Severity Of Mental Retardation Research Articles

A genetic study of autism in Costa Rica: multiple variables affecting IQ scores observed in a preliminary sample of autistic cases

BackgroundAutism is a heritable developmental disorder of communication and socialization that has not been well studied in Hispanic populations. Therefore, we are collecting and evaluating all possible cases of autism from a population isolate in the Central Valley of Costa Rica (CVCR) for a clinical and genetic study.MethodsWe are assessing all subjects and parents, as appropriate, using the newly translated Spanish versions of the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS) as well as tests of intelligence and adaptive behavior. Detailed obstetric and family medical/psychiatric histories are taken. All cases are tested for Fragile X and will be extensively evaluated for cytogenetic abnormalities.ResultsTo date we have obtained clinical evaluations on over 76 cases of possible autism referred to our study and report data for the initial 35 complete cases. The mean age of the probands is 6.7 years, and 31 of the 35 cases are male. Twenty-one of the cases have IQs <50 and only 6 cases have IQs ≥ 70. Over half of the mothers had complications during pregnancy and/or delivery. No cases have tested positively for Fragile X or PKU. Chromosomal G-banding is not yet complete for all cases.ConclusionDiagnostic data gathered on cases of autism in the CVCR using Spanish versions of the ADI-R and ADOS look similar to that generated by studies of English-speaking cases. However, only 17% of our cases have IQs within the normal range, compared to the figure of 25% seen in most studies. This result reflects an ascertainment bias in that only severe cases of autism come to treatment in the CVCR because there are no government-sponsored support programs or early intervention programs providing an incentive to diagnose autism. The severity of mental retardation seen in most of our cases may also be exaggerated by the lack of early intervention programs and the use of IQ tests without Costa Rican norms. Still, we must formally train healthcare providers and teachers to recognize and refer autistic cases with normal or near normal IQs that are not seen in treatment.

Etiology of Mental Retardation in Children Referred to a Tertiary Care Center: A Prospective Study

A prospective assessment following a step-wise protocol in 281 patients with unexplained cognitive delay was used to assess diagnostic possibilities. Diagnostic procedures were complex and required a multidisciplinary approach. One third of diagnoses was established based on clinical history and physical exam only; for another third, clinical history and physical exam provided essential clues for additional investigations; and a third were established by additional investigations only. The likelihood to reach a diagnosis did not depend on the severity of mental retardation. We found that in a tertiary care center, a diagnosis can be established in 1 out of every 2 patients. Clinical history and physical examination are the most important instruments to reach a diagnosis.

Diagnostic investigations in individuals with mental retardation: a systematic literature review of their usefulness

There are no guidelines available for diagnostic studies in patients with mental retardation (MR) established in an evidence-based manner. Here we report such study, based on information from original studies on the results with respect to detected significant anomalies (yield) of six major diagnostic investigations, and evaluate whether the yield differs depending on setting, MR severity, and gender. Results for cytogenetic studies showed the mean yield of chromosome aberrations in classical cytogenetics to be 9.5% (variation: 5.4% in school populations to 13.3% in institute populations; 4.1% in borderline-mild MR to 13.3% in moderate-profound MR; more frequent structural anomalies in females). The median yield of subtelomeric studies was 4.4% (also showing female predominance). For fragile X screening, yields were 5.4% (cytogenetic studies) and 2.0% (molecular studies) (higher yield in moderate-profound MR; checklist use useful). In metabolic investigations, the mean yield of all studies was 1.0% (results depending on neonatal screening programmes; in individual populations higher yield for specific metabolic disorders). Studies on neurological examination all showed a high yield (mean 42.9%; irrespective of setting, degree of MR, and gender). The yield of neuroimaging studies for abnormalities was 30.0% (higher yield if performed on an indicated basis) and the yield for finding a diagnosis based on neuroradiological studies only was 1.3% (no data available on value of negative findings). A very high yield was found for dysmorphologic examination (variation 39-81%). The data from this review allow conclusions for most types of diagnostic investigations in MR patients. Recommendations for further studies are provided.

