Neurologic examination abnormalities in children with bipolar disorder or attention-deficit/hyperactivity disorder

Associations between neurological soft signs, executive functions, and brain-derived neurotrophic factor in boys with attention-deficit hyperactivity disorder

Background

To determine the association between neurological soft signs, executive functions, and serum brain-derived neurotrophic factor (BDNF) levels in children with attention-deficit hyperactivity disorder (ADHD).

Methods

Serum BDNF levels were measured in 87 drug-naive boys with ADHD, aged 7-12 years. The Revised Physical and Neurological Examination for Subtle Signs for neurological soft signs, Stroop Color-Word Test for attention functions, and Judgment of Line Orientation Test (JLOT) for visuospatial abilities were performed.

Results

Age correlated negatively with dysrhythmia, total time, and total overflow in timed movements, Stroop Color-Word Time (SCWT), and serum BDNF levels. The JLOT significantly negatively correlated with Total Gaits and Stations (P1) and Total Time in Timed Movements (adjusted R 2 = 0.247). In addition, SCWT maintained a significant correlation with Total Overflow in Timed Movements (adjusted R 2 = 0.206). There was no correlation between serum BDNF levels and NSS.

Conclusion

The association between NSS, visuospatial abilities, and selective attention may express a maturational delay in ADHD pathophysiology. Moreover, BDNF may play a role in this maturational delay. Future studies should investigate the contribution of BDNF to neuronal maturation in ADHD.

Exploring the impact of COVID-19 on newborn neurodevelopment: a pilot study

The COVID-19 pandemic can seize the opportunity to explore the hypothesis of prenatal exposure to viral infections increases the risk for neurodevelopmental disorders. Advancing our knowledge in this regard would improve primary prevention of mental disorders in children. For this pilot study, six-week-old infants born to mothers exposed (n = 21) or unexposed (n = 21) to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were assessed in Santander-Cantabria (Spain) using the Neonatal Behavioral Assessment Scale (NBAS). Groups comparisons were performed to explore the effects that infection and timing of exposure (in terms of the three trimesters of pregnancy). The infants' competencies and performances on the NBAS were generally similar in the exposed and unexposed to SARS-CoV-2 groups. The most significant difference found was a less optimally response to cuddliness (item on the state regulation domain) particularly in infants born to mothers exposed in the third trimester of pregnancy, and in pull-to-sit (item on the motor system domain). Although our interpretations must be careful, these preliminary results highlight the possible association between prenatal SARS-CoV-2 exposure and poorer development in motor skills and infant interactive behavior. Further longitudinal studies are needed to explore these relationships and disentangle the biological mechanisms implicated.

Presence of neurologic signs in children with neurofibromatosis type 1

BACKGROUND

Neurofibromatosis type 1 is a common neurogenetic disorder affecting nervous system, caused by germiline mutations of the NF1 gene. Although the clinical diagnosis of NF1 is defined by presence of cafe-au-laits spots, freckling and benign tumors (neurofibromatosis), neurocognitive impairment and neuropsychiatric disorders are reported in comorbidity. Children with NF1 show higher incidence of executive deficits, such attention, response inhibition, executive planning and problem solving, working memory, and learning impairment. In this study we examine the presence of neurological soft signs and planning function in subjects with NF1. The NSS are minor motor and sensory abnormalities without focal brain damage.

METHODS

Eleven drug naïve children between 7-15 years with clinical and molecular diagnosis of NF are matched to 11 healthy controls to ass the presence of neurological soft signs and planning executive functions. NSS were assessed using Physical and Neurological Examination for Subtle Signs and the Tower of London task is performance test to assess the capacity of planning, organization and execution of a work.

RESULTS

Our results revealed highest rate of NSS and planning deficit in children with NF1 compared to healthy controls.

CONCLUSIONS

The motor abnormalities and planning deficit are possible markers to confirm that NF1 could be considering a neurodevelopmental disorder.

Motor Functional Characteristics in Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorders: A Systematic Review

BACKGROUND

The development of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorders (ASDs) has various influences on physical abilities. Identification of specific physical abilities of people with ADHD/ASDs as biomarkers for diagnosing these conditions is necessary. Therefore, in the present review, we aimed firstly to extract the difference in physical abilities of people with ADHD or ASDs compared to those of normal individuals. Secondly, we aimed to extract the specific physical ability characteristics for identifying potential diagnostic biomarkers in people with ADHD/ASDs.

METHODS

A systematic literature review was performed. The databases were searched for relevant articles on motor function deficits and characteristics of ADHD or ASD.

RESULTS

Forty-one cross-sectional studies and three randomized controlled trials were identified, comprising 33 studies of ADHD, 10 studies of ASDs, and 1 study of both ADHD and ASDs. The quality of studies varied. Three types of physical activities/exercises were identified, including coordinated movement, resistance-type sports, and aerobic-type sports. People with ADHD/ASDs generally exhibited poorer physical abilities for all types of activities, possibly because of low levels of physical activity. Specifically, we found temporal discoordination of movement in ADHD and integration or synchronization of separate movements in ASDs.

CONCLUSION

Specific deficits in physical ability may be attributed to ADHD/ASDs. However, there is not enough research on the physical abilities of people with ADHD and ASDs to clarify the specific deficits. Investigation of specific motor functions that characterize ADHD/ASDs should be facilitated.

Anxiety disorders comorbidity in pediatric bipolar disorder: a meta-analysis and meta-regression study

OBJECTIVE

Anxiety disorders (AD) are known for its comorbidity and negative impact on the course of adult bipolar disorder (BD). However, there is limited research on AD comorbidity in pediatric BD (PBD). Here, we aimed to conduct a meta-analysis and meta-regression study about the comorbidity and covariates of AD and PBD.

