Attention and executive functions profile in drug naive ADHD subtypes

Attention deficit hyperactivity disorder (ADHD) has been associated with executive functioning and sustained and divided attention deficits. In order to clarify the questions on neurocognitive impairment in ADHD, we investigated the presence of specific executive functions (EFs) and attention deficit patterns in ADHD clinical subtypes. 50 patients with ADHD and 44 controls were evaluated. All subjects were boys and performed a clinical-psychopathological and neuropsychological battery. Five main domains of EFs and attention were studied. Executive functions-related neurocognitive abilities were used as control tasks. ADHD patients, inattentive and combined subtypes differ from controls on response inhibition, divided attention, phonological, and visual object working memory and on variability of reaction times measured with CPT. Comparison of ADHD subtypes, in five main domains of EFs, did not show evidence of different executive functioning profiles. Response inhibition can predict performance on working memory tests but it cannot predict performance on divided attention/set shifting and on sustained attention. ADHD boys exhibit a selective impairment on executive functions and attention tasks. These data suggest the involvement of partially independent neural circuits which control inhibition and divided attention in ADHD. Since right prefrontal cortex seems to be crucial in controlling response inhibition, while left dorsolateral prefrontal cortex seems important in modulating divided attention, these areas are deputated to be involved in the pathogenesis of neuropsychological deficits in ADHD subtypes. In addition, this study candidates the impairment in phonological and visual-object working memory as a possible neuropsychological trait in ADHD males with inattentive or combined subtypes.     

Attention profiles in childhood absence epilepsy compared with attention-deficit/hyperactivity disorder

Objective

This study aimed to compare the attention profiles of subjects with childhood absence epilepsy (CAE) to those of children with attention-deficit/hyperactivity disorder (ADHD) and controls.

The influence of executive functions on spatial biases varies during the lifespan

Many perceptual processes, such as language or face perception, are asymmetrically organised in the hemispheres already in childhood. These asymmetries induce behaviourally observable spatial biases in which the observer perceives stimuli in one of the hemispaces more efficiently or more frequently than in the other one. Another source for spatial biases is spatial attention which is also asymmetrically organised in the hemispheres. The bias induced by attention is directed towards the right side, which is clearly demonstrated by patients with neglect but also in lesser degree by healthy observers in cognitively loading situations. Recent findings indicate that children and older adults show stronger spatial biases than young adults. We discuss how the development of executive functions might contribute to the manifestation of spatial biases during the lifespan. We present a model in which the interaction between the asymmetrical perceptual processes, the age-related development of the lateralised spatial attention and the development of the executive functions influence spatial perceptual performance and in which the development and decline of the executive processes during the lifespan modify the spatial biases.     

Switching attention and resolving interference: fMRI measures of executive functions

Is there a single executive process or are there multiple executive processes that work together towards the same goal in some task? In these experiments, we use counter switching and response inhibition tasks to examine the neural underpinnings of two cognitive processes that have often been identified as potential executive processes: the switching of attention between tasks, and the resolution of interference between competing task responses. Using functional magnetic resonance imaging (fMRI), for both event-related and blocked design tasks, we find evidence for common neural areas across both tasks in bilateral parietal cortex (BA 40), left dorsolateral prefrontal cortex (DLPFC; BA 9), premotor cortex (BA 6) and medial frontal cortex (BA 6/32). However, we also find areas preferentially involved in the switching of attention between mental counts (BA 7, BA 18) and the inhibition of a prepotent motor response (BA 6, BA 10), respectively. These findings provide evidence for the separability of cognitive processes underlying executive control.     

Delayed episodic memory recall after one week is associated with executive functions and divided attention in pediatric epilepsy patients

AimRecent studies suggest that although children with epilepsy may show normal learning and memory performance, accelerated long-term forgetting (ALF) may become evident over time. Our study examined associations between delayed episodic memory performance (recall 1-week after learning) and executive functions.MethodA consecutive sample of children with a diagnosis of idiopathic epilepsy with focal or generalized seizures, without morphologic or metabolic abnormalities (n = 20, mean age: 11.70 years) was compared to an IQ-matched healthy control group (n = 20, mean age: 11.55 years). We also assessed parents’ and children’s rating of forgetting in everyday life and explored its association with delayed episodic memory recall.ResultsSimilar to results from recent studies of pediatric patients with temporal lobe epilepsy or genetic generalized epilepsy, our pediatric epilepsy patients showed a significantly elevated recall loss over time, although verbal learning, immediate and 30-minute recall was comparable to the matched control group. Additionally, delayed memory recall in patients was moderately associated with their subjective rating of forgetting, as well as with executive functions (verbal fluency and switching) and divided attention.InterpretationWe assume that executive functions play a crucial role in deep memory encoding, facilitating stronger and more enduring memory traces. Given that approximately 20% of epilepsy patients – compared to a healthy reference sample – had a significantly reduced delayed recall and due to the clinical relevance of long-term memory, age-appropriate standard norms for free memory recall after 1-week are desirable.     