Pilot study on the use of psychotropic medication in persons with mental retardation

Objective: To explore the status of the psychotropic medication in persons with mental retardation 6 years after their deinstitutionalization. Method: The authors compared the profiles of psychotropic medication of 60 persons with mental retardation deinstitutionalized (D-sample) from our local mental hospital 6 years ago, to their actual pharmacological profile. Later, we compared our results to the ones of persons with mental retardation on an in-patient (In-sample) unit where existed a concerted team effort to lower the medication when deemed appropriate. Results: Six years post-deinstitutionalization, the authors observed that the same percentage of patients remained on antipsychotic and benzodiazepine medication in our D-sample, and a threefold increase of those using antidepressive medication. However, we observe a general decrease of all types of psychotropic medication in the In-sample with complete withdrawal in a substantial number of patients. Conclusions: The authors take these pilot data to mean that a concerted team effort at lowering medication in persons with mental retardation makes a significant difference. The possibility of other factors (age, sex, severity of mental retardation, psychiatric diagnosis) explaining the difference in the results is discussed.

Neuroimaging in mental retardation.

To determine the diagnostic yield of neuroimaging in a cohort of children with mental retardation of unknown origin. Neuroimaging was performed in a total of 47 patients with developmental delay/mental retardation, where no etiologic diagnosis could be made following clinical examination and preliminary investigations. Thirty (63.82%) children had abnormal neuroimaging findings of which 19 (42.42%) were specific abnormalities useful in arriving at etiological diagnosis. Positive outcome of neuroimaging increased with the severity of mental retardation and in presence of microcephaly and neurologic deficits other than mental retardation. Neuroimaging should be the standard clinical practice for a child with global developmental delay where no cause is apparent after examination and relevant investigations.

Life expectancy for children with cerebral palsy and mental retardation: Implications for life care planning

Physicians may be asked by attorneys or other patient advocates to help plan for the long-term needs of children with cerebral palsy (CP) and developmental disability (DD). The first step in such planning is to thoroughly examine the literature dealing with life expectancy in these populations. This review paper comprehensively reviews the literature relating to survival in children with cerebral palsy and developmental disability. A Medline data search was completed using the terms cerebral palsy, life expectancy, survival, as well as other pertinent terms. Further articles were gleaned from bibliographies of pertinent literature. Certain key disabilities can be used to accurately predict life expectancy in children with cerebral palsy and mental retardation. These include: (1) presence and severity of mental retardation, (2) inability to speak intelligible words, (3) inability to recognize voices, (4) inability to interact with peers, (4) severity of physical disability, (5) use of tube feeding, (6) incontinence, and (7) presence and severity of seizures. Literature review definitively shows that children with CP and DD have a diminished life expectancy, which can be assessed based on simple clinical examination findings.

Another case of cerebro-facio-thoracic dysplasia (Pascual-Castroviejo syndrome)

We report another case of cerebro-facio-thoracic dysplasia (Pascual-Castroviejo syndrome) characterized by mental retardation and characteristic facies: narrow forehead, synophris, hypertelorism, broad nasal bridge, long philtrum, micrognathia, triangular-shaped mouth and low posterior hairline, and also brachycephaly, calcified clinoid ligaments, and upper rib deformities. Although the severity of mental retardation within the syndrome varies, the reported case shows not only a severe degree, but also cerebral malformations not reported in any of the previous cases of cerebro-facio-thoracic syndrome. These include cortical–subcortical atrophy with hypoplasia of the corpus callosum, and of the cerebellar vermis. We also discuss the inheritance pattern and differential diagnosis, comparing this phenotype to other similar dysmorphic syndromes.

TM4SF2 gene involvement reconsidered in an XLMR family after neuropsychological assessment.