METHOD

We systematically searched relevant articles published until May 2019, as defined in PRISMA guidelines. Variables for associated features and prevalence of AD were extracted.

RESULTS

Thirty-seven articles represented data for the analysis. Lifetime any AD comorbidity was 44.7%; panic disorder (PD) was 12.7%; generalized anxiety disorder (GAD) was 27.4%; social phobia was 20.1%; separation anxiety disorder (SAD) was 26.1%; and obsessive-compulsive disorder (OCD) was 16.7%. Childhood-onset studies reported higher GAD and SAD comorbidity, while adolescent-onset studies reported higher PD, OCD, and social phobia. Age of onset, gender, comorbidity of ADHD, substance use, oppositional defiant disorder and conduct disorder affected each anxiety disorders' comorbidity with PBD differently.

CONCLUSION

Anxiety disorders are highly comorbid with PBD. Early-onset PBD increases the risk of AD. Biopsychosocial aspects of this comorbidity and its course needs to be evaluated further.

Preliminary analysis of resting state functional connectivity in young adults with subtypes of bipolar disorder

BACKGROUND

A precision medicine approach to bipolar disorder (BD) requires greater knowledge of neural mechanisms, especially within the BD phenotype. The present study evaluated differences in resting state functional connectivity (RSFC) between young adults followed longitudinally since childhood with full-threshold type I BD (BD-I)-characterized by distinct manic episodes-or a more sub-syndromal presentation of BD (BD Not Otherwise Specified [BD-NOS]), compared to one another and to healthy controls (HC). Independent Components Analysis (ICA), a multivariate data-driven method, and dual regression were used to explore whether connectivity within resting state networks (RSNs) differentiated the groups, especially for characteristic fronto-limbic alterations in BD.

METHODS

Young adults (ages 18-30) with BD-I (n = 28), BD-NOS (n = 14), and HCs (n = 52) underwent structural and RSFC neuroimaging. ICA derived 30 components from RSFC data; a subset of these components, representing well-characterized RSNs, was used for between-group analyses.

RESULTS

Participants with BD-I had significantly greater connectivity strength between the executive control network and right caudate vs. HCs. Participants with BD-NOS had significantly greater connectivity strength between the sensorimotor network and left precentral gyrus vs. HCs, which was significantly related to psychiatric symptoms.

LIMITATIONS

Limitations included small BD-NOS sample size and variation in BD mood state and medication status.

CONCLUSIONS

Results for BD-I participants support prior findings of fronto-limbic alterations characterizing BD. Alterations in the sensorimotor network for adults with BD-NOS aligns with the small but growing body of evidence that sensorimotor network alterations may represent a marker for vulnerability to BD. Further study is required to evaluate specificity.

Neurological soft signs in familial and sporadic schizophrenia

OBJECTIVE

Neurological soft signs (NSS) are a group of minor non-localizable neurological abnormalities found more often in patients with schizophrenia. The aim of the current study was investigate whether there is any difference in their manifestation in familial vs. sporadic schizophrenia.

MATERIAL AND METHODS

The study sample included 120 patients suffering from schizophrenia according to DSM-5 (71 males and 49 females; aged 32.79 ± 11.11 years old) and 110 normal controls (57 males and 53 females; aged 33.38 ± 10.14 years old). The assessment included the Neurological Evaluation Scale (NES) and the detailed investigation family history. The statistical analysis included exploratory Analysis of Covariance.

RESULTS

The results of the current study suggest that NSS are more frequent in familial cases of schizophrenia and are even more pronounced in cases with family history of psychosis in either first or second degree relatives.

DISCUSSION

Overall the results suggest the presence of a spectrum of increasing severity from healthy controls to sporadic cases, to cases with non-psychotic family history and eventually to cases with psychotic family history, rather than a categorical distribution.

Attention deficit-hyperactivity disorder in adult bipolar disorder patients

BACKGROUND

It has long been recognized that bipolar disorder (BD) and attention deficit-hyperactivity disorder (ADHD) co-occur in an uncertain proportion of patients, recognized commonly in juvenile years. There is growing suspicion that such co-occurrence is associated with several clinically unfavorable characteristics. Accordingly, we compared 703 type I or II BD subjects with vs. without a lifetime diagnosis of ADHD.

METHODS

We compared 173 BD patients with vs. 530 without co-occurring ADHD for selected demographic and clinical factors, using standard initial bivariate comparisons followed by multivariable logistic regression modeling.

RESULTS

ADHD was found in 25% of BD subjects, more among men and with type I BD. Those with ADHD had higher scores at the Adult ADHD Self-Report Scale (ASRS), were more likely to have had less successful school performance, unemployment, lower socioeconomic status, less marriage and more divorce, as well as more substance abuse, suicide attempts, and [hypo]mania, but were less likely to have an anxiety disorder or a family history of mood disorder. Multivariable logistic regression modeling found six factors differing between BD subjects with versus without ADHD: less education after high school, higher ASRS score for inattention, ever separated or divorced, irritable temperament, male sex, and lower scores on the Hamilton Depression Rating Scale (HDRS) at intake.

COMMENTS

Co-occurrence of ADHD with BD was identified at a moderate rate, and was associated with several unfavorable outcomes as well as a tendency toward [hypo]mania.

