Capute and Accardo's Neurodevelopmental Disabilities in Infancy and Childhood v. I; Neurodevelopmental Diagnosis and Treatment - Hardcover

Ann W. Cox, Ph.D.
Director, National Professional
Development Center on Autism Spectrum Disorder
Frank Porter Graham Child
Development Institute
University of North Carolina at Chapel Hill
Chapel Hill, North Carolina

Louis Pellegrino, M.D., is a pediatrician who completed subspecialty training in Neurodevelopmental Pediatrics at the University of Rochester, New York. Following his fellowship training, he joined the faculty at the University of Pennsylvania School of Medicine as an assistant professor and was Medical Director of the Cerebral Palsy Program at The Children's Hospital of Philadelphia and Children's Seashore House. He is now Assistant Professor of Clinical Pediatrics at the University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School. He has written extensively on the subject of cerebral palsy and maintains cerebral palsy as a primary focus in his clinical, teaching, and academic pursuits, working in a variety of medical and educational settings in collaboration with many different professionals who devote themselves to the care of children with developmental disabilities. Dr. Pellegrino is board-certified in pediatrics and is a fellow of the American Academy of Pediatrics. He is a member of the American Academy of Pediatrics, the American Academy of Cerebral Palsy and Developmental Medicine, and the Society for Developmental Pediatrics. He lives in Hillsborough, New Jersey with his wife, Joan, and daughter, Elizabeth.

Pasquale J. Accardo, M.D., is Professor of Pediatrics at Virginia Commonwealth University in Richmond. He received his medical degree from Downstate Medical Center, Brooklyn, New York; completed his pediatric residency at James Whitcomb Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, and obtained his developmental pediatrics training at the John F. Kennedy Institute for Handicapped Children (now called the Kennedy Krieger Institute), an affiliate of Johns Hopkins University School of Medicine, Baltimore, Maryland. He is subcertified in neurodevelopmental disabilities in pediatrics by the American Board of Pediatrics. Dr. Accardo is the author and editor of several books including Attention Deficit Hyperactivity Disorder: The Clinical Spectrum (York Press, 2001); Austim: Clinical and Research Issues (York Press, 2000), and Developmental Disabilities in Infancy and Childhood, Second Edition, Volumes I and II (Paul H. Brookes Publishing Co., 1996).

Excerpted from Chapter 1 of Capute & Accardo's Neurodevelopmental Disabilities in Infancy and Childhood, Third Edition: Volume I. Neurodevelopmental Diagnosis and Treatment, edited by Pasquale J. Accardo, M.D.

Copyright© 2008 by Paul H. Brookes Publishing Co. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.

Implicit in the term developmental is the effect of time. Development is a rate phenomenon. Even though a child's developmental rate may appear stable, the component behaviors exhibit a complex evolution over time. The resulting interweaving of continuity and change can appear confusing and may complicate both diagnosis and prognosis. An example of a child with attention-deficit/ hyperactivity disorder (ADHD) and a specific learning disability will help clarify the difficulties (Figure 1.1).

Whereas severe neurodevelopmental disorders are easy to diagnose, with appropriate intervention and support typically initiated in early infancy, milder central nervous system (CNS) impairment is frequently misinterpreted by both professionals and parents as inadequate parenting. Regardless of how challenging the irritability of an infant is to parents, the subsequent clumsiness, disarticulation, and hyperactivity of the toddler tend to be viewed as an entirely new set of problems-and one that reconfirms the perception of parental inadequacy. Preschool behavior problems can set the stage for misinterpreting the academic underachievement that follows. By the time an accurate, comprehensive diagnosis is made, secondary emotional complications such as learned helplessness and possibly depression may render late intervention more difficult.