EpiTrack: tracking cognitive side effects of medication on attention and executive functions in patients with epilepsy

RATIONALE: Achievement of maximum seizure control with preservation or even improvement of patient's cognitive capabilities is the major aim of epilepsy therapy. EpiTrack is a brief screening tool for the tracking of cognitive side effects of antiepileptic drugs. Test selection was based on recent studies on the effects of topiramate on cognition and retrospective inspection of results from patients with antiepileptic drug (AED) side effects. METHODS: The 15-minute screening tool comprises six subtests: the Trail-Making Test (parts A and B), a test of response inhibition, digit span backward, written word fluency, and a maze test. These tests were standardized in 220 healthy subjects, 100 of whom were reevaluated after 5.3 months to obtain information on reliability and practice effects. Criterion validity was determined by correlation to other neuropsychological measures. For a first clinical evaluation, the impact of epilepsy (seizures) and medication on EpiTrack scores was evaluated cross-sectionally in 184 consecutive inpatients with chronic epilepsy. RESULTS: According to the normative data, we developed an easy scoring scheme assigning test scores on a 7-point scale. The EpiTrack is suitable for patients between 18 and 60 years of age. Age corrections were included for patients between 40 and 60 years. EpiTrack scores on subtests for both controls and patients were submitted to principal component analysis. VARIMAX rotation yielded a two-factor solution (verbal/visuo-spatial) that accounted for 63.8% of the total variance in controls. In the patient group, only one factor emerged accounting for 54.7% of variance. EpiTrack correlates with global scores of attention (r=0.85) and language (r=0.67) (P's<0.001). At a cutoff score of 25, only 2.7% of the controls were classified as impaired, while impairment was indicated in 48.4% of the patients. The score is sensitive to monthly frequency of complex partial seizures and to number of AEDs. It shows negative cognitive effects of valproate and topiramate given in mono/polytherapy. CONCLUSION: EpiTrack is a promising 15-minute screening tool for the detection and tracking of cognitive side effects of AEDs and adverse effects of seizures in patients with epilepsy. Future application will show its value in prospective follow-up studies on AED side effects.     

Elucidating X chromosome influences on Attention Deficit Hyperactivity Disorder and executive function

ObjectiveTo identify distinct behavioral and cognitive profiles associated with ADHD in Turner syndrome (TS), relative to idiopathic ADHD and neurotypical controls, in order to elucidate X-linked influences contributing to ADHD.MethodsWe used a multilevel-model approach to compare 49 girls with TS to 37 neurotypical females, aged 5–12, on established measures of behavior (BASC-2) and neurocognitive function (NEPSY). We further compared girls with TS to BASC-2 and NEPSY age-matched reference data obtained from children with idiopathic ADHD.ResultsWithin the TS group, 51% scored at or above the “at-risk” range for ADHD-associated behaviors on the BASC-2 (TS/+ADHD). The BASC-2 behavioral profile in this TS/+ADHD-subgroup was comparable to a reference group of boys with ADHD with respect to attentional problems and hyperactivity. However, the TS/+ADHD-subgroup had significantly higher hyperactivity scores relative to a reference sample of girls with ADHD (p = 0.016). The behavioral profile in TS was associated with significantly lower attention and executive function scores on the NEPSY relative to neurotypical controls (p = 0.015); but was comparable to scores from a reference sample of children with idiopathic ADHD. Deficits in attention and executive function were not observed in girls with TS having low levels of ADHD-associated behavior (TS/-ADHD).ConclusionsADHD-associated behavioral and cognitive problems in TS are prevalent and comparable in severity to those found in children with idiopathic ADHD. The ADHD phenotype in TS also appears relatively independent of cognitive features typically associated with TS, like visuospatial weaknesses. These findings suggest that X-linked haploinsufficiency and downstream biological effects contribute to increased risk for ADHD.     