Neurological soft signs in bipolar disorder in comparison to healthy controls and schizophrenia: A meta-analysis

Neurological soft signs (NSS) are subtle deficits in motor coordination, sensory integration, and sequencing of complex motor acts. Increased NSS is a well-established feature of patients with schizophrenia but a relatively smaller number of studies have investigated NSS in bipolar disorder (BD). Some authors but not others suggested that NSS can distinguish schizophrenia from BD. We conducted a meta-analysis of 18 studies to quantitatively review NSS in BD in comparison to schizophrenia and healthy controls. The current meta-analysis compared NSS scores of 725 BD patients and 634 healthy controls, and 391 BD and 471 schizophrenia patients. Patients with BD had significantly higher NSS scores (d = 1.14, CI = 0.89-1.44) than healthy controls and increased scores in BD was evident in all aspects of NSS (d = 0.88-0.99). BD was associated with a less severe increase in NSS compared to schizophrenia, however, between-group difference was modest (d = 0.42, CI = 0.18-0.65). The results of this meta-analysis demonstrated that BD is characterized by a robust increase in NSS which is only moderately less severe than schizophrenia. Increased NSS is a common feature of both disorders.

Motor dysfunction as research domain across bipolar, obsessive-compulsive and neurodevelopmental disorders

Although genuine motor abnormalities (GMA) are frequently found in schizophrenia, they are also considered as an intrinsic feature of bipolar, obsessive-compulsive, and neurodevelopmental disorders with early onset such as autism, ADHD, and Tourette syndrome. Such transnosological observations strongly suggest a common neural pathophysiology. This systematic review highlights the evidence on GMA and their neuroanatomical substrates in bipolar, obsessive-compulsive, and neurodevelopmental disorders. The data lends support for a common pattern contributing to GMA expression in these diseases that seems to be related to cerebello-thalamo-cortical, fronto-parietal, and cortico-subcortical motor circuit dysfunction. The identified studies provide first evidence for a motor network dysfunction as a correlate of early neurodevelopmental deviance prior to clinical symptom expression. There are also first hints for a developmental risk factor model of these mental disorders. An in-depth analysis of motor networks and related patho-(physiological) mechanisms will not only help promoting Research Domain Criteria (RDoC) Motor System construct, but also facilitate the development of novel psychopharmacological models, as well as the identification of neurobiologically plausible target sites for non-invasive brain stimulation.

Scientific Evidence for the Evaluation of Neurological Soft Signs as Atypical Neurodevelopment Markers in Childhood Neuropsychiatric Disorders

Motor dysfunction is commonly present in children with neurodevelopmental disorders. Developmental changes in voluntary control of motor skills include improvements in speed and motor coordination as well as reduced frequency of neurological soft signs (NSS) that are commonly observed in typically developing younger children. NSS are motor and sensory conditions that cannot be linked to specific cerebral lesions. The persistence of NSS into later childhood and adolescence is linked with an increased risk of psychiatric disorders. This finding gives support to the neurodevelopmental model of NSS in which minor neurological impairments may be viewed as potential signs of deviant brain development and might represent trait markers of vulnerability for neurodevelopmental disorders. Given that NSS are easily detectable, it is important that clinicians increase their knowledge of the clinical presentation and research implications of the relationship between NSS and childhood neurodevelopmental disorders. To the best of our knowledge, this is the first review article to give an updated overview of the current knowledge of NSS in the most common neuropsychiatric disorders of childhood/adolescence, such as attention-deficit/hyperactivity disorder, autism spectrum disorder, obsessive-compulsive disorder, bipolar disorder, and first episode of psychosis. The article also presents key points for future research studies on this topic.

Emotional Lability in Preschoolers With Symptoms of ADHD

OBJECTIVE

The aim of this study was to examine occurrence of emotional lability (EL) in preschoolers with ADHD symptoms versus controls.

METHOD

The study was part of the Norwegian Mother and Child Cohort Study (MoBa) at the Norwegian Institute of Public Health. In the present study, 495 preschoolers were clinically examined. Symptoms of ADHD, anxiety, and oppositional defiant disorder (ODD) were measured with the Preschool Age Psychiatric Assessment Interview. An EL measure was obtained from the Emotional Control subscale of the Behavior Rating Inventory of Executive Function-Preschool Version (BRIEF-P), which parents and teachers completed.

RESULTS

EL was significantly more frequent in the ADHD group compared with controls (25% vs. 7%, p < .001). By parent report, EL correlated significantly with ADHD-, anxiety-, and ODD symptoms. By teacher report, EL was significantly correlated only with hyperactivity-impulsivity.

CONCLUSION

EL appears identifiable in young preschoolers and was particularly associated with ODD in children with ADHD symptoms.

Prevalence and correlates of neurological soft signs in healthy controls without family history of any mental disorder: A neurodevelopmental variation rather than a specific risk factor?

OBJECTIVE

Neurological soft signs (NSS) are a group of minor non-localizable neurological abnormalities found more often in patients with schizophrenia and other mental disorders. The aim of the current study was to investigate their prevalence and correlates in healthy controls without family history of any mental disorder.

MATERIAL AND METHODS

The study sample included 122 normal subjects (66 males and 56 females; aged 32.89 ± 9.91 years old). The assessment included the Neurological Evaluation Scale (NES), and a number of scales assessing the subthreshold symptoms (MADRS, STAI) and functioning (GAF). Data on a number of socio-demographic variables were also gathered. The statistical analysis included the development of basic statistics tables and the calculation of Pearson correlation coefficients.

RESULTS

The results of the current study suggest that more than half of the study sample manifested at least one NSS and approximately 5% more than four. Still, the reported prevalence and NES scores are lower form those reported in the literature probably because of the carefully selected study sample. There were no significant correlations between NSS and any socio-demographic or clinical variable.

