Biomedical subjects

E Mark Mahone

Publications and source records attributed to E Mark Mahone.

14 recordsLinked to original sources

PubMed2006

Neuropsychological morbidity linked to childhood sleep-disordered breathing.

Understanding the long-term neuropsychological consequences of sleep disorders in children poses a significant challenge to researchers. Since children are in a state of rapidly changing cognition and neurobehavioral function, impacts on development may have profound consequences. Recent studies now demonstrate that mild sleep apnea and snoring, once considered within the spectrum of normal sleep patterns, are associated with deficits of neuropsychological function. Preliminary data suggest that some of these cognitive deficits may be reversible following treatment of mild sleep apnea in children; however, factors such as age at treatment, duration of sleep disordered breathing, pre-morbid intellectual level, socioeconomic status, or the effectiveness of treatment may adversely affect long-term outcome. Furthermore, it is imperative that researchers determine whether the developing brain exhibits critical periods of plasticity during which episodes of sleep-disordered breathing might cause long-term or permanent neuropsychological effects.

Child↗

PubMed2006

Motor persistence and inhibition in autism and ADHD.

The present study compared performance of children with Attention-Deficit/Hyperactivity Disorder (ADHD) and high functioning autism (HFA) with that of controls on 4 tasks assessing 2 components of motor control: motor response inhibition and motor persistence. A total of 136 children (52 ADHD, 24 HFA, 60 controls) ages 7 to 13 years completed 2 measures of motor inhibition (Conflicting Motor Response and Contralateral Motor Response Tasks) and 2 measures of motor persistence (Lateral Gaze Fixation and NEPSY Statue). After controlling for age, IQ, gender, and basic motor speed, children with ADHD performed significantly more poorly than controls on the Conflicting Motor Response and Contralateral Motor Response Tasks, as well as on Statue. In contrast, children with HFA achieved lower scores than controls only on measures of motor persistence, with no concomitant impairment on either motor inhibition task. These results are consistent with prior research that has demonstrated relatively spared motor inhibition in autism. The findings highlight the utility of brief assessments of motor control in delineating the unique neurobehavioral phenotypes of ADHD and HFA.

Adolescent↗

PubMed2006

Childhood obstructive sleep apnea associates with neuropsychological deficits and neuronal brain injury.

BACKGROUND: Childhood obstructive sleep apnea (OSA) is associated with neuropsychological deficits of memory, learning, and executive function. There is no evidence of neuronal brain injury in children with OSA. We hypothesized that childhood OSA is associated with neuropsychological performance dysfunction, and with neuronal metabolite alterations in the brain, indicative of neuronal injury in areas corresponding to neuropsychological function. METHODS AND FINDINGS: We conducted a cross-sectional study of 31 children (19 with OSA and 12 healthy controls, aged 6-16 y) group-matched by age, ethnicity, gender, and socioeconomic status. Participants underwent polysomnography and neuropsychological assessments. Proton magnetic resonance spectroscopic imaging was performed on a subset of children with OSA and on matched controls. Neuropsychological test scores and mean neuronal metabolite ratios of target brain areas were compared. Relative to controls, children with severe OSA had significant deficits in IQ and executive functions (verbal working memory and verbal fluency). Children with OSA demonstrated decreases of the mean neuronal metabolite ratio N-acetyl aspartate/choline in the left hippocampus (controls: 1.29, standard deviation [SD] 0.21; OSA: 0.91, SD 0.05; p = 0.001) and right frontal cortex (controls: 2.2, SD 0.4; OSA: 1.6, SD 0.4; p = 0.03). CONCLUSIONS: Childhood OSA is associated with deficits of IQ and executive function and also with possible neuronal injury in the hippocampus and frontal cortex. We speculate that untreated childhood OSA could permanently alter a developing child's cognitive potential.

Adolescent↗

PubMed2006

Hand and eye preference and their association with task approach by preschoolers.

