Biomedical subjects

D A Benavidez

Publications and source records attributed to D A Benavidez.

7 recordsLinked to original sources

PubMed2000

Reduction of corpus callosum growth after severe traumatic brain injury in children.

OBJECTIVE: To study effects of closed head injury (CHI) severity on development of corpus callosum (CC) in children, using MRI. BACKGROUND: Vulnerability of CC to diffuse axonal injury has been shown in adults and children by neuropathologic and MRI studies. Given continued development of CC through the second decade, serial MRI could characterize effects of CHI on CC growth in children. METHOD: MRI performed at 3 and 36 months after severe (mean age = 10.3 years, n = 25) and mild to moderate (mean age = 9.7 years, n = 28) CHI. Mild to moderate and severe CHI groups did not differ in demographic features. Morphometry of T1-weighted midsagittal CC by two operators with satisfactory interrater reliability yielded uncorrected and corrected CC volume. RESULTS: An interaction of occasion with CHI severity was present as CC area decreased from 3 to 36 months in severely injured children and increased in the mild to moderate CHI group. Uncorrected CC area was correlated with acute CHI severity and functional outcome at 36 months postinjury. CONCLUSIONS: Morphometric measurement of CC area provides a useful index of diffuse injury, which is related to functional outcome of CHI in children.

Brain Injuries↗

PubMed1999

Corpus callosum damage and interhemispheric transfer of information following closed head injury in children.

We evaluated the relationship of corpus callosum atrophy and/or lesions on magnetic resonance imaging (MRI) to functional hemispheric disconnection following closed head injury (CHI) in 51 pediatric patients, including mild CHI, moderate to severe CHI with extracallosal lesions, and moderate to severe CHI with callosal atrophy and/or lesions. Interhemispheric transfer of information was assessed using auditory, motor, tactile, and visual tests in patients and in 16 uninjured children. Total and regional callosal areas were measured from the midsagittal MRI slice by morphometry. The corpus callosum lesion group demonstrated a greater right ear advantage on verbal dichotic listening than all other groups. Areas of the posterior corpus callosum were negatively correlated with laterality indices of verbal dichotic listening performance and tachistoscopic identification of verbal material. The relationship of corpus callosum atrophy and/or lesions to asymmetry in dichotic listening is consistent with previous investigation of posttraumatic hemispheric disconnection effects in adults.

Adolescent↗

PubMed1995

Empirically derived subtypes of pervasive developmental disorders: a cluster analytic study.

A cluster analytic study was conducted to empirically derive behaviorally homogeneous subtypes of pervasive developmental disorders (PDD). Subjects were clustered based on a broad range of behavioral symptoms which characterize autism. Behavioral variables were measured using several of the standardized psychometric instruments most commonly employed in assessing autistic individuals. The cluster solution indicated the presence of four distinct groups. Validity checks generally confirmed significant between-group differences on independent measures of social, language, and stereotyped behaviors. In addition, the four-group cluster solution was compared to previously developed typological systems of PDD (i.e., subcategories based on IQ early onset, styles of social interaction, and DSM-III-R diagnosis). Results generally supported both the behavioral homogeneity of the four subgroups and also several important between-group differences. The potential utility of using cluster analyses to explore subtypes of PDD is discussed.

Adolescent↗

PubMed1993

The differential validity of hyperactivity/attention deficits and conduct problems among mentally retarded children.

The independence of hyperactivity, attention deficits, and conduct problems among mentally retarded children was addressed using factors of the Conners' Teacher Rating Scale-39 (CTRS-39) and the more recently developed IOWA Conners' inattention/overactivity (IO) and aggression (A) subscales. CTRS-39 ratings were obtained for children of normal intelligence and for mentally retarded children. Differences between the groups were examined as were intercorrelations of the Conners' factors and IOWA subscales. Conduct problems proved to be less strongly associated with hyperactivity and attention deficits among mentally retarded children compared to children of normal intelligence. However, attention problems and conduct problems may be associated with mental retardation in general. Implications of these data and CTRS scoring system recommendations for mentally retarded children are discussed.

Aggression↗

PubMedDate not supplied

Assessment of depression in mentally retarded adolescents.

The performance of 25 mentally retarded and 25 normal IQ adolescents was investigated on self-report and informant versions of three childhood depression measures. These measures included the Children's Depression Inventory, the Bellevue Index of Depression, and the Reynolds Child Depression Scale. Adolescents with mild to severe levels of mental retardation were studied. Strong correlations between total scores of measures were found. Analyses of variance comparing mentally retarded and intellectually average adolescents differed significantly only on the Bellevue Index of Depression. Finally, the relationship between self-report and informant versions of these measures were correlated, with mixed results. Implications for the use of these scales in assessing depression of mentally retarded adolescents are discussed.

Adolescent↗

PubMedDate not supplied

Attention deficit-hyperactivity disorder among mentally retarded children.

Teachers completed the Connors' Teacher Rating Scale (CTRS-39) on 100 boys assigned to one of four groups based on an IQ screen and scores on a DSM-III-R checklist of the symptoms for Attention Deficit-Hyperactivity Disorder (AD-HD). The groups included children rated high on AD-HD, mentally retarded children, mentally retarded children rated high on AD-HD, and a normal control group. Using the CTRS-39, there were no significant differences between the normal IQ AD-HD group and the mentally retarded AD-HD group on all but one of the factors. Mentally retarded children in general were found to be more anxious than their normal peers, whereas normal IQ AD-HD children were rated higher than the other groups on the Asocial factor. Implications of these data and future directions are discussed.

Attention Deficit Disorder with Hyperactivity↗

PubMedDate not supplied

Behavioral treatment of autistic persons: a review of research from 1980 to the present.

Studies evaluating behavioral treatment of autism from 1980 to the present were reviewed. Studies included were published in journal articles and utilized behavioral methodology. A total of 251 studies were included in the review. Each study was analyzed for target behaviors and behavioral techniques implemented. Target behaviors were divided into categories, which included aberrant behaviors, social skills, language, daily living skills, and academic skills. Behavioral techniques were classified as positive, negative, extinction, or combined. Results were presented for each category. Recent trends in the treatment literature were also reviewed, and recommendations for future research were presented.

Autistic Disorder↗