DISCUSSION

The current study is the first to study NSS in subjects without family history of any mental disorder and reports the presence of frequent silent neurodevelopmental events in the general population, probably in the form of a neurodevelopmental variation and possibly a weak generic rather than specific risk factor.

Assessment of neurological soft signs in pediatric patients with HIV infection

BACKGROUND

Children and adolescents comprise a significant proportion of people living with HIV. The effects of HIV on the growing brain have generated interest among researchers in this field. Deficits arising during this crucial phase of neuromaturation due to HIV infection need to be assessed and addressed. Neurological soft signs (NSSs) can act as a proxy marker for underlying neuropsychological deficits. The present study aims to study the NSSs in pediatric patients with HIV and compare with healthy controls (HCs).

MATERIALS AND METHODS

Forty-eight children aged between 6 and 16 years diagnosed with HIV were selected by purposive sampling, and the Physical and Neurological Examination of Soft Signs (PANESS) scale was applied. Fifty children matched by age and sex were recruited from a nearby school, and the PANESS scale was applied. Children were divided into age- and gender-specific groups. The outcome scores of cases and controls groups were compared.

RESULTS

Males and females aged 13-16 years with HIV showed more soft signs as compared to HCs, with respect to gait errors, dysrhythmia, impersistence, speed of repetitive and sequenced movements, overflow with gaits, overflow with sequenced movements, total overflow, and overflow in excess of age. The differences in scores were less marked in younger age groups among both the genders.

CONCLUSIONS

The persistence of NSSs in older age group in HIV-infected children may point toward the presence of HIV-associated neurological disorder.

ADHD research in India: A narrative review

INTRODUCTION

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder with no clear etiopathogenesis. Owing to unique socio cultural milieu of India, it is worthwhile reviewing research on ADHD from India and comparing findings with global research. Thereby, we attempted to provide a comprehensive overview of research on ADHD from India.

METHODS

A boolean search of articles published in English from September 1966 to January 2017 on electronic search engines Google Scholar, PubMed, IndMED, MedIND, using the search terms "ADHD", "Attention Deficit and Hyperactivity Disorder", "Hyperactivity" ,"Child psychiatry", "Hyperkinetic disorder", "Attention Deficit Disorder", "India"was carried out and peer - reviewed studies conducted among human subjects in India were included for review. Case reports, animal studies, previous reviews were excluded from the current review.

RESULTS

Results of 73 studies found eligible for the review were organized into broad themes such as epidemiology, etiology, course and follow up, clinical profile and comorbidity, assessment /biomarkers, intervention/treatment parameters, pathways to care and knowledge and attitude towards ADHD.

DISCUSSION

There was a gap noted in research from India in the domains of biomarkers, course and follow up and non-pharmacological intervention. The prevalence of ADHD as well as comorbidity of Bipolar Disorder was comparatively lower compared to western studies. The studies found unique to India include comparing the effect of allopathic intervention with Ayurvedic intervention, yoga as a non pharmacological intervention. There is a need for studies from India on biomarkers, studies with prospective research design, larger sample size and with matched controls.

Neurological soft signs, but not theory of mind and emotion recognition deficit distinguished children with ADHD from healthy control

Attention Deficit Hyperactivity Disorder (ADHD) is associated with social cognition impairment, executive dysfunction and motor abnormalities, consisting in the persistence of neurological soft signs (NSS). Theory of mind (ToM) and emotion recognition (ER) deficit of children with ADHD have been interpreted as a consequence of their executive dysfunction, particularly inhibitory control deficit. To our knowledge, there are not studies that evaluate the possible correlation between the ToM and ER deficit and NSS in the population with ADHD, while this association has been studied in other psychiatric disorders, such as schizophrenia. Therefore, the aim of this study was to evaluate ToM and ER and NSS in a sample of 23 drug-naïve children with ADHD and a sample of 20 healthy children and the possible correlation between social cognition dysfunction and NSS in ADHD. Our findings suggest that ToM and ER dysfunction is not a constant feature in the population with ADHD, while NSS confirmed as a markers of atypical neurodevelopment and predictors of the severity of functional impairment in children with ADHD.

Retinal photography: A window into the cardiovascular-brain link in adolescent bipolar disorder

OBJECTIVE

The burden of cardiovascular disease in bipolar disorder (BD) exceeds what can be explained by traditional cardiovascular risk factors (CVRFs), lifestyle, and/or medications. Moreover, neurocognitive deficits are a core feature of BD, and are also related to CVRFs. We examined retinal vascular photography, a proxy for cerebral microvasculature, in relation to CVRFs, peripheral microvascular function, and neurocognition among BD adolescents.

METHODS

Subjects were 30 adolescents with BD and 32 healthy controls (HC). Retinal photography was conducted using a Topcon TRC 50 DX, Type IA camera, following pupil dilation. Retinal arteriolar and venular caliber was measured, from which the arterio-venular ratio (AVR) was computed. All measures were conducted masked to participant diagnosis. Peripheral arterial tonometry measured endothelial function. Neurocognition was assessed using the Cambridge Neuropsychological Tests Automated Battery.

RESULTS

AVR was not significantly different between groups (Cohen's d=0.18, p=0.103). Higher diastolic blood pressure (BP) was associated with lower (worse) AVR in BD (r=-0.441, p=0.015) but not HC (r=-0.192, p=0.293). Similarly, in the BD group only, higher (better) endothelial function was associated with higher AVR (r=0.375, p=0.041). Hierarchical regression models confirmed that, independent of covariates, retinal vascular caliber was significantly associated with diastolic BP and endothelial function in BD. Within the BD group, mood scores were significantly negatively correlated with AVR (β=-0.451, p=0.044).

