ISSN:1080-4013    

DOI:10.1002/(SICI)1098-2779(1998)4:1<1::AID-MRDD1>3.0.CO;2-U

出版商:John Wiley&Sons, Inc.    

年代:1998

数据来源: WILEY

摘要:

AbstractMental retardation is not a medical diagnosis, but serious cognitive limitation is a neurologic symptom that requires medical assessment. Severe mental retardation is medically equivalent to brain damage or brain dysfunction. The new American Association on Mental Retardation definition of mental retardation is not compatible with a biomedical approach. There exist no generally accepted clinical practice guidelines for the medical assessment of mental retardation and developmental delay. The physician who is participating in the assessment needs to investigate developmental processes and possible medical etiologies. Attempts should be made to assess language and nonverbal problem‐solving abilities separately, even in infancy and early childhood. A number of factors from the history (e.g., fetal hypoactivity) and physical examination (e.g., minor dysmorphic features) can be quite useful components of the assessment. More problems and unanswered clinical questions occur at the boundary between mild mental retardation and developmental delay (development that is slow but not quite slow enough to qualify for a formal diagnosis of mental retardation). Current medical research is fragmenting mental retardation into diverse and quite specific syndromes. MRDD Research Reviews 1998;4:2‐5. © 1998 Wiley‐Lis

ISSN:1080-4013    

DOI:10.1002/(SICI)1098-2779(1998)4:1<2::AID-MRDD2>3.0.CO;2-T

出版商:John Wiley&Sons, Inc.    

年代:1998

数据来源: WILEY

摘要:

AbstractMental retardation (MR) in children is a heterogeneous group of disorders with varied causes. This article describes well‐known causes of MR and epidemiologically established risk factors. Approximately 43–70% of children with severe MR (i.e., intelligence quotient [IQ] of<50) have a known cause of MR, compared with 20–24% of those with mild MR (IQ of 50–70). Investigators will need to continue refining research methods to define homogeneous groups for the further identification of causes of MR in children. Discovery of additional genetic factors and their causal link to MR will continue to diminish the proportion of MR with unknown causes. Areas of MR research that will be particularly challenging are (1) the relationship between socioeconomic factors and other risk factors or causes of MR and (2) how much of the variation in prevalence of MR associated with prenatal or perinatal biologic insults is due to differences in the quality of intervening care and the postnatal environment. MRDD Research Reviews 1998;4:6–13. Published 1998 Wiley

ISSN:1080-4013    

DOI:10.1002/(SICI)1098-2779(1998)4:1<6::AID-MRDD3>3.0.CO;2-P

出版商:John Wiley&Sons, Inc.    

年代:1998

数据来源: WILEY

摘要:

AbstractThe early identification of communication disorders and mental retardation necessitates an assessment measure that differentiates these two disorders in infancy and early childhood. The Cognitive Adaptive Test/Clinical Linguistic and Auditory Milestone Scale (CAT/CLAMS) was devised to diagnose global cognitive delay and language delay by evaluating language and problem‐solving skills independently. It does so in an efficient and accurate manner that differentiates type and degree of delay. The use of CAT/CLAMS is well established in populations of children thought to be either delayed or at risk of delay. This article reports the use of the CAT/CLAMS for identifying children with language or cognitive delay (≤75% of expected) in a cohort of asymptomatic children with no known risk for delay. When compared with the Bayley Scales of Infant Development II, the CAT/CLAMS was effective in identifying delay. In a primary care setting, the CAT/CLAMS proved to be a practical, reliable assessment tool for identifying and quantifying delays in language and cognition in children 36 months of age or younger. MRDD Research Reviews 1998;4:14–19. © 1998 Wiley‐L

ISSN:1080-4013    

DOI:10.1002/(SICI)1098-2779(1998)4:1<14::AID-MRDD4>3.0.CO;2-X

出版商:John Wiley&Sons, Inc.    

年代:1998

数据来源: WILEY

摘要:

AbstractIncreasing research efforts and rapidly expanding knowledge in the neuroscientific foundations of learning, memory, and developmental disabilities have provided insights into the normal development and plasticity of neuronal circuits. Likewise, the neurobiologic and molecular genetic substrates of developmental disabilities and mental retardation syndromes are unfolding and leading to potential manipulations of these disorders in children with developmental disabilities. This review highlights the mechanisms of synaptic plasticity, long‐term potentiation, and molecular mechanisms of memory. Some mental retardation syndromes due to abnormal genetic regulation are mentioned. MRDD Research Reviews 1998;4:20–25. © 1998 Wiley‐Lis

ISSN:1080-4013    

DOI:10.1002/(SICI)1098-2779(1998)4:1<20::AID-MRDD5>3.0.CO;2-0

出版商:John Wiley&Sons, Inc.    