Underlying any ostensible change in the condition of a child with a neurodevelopmental disability is the permanent CNS impairment. The more severe the degree of intellectual disability, the more stable the intelligence quotient (IQ) over time. Disorders of attention and learning (disorders of higher cortical functioning) also exhibit continuity over time; for example, fairly constant rates of reading acquisition are reported for specific learning disorder in reading. The persistence of the neurodevelopmental disability into adulthood contributes to the impact of secondary emotional diagnoses. Although the underlying CNS pathology remains constant, both the manner in which a neurodevelopmental disability presents clinically and the priorities on the child's problem list will change over time. Helping families and involved professionals comprehend this evolving temporal expression represents a major goal of neurodevelopmental pediatrics. Before breaking up the process of neurodevelopment into its phenomenological components, it is necessary to stress the importance of the forest over the trees. There is effectively no practical limit to the potential number of gene defects and organic brain syndromes that could contribute to neurodevelopmental disabilities, nor is there any anticipated ceiling on the number of odd and atypical behaviors, splinter skills, and unique stereotypies that may at first defy explanation. However, understanding and interpretation of the global pattern and what influences it represent the fundamental goals of neurodevelopmental pediatrics. The number of basic patterns is quite limited, but variety and novelty are not absent from their presentations. Unexpected curves have been described, and the diversity hidden within many rare genetic syndromes is only beginning to be explored (Figure 1.2). The roots of this diversity lie in the interaction among four levels or paradigms of the developmental process: 1) the three developmental phenomena of delay, dissociation, and deviance; 2) the streams of development; 3) the spectrum and continuum of developmental disorders; and 4) patternological diagnosis.

What mothers worry most about in young children are a perceived lateness in achieving certain developmental milestones and an unevenness or peculiarity in the way their children achieve these milestones. These parental concerns appropriately presume the normative, orderly, and sequential process of child development within well-recognized age cutoffs. In addressing such parental concerns in a clinically responsible manner, the neurodevelopmental pediatrician attempts to understand and interpret both individual milestones and milestone sequences in terms of delay, dissociation, and deviance.

Developmental quotient (DQ) is used to quantify lags in development. This consists simply of a ratio: the child's functional age equivalent in one or more areas of development divided by the child's chronological age. DQ may be perceived to imply rate—a child with a DQ of 50 in expressive language could easily be assumed to have acquired milestones in speech at half the rate of his or her typically developing peers. This is a potentially misleading interpretation as the rate may have been stable over time, accelerated, or altered by regression (see Figure 1.2). Detailed developmental history and multiple assessments separated in time are required to determine a clinically predictive developmental rate.

Delay refers to a significant lag in one or more areas of development, and sometimes a global delay across all areas of development. When using a DQ to quantitate the degree of delay, cutoff points for concern, further evaluation, and intervention will depend on any concurrent medical diagnoses, the age of the child, previous therapeutic response, and the specific areas of delay. If an infant is progressing at or below a DQ of 80 and this degree of delay is confirmed on two consecutive examinations, serious consideration should be given to a comprehensive neurodevelopmental assessment. If the DQ is 60 or below in any single area of development, then a full assessment is indicated. Global retardation refers to a DQ of 70 or less in all of the streams of development; in infancy, it presents with a DQ below 70 in both the language and problem-solving components of assessments such as The Capute Scales (see Chapter 19, this volume).

The degree of delay has biological implications. For children with DQs below 50 in a given area, it is often easy to find a cause through evaluation for organic etiology, even if it is "presumed genetic syndrome." However, this can contribute to a misunderstanding of the role of organic CNS damage in developmental delay by presuming the precedence of emotional, sociocultural, or environmental factors alone for children with DQs in the 50-75 range. Logic and common sense would suggest that mild but real brain damage leading to less severe neurodevelopmental disabilities should occur much more frequently than severe brain damage and severe disabilities. Recent research in twins has indeed described a much higher percentage of people with mild intellectual disabilities and slow learners, or those with " borderline" intellectual disabilities, as having genetic-based etiologies. Thus, although severity of delay appears to be directly correlated with the ease of identifying a specific organic etiology, the absence of an identified specific etiology in cases of milder delays does not necessarily imply nonorganic etiologies (Table 1.1).

Dissociation is manifested by a difference between the developmental rates of two streams of development, with one stream significantly more delayed. If severe intellectual disability is present, language is often more delayed than motor-dependent skills. In communication disorders and pervasive develop mental disorders, language abilities typically lag behind visual-motor problem solving. The dissociation phenomenon is most often observed in older children with learning disabilities. In these children, school underachievement reflectsanunderlying...