gene in a t(12;22)(q24.1;q13.3) is associated with the 22q13.3 deletion syndrome.
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The terminal 22q13.3 deletion syndrome is characterized by severe expressive-language delay, mild mental retardation, hypotonia, joint laxity, dolichocephaly, and minor facial dysmorphisms. We identified a child with all the features of 22q13.3 deletion syndrome. The patient's karyotype showed a de novo balanced translocation between chromosomes 12 and 22, with the breakpoint in the 22q13.3 critical region of the 22q distal deletion syndrome [46, XY, t(12;22)(q24.1;q13.3)]. FISH investigations revealed that the translocation was reciprocal, with the chromosome 22 breakpoint within the 22q subtelomeric cosmid 106G1220 and the chromosome 12q breakpoint near STS D12S317. Using Southern blot analysis and inverse PCR, we located the chromosome 12 breakpoint in an intron of the FLJ10659 gene and located the chromosome 22 breakpoint within exon 21 of the human homologue of the ProSAP2 gene. Short homologous sequences (5-bp, CTG[C/A]C) were found at the breakpoint on both derivative chromosomes. The translocation does not lead to the loss of any portion of DNA. Northern blot analysis of human tissues, using the rat ProSAP2 cDNA, showed that full-length transcripts were found only in the cerebral cortex and the cerebellum. The FLJ10659 gene is expressed in various tissues and does not show tissue-specific isoforms. The finding that ProSAP2 is included in the critical region of the 22q deletion syndrome and that our proband displays all signs and symptoms of the syndrome suggests that ProSAP2 haploinsufficiency is the cause of the 22q13.3 deletion syndrome. ProSAP2 is a good candidate for this syndrome, because it is preferentially expressed in the cerebral cortex and the cerebellum and encodes a scaffold protein involved in the postsynaptic density of excitatory synapses. (+info)
Theoretical and practical considerations in the psychological and educational assessment of the student with intractable epilepsy: dynamic assessment as an adjunct to static assessment.
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Assessing the student with intractable epilepsy requires skill not only in evaluating cognitive problems, but also detecting seizures and discovering how to adapt instruction to minimize their negative impact on learning. Ironically, assessment efforts are seen as compromised by the occurrence of seizures during testing, when determining how seizure events may interfere with learning and the instructional modifications that are necessary to cope with them, should be a key part of assessment. A dual approach to assessment is recommended that combines the identification of cognitive deficits with an evaluation of how recurring seizures may prevent the student from engaging in instruction. Without also evaluating the student's response to instruction, teaching to specific cognitive needs is limited by insufficient knowledge about how to keep the student involved in instruction when seizures occur. Static assessment evaluates cognitive functioning at the time of testing, without changing the way that the student learns and responds. By engaging the student in teaching/learning sessions, dynamic assessment explores how the student best learns despite cognitive deficits and the disruptive effect of seizures. This paper includes a description of the authors'experience in using dynamic assessment as an adjunct to static assessment in evaluating a student with intractable epilepsy. (+info)
Does early detection of otitis media with effusion prevent delayed language development?
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OBJECTIVE: To consider whether earlier detection of otitis media with effusion (OME) in asymptomatic children in the first 4 years of life prevents delayed language development. METHODS: MEDLINE and other databases were searched and relevant references from articles reviewed. Critical appraisal and consensus development were in accordance with the methods of the Canadian Task Force on Preventive Health Care. RESULTS: No randomised controlled trials assessing the overall screening for OME and early intervention to prevent delay in acquiring language were identified, although one trial evaluated treatment in a screened population and found no benefit. The "analytic pathway" approach was therefore used, where evidence is evaluated for individual steps in a screening process. The evidence supporting the use of tools for early detection such as tympanometry, microtympanometry, acoustic reflectometry, and pneumatic otoscopy in the first 4 years of life is unclear. Some treatments (mucolytics, antibiotics, steroids) resulted in the short term resolution of effusions as measured by tympanometry. Ventilation tubes resolved effusions and improved hearing. Ventilation tubes in children with hearing loss associated with OME benefited children in the short term, but after 18 months there was no difference in comparison with those assigned to watchful waiting. Most prospective cohort studies that evaluated the association between OME and language development lacked adequate measurement of exposure or outcome, or suffered from attrition bias. Findings with regard to the association were inconsistent. CONCLUSIONS: There is insufficient evidence to support attempts at early detection of OME in the first 4 years of life in the asymptomatic child to prevent delayed language development. (+info)
Meningitis in infancy in England and Wales: follow up at age 5 years.
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OBJECTIVE: To describe important sequelae occurring among a cohort of children aged 5 years who had had meningitis during the first year of life and who had been identified by a prospective national study of meningitis in infancy in England and Wales between 1985 and 1987. DESIGN: Follow up questionnaires asking about the children's health and development were sent to general practitioners and parents of the children and to parents of matched controls. The organism that caused the infection and age at infection were also recorded. SETTING: England and Wales. PARTICIPANTS: General practitioners and parents of children who had had meningitis before the age of 1 year and of matched controls. MAIN OUTCOME MEASURES: The prevalence of health and developmental problems and overall disability among children who had had meningitis compared with controls. RESULTS: Altogether, 1584 of 1717 (92.2%) children who had had meningitis and 1391 of 1485 (93.6%) controls were successfully followed up. Among children who survived to age 5 years 247 of 1584 (15.6%) had a disability; there was a 10-fold increase in the risk of severe or moderate disability at 5 years of age among children who had had meningitis (relative risk 10.3, 95% confidence interval 6.7 to 16.0, P<0.001). There was considerable variation in the rates of severe or moderate disability in children infected with different organisms. CONCLUSION: The long term consequences of having meningitis during the first year of life are significant: 32 of 1717 (1.8%) children died within five years. Not only did almost a fifth of children with meningitis have a permanent, severe or moderately severe disability, but subtle deficits were also more prevalent. (+info)