Attention and executive functions in the early course of pediatric epilepsy

ObjectiveOur prospective study aimed at exploring attention and executive functions in children with new-onset epilepsy prior to and during the early course of antiepileptic treatment. Sociodemographic and epilepsy-related factors were analyzed as potential predictors both of impaired cognitive functions as well as for changes in cognitive functioning in the early course of illness.MethodsFrom a total group of 115 children aged six to 17 years without major disabilities, 76 children were assessed longitudinally with a screening tool for attention and executive functions (EpiTrack Junior®). Sociodemographic variables (gender, age at epilepsy onset, need of special education) and epilepsy-related variables (etiology of epilepsy, semiology of seizures, number of seizures) were considered as potential predictors for impaired functions prior to treatment and for deterioration/amelioration in cognitive functions in the early course.ResultsAttention and executive functions of children with new-onset epilepsy were significantly more often impaired when compared with a healthy population, but less often when compared with children with chronic epilepsy. The majority of children showed stable cognitive functioning in the early course of treatment. The risk of impaired cognitive functions was significantly heightened when etiology of epilepsy was unknown or not classifiable. The chance for improvement of functioning was lowered by having a genetic epilepsy, or an unknown semiology of seizures.ConclusionsChildren with new-onset epilepsy are at high risk for impaired attention and executive functions even prior to antiepileptic treatment, especially when etiology of their epilepsy remains unclear. The high stability of cognitive functioning in the early course can be used in counseling of families who worry about negative side effects of drug treatment. Finally, a systematic assessment of cognitive functions in children with new-onset epilepsy is necessary to detect subtle deficits in the early course and adjust treatment accordingly.     

The impact of executive functions on verb production in patients with Parkinson's disease

A growing number of studies suggest that language problems in Parkinson's disease (PD) are a result of executive dysfunction. To test this hypothesis we compared Dutch verb production in sentence context in a group of 28 PD patients with a control group consisting of 28 healthy participants matched for age, gender and education. All subjects were assessed on both verb production in sentence context as well as on cognitive functions relevant for sentence processing.PD patients scored lower than healthy controls on the verb production ability-scale and showed a response pattern in which performance was worse (1) in base than in derived position; (2) in present than in past tense; (3) for intransitive than in transitive verbs. For the PD group the score on the verb production ability-scale correlated significantly with set-switching and working memory. These results provide support for previous research suggesting that executive dysfunctions underlie the performance of the PD patients on verb production. It is furthermore suggested that because of failing automaticity, PD patients rely more on the cortically represented executive functions. Unfortunately, due to the disturbed intimate relation between the basal ganglia and the frontal cortex, these executive functions are also dysfunctional.     

Measuring the executive functions in schizophrenia: the voluntary allocation of effort

INTRODUCTION: Executive functioning reflects not only what a patient does, but also how he does it or whether he does it at all [Lezak MD. The problem of assessing executive functions. Int. J. Psychol. 17 (1982) 281]. Standard test procedures strongly prompt subjects to certain behavior, so that initiative and the amount of voluntary effort one is willing to invest are therefore not being adequately assessed. METHODS: We developed the Cognitive Effort Test (CET); a test for executive functioning specifically aimed at measuring subject's free initiatives, and the amount of effort they invest voluntarily. It is a complex planning task, and performance is being judged by three subscales: Initiative, Planning, and Workload. 36 schizophrenia patients and 30 healthy controls were tested with the CET, and a battery of other cognitive tests (executive functioning, memory, attention and psychomotor speed) was added to investigate construct and divergent validity. Negative symptoms were also recorded (predictive validity). RESULTS: Patients scored below controls on Planning and Workload, but not on Initiative. The CET was significantly related to other tests for cognition but not to negative symptoms. CET Planning and Workload predicted group membership (patients-controls) better than the other tests for executive functioning combined. CONCLUSION: The CET appears to be a clinically useful test that measures an aspect of schizophrenia that is not being assessed by existing tests, presumably the voluntarily allocation of effort.     