LIMITATIONS

This study's limitations include a small sample size, a cross-sectional study design, and a heterogeneous sample.

CONCLUSION

Retinal photography may offer unique insights regarding the cardiovascular and neurocognitive burden of BD. Larger longitudinal studies are warranted.

Cognitive flexibility and performance in children and adolescents with threshold and sub-threshold bipolar disorder

Greater understanding of cognitive function in children and adolescents with bipolar disorder (BD) is of critical importance to improve our ability to design targeted treatments to help with real-world impairment, including academic performance. We sought to evaluate cognitive performance among children with either BD type I, II, or "not otherwise specified" (NOS) participating in multi-site Course and Outcome of Bipolar Youth study compared to typically developing controls (TDC) without psychopathology. In particular, we sought to test the hypothesis that BD-I and BD-II youths with full threshold episodes of mania or hypomania would have cognitive deficits, including in reversal learning, vs. those BD-NOS participants with sub-threshold episodes and TDCs. N = 175 participants (BD-I = 81, BD-II = 11, BD-NOS = 28, TDC = 55) completed Cambridge Neuropsychological Automated Testing Battery (CANTAB) tasks. A priori analyses of the simple reversal stage of the CANTAB intra-/extra-dimensional shift task showed that aggregated BD-I/II participants required significantly more trials to complete the task than either BD-NOS participants with sub-syndromal manic/hypomanic symptoms or than TDCs. BD participants across sub-types had impairments in sustained attention and information processing for emotionally valenced words. Our results align with prior findings showing that BD-I/II youths with distinct episodes have specific alterations in reversal learning. More broadly, our study suggests that further work is necessary to see the interaction between neurocognitive performance and longitudinal illness course. Additional work is required to identify the neural underpinnings of these differences as targets for potential novel treatments, such as cognitive remediation.

Association of Attention Deficit Disorder With Bedside Anti-saccades in Survivors of Childhood Leukemia

Impaired attention is well recognized in childhood cancer survivors. We prospectively evaluated 162 long-term survivors of childhood acute lymphoblastic leukemia to study an association between presence of neurologic soft signs as measured by Zurich Neuromotor Scale, bedside evaluation of anti-saccades, and attention deficit disorder. Attention deficit disorder was recognized in 10.5% of the study cohort. We did not find an association of attention deficit with presence of any soft sign. However, there was an association between presence of abnormal anti-saccades and attention deficit (P = .04). These results will require further validation and if confirmed may introduce a quick bedside method of assessing impaired attention in cancer survivors.

Neurological soft signs in children with attention deficit hyperactivity disorder: Their relationship to executive function and parental neurological soft signs

The correlations between neurological soft signs (NSS) in children with attention deficit hyperactivity disorder (ADHD) and their executive function, symptoms of inattention, and hyperactivity-impulsivity and the NSS of their parents remain unclear. This study aimed to examine: (1) the prevalence of NSS in children with ADHD and their parents; (2) the correlation between the NSS of children with ADHD and the NSS of their parents; and (3) the correlation between the NSS of children with ADHD and their executive function and symptoms. NSS were assessed with the Cambridge Neurological Inventory (CNI) in 57 children with ADHD (and 80 parents) and 60 healthy children (and 75 parents). Executive function was measured with the Behavioral Rating Inventory of Executive Function (BRIEF). Children with ADHD and their parents had significantly higher NSS than normal children and their parents, respectively, and the NSS of children with ADHD were correlated more strongly with the NSS of their fathers than their mothers. No correlation was found between NSS and BRIEF executive function, but Disinhibition in children with ADHD was significantly correlated with hyperactivity-impulsivity symptoms. Paternal and maternal NSS provided different predictions for child NSS. It may be that NSS are more likely to be genetically transmitted by fathers.

Comorbidity in pediatric bipolar disorder: prevalence, clinical impact, etiology and treatment

BACKGROUND

Research on pediatric bipolar disorder (PBD) is providing a plethora of empirical findings regarding its comorbidity. We addressed this question through a systematic review concerning the prevalence, clinical impact, etiology and treatment of main comorbid disorders involved.

METHOD

A comprehensive database search was performed from 1990 to August 2014. Overall, 167 studies fulfilled the inclusion criteria.

RESULTS

Bipolar youth tend to suffer from comorbid disorders, with highest weighted mean prevalence rate arising from anxiety disorders (54%), followed by attention deficit hyperactivity disorder (ADHD) (48%), disruptive behavior disorders (31%), and substance use disorders (SUD) (31%). Furthermore, evidence indicates that ADHD and anxiety disorders negatively affect the symptomatology, neurocognitive profile, clinical course and the global functioning of PBD. Likewise, several theories have been posited to explain comorbidity rates in PBD, specifically common risk factors, one disorder being a risk factor for the other and nosological artefacts. Lastly, randomized controlled trials highlight a stronger therapeutic response to stimulants and atomoxetine (vs. placebo) as adjunctive interventions for comorbid ADHD symptoms. In addition, research focused on the treatment of other comorbid disorders postulates some benefits from mood stabilizers and/or SGA.

LIMITATIONS

Epidemiologic follow-up studies are needed to avoid the risk of nosological artefacts. Likewise, more research is needed on pervasive developmental disorders and anxiety disorders, especially regarding their etiology and treatment.

CONCLUSIONS

Psychiatric comorbidity is highly prevalent and is associated with a deleterious clinical effect on pediatric bipolarity. Different etiological pathways may explain the presence of these comorbid disorders among bipolar youth. Standardized treatments are providing ongoing data regarding their effectiveness for these comorbidities among bipolar youth.