Hand preference, eye preference, and the concordance of hand-eye preference were assessed in 99 healthy preschool-age children (46 boys: Mage= 55.4 mo., SD= 10.5 and 53 girls: Mage=53.6 mo., SD= 11.8). Children were also administered neuropsychological measures requiring attention and reaching to both sides of midline including the Peabody Picture Vocabulary Test, Third Edition, Multiple Boxes Test, Developmental Neuropsychological Assessment Visual Attention, and Imitating Hand Positions. All groups performed in the average range using standard administration and scoring of the neuropsychological tests, and no significant differences were found in performance between those with left- versus right-hand preference, left-versus right-eye preference, or concordant versus discordant hand/eye preference. In contrast, significant differences were noted in task approach to neuropsychological measures depending on hand preference. Rate of left-hand preference in this sample was consistent with that seen for adults; and rate of left-eye preference, and hand/eye concordance remained stable across age groups 3 to 6 years. While the presence of left-hand or -eye preference or discordance in the preschool years appears to be a benign characteristic in relation to standardized test performance, some aspects of test-taking efficiency may be affected.

Child↗

PubMed2005

Measurement of attention and related functions in the preschool child.

The goal of this review of the clinical and research literature is to identify, describe, and critique published methods for assessment of attention and related functions in preschool children (ages 6 and younger). The need for valid assessment of preschool children has grown dramatically in the past two decades following the implementation of special education services for infants, toddlers, and preschoolers under Public Law 99-457. At the same time, the number of preschool children presenting to clinicians for assessment of attention problems has grown at a steady rate. In contrast to assessment methods for school-age children, the availability of reliable and valid measures of attention for preschool children is much more limited. The majority of instruments developed to measure attention in preschoolers are described in the experimental literature, with fewer available commercially. Attention tests that can be appropriately used with children aged 3 and younger are scarce. Most preschool tests of attention report validity data involving sensitivity in contrasting clinical groups to controls, while the literature describing the utility of these measures in differentiating between clinical groups is much more limited. The review provides information on performance based tests (e.g., continuous performance, cancellation, auditory/visual span), as well as parent and teacher rating scales. The review concludes that valid assessment of attention and related skills can be effectively achieved in preschool children, with appropriate cautions.

Attention↗

PubMed2005

Serial neuropsychological assessment and evidence of shunt malfunction in spina bifida: a longitudinal case study.

Myelomeningocele is often accompanied by hydrocephalus (MMH), making it a potentially unstable neurological condition requiring shunt placement and possible revisions. Serial neuropsychological assessment is an important tool in monitoring children with MMH, as cognitive changes can indicate shunt malfunction and hydrocephalus. We present the case of a girl with MMH who had five neuropsychological assessments (ages 5, 7, 11, 12, and 14). Despite a lack of overt neurological symptoms or report of behavioral decline, testing at age 11 revealed decline in multiple neurobehavioral domains, and imaging at that time showed increased hydrocephalus, requiring shunt revision. Subsequent neuropsychological assessment conducted after a 2-year period of medical stability showed improvement and/or a return to baseline levels in some skill areas (i.e., working memory, verbal memory, visuomotor integration, and sustained attention), yet more lasting impairments in others (i.e., Verbal IQ, processing speed, organization, and response inhibition). These lasting cognitive deficits potentially impact independent completion of complex medical self-care tasks. This pattern of recovery highlights vulnerability of brain systems supporting executive functions in children with hydrocephalus and shunt failure.

Adolescent↗

PubMed2005

Construct validity of the auditory continuous performance test for preschoolers.

Development of diagnostic instruments directed toward neuropsychological assessment of preschoolers lags significantly behind those available for school-age children (DeWolfe, Byrne, & Bawden, 2000). This is particularly true for measures of executive function (EF). The Auditory Continuous Performance Test for Preschoolers (ACPT-P; Mahone, Pillion, & Hiemenz, 2001) is a computerized, Go-No-go test developed to measure selected EF skills in preschoolers. First, to determine whether performance on the ACPT-P is associated with hearing impairment, we compared performance of children with mild hearing loss (MHL) to controls on the ACPT-P, and measures of spatial working memory (SWM) and motor persistence (MP). There were no differences between performance of the MHL group and controls on any of these measures. Second, to examine the construct validity of the ACPT-P, we compared performance of 40 preschoolers with ADHD to 40 age- and sex-matched controls, using the ACPT-P to measure response preparation, sustained attention, and inhibitory control. We also compared these groups on measures of SWM and MP. The group with attention deficit hyperactivity disorder (ADHD) performed significantly worse than controls on the ACPT-P (omissions, mean response time, variability) and MP. The ACPT-P was correlated with the MP, but not with the SWM measure. Both the ACPT-P and the MP measures showed low to moderate correlations with parent ratings of behavior associated with ADHD. These findings support the use of performance-based assessment of executive control skills in preschoolers suspected of having ADHD. In this age group, the ACPT-P may be particularly useful in assessing sustained attention and response preparation and may complement behavior rating scales.