The TM4SF2 gene (localized at Xp11.4 between the loci DXS564 and DXS556) has been found to be mutated in one MRX family. In order to define the corresponding behavioral phenotype, global IQ and specific cognitive skills were assessed in seven males and three females of this family, independent of subject status. Mental retardation (MR) was mild in three patients and moderate in three others. Despite the broad variability of severity of MR, a cognitive profile specific to the MR in this family was documented. It was characterized by language disorder that was more marked in the articulatory component and spatial/verbal short-term memory dissociation with larger mnemonic span for spatial than for verbal cues. Linkage analysis was then performed on the basis of the cognitively determined status. Recombinations were observed with the loci DXS556 at Xp11.4 and DXS441 at Xq13.2 (maximum LOD score = 2.23 at theta = 0 for ALAS2). This localization region does not include the TM4SF2 gene that has been found mutated in both patients with MR and in one non-MR male subject of this family. The present results suggest two main hypotheses. First, TM4SF2 gene mutation could be involved in MR in this family, therefore representing accentuated intra familial phenotypic variability. Second, the structural particularity detected in the TM4SF2 gene might reflect a rare polymorphism rather than a pathogenic mutation, with the gene responsible for MR in this family being therefore more likely to be searched for in the pericentromeric region of the X chromosome.

Repercusión del retraso mental y de la parálisis cerebral asociada sobre la maduración ósea

Mental retardation (MR) constitutes a clinical and social relevant condition accounting for 3% of the pediatric population. Studies focusing the repercussion of MR on nutritional status are scarce and, in occasions, have produced contradictory results.To evaluate the nutritional status of mentally retarded children in our Region, on the basis of skeletal maturation.Our sample comprise 128 mentally retarded children (81 boys and 47 girls) aged 0 17 years. In all children a nutritional and social family environment questionnaires and a valuation of a series of nutritional and anthropometric variables were performed. Additionally, bone age was assessed by means of left hand wrist radiograph in a subset of 53 children. A factorial analysis was carried out by means of the statistical package SPSS allowing the obtaining of 2 anthropometric factors and 3 biochemical factors that condensed the most information content. Results of the bone maturation were correlated with age, sex, presence of cerebral palsy (CP), severity of mental retardation, results of nutritional and sociofamilial questionnaire, antiepileptic treatment and nutritional status (anthropometric and biochemical factors).Although a good correlation exists between bone age and chronological age, 50% of mentally retarded children presented delay in their skeletal maturation. The bone maturation was higher in the boys than in the girls. The presence of CP induced an increase of 12% in the delay of the skeletal maturation. The severity of MR induced differences in the bone age. Both quality of diet and score of anthropometric factor I inversely correlated with bone maturation delay. Parent s age and geographical precedence but not antiepileptic therapy affected the bone maturation.Delay in the bone maturation occurs with high prevalence among mentally retarded children. The presence of CP, severity of MR, quality of the diet and sociofamilial and nutritional factors influenced in an outstanding way in the bone maturation.

Parents' Expectations About Future Outcomes of Children with MR in Kenya

This study defined and validated three constructs of parents' expectations about future outcomes for children with mental retardation in Kenya: adult responsibilities, community membership, and educational attainment. The purpose was to investigate changes in these constructs across child's gender and severity of mental retardation. Using a maximum-likelihood confirmatory factor analysis on a questionnaire developed for the purposes of this study, it was found that the hypothesized model of parents' expectations was adequate and fit with data. Gender differences in favor of boys were found for the parents' expectations about future adult responsibilities and educational attainment, but not about community membership. Overall, parents' expectations about future outcomes for children with severe mental retardation were much lower than those for children with mild or moderate mental retardation. However, there was also an interaction between the child's gender and level of mental retardation for the parents' expectations about the child's educational attainment.

Nonconvulsive status epilepticus--a possible cause of mental retardation in patients with Lennox-Gastaut syndrome.

Lennox-Gastaut syndrome (LGS) is one of the most severe types of childhood epilepsy. It is usually resistant to treatment and associated with mental retardation. To delineate the risk factors associated with the outcome of LGS, we evaluated, in a retrospective and multicentre study, the course of the disease, EEG tracings, and intellectual function in 101 patients. Inclusion criteria were the presence of tonic seizures as well as slow spike and wave complexes in the EEG. The average documented observation period was 16 years (range 4-31 years). Overall, the intellectual and neurological outcome was poor. At the last follow-up, 38% of the patients could not speak, 21% were unable to walk and only 4% were free of seizures. Four independent risk factors for severe mental retardation were identified by multivariate analysis. These were in a decreasing order of importance: nonconvulsive status epilepticus (NCSE), odds ratio (OR) 25.2, a previous diagnosis of West syndrome (OR 11.6), a symptomatic etiology of epilepsy (OR 9.5), and an early age at onset of epilepsy (OR 4.7). The results highlight the association between NCSE and the severity of mental retardation in patients with LGS; this association appears to be independent of symptomatic etiology. Our data provide an indirect evidence that, at least in some of the patients, NCSE is not only a concomitant feature, but also a cause of severe mental retardation.