Sensory and motor secondary symptoms as indicators of brain vulnerability

In addition to the primary symptoms that distinguish one disorder from the next, clinicians have identified, yet largely overlooked, another set of symptoms that appear across many disorders, termed secondary symptoms. In the emerging era of systems neuroscience, which highlights that many disorders share common deficits in global network features, the nonspecific nature of secondary symptoms should attract attention. Herein we provide a scholarly review of the literature on a subset of secondary symptoms––sensory and motor. We demonstrate that their pattern of appearance––across a wide range of psychopathologies, much before the full-blown disorder appears, and in healthy individuals who display a variety of negative symptoms––resembles the pattern of appearance of network abnormalities. We propose that sensory and motor secondary symptoms can be important indicators of underlying network aberrations and thus of vulnerable brain states putting individuals at risk for psychopathology following extreme circumstances.

Negative emotion interference during a synonym matching task in pediatric bipolar disorder with and without attention deficit hyperactivity disorder

This study examined whether processing of emotional words impairs cognitive performance in acutely ill patients with pediatric bipolar disorder (PBD), with or without comorbid attention-deficit hyperactivity disorder (ADHD), relative to healthy controls (HC). Forty youths with PBD without ADHD, 20 youths with PBD and ADHD, and 29 HC (mean age = 12.97 ± 3.13) performed a Synonym Matching task, where they decided which of two probe words was the synonym of a target word. The three words presented on each trial all had the same emotional valence, which could be negative, positive, or neutral. Relative to HC both PBD groups exhibited worse accuracy for emotional words relative to neutral ones. This effect was greater with negative words and observed regardless of whether PBD patients had comorbid ADHD. In the PBD group without ADHD, manic symptoms correlated negatively with accuracy for negative words, and positively with reaction time (RT) for all word types. Our findings suggest a greater disruptive effect of emotional valence in both PBD groups relative to HC, reflecting the adverse effect of altered emotion processing on cognitive function in PBD. Future studies including an ADHD group will help clarify how ADHD symptoms may affect emotional interference independently of PBD.

White matter microstructural abnormalities in bipolar disorder: A whole brain diffusion tensor imaging study

Background

Bipolar disorder (BD) is a chronic mental illness characterized by severe disruptions in mood and cognition. Diffusion tensor imaging (DTI) studies suggest that white matter (WM) tract abnormalities may contribute to the clinical hallmarks of the disorder. Using DTI and whole brain voxel-based analysis, we mapped the profile of WM anomalies in BD. All patients in our sample were euthymic and lithium free when scanned.

Methods

Diffusion-weighted and T1-weighted structural brain images were acquired from 23 lithium-free euthymic subjects with bipolar I disorder and 19 age- and sex-matched healthy control subjects on a 1.5 T MRI scanner. Scans were processed to provide measures of fractional anisotropy (FA) and mean and radial diffusivity (MD and RD) at each WM voxel, and processed scans were nonlinearly aligned to a customized brain imaging template for statistical group comparisons.

Results

Relative to controls, the bipolar group showed widespread regions of lower FA, including the corpus callosum, cortical and thalamic association fibers. MD and RD were abnormally elevated in patients in many of these same regions.

Conclusions

Our findings agree with prior reports of WM abnormalities in the corpus callosum and further link a bipolar diagnosis with structural abnormalities of the tapetum, fornix and stria terminalis. Future studies assessing the diagnostic specificity and prognostic implications of these abnormalities would be of interest.

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Using DTI and whole brain voxel-based analysis, we mapped WM anomalies in BD.

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Relative to controls, the bipolar group showed widespread regions of lower FA.

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MD and RD were abnormally elevated in patients in many of these same regions.

Executive deficits in early onset bipolar disorder versus ADHD: impact of processing speed and lifetime psychosis

Executive deficits are reported in both early onset bipolar disorder (BD) and attention-deficit hyperactivity disorder (ADHD), and controversies regarding comorbidity and symptom overlap have complicated the research on executive function in BD. Reports of the negative impact of executive difficulties on academic functioning indicate a need for a greater focus on executive difficulties in early onset psychiatric disorders. Executive function and processing speed in youths with BD (n = 4), ADHD (n = 26) and BD + ADHD (n = 13) were compared with controls (n = 69). All clinical groups demonstrated executive impairment. The combined group was most impaired. There were no significant differences between the groups. Executive deficit in the BD group was associated with a history of psychotic symptoms. The BD-nonpsychotic group was impaired only with regard to processing speed. Processing speed adjustment improved working memory and normalized interference control in both BD and ADHD.

CONCLUSION

executive deficits in BD may be determined by a history of psychotic symptoms rather than by comorbid ADHD. Some aspects of executive problems appear speed-related.

An update on the debated association between ADHD and bipolar disorder across the lifespan

Diagnostic formulations for attention deficit hyperactivity disorder (ADHD) and bipolar disorder (BD) both include symptoms of distractibility, psychomotor agitation and talkativeness, alongside associated emotional features (irritability and emotional lability). Treatment studies suggest the importance of accurate delineation of ADHD and BD. However, boundaries between the two disorders are blurred by the introduction of broader conceptualisations of BD. This review attempts to elucidate whether associations between ADHD and BD are likely to be driven by superficial symptomatological similarities or by a more meaningful etiological relationship between the disorders. This is achieved by outlining findings on comorbidity, temporal progression of the disorders, familial co-variation, and neurobiology in ADHD and BD across the lifespan. Longitudinal studies fail to consistently show developmental trajectories between ADHD and BD. Comparative research investigating neurobiology is in its infancy, and although some similarities are seen between ADHD and BD, studies also emphasise differences between the two disorders. However, comorbidity and family studies appear to show that the two disorders occur together and aggregate in families at higher than expected rates. Furthermore close inspection of results from population studies reveals heightened co-occurrence of ADHD and BD even in the context of high comorbidity commonly noted in psychopathology. These results point towards a meaningful association between ADHD and BD, going beyond symptomatic similarities. However, future research needs to account for heterogeneity of BD, making clear distinctions between classical episodic forms of BD, and broader conceptualisations of the disorder characterised by irritability and emotional lability, when evaluating the relationship with ADHD.

