Biomedical subjects

Margaret Semrud-Clikeman

Publications and source records attributed to Margaret Semrud-Clikeman.

9 recordsLinked to original sources

PubMed2006

Volumetric MRI differences in treatment-naïve vs chronically treated children with ADHD.

OBJECTIVE: To determine if there are differences in the volume of the caudate and anterior cingulate cortex (ACC) between children with attention deficit hyperactivity disorder (ADHD) and controls, and if such differences are related to the subjects' history of stimulant treatment. METHODS: We performed a case-control study in an academic medical center. Twenty-one healthy controls, 16 children with ADHD, combined type with a history of stimulant treatment, and 14 children with ADHD, combined type treatment naïve, underwent structural MRI. All children with ADHD were medication-free at the time of the MRI. Regional hemispheric volumes (in cm3) of caudate and anterior cingulate cortex were determined. RESULTS: There were significant differences bilaterally on caudate volume for both ADHD groups vs controls, with no difference between the ADHD groups on either side. In contrast, the right ACC was significantly smaller for the ADHD-treatment naïve (ADHD/TN) group compared to the ADHD-treated (ADHD/Rx) and control group. The volume of left ACC approached significance contrast between ADHD/RX and ADHD/TN. There were no differences found between the ADHD/Rx and controls on the ACC volumes bilaterally. CONCLUSIONS: The results from this study indicate a relationship of previous treatment history with caudate and anterior cingulate volumetric changes in children with attention deficit hyperactivity disorder-combined type.

Adolescent↗

PubMed2006

Neuroimaging of inhibitory control areas in children with attention deficit hyperactivity disorder who were treatment naive or in long-term treatment.

OBJECTIVE: Difficulty with response inhibition is a cardinal symptom of attention deficit hyperactivity disorder (ADHD), combined type. Prefrontal and cingulate brain regions are known to be involved in inhibitory control. Event-related functional magnetic resonance imaging (fMRI) might establish if these regions differ in their activity in ADHD children relative to healthy comparison subjects. METHOD: Fifteen healthy comparison subjects and 17 children with ADHD, combined type, completed fMRI studies while performing the Stop Signal Task. Eight ADHD subjects were treatment naive; the remainder had a history of long-term treatment with stimulants, but they were medication free at the time of the fMRI. No subject had a learning disorder or a comorbid psychiatric condition (other than oppositional defiant disorder in the ADHD subjects). RESULTS: Both the ADHD and comparison subjects activated the right dorsolateral prefrontal cortex on "stop" trials relative to "go" trials; this increase was greater in ADHD subjects. When inhibition was unsuccessful (relative to successful inhibition), healthy comparison subjects strongly activated the anterior cingulate cortex and the left ventrolateral prefrontal cortex. In contrast, the ADHD subjects did not show these differences. Activations in treatment-naive and ADHD subjects treated in the long term did not differ significantly in any brain regions. CONCLUSIONS: In relation to comparison subjects, ADHD subjects failed to activate the anterior cingulate cortex and the left ventrolateral prefrontal cortex after unsuccessful inhibition. These findings appear in treatment-naive ADHD individuals and are unlikely to be an artifact of long-term treatment with stimulants or of abrupt termination of stimulants before imaging.

Adolescent↗

PubMed2006

Magnetic resonance imaging volumetric analysis of the putamen in children with ADHD: combined type versus control.

OBJECTIVE: Volumetric differences in the putamen of boys with ADHD combined subtype with psychopathic traits and controls are investigated. METHOD: The putamen in 24 archival magnetic resonance imaging scans of 12 boys in residential treatment with symptoms of ADHD and psychopathic traits and 12 community control boys are analyzed using Display software. RESULTS: There are no differences found in the total, left, and right putamen volumes across the ADHD or control group. A significant reversal of asymmetry across groups is found; children with ADHD more frequently have a smaller left putamen than right. In contrast, the control group more frequently has a smaller right than left putamen. CONCLUSION: A reversal of symmetry in the putamen (as found in the caudate) may relate to ADHD symptomology as well as to psychopathic traits.

Adolescent↗

PubMed2005

Growth hormone benefits children with 18q deletions.

Most individuals with constitutional deletions of chromosome 18q have developmental delays, dysmyelination of the brain, and growth failure due to growth hormone deficiency. We monitored the effects of growth hormone treatment by evaluating 23 individuals for changes in growth, nonverbal intelligence quotient (nIQ), and quantitative brain MRI changes. Over an average of 37 months, the treated group of 13 children had an average nIQ increase of 17 points, an increase in height standard deviation score of 1.7, and significant change in T1 relaxation times in the caudate and frontal white matter. Cognitive changes of this magnitude are clinically significant and are anticipated to have an effect on the long-term outcomes for the treated individuals.

Abnormalities, Multiple↗

PubMed2005

Cognitive ability predicts degree of genetic abnormality in participants with 18q deletions.

