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Dive into the research topics where Peter K. Isquith is active.

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Featured researches published by Peter K. Isquith.


Child Neuropsychology | 2002

Profiles of Everyday Executive Function in Acquired and Developmental Disorders

Gerard A. Gioia; Peter K. Isquith; Lauren Kenworthy; Richard M. Barton

Executive function profiles were examined within and between several clinical disorders via the multidomain Behavior Rating Inventory of Executive Function (BRIEF; Gioia, Isquith, Guy, & Kenworthy, 2000). Parent ratings of children with Inattentive and Combined types of Attention-Deficit/Hyperactivity Disorder (ADHD-I, ADHD-C), Autistic Spectrum Disorders (ASD), moderate and severe Traumatic Brain Injury (TBI), and Reading Disabilities (RD) were compared with controls. Profile analysis revealed significant (p <.01) and substantial (? 2 >.10) differences in global elevations and in profile of scale elevations between diagnostic groups. ASD, ADHD-I and ADHD-C groups exhibited greater elevations across the BRIEF scales than did RD and Severe TBI groups, who were in turn more elevated than Moderate TBI and Control groups. The ADHD-C group was unique in its frequency and severity of inhibitory deficits, while the ASD group was distinguishable by its deficits in flexibility. Within diagnostic groups, relative risk for executive dysfunction was calculated with variability present in the frequency of clinically elevated scales. While the BRIEF captures executive profiles characteristic of specific disorders in the clinical setting, it is not diagnostic in its own right and is best used within the context of a broad based evaluation.


Developmental Neuropsychology | 2004

Ecological assessment of executive function in traumatic brain injury.

Gerard A. Gioia; Peter K. Isquith

Executive dysfunction is a common outcome in children who have sustained traumatic brain injury (TBI). Appropriate assessment of these complex interrelated regulatory functions is critical to plan for the necessary interventions yet present a challenge to our traditional methodologies. Ecological validity has become an increasingly important focus in neuropsychological assessment with particular relevance for the executive functions, which coordinate ones cognitive and behavioral capacities with real-world demand situations. The Behavior Rating Inventory of Executive Function (BRIEF) was developed to capture the real-world behavioral manifestations of executive dysfunction. Its development and various forms of validity, including ecological validity, are described. Application of the BRIEFs methodology to the assessment of executive dysfunction in TBI is provided. We advocate a multilevel approach to understanding executive function outcome in TBI, including traditional test-based measures of executive function, real-world behavioral manifestation of executive dysfunction, and the environmental system factors that impact the child. In this model, ecologically valid assessment of executive dysfunction provides an important bridge toward understanding the impact of component-level (i.e., test-based) deficits on the childs everyday adaptive functioning, which can assist the definition of targets for intervention.


Child Neuropsychology | 2002

Confirmatory Factor Analysis of the Behavior Rating Inventory of Executive Function (BRIEF) in a Clinical Sample

Gerard A. Gioia; Peter K. Isquith; Paul D. Retzlaff; Kimberly Andrews Espy

Evidence for the validity of the Behavior Rating Inventory of Executive Function (BRIEF; Gioia, Isquith, Guy, & Kenworthy, 2000) based on internal structure was examined in a sample of children with mixed clinical diagnoses via maximum likelihood confirmatory factor analysis. Four alternative factor models of childrens executive function, based on current theories that posit a unidimensional versus fractionated model (Rabbitt, 1997; Shallice & Burgess, 1991), using the revised 9-scale BRIEF configuration that separates two components of the Monitor scale, were examined for model fit. A 3-factor structure best modeled the data when compared directly with 1-, 2-, and 4-factor models. The 3-factor model was defined by a Behavior Regulation factor consisting of the BRIEF Inhibit and Self-Monitor scales, an Emotional Regulation factor consisting of the Emotional Control and Shift scales, and a Metacognition factor composed of the Working Memory, Initiate, Plan/Organize, Organization of Materials, and Task-Monitor scales. The findings support a fractionated, multi-component view of executive function as measured by the BRIEF.


Journal of Clinical Oncology | 1995

Cognitive sequelae of treatment in childhood acute lymphoblastic leukemia: cranial radiation requires an accomplice.