Examination of neurological subtle signs in ADHD as a clinical tool for the diagnosis and their relationship to spatial working memory

BACKGROUND

  Neurological subtle signs (NSS) are minor neurological abnormalities that have been shown to be increased in a number of neurodevelopmental conditions. For attention deficit/hyperactivity disorder (ADHD), it remains unclear whether NSS may aid the clinical diagnostic process.

METHODS

  This study explored the association of total and specific domains of NSS in 1,055 children and adolescents with ADHD compared to 130 age-matched typically developing participants; the relationship between NSS and Spatial Working Memory (SWM) as a cognitive process integrally involved in ADHD was also assessed. To determine the diagnostic and predictive efficiency of NSS, a receiver operating curve analysis was performed and the area under the curve (AUC) quantified. The best discriminant points for differentiating between ADHD and typically developing participants and the predictive power of NSS for SWM impairment in ADHD young people were also calculated.

RESULTS

  Area under the curves for total NSS, smoothness/accuracy, cerebellar signs and choreo-athetoid movements scores were considered good (.84, .79, .74 and .73 respectively), and the results remained after controlling for gender and IQ. A total score of 13 or over on the Scored Developmental Neurological Examination proved to be a good threshold point for differentiating between the ADHD and typically developing participants. For ADHD children, the AUC of total NSS to distinguish between those below 25th and above 75th percentile were .77 and .73 for Spatial Span and for Between Search Errors respectively (the two SWM-dependent measures examined).

CONCLUSIONS

  This study provides evidence suggesting that NSS may aid the clinical evaluation of a child or adolescent with ADHD. In children and adolescents with ADHD, NSS are associated with difficulties in SWM, specifically the Spatial Span and Between Search Error components.

Neurological soft signs in children with attention deficit hyperactivity disorder

CONTEXT

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder with wide repercussions. Since it is etiologically related to delayed maturation, neurological soft signs (NSS) could be a tool to assess this. Further the correlation of NSS with severity and type of ADHD and presence of Specific Learning Disability (SLD) would give further insight into it.

AIMS

To study neurological soft signs and risk factors (type, mode of delivery, and milestones) in children with ADHD and to correlate NSS with type and severity of ADHD and with co-morbid Specific Learning Disability.

SETTINGS AND DESIGN

The study was carried out in Child care services of a tertiary teaching urban hospital. It was a cross-sectional single interview study.

MATERIALS AND METHODS

52 consecutive children diagnosed as having ADHD were assessed for the presence of neurological soft signs using Revised Physical and Neurological Examination soft Signs scale (PANESS). The ADHD was rated by parents using ADHD parent rating scale.

STATISTICAL ANALYSIS

The data was analyzed using the chi-squared test and Pearson's co-relational analysis.

RESULTS AND CONCLUSIONS

Neurological soft signs are present in 84% of children. They are equally present in both the inattentive-hyperactive and impulsive-hyperactive types of ADHD. The presence of neurological soft signs in ADHD are independent of the presence of co-morbid SLD. Dysrrhythmias and overflow with gait were typically seen for impulsive-hyperactive type and higher severity of ADHD is related to more errors.

Neural recruitment during failed motor inhibition differentiates youths with bipolar disorder and severe mood dysregulation

Controversy exists about whether non-episodic irritability (operationalized as severe mood dysregulation, SMD) should be considered a developmental presentation of pediatric bipolar disorder (BD). While assessments of brain function may address this controversy, only one fMRI study has compared BD versus SMD. We compared neural activation in BD, SMD, and controls during a motor inhibition task, since motor disinhibition is an important clinical feature in both BD and SMD. During failed inhibition, BD youths exhibited less activation in the right anterior cingulate cortex (ACC) and right nucleus accumbens relative to both SMD and healthy youths. Exploratory analyses indicate that, in BD youths, reduced activation in the right ACC may be independent of comorbid ADHD. These findings highlight neural distinctions between the phenotypically related BD and SMD populations.

Neural correlates of reversal learning in severe mood dysregulation and pediatric bipolar disorder

OBJECTIVE

Outcome and family history data differentiate children with severe mood dysregulation (SMD), a syndrome characterized by chronic irritability, from children with "classic" episodic bipolar disorder (BD). Nevertheless, the presence of cognitive inflexibility in SMD and BD highlights the need to delineate neurophysiologic similarities and differences between the two patient groups. Functional magnetic resonance imaging was used to examine neural correlates of cognitive flexibility deficits in patients with SMD and BD versus healthy volunteers (HV).

METHOD

During functional magnetic resonance imaging, subjects completed a response reversal task that assessed cognitive flexibility (n = 22 with SMD, 26 with BD, 34 HV). Task effects were examined in four regions of interest: caudate, cingulate gyrus, inferior frontal gyrus (IFG), and ventromedial prefrontal cortex.

RESULTS

Diagnosis-by-accuracy interactions emerged in the caudate and IFG. In these regions, the difference in activation was calculated between incorrect and correct trials. In the caudate, this value was smaller in subjects with SMD and with BD than in HV. In the IFG, however, this value was smaller in subjects with SMD than in those with BD and in HV. Post hoc analyses indicated that comorbid attention-deficit/hyperactivity disorder in patients may influence the caudate findings. Exploratory whole-brain analysis confirmed the caudate and IFG findings. In addition, other regions differentiating SMD from BD were identified (e.g., superior parietal lobule/precuneus and inferior temporal gyrus).