Association between executive/attentional functions and caries in children with cerebral palsy

The aim of the present study was to evaluate the existence of an association between attention/executive functions and the development of dental caries in individuals with cerebral palsy (CP). Seventy-six children with CP were selected from a physical rehabilitation center and a school serving children with disabilities. The control group was made up of 89 children without neurological impairment. Socioeconomic status, presence of teeth with cavities due to caries, degree of motor impairment and intellectual, executive and attentional functions were assessed. Mean age of participants was 8.9 years (SD = 3.56). The CP group had a significantly lower performance (p < 0.05, Mann–Whitney test) on the intelligence, attentional function and executive function tests in comparison to the control group. Controlling for the clinical diagnosis (CP or control group), motor impairment and intellectual function, the significant explanatory variables for the presence of teeth with cavities were performance on the Complex Rey figure test (OR = 0.941) and the Digit Span subtest of the Wechsler Intelligence Scale for Children in backward order (OR = 0.581). After controlling for intellectual function, clinical diagnosis and motor impairment, deficits in executive and attentional functions increased the odds of developing dental caries in children with cerebral palsy.     

Deficits in inhibitory executive functions in Klinefelter (47, XXY) syndrome

Klinefelter syndrome (47, XXY) is a sex chromosome aneuploidy associated with mild deficits in cognitive and language functions. Dysfunctions have also been reported in performance of tasks which examine executive functions. However, it is unclear whether the impaired performance is caused or accentuated by problems with semantic processing and information processing speed. In the present study we used an experimental task which is relatively insensitive to these confounding factors. We examined inhibitory executive functions in a group of XXY males compared with male (XY) and female (XX) controls, using a dichotic listening speech sound task with instructions to focus attention on either the right or the left ear stimulus. With this task, inhibitory executive functions can be assessed separately from language, processing speed, and attention orientation abilities. We found that XXY males showed a selective deficit in inhibitory executive functions compared to both control groups, whereas attentional orientation was not impaired. The present findings suggest that executive dysfunctions associated to Klinefelter syndrome can be selectively identified, and are particularly accentuated in the inhibitory sub-component. Such improved understanding of the nature of executive dysfunctions in XXY males may aid the development of specific neuropsychological rehabilitation strategies.     

Neuroanatomical correlates of selected executive functions in middle-aged and older adults: a prospective MRI study

Neuroanatomical substrates of age-related differences in working memory and perseverative behavior were examined in a sample of healthy adults (50–81 years old). The participants, who were screened for history of neurological, psychiatric, and medical conditions known to be linked to poor cognitive performance, underwent magnetic resonance imaging (MRI) and were administered tests of working memory and perseveration. Regional brain volumes and the volume of white matter hyperintensities (WMH) were measured on magnetic resonance images. The analyses indicate that the volume of the prefrontal cortex (PFC) and the volume of white matter hyperintensities in the prefrontal region are independently associated with age-related increases in perseverative errors on the Wisconsin Card Sorting Test (WCST). When participants taking antihypertensive medication were excluded from the analysis, both the volume of the prefrontal cortex and the frontal white matter hyperintensities (FWMH) still predicted increases in perseveration. Neither reduced volume of the prefrontal cortex nor the FWMH volume was linked to age-associated declines in working memory. The volumes of the fusiform gyrus (FG) and the temporal white matter hyperintensities (TWMH) were unrelated to cognitive performance.     

Deprivation and threat as developmental mediators in the relation between early life socioeconomic status and executive functioning outcomes in early childhood

There has been a shift in the study of childhood adversity towards a focus on dimensions of adversity as opposed to a focus on cumulative risk or specific adversities. The Dimensional Model of Adversity and Psychopathology (DMAP) proposes deprivation and threat as core dimensions of childhood adversity. Previous work using DMAP has found links between deprivation and cognitive development and threat and emotional development in adolescence, but few studies have applied this framework to a poverty context, in which children are at heightened risk for adversity experiences, and none have examined outcomes in early childhood. We use data from the Family Life Project (n = 1292) to examine deprivation and threat at child age 24 months as developmental mediators in the association between socioeconomic status (SES) measured at 15 months and executive functions (EF) measured at 48 months. In a multiple mediation model, lower SES was related to higher deprivation and threat. Deprivation was negatively associated with EF, and threat was not associated with EF. Deprivation fully mediated association between SES and EF. These results expand previous work using the DMAP and point to new directions in understanding children’s cognitive adaptations to adversity.     