One of the most common chromosomal deletions is a loss of genetic material from the long arm of chromosome 18. Most individuals with this condition exhibit mental retardation (68%), yet previous attempts to link cognitive status to deletion size have not shown an association, possibly because cases with additional genetic abnormalities were included. We studied 46 participants ranging from 3 to 35 years of age who had a pure genetic abnormality by excluding those with mosaicism or complex genetic rearrangements. Our patients had terminal deletions ranging from a proximal breakpoint at 18q21.1 (greater genetic abnormality, larger deletion size) to a more distal breakpoint at 18q23 characterized with molecular genetic techniques. Cognitive ability, assessed with the age-appropriate measure (Bayley, 1993 , Differential Ability Scale, Wechsler Scales), ranged from IQ = 49 to 113, with a predominance of mild and moderate mental retardation. Using multivariate regression, deletion size breakpoint rank order was predicted by cognitive ability, age, and adaptive behavior (Vineland Adaptive Behavior Scales), accounting for 36% of the variance in deletion size. However, lower cognitive ability (beta = .34, p = .032) and younger age (beta = .296, p = .024) predicted a larger deletion size, but adaptive behavior (beta = .225, p = .15) did not. An additional multivariate regression showed that cognitive ability and age together accounted for 33% of the variance in deletion size, whereas univariate regression showed that cognitive ability accounted for 26% of the variance and age accounted for 11% of the variance. These findings suggest that degree of cognitive impairment is associated with genetic abnormality when a large sample of individuals with "pure" deletions of genetic material from chromosome 18 is examined.

Adaptation, Psychological↗

PubMed2005

Neuropsychological deficits in adolescents with conduct disorder and comorbid bipolar disorder: a pilot study.

OBJECTIVE: We report pilot data on neuropsychological deficits in aggressive juvenile offenders with and without bipolar disorder compared with each other and healthy controls. METHOD: We assessed 52 adolescents and their parent or guardians: 36 incarcerated juvenile offenders and 16 community controls using the Schedule for Affective Disorders and Schizophrenia for School Age Children, Present and Life-Time Version and a neuropsychological testing battery. All incarcerated subjects (n=34) met criteria for Conduct Disorder (CD); 26 are classified as Non-BD-CD, and eight with CD and Bipolar disorder (CD-BD). These subjects were compared to community controls (n=16) matched for age, gender, SES and ethnicity. RESULTS: Relative to controls, the Non-BD-CD subjects' impairments (p<0.05) were in cognitive ability, set shifting/inhibition, planning and verbal memory-language functioning. The CD-BD group displayed impairments (p<0.05) relative to controls in cognitive ability, set shifting, verbal memory-language functioning, and visuospatial tasks. The Non-BD-CD and CD-BD groups however did not display significant differences on most neuropsychological measures compared with each other. When we controlled for Attention Deficit Hyperactivity Disorder, the Non-CD-BP subjects continued to show deficits on Verbal measures where the CD-BD subjects maintained deficits in measures of cognitive ability, verbal measures and visual spatial tests. CONCLUSIONS: Juvenile offender with CD displayed a wide range of deficits on neuropsychological testing compared with controls. Although juvenile offenders with and without BD differed on their clinical presentation, differences on neuropsychological measures are not specific and may be related to comorbid diagnoses.

Adolescent↗

PubMed2005

Delinquency, hyperactivity, and phonological awareness: a comparison of adolescents with ODD and ADHD.

The incidence of reading disabilities in children with attention deficit hyperactivity disorder (ADHD) has been found at a higher proportion than would be expected by chance. This study explored the relationship between reading problems-comprehension and phonological awareness, and externalizing behaviors-hyperactivity (ADHD), and oppositional defiant disorder (ODD). One hundred boys from Central Texas area alternative education schools between the ages of 11 and 15 were grouped by categories: ADHD-Combined Type (ADHD:C), ODD only, a combination of ADHD:C and ODD, and children without either ADHD or ODD. Results indicated that there were no significant differences among the four groups in terms of reading skills. However, findings suggest a significant negative linear relationship between hyperactivity and reading skills. Application of these findings is discussed.

Adolescent↗

PubMedDate not supplied

Emotional adjustment and school functioning of young adolescents with multiple versus single learning disabilities.

Early adolescents (Grades 6-8) with multiple learning disabilities (LD; reading and math) in inclusive settings were compared to adolescents with single LD (reading or math) and typically achieving (TA) peers regarding their psychosocial functioning in two areas of adolescent well-being: emotional adjustment and school functioning. The Behavior Assessment System for Children (Reynolds & Kamphaus, 1998) Self-Report of Personality for adolescents was used to determine well-being. One hundred twenty middle school students-15 boys and 15 girls in each group-were included in the current study. The results confirmed that adolescents with multiple LD (reading and math) reported poorer functioning (i.e., higher T scores) on school maladjustment, clinical maladjustment, emotional symptoms index, attitude to school, atypicality, and depression when compared to TA peers but not when compared to peers with a single LD (reading or math). All three groups differed from the TA group (but not from each other) on sense of inadequacy, with the multiple LD group reporting the highest T scores. Additional analyses indicated significant differences between girls and boys, regardless of disability status. Girls reported higher T scores on the emotional symptoms index, social stress, and depression, but boys reported greater school maladjustment and sensation seeking. Implications for practice and recommendations for future research are discussed.

Adaptation, Psychological↗

PubMedDate not supplied

Neuropsychological aspects for evaluating learning disabilities.

This review surveys the empirical literature for assessments of learning problems in children from a neuropsychological perspective. An evaluation of children with learning problems must consider measures of working memory, attention, executive function, and comprehension (listening and written), particularly for children who do not respond to intervention. These constructs must be tied to intervention techniques, and their connections must be empirically verified. The response-to-intervention (RTI) perspective provides excellent support for the process in young children but is still developing the process for students above the second grade. This review provides information about the existing research on neurobiological correlates of learning disabilities, possible areas for further evaluation, and the link to the RTI movement.

Child↗