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Executive Function Part 2 Development, Dysfunction, Approach to Evaluation. Puja Patel March 21, 2013. Development. Know healthy brain development for better understanding of functional recovery and outcome in children with brain lesions
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Executive Function Part 2Development, Dysfunction, Approach to Evaluation Puja Patel March 21, 2013
Development • Know healthy brain development for better understanding of functional recovery and outcome in children with brain lesions • PFC is especially vulnerable to brain lesions due to its extended developmental trajectory • Adults rely on PFC; cognitive fnc less localized in children • Development of executive skills progresses in spurts
Development of Foundational Executive Skills Selective attention • Elements formed in first years of life • Develops considerably between 2.5–6 years, ceiling effects by 6 years • Another peak from 8–10 years of age; skills functioning reliably • Less rapid improvement from 10 years to early adolescence
Development of Foundational Executive Skills Inhibition • Emerges as early as 7–8 months of age, but not consistently employed reflecting skill immaturity • By age 4, signs of successful performance on simple and complex inhibition tasks • Improves from age 5-8, particularly for tasks that combine inhibition and WM • Complete by age 10; mastery by age 12
Development of Foundational Executive Skills WM • Improvement during the preschool years • By age 6 executive components sufficient to be used during complex tasks • Linear increase from ages 4 to 14 and a leveling off between ages 14 and 15 across nearly all WM tasks examined
Development of Foundational Executive Skills Planning • Simple planning in children as young as 3 • Greatest period of development between ages of 5-8 • By age 7-11, strategic behavior and reasoning abilities leads to moreorganized and efficient planning • Reach adult levels between the ages of 9-13 • Improvements continue into early adulthood period
Development of Foundational Executive Skills Shifting • Preschoolers can shift between two simple response sets when demands on inhibition are reduced • Inhibition and WM interrelated; prerequisites for successful shifting • Ability to perform on complex shifting tasks improves from age 7-9 • By middle adolescence, reaches adult-like levels
Risky Behaviors in Adolescence • Imbalance of development of prefrontal regions relative to subcortical regions (limbic system; involved in desire and fear) maximal during adolescence
Executive dysfunction in the clinical setting • EF is multi-dimensionalpresents in a variety of ways • Lesions affecting the prefrontal-subcortical system can have delayed manifestations in children • TBI in children vs adults • EF still developing throughout childhood and adolescents, and children have fewer well established routines and skills to rely upon
EF in Clinical Practice Neuropsychiatric Syndromes that involve Executive Dysfunction
Autism • Deficits in communication, social interactions, presence of restricted interests and repetitive behaviors • Related to WM and cognitive flexibility • “stuck-in-set” perseveration, difficulty in the inhibition of a prepotent response and planning • BUT may be preservation vs compensatory mechanismsresponse inhibition and WM intact
ADHD • Developmentally inappropriate symptoms of inattention, impulsivity and motor restlessness • EF deficits: • inhibitory control and suppression of overlearned responsesimpulsive • sustained attentiondistractible • WMforgetful, slow processors • planning and organizing • monitoring and regulating self-actionfail to modify behaviors
Disruptive behavioral disorders (CD/ODD) • Oppositional, aggressive, and antisocial behaviors • fMRI shows underactivation of R-FOC (involved in sense of euphoria, uncontained responsiveness to impulses, behavioral disinhibition) • compromised processing of reward cues • Impaired inhibition after controlling for attention • Response perseveration
Frontal Lobe Epilepsy • Impacts wide scale of cognitive domains; impaired EF and attention most frequent • RFs unclear • Age of onset, sz frequency, localization, ↑AEDs, duration • Behavioral disturbances can be ictal, interictal, or postictal • FL/executive dysfunction in up to 84% of children and adolescents with TLE! • Wider anatomic and functional network connects temporal and FL • Hypometabolism of prefrontal regions in TLE ? protection against epileptiform discharge propagation by FL function inhibition
Approach to Evaluation • Accurate diagnosis is basis for effective management plan • Challenges of diagnosis • Delayed manifestations • Identifying threshold of childish behavior • Comorbid LD or severe behavioral problems
Approach to Evaluation Multidisciplinary approach • Psychological • Intelligence testing • Personality assessment • Behavioral observation • Achievement testing
Approach to Evaluation • Neuropsychological: sensory processes, motor systems, attention and concentration, learning and memory, language, visuospatial processing, conceptual skills, executive functions • EF assessment challenging • Not easily measured in office setting • Formal testing may not correlate to daily life • Limitless opportunities for dysfunction • Parents and teachers should describe problems in real word • Multiple tests (Dr. Goldman)
Approach to Evaluation • Psychiatry • Prefrontal EF impairment important feature of many psychiatric disorders listed in the DSM-IV • Treat psychiatric symptoms vs EF deficits vs both • Neurologic exam to r/o focal structural lesions, genetic/metabolic disorders • Normal exam DOES NOT r/o prefrontal lesion
Interventional Methods • Delayed responding • Increases time devoted to objective goal-setting, systematic screening for appropriate responses, response selection and enactment • Plan-Execute-Repair (P-E-R) • Thinking maps to aid organizational strategies • Self talk to enhance skills related to inhibition, stress/anxiety, anger management, appropriate goal setting • Self-regulated strategy development (SRSD) intervention model to enhance self-regulation and increase positive self-concept