CONCLUSIONS

In response to errors, similar perturbations occur in the caudate for youth with SMD and BD compared with HV youth. IFG deficits, in contrast, manifest in youth with SMD, but not with BD.

Brain functional domains inform therapeutic interventions in attention-deficit/hyperactivity disorder and pediatric bipolar disorder

A deeper understanding of how the relationships between impulsivity, reward systems and executive function deficits may be similar or different in attention-deficit/hyperactivity disorder (ADHD) and pediatric bipolar disorder (PBD) is fundamental for better defining phenotypy in these two developmental illnesses, and moving towards improved treatment and intervention. We focus our article on recent neurocognitive and neuroimaging data examining the behavioral and neural aspects of poor behavior regulation, response inhibition and reward systems in ADHD and PBD. In light of recent research evidence, we propose that the common behavioral manifestations of impulsivity in ADHD and PBD may indeed originate from different neural mechanisms mediated by altered reward systems. In order to define and differentiate these mechanisms, unlike previous approaches, our theoretical model examines the interface of the dorsal frontostriatal circuit, involved in behavior regulation, and the ventral frontostriatal circuit, which is involved in reward-related and affect processes. Preliminary evidence suggests that the neural systems involved in impulsivity, reward systems and executive function engage differently in the two illnesses. In PBD, 'emotional impulsivity' is predominantly 'bottom-up' and emotionally/motivationally driven, and stems from ventral frontostriatal circuitry dysfunction. By contrast, in ADHD 'cognitive impulsivity' is predominantly 'top-down' and more 'cognitively driven', and stems from dorsal frontostriatal dysfunction. We discuss this evidence in view of clinically relevant questions and implications for illness-based intervention. We conclude that the reward-related mechanisms underlying the interactions between executive function, behavior regulation and impulsivity in PBD and ADHD may be differentially compromised, and in accordance differently shape the clinical symptoms of impulsivity and goal-directed behavior.

Poor fine-motor and visuospatial skills predict persistence of pediatric-onset obsessive-compulsive disorder into adulthood

BACKGROUND

Half of pediatric-onset OCD cases remit by adulthood. Studies have demonstrated that initial response to pharmacotherapy, age of onset, prominent hoarding symptoms, and the presence of comorbid tic disorders are associated with long-term outcome. Our goal was to examine the association between childhood performance on neuropsychological testing and persistence of OCD into adulthood.

METHODS

Twenty-four children with OCD were followed for an average of 7.5 years into early adulthood. Neuropsychological performance in childhood (<16 years) was measured. The battery included the Wechsler Intelligence Scale for Children (WISC-III), the Purdue pegboard test, the Rey-Osterreith Complex Figure Task (RCFT) and the Beery-Buktenica test of Visual Motor Integration (VMI). We hypothesized that deficits in fine-motor skills, visuospatial skills, and nonverbal memory as well as overall intelligence would be associated with adulthood outcome. We used a Cox proportional hazard model of survival analysis in which time to remission of OCD symptoms was the main outcome variable.

RESULTS

Poor childhood performance on the Purdue pegboard task and the block design subscale of WISC-III was associated with persistence of OCD symptoms into adulthood. IQ, VMI, and nonverbal memory performance did not predict significantly the persistence of OCD.

CONCLUSIONS

These results suggest that visuospatial and fine-motor skill deficits are predictive of poor long-term outcome in pediatric-onset OCD. Future longitudinal studies are needed to chart the course of these deficits relative to the course of symptoms in OCD and to determine whether the association of these neuropsychiatric deficits with long-term outcome is specific to pediatric-onset OCD or generalizes to other psychiatric disorders.

The structure of cognitive abilities in youths with manic symptoms: a factorial invariance study

This study compared the structure of cognitive ability (specifically, verbal/crystallized [Gc] and visual-spatial ability [Gv]), as measured in the Wechsler Intelligence Scale for Children, in youth with manic symptoms with a nationally representative group of similarly aged youth. Multigroup confirmatory factor analysis found the majority of the estimated parameters were invariant between the groups, although there was a difference in the intercepts for the Similarities subtest and difference in unique variances for the Picture Completion, Comprehension, and Picture Arrangement subtests. Thus, although there are many neurological changes associated with manic symptoms, the structure of verbal/crystallized and visual-spatial abilities appear relatively robust and invariant. As Gc and Gv are the primary domains on all the Wechsler Intelligence Scales for Children, results also indicate that clinical interpretation of the Wechsler scales may be appropriate to measure cognitive performance in youths with manic symptoms.

Altered neural function in pediatric bipolar disorder during reversal learning

OBJECTIVE

Data documenting the functional impairment associated with the diagnosis of bipolar disorder (BD) in children and adolescents highlight the need for greater understanding of its pathophysiology. Toward that end, we demonstrated previously that BD youth have behavioral deficits on reversal learning tasks. On such tasks, participants must first acquire a stimulus/response relationship through trial-and-error learning, and then discern when the stimulus/reward relationship reverses. Here, we use event-related functional magnetic resonance imaging (fMRI) to elucidate neural correlates of reversal learning deficits in euthymic BD youth compared to typically developing controls.

METHOD

  We compared euthymic pediatric BD participants (n = 16) versus age-, sex-, and IQ-matched controls (n = 16). Our main outcome measure was blood oxygen level-dependent (BOLD) signal measured