Epidemiology and Treatment of Epilepsy in Patients who are Mentally Retarded

Epilepsy affects approximately 14 to 24% of patients who are mentally retarded. The prevalence increases in those patients who have associated neurological disorders. The severity of mental retardation also influences prevalence. Approximately 7 to 15% of patients with mild to moderate mental retardation, 45 to 67% of those with severe retardation and about 50 to 82% of patients with profound retardation have a lifetime history of epilepsy. The prevalence of epilepsy also varies according to patients’ age and the aetiology of mental retardation. Both false positive and false negative diagnoses of epilepsy remain possible in patients who are mentally retarded.

Comprehensive mutational analysis of the TSC1 gene: observations on frequency of mutation, associated features, and nonpenetrance.

We performed a comprehensive analysis for mutations in the TSC1 gene using Southern blot analysis, and SSCP and heteroduplex analysis of amplified exons in 13 families with genetic linkage to the TSC1 region, 22 small families without linkage information, and 126 sporadic patients. 17 unique mutations were identified in 21 patients. Mutations were found in 7/13 (54%) TSC1-linked families, 1/22 (5%) small families without linkage, and 13 of 126 (10%) sporadic cases. The mutations were all chain-terminating, with 14 small deletions, 1 small insertion, and 6 nonsense mutations. In families with mutations, all individuals carrying a mutation met formal diagnostic criteria for TSC, apart from a 3-year-old girl who had inherited a deletion mutation, and who had no seizures, normal intelligence, normal abdominal ultrasound, and hypomelanotic macules only on physical exam. We assessed the incidence and severity of mental retardation in the 13 sporadic patients with TSC1 mutations versus the entire sporadic cohort, and found no significant difference. The observations indicate that TSC1 mutations are all inactivating, suggest that TSC1 disease occurs in only 15-20% of the sporadic TSC population, and demonstrate that presymptomatic TSC does occur.

Life expectancy of children with cerebral palsy

Risk factors for mortality of young children with cerebral palsy were studied using a sample of 12,709 children aged 0.5–3.5 years with cerebral palsy who had received services from the State of California between 1980 and 1995. The most powerful prognostic factors for survival were simple functional items: mobility and feeding skills. Once these were known, factors such as severity of mental retardation and presence of quadriplegia contributed relatively little. Children with fair motor and eating skills had good survival prospects, with 90% or more reaching adulthood, but those without such skills had much poorer prospects. Among children who were unable to lift their heads, median survival time was 7 additional years for those who were tube fed (n = 557) and 14 years for those fed entirely by others (n = 997). Although a child's approximate survival chances can be assessed from such functional classifications, we indicate the manner in which additional information on the child's condition can be used to obtain more accurate survival data.

Longitudinal changes in adaptive behavior in adults with Down syndrome: interim findings from a longitudinal study.

Age-related changes in adaptive behavior have been established in adults with Down syndrome. However, most studies have been cross-sectional, without controls for cohort and survival effects. We examined underlying factors for age-related decline in adaptive behavior in 128 adults with trisomy 21 over a 3-year period. Presence of dementia was the only determining factor, although the difference in trend over time as compared to subjects without dementia was not significant. No association between gender, sensory loss, severity of mental retardation, or place of residence was found. For subjects with no significant medical disorder (physical or psychological), no decline was seen. This longitudinal study confirms previously reported findings.