Acoustic Stimulation↗

PubMed2004

Repetitive arm and hand movements (complex motor stereotypies) in children.

OBJECTIVE: To characterize clinical features, associated problems, and outcomes for children with complex motor stereotypies who do not have mental retardation or pervasive developmental disorders. STUDY DESIGN: We performed a record review for 40 children (63% male) aged 9 months to 17 years with complex motor stereotypies between 1993 and 2003. RESULTS: Age at onset was at or before 3 years in 90% of the sample. Symptoms occurred at least once daily in 90%. Excitement was identified as a trigger in 70%. Movements stopped when cued in 98%, and none had stereotypies during sleep. A total of 25% had comorbid attention deficit hyperactivity disorder (ADHD), and 20% had a learning disability. Family history of stereotypies was identified in 25%, tics in 33%, ADHD in 10%, and mood-anxiety disorder in 38%. Pharmacotherapy to target associated conditions was used in 40%, and behavioral therapy was used in 23%. A total of 53% identified symptoms for more than 5 years. Movements resolved in 5% of the children, improved in 33%, were unchanged in 50%, and worsened in 13%. CONCLUSIONS: The clinical course of complex motor stereotypies appears chronic. Better understanding of the clinical features of complex stereotypies in primary care settings is essential for early diagnosis and management.

Adolescent↗

PubMed2003

Age and task parameters in continuous performance tests for preschoolers.

66 children (M=56.2 mo., SD=10.9), recruited from preschool and daycare centers, were administered two continuous performance tests, one auditory and one visual. Both tests utilized a format with one target and one nontarget. Interstimulus interval was fixed at 1350 msec. for the visual test and 5000 msec. for the auditory test. The visual test produced greater rates of omission and commission errors than the auditory test. Age was significantly related to mean reaction time and response variability for both tests; however, the visual test produced an unexpected pattern of increasing response time across age groups. On both tests omission rates improved significantly with age, while commission rates were consistent across ages 3-6 years. When considering continuous performance test paradigms for preschoolers, 3-yr.-olds may need at least a 4000-msec. interstimulus interval to make a choice for the stimulus cue. Hits following an interstimulus interval shorter than 1400 msec. may reflect younger preschoolers' response to a previous stimulus.

Age Factors↗

PubMed2002

Effects of IQ on executive function measures in children with ADHD.

The present study compared children with Attention-Deficit Hyperactivity Disorder (ADHD) and controls on a selected set of clinical measures of executive function (EF). A total of 92 children (51 ADHD, 41 control), ages 6-16, completed measures chosen from a larger neuropsychological battery to illustrate diverse components of the EF construct (planning, inhibitory control, response preparation, memory search). The selected measures were moderately correlated with one another, and moderately correlated with IQ. After controlling for age, sex, presence of learning disability (LD), ADHD, and IQ test version, Full Scale IQ was significantly related to four of the five selected EF measures. A second analysis showed group differences on the EF measures at different IQ levels. After covarying for age, there was a significant multivariate effect for IQ level (average, high average, superior) and a significant multivariate interaction between group (ADHD vs. control) and IQ level. Three of the five selected EF measures showed significant univariate group effects (controls performing better than ADHD) at the average IQ level; however, there were no significant group differences between children with ADHD and controls at high average or superior IQ levels. These results suggest that clinical measures of EF may differ among children with ADHD and controls at average IQ levels, but there is poorer discriminatory power for these measures among children with above average IQ.

Adolescent↗

PubMed2002

Parent and self-report ratings of executive function in adolescents with myelomeningocele and hydrocephalus.