Deborah P. Waber; Nancy J. Tarbell; Diane L. Fairclough; K Atmore; R Castro; Peter K. Isquith; F Lussier; Ivonne Romero; P J Carpenter; M Schiller

PURPOSE We evaluated cognitive sequelae of treatment for childhood acute lymphoblastic leukemia (ALL). CNS therapy consisted of cranial irradiation (CRT) or no radiation. Children were also randomized to single intravenous high-dose methotrexate (HD-MTX) or conventional-dose methotrexate (CD-MTX) during induction, and all patients received intrathecal (IT) and systemic continuation chemotherapy. PATIENTS AND METHODS Sixty-six patients treated for ALL on Dana-Farber Cancer Institute protocol 87-01 were evaluated by standardized cognitive and achievement tests. These children had been assigned at diagnosis to a standard-risk (SR) or high-risk (HR) group and received no CRT or 18 Gy CRT, respectively. All patients were randomized to receive MTX during remission induction, either as CD-MTX (40 mg/m2) or HD-MTX (4 g/m2) with leucovorin rescue. RESULTS There was no difference in cognitive outcomes between radiated and unirradiated patients (P > .4). However, the HD-MTX/CRT combination was associated with decreased intelligence quotient (IQ estimate, 9.3 points) for girls only (P < .08). A specific deficit in verbal coding and memory was documented for all patients (P < .0001). CONCLUSION We conclude the following: (1) 18 Gy CRT per se was not an independent toxic agent for cognitive outcome; (2) HD-MTX during induction was associated with IQ decline in girls, but only when it was followed by CRT; and (3) impairment of verbal memory and coding was a consistent finding that was independent of CRT, which implicates some component of chemotherapy, possibly prednisone, as a CNS toxin.


British Journal of Sports Medicine | 2009

Which symptom assessments and approaches are uniquely appropriate for paediatric concussion

Gerard A. Gioia; J C Schneider; Christopher G. Vaughan; Peter K. Isquith

Objective: To (a) identify post-concussion symptom scales appropriate for children and adolescents in sports; (b) review evidence for reliability and validity; and (c) recommend future directions for scale development. Design: Quantitative and qualitative literature review of symptom rating scales appropriate for children and adolescents aged 5 to 22 years. Intervention: Literature identified via search of Medline, Ovid-Medline and PsycInfo databases; review of reference lists in identified articles; querying sports concussion specialists. 29 articles met study inclusion criteria. Results: 5 symptom scales examined in 11 studies for ages 5–12 years and in 25 studies for ages 13–22. 10 of 11 studies for 5–12-year-olds presented validity evidence for three scales; 7 studies provided reliability evidence for two scales; 7 studies used serial administrations but no reliable change metrics. Two scales included parent-reports and one included a teacher report. 24 of 25 studies for 13–22 year-olds presented validity evidence for five measures; seven studies provided reliability evidence for four measures with 18 studies including serial administrations and two examining Reliable Change. Conclusions: Psychometric evidence for symptom scales is stronger for adolescents than for younger children. Most scales provide evidence of concurrent validity, discriminating concussed and non-concussed groups. Few report reliability and evidence for validity is narrow. Two measures include parent/teacher reports. Few scales examine reliable change statistics, limiting interpretability of temporal changes. Future studies are needed to fully define symptom scale psychometric properties with the greatest need in younger student-athletes.


Pediatrics | 2006

Relationship of Surgical Approach to Neurodevelopmental Outcomes in Hypoplastic Left Heart Syndrome

William T. Mahle; Karen J. Visconti; M. Catherin Freier; Stephen M. Kanne; William G. Hamilton; Angela Sharkey; Richard Chinnock; Kathy J. Jenkins; Peter K. Isquith; Thomas G. Burns; Pamela C. Jenkins

OBJECTIVE. Two strategies for surgical management are used for infants with hypoplastic left heart syndrome (HLHS), primary heart transplantation and the Norwood procedure. We sought to determine how these 2 surgical approaches influence neurodevelopmental outcomes at school age. METHODS. A multicenter, cross-sectional study of neurodevelopmental outcomes among school-aged children (>8 years of age) with HLHS was undertaken between July 2003 and September 2004. Four centers enrolled 48 subjects, of whom 47 completed neuropsychologic testing. Twenty-six subjects (55%) had undergone the Norwood procedure and 21 (45%) had undergone transplantation, with an intention-to-treat analysis. The mean age at testing was 12.4 ± 2.5 years. Evaluations included the Wechsler Abbreviated Scale of Intelligence, Clinical Evaluation of Language Fundamentals, Wechsler Individual Achievement Test, and Beery-Buktenica Developmental Test of Visual-Motor Integration. RESULTS. The mean neurocognitive test results were significantly below population normative values. The mean full-scale IQ for the entire cohort was 86 ± 14. In a multivariate model, there was no association of surgical strategy with any measure of developmental outcome. A longer hospital stay, however, was associated significantly with lower verbal, performance, and full-scale IQ scores. Aortic valve atresia was associated with lower math achievement test scores. CONCLUSIONS. Neurodevelopmental deficits are prevalent among school-aged children with HLHS, regardless of surgical approach. Complications that result in prolonged hospitalization at the time of the initial operation are associated with neurodevelopmental status at school age.