低频重复经颅磁刺激对强迫症患者执行功能的影响

目的：探讨低频重复经颅磁刺激(rTMS)对强迫症患者执行功能的影响.方法30例强迫症(OCD)患者随机分为研究组和对照组,研究组给予舍曲林联合6周 rTMS 治疗;对照组给予舍曲林联合6周的 rTMS 伪刺激治疗.采用耶鲁－布朗量表(Y－BOCS)对两组患者于治疗前及治疗6周末进行疗效评定,并采用威斯康星卡片分类测验(WCST)及 Stroop 色词测验评估执行功能.结果 Y－BOCS 评分显示,研究组疗效较对照组好,差异有统计学意义(P ＜0．05). WSCT 评分结果显示,研究组治疗前后总操作时间、完成归类数和持续性错误改变量明显高于对照组,差异有统计学意义(P ＜0.05). Stroop 色词测验结果显示,研究组治疗前后的所有测验的测试时间改变量明显高于对照组,差异有统计学意义(P ＜0．05).结论两组 OCD 患者的临床症状及执行功能在治疗后均有改善,而且联合 rTMS 治疗效果更好.     

Subclinical hypothyroidism and neurocognitive functioning in bipolar disorder

The aim of this study was to compare neurocognitive functioning between euthymic bipolar disorder (BD) patients with and without subclinical hypothyroidism (SCH). Patients with SCH had poorer performance than patients without SCH in measures of verbal memory, attention, language, and executive functions. These preliminary results suggest that SCH could have some impact on the neurocognitive performance of euthymic patients with BD and warrant further research in this field.     

Hyperactivity in boys with attention-deficit/hyperactivity disorder (ADHD): The role of executive and non-executive functions

Motor activity of boys (age 8–12 years) with (n = 19) and without (n = 18) ADHD was objectively measured with actigraphy across experimental conditions that varied with regard to demands on executive functions. Activity exhibited during two n-back (1-back, 2-back) working memory tasks was compared to activity during a choice-reaction time (CRT) task that placed relatively fewer demands on executive processes and during a simple reaction time (SRT) task that required mostly automatic processing with minimal executive demands. Results indicated that children in the ADHD group exhibited greater activity compared to children in the non-ADHD group. Further, both groups exhibited the greatest activity during conditions with high working memory demands, followed by the reaction time and control task conditions, respectively. The findings indicate that large-magnitude increases in motor activity are predominantly associated with increased demands on working memory, though demands on non-executive processes are sufficient to elicit small to moderate increases in motor activity as well.     

An intranasal herbal medicine improves executive functions and activates the underlying neural network in children with autism

Our animal and human studies have provided empirical evidence that a patented intranasal herbal medicine alters brain functions and neurophysiology. In particular, it reduces clinical symptoms and immunological anomalies in children with autism spectrum disorders (ASD). The present study explored whether the herbal formula can improve executive functions and the associated neuroelectrophysiological activity in ASD. Thirty children with ASD were evenly assigned to receive a daily intranasal administration of the herbal formula or no treatment. Their executive functions, behavioral problems, and electroencephalographic activity during an executive control task were measured before and after six months of treatment with the herbal formula. After treatment, the experimental group showed significantly improved inhibitory control, mental flexibility, and planning, which coincided with an event-related elevation in the activity of their prefrontal and anterior cingulate cortices (regions that are critical for executive control of behaviors) as well as reduced daily dysexecutive behaviors. In contrast, the control group showed no significant changes in executive functions or neural system activity. These findings support the administration of the intranasal herbal medicine as a possible intervention for improving executive functions in ASD.     

Retinal Nerve Fiber Layer Thickness and Its Relationship With Executive Functions in Adult Attention Deficit Hyperactivity Disorder Patients

ObjectiveThe aim of this study was to compare the thickness of the retinal nerve fiber layer (RNFL) with controls in individuals with attention deficit hyperactivity disorder (ADHD) and to examine the relationship between RNFL thickness and the level of performance in disease severity and executive function tests in ADHD cases. MethodsThe study included 38 volunteer patients diagnosed with ADHD and 30 healthy volunteers. Adult ADHD self-report scale was used for ADHD symptom severity. Executive functions were evaluated by Digit Span Test, Verbal Fluency Test, Stroop Test, and Trail Making Test. RNFL thickness of all participants was evaluated using optical coherence tomography (OCT). ResultsIn the comparison of RNFL values, it was found that right mean, right temporal, right temporal inferior, left mean, left nasal, and left nasal inferior quadrant values were statistically thinner in ADHD cases compared to the control group (p<0.05). There was no statistically significant correlation between the mean RNFL thickness values of the right and left eyes of ADHD cases and the symptom severity and performance levels in executive function tests. ConclusionThis study is a guide in terms of being the first study investigating the relationship between RNFL thickness, symptom severity, and various neuropsychological tests in adults with ADHD.