RETARDATION, CRIMINALITY, AND COMPETENCY TO STAND TRIAL AMONG MENTALLY RETARDED CRIMINAL DEFENDANTS: VIOLENT VERSUS NON-VIOLENT DEFENDANTS

ABSTRACT The mentally retarded criminal defendant has created substantial difficulty for the judicial system in terms of the determination of competency to stand trial. Mentally retarded criminal offenders are often portrayed as aggressive, violent, and sexually promiscuous. This study examines the interrelationship of mental retardation, violent behavior, and a judge's determination on competency to stand trial among 288 mentally retarded criminal defendants. Results show that the proclivity toward violent behavior is not correlated with the severity of mental retardation among retarded criminal defendants and the retarded defendant's criminality (violent or non-violent) has no effect on a judge's competency determination.

Maladaptive behaviour in Prader‐Willi syndrome in adult life

Thirty adults with Prader-Willi syndrome (PWS) were compared with 30 adults with non-specific learning disability matched for age, sex and severity of mental retardation. Maladaptive behaviour was assessed with the Aberrant Behavior Checklist (ABC), a 58-item structured interview which rates behaviours from 0 (not a problem) to 3 (severe problem) and which yields five factors (I) irritability, agitation; (II) lethargy, withdrawal; (III) stereotypic behavior; (IV) hyperactivity, non-compliance; and (V) inappropriate speech). The PWS sample had significantly higher factor I (P < 0.001) and factor V (P < 0.05) scores. The PWS sample had mean scores above 1 for 17 ABC items; the contrast subjects had no mean scores above 1. The factor I scores for the PWS sample were similar to those of inpatients in hospital facilities for adults with mental retardation and mental illness or severely challenging behaviour. The results support previous work, and extend it by suggesting that temper tantrums, self-injury, impulsiveness, lability of mood, inactivity and repetitive speech are characteristic behaviours in PWS in adult life. Studies of the reasons for heterogeneity in behaviour are now needed.

Facial emotion recognition by persons with mental retardation: A review of the experimental literature

This paper provides an exhaustive review of emotion research in mental retardation, namely the recognition of facial emotion expressions. 21 experimental studies were identified and reviewed for methodological characteristics. The literature was further explored for evidence concerning the relationships between emotion recognition skills and the severity of mental retardation, gender, chronological age, and concurrent mental illness.

USE OF ICD‐10 RESEARCH DIAGNOSTIC CRITERIA TO CATEGORISE PSYCHIATRIC AND BEHAVIOURAL ABNORMALITIES AMONG PEOPLE WITH LEARNING DISABILITIES: THE WEST MIDLANDS FIELD TRIAL

AbstractICD‐10 Diagnostic Criteria for Research (DCR) based on the Clinical Descriptions and Diagnostic Guidelines for Mental and Behavioural Disorders were used to assign diagnoses to 38 people with mental retardation (MR) who had additional behavioural or psychiatric disorders. Problems were encountered with criteria for schizophrenia and related disorders. Recommendations were made regarding some diagnostic criteria, the method of coding diagnoses, and the need for additional guidance when classifying disorders associated with MR.Multiaxial classification during the field trial allowed mental and physical health problems and the severity of MR to be summarised in a standard format, assisting record keeping and the communication of information. The DCR represent an advance on previous diagnostic systems, and with additional axes (now being developed for use with a MR fascicle) will be a useful research tool. Psychiatric diagnoses and classificatory systems still suffer from the lack of external validating criteria or specific treatment responses for many disorders within them, and this poses special problems when the person with the disorder has difficulties with communication.

Double cortex syndrome: Electroclinical study of three cases

We describe three female patients (aged 10, 11 and 21 years) with a Magnetic Resonance appearance of band heterotopia, a diffuse neuronal migration disorder, also known as double cortex syndrome. The clinical picture was characterized by the association of epilepsy and mental retardation in all three cases, as has been previously described in patients with double cortex syndrome. The epileptic syndrome (Lennox-Gastaut syndrome in one case, and symptomatic partial epilepsy in the other two), the response to medical treatment, and the severity of mental retardation were markedly different in the three patients. No clear-cut relationship was found between the clinical picture and the severity of the neuronal migration disorder, as revealed by magnetic resonance imaging. In the three cases, EEG shares some common features: multifocal epileptic activity with frequent bilateral diffusion, and high-amplitude anterior fast activity, intermingled in two patients with bursts of repetitive spikes.