Journal of Head Trauma Rehabilitation | 2008

Improving identification and diagnosis of mild traumatic brain injury with evidence: psychometric support for the acute concussion evaluation.

Gerard A. Gioia; Michael W. Collins; Peter K. Isquith

ObjectivesA dearth of standardized assessment tools exists to properly assess and triage mild traumatic brain injury (mTBI) in primary care and acute care settings. This article presents evidence of appropriate psychometric properties for the Acute Concussion Evaluation (ACE), a new structured clinical interview. ParticipantsParent informants of 354 patients, aged 3 to 18 years, with suspected mTBI completed the ACE via telephone interview. MeasureAcute Concussion Evaluation. ResultsEvidence is presented for appropriate item-scale membership, internal consistency reliability as well as content, predictive, convergent/divergent, and construct validity of the ACE symptom checklist. ConclusionsOverall, the ACE symptom checklist exhibits reasonably strong psychometric properties as an initial assessment tool for mTBI.


Applied neuropsychology. Child | 2013

Contribution of Rating Scales to the Assessment of Executive Functions

Peter K. Isquith; Robert M. Roth; Gerard A. Gioia

Abstract Executive functions play a vital role in the everyday functioning of healthy individuals across the lifespan and have been implicated in a wide variety of clinical conditions. Historically, the assessment of executive functions in clinical and research settings relied on performance-based measures. A number of authors have argued, however, that such measures have limited ecological validity. In response to this limitation of performance-based measures, several rating scales have been developed that seek to gauge a persons or their knowledgeable informants (e.g., parent or teacher) subjective view of executive functioning in everyday life. In this article we review evidence supporting the use of rating scales of executive function including profiles in clinical populations, biological correlates, relationships to relevant outcome measures such as academic performance, and correlations with performance-based measures. We conclude that performance-based and rating scale measures provide complementary information with respect to a childs executive functions, offering a more comprehension view than either approach alone.


Community Mental Health Journal | 2005

Psychosocial treatment of children in foster care: a review.

Robert Racusin; Arthur C. Maerlender; Anjana Sengupta; Peter K. Isquith; Martha B. Straus

A substantial number of children in foster care exhibit psychiatric difficulties. Recent epidemiological and historical trends in foster care, clinical findings about the adjustment of children in foster care and adult outcomes are reviewed, followed by a description of current approaches to treatment and extant empirical support. Available interventions for these children can be categorized as either symptom-focused or systemic, with empirical support for specific methods ranging from scant to substantial. Even with treatment, behavioral and emotional problems often persist into adulthood resulting in poor functional outcomes. We suggest that self-regulation may be an important mediating factor in the appearance of emotional and behavioral disturbance in these children.


Journal of Head Trauma Rehabilitation | 2010

Executive Function in the Real World: BRIEF lessons from Mark Ylvisaker.

Gerard A. Gioia; Lauren Kenworthy; Peter K. Isquith

It is well established that brain injuries adversely affect the executive functions and their development. Mark Ylvisaker had a substantial impact on how we assess and treat children and adolescents with disrupted executive functions secondary to traumatic brain injury. He articulated core principles for effective assessment and intervention that emphasized the importance of real-world meaning and application. He taught us that assessment that captures a childs everyday functioning in the context of real-world demands is often more informative than traditional neuropsychological measures alone and that interventions that improve functioning in the real-world environment are most useful. His pragmatic model influenced our own efforts to measure executive function and to develop intervention systems for children with executive function deficits. This article reviews the development of the Behavior Rating Inventory for Executive Function as an approach to ecological assessment of children and adolescents with traumatic brain injury. As we take what we learned from Mark Ylvisaker, it becomes increasingly apparent that our assessment and intervention methods, especially as related to the executive functions, demand an everyday, real-world context.

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Gerard A. Gioia

George Washington University

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Lauren Kenworthy

Children's National Medical Center

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Kimberly Andrews Espy

University of Nebraska–Lincoln

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Arthur C. Maerlender

University of Nebraska–Lincoln

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Deborah P. Waber

Boston Children's Hospital

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