年代:1998

数据来源: WILEY

摘要:

AbstractHaving an appreciation for neurobiologic complexity in developmentally disabled children and adolescents with behavior disorders improves our ability to treat them with drugs that have become increasingly specific in their effects. Reductionist analysis of phenotypic and genotypic disorders improves our understanding of the pathogenesis of unique patterns of adverse behaviors. Although drugs can be effective for treating specific behaviors, the cerebral mechanisms underlying these behaviors are not simple or linear in their pathways from genotype to phenotype. Our emerging knowledge about Lesch‐Nyhan disease demonstrates unexpected complexity from a single abnormal gene of purine metabolism and its diverse effects on cells, receptors, and neurotransmitters that produce characteristic self‐injurious behaviors. Several hypotheses for pathogenesis suggest ways that a defective gene might affect the developing brain and strategies for treatment. For disorders that have several abnormal genes, such as autism and bipolar disorder, biologic effects are likely to be even more complex due to gene interactions and compounded with added environmental effects, learning, and experience. There is a high incidence of comorbidity in conditions that affect behavior in children with mental retardation and developmental disabilities. Accurate diagnoses and follow‐up are essential for advanced neuropharmacology to be effective. Guidelines for the evaluation and treatment of patients who have comorbid neuropsychiatric disorders are suggested. MRDD Research Reviews 1998;4:26–35. © 1998 Wiley

ISSN:1080-4013    

DOI:10.1002/(SICI)1098-2779(1998)4:1<26::AID-MRDD6>3.0.CO;2-V

出版商:John Wiley&Sons, Inc.    

年代:1998

数据来源: WILEY

摘要:

AbstractDue in part to the favorable demographics of Alzheimer's disease in the general population, pharmaceutical companies worldwide are aggressively pursuing the research and development of cognitive‐enhancing drugs. There have been two rather noteworthy successes in recent years as both tacrine and donepezil have received FDA approval as useful pharmacologic treatment for Alzheimer's disease. Given what is now known regarding the critical periods for synaptic development and the organization of large‐scale neuronal circuits in the developing cerebral cortex, it appears that there may exist a window of opportunity during which specifically targeted, pharmacologic intervention could exert a significantly favorable biologic effect during development. Pharmacologic agents that increase the brain's responsiveness to activity‐dependent plasticity may be of particular therapeutic benefit to children with some forms of mental retardation. Currently available medications designed for use in adults with dementia have targeted cholinergic neurotransmission and to a lesser degree glutamatergic neurotransmission, both of which play important roles in learning, memory, and developmental organization of the brain. The “cholinergic hypothesis” of memory dysfunction has done much to focus research efforts on cholinergic strategies for the enhancement of learning and memory. Medications that affect cholinergic neurotransmission include acetylcholine precursors, acetylcholinesterase inhibitors, and muscarinic agonists. Drugs targeting the glutamatergic system are among the most novel modalities in treating disorders of memory and learning. These drugs have grown in proportion to advancements in our understanding of the physiologic and pathologic effects of this important excitatory amino acid neurotransmitter. The most important class of medications that affect glutamatergic neurotransmission include nootropics (ampakines) and glycinergic compounds. The rationale for using drugs that act on the glutamatergic system during critical periods for neuronal organization depends, in part, on the degree to which abnormal dendritic spine morphology and/or function associated with some forms of mental retardation is mediated by dysfunctional glutamatergic neurotransmission. It also depends to what degree spine morphology and/or function can be modified in these conditions. MRDD Research Reviews 1998;4:36–49. © 1998 Wil

ISSN:1080-4013    

DOI:10.1002/(SICI)1098-2779(1998)4:1<36::AID-MRDD7>3.0.CO;2-V

出版商:John Wiley&Sons, Inc.    

年代:1998

数据来源: WILEY

摘要:

AbstractIn the absence of curative therapy, and with treatment difficult and only partially successful, prevention plays a particularly important role in mental retardation. Research conducted during the past 40 years has identified new causes of mental retardation, new means of early diagnosis, and new ways of prevention. Prenatal diagnosis, newborn screening, dietary supplementation or restriction, hormone replacement, vaccination, and immunotherapy are just some of the techniques that have been applied to prevent mental retardation. Together, these interventions have slightly reduced the overall prevalence of mental retardation, and in some instances have nearly eliminated specific causes. Much remains to be done, including developing better means of early intervention for sociocultural mental retardation and convincing society of the value of investment in such approaches. In addition to these approaches, the research frontiers today are neurobiology, earlier prenatal diagnosis, fetal therapy, gene therapy, and reducing premature birth. The potential of these investigations makes the frontier of prevention research in mental retardation an exciting place to be. MRDD Research Reviews 1998;4:50–58. Published 1998 Wiley‐Liss,

ISSN:1080-4013    

DOI:10.1002/(SICI)1098-2779(1998)4:1<50::AID-MRDD8>3.0.CO;2-0

出版商:John Wiley&Sons, Inc.    

年代:1998

数据来源: WILEY