Parent and self-report ratings were obtained for 28 adolescents with myelomeningocele and congenital hydrocephalus using the Behavior Assessment System for Children (BASC; Reynolds & Kamphaus, 1998a, 1998b) and the Behavior Rating Inventory of Executive Function (BRIEF; Gioia, Isquith, Guy, & Kenworthy, 2000; Guy, Gioia, & Isquith, 1998). Parents rated their children as having significantly more problems, compared to published norms, on the BRIEF but not the BASC. Adolescents rated themselves as having significantly more problems, compared to parent ratings, on scales comprising the BRIEF Behavioral Regulation Index; but not on common scales of the BASC. Parents also reported more problems on the BRIEF Global Executive Composite than on all three primary BASC indices, and more problems on the BRIEF Metacognition Index than on the BRIEF Behavioral Regulation Index. We conclude that the BRIEF captures salient executive dysfunction among individuals with myelomeningocele and hydrocephalus, and may be useful in identifying needs for intervention that might not be identified by broad-band behavior rating scales alone.

Adolescent↗

PubMed2002

Validity of the behavior rating inventory of executive function in children with ADHD and/or Tourette syndrome.

The dynamic, multidimensional nature of executive function (EF), thought to be characteristically impaired in those with attention deficit hyperactivity disorder (ADHD), has been challenging to operationalize and assess in a clinical setting [Barkley, R. A. (1997). ADHD and the nature of self-control. New York: Guilford Press.]. Gioia, Isquith, Guy, and Kenworthy [Gioia, G. A., Isquith, P. K., Guy, S. C., & Kenworthy, L. (2000) Behavior Rating Inventory of Executive Function. Odessa, FL: Psychological Assessment Resources.] developed the Behavior Rating Inventory of Executive Function (BRIEF) to address these concerns. In order to provide concurrent validity information on the BRIEF, parents of 76 children (ADHD=18; Tourette syndrome (TS)=21; TS+ADHD=17; controls=20) completed the BRIEF, additional behavior rating scales and interviews, measures of psychoeducational (PE) competence, and performance-based measures of EF. Both ADHD and TS+ADHD groups were rated as more impaired (P<.0001) than the other groups on the five primary BRIEF indices. BRIEF index scores showed no significant correlation with performance-based EF or PE measures, with the exception of math achievement; however, the BRIEF showed a strong relationship with interviews and other parent rating measures of behaviors seen in ADHD. Future attempts to validate the BRIEF should focus on differences within subtypes of ADHD (e.g., inattentive, combined subtypes), and separating ADHD from other clinical groups in which EF is reported to be a problem.

Journal Article↗

PubMedDate not supplied

Neuropsychiatric effects of guanfacine in children with mild tourette syndrome: a pilot study.

The objective of this study was to evaluate the neuropsychiatric effects of the alpha-2a adrenergic agonist guanfacine in children with Tourette syndrome (TS). Twenty-four children with TS participated in a 4-week, double-blind, placebo-controlled study of guanfacine. Tic severity, neuropsychologic functioning, and parent ratings of behavior were evaluated pre- and post-treatment. The sample had mild tic severity and subtle neuropsychologic dysfunction pretreatment. Post-treatment, patients receiving guanfacine were rated by parents as significantly improved (compared to placebo) on one measure of executive function (parent-rated metacognition). Improvement on tic severity, performance-based neuropsychologic measures, and all other parent ratings were not significantly better than placebo. At a moderate dose and short-term treatment duration, guanfacine did not provide significant neuropsychiatric benefits in this group of children with mild TS.

Adolescent↗

PubMedDate not supplied

Evidence for unexpected weaknesses in learning in children with attention-deficit/hyperactivity disorder without reading disabilities.

This study examined the mechanisms underlying verbal learning in children with and without attention-deficit/hyperactivity disorder (ADHD), none of whom had reading disabilities. Children with ADHD were compared to typically developing children on both process and product scores from the California Verbal Learning Test for Children. The findings indicated that children with ADHD initially learned the same number of words as controls but showed weaknesses recalling the words after delays, suggesting that children with ADHD are less efficient learners. Regardless of ADHD status, boys and girls performed differently. Boys used semantic clustering less frequently and recalled fewer words from the middle region of the list than girls; girls also outperformed boys in terms of overall performance, despite lower verbal IQ scores. These findings show that children with ADHD can exhibit unexpected weaknesses in learning even without a formal learning disability. Gender differences in verbal learning are also illustrated.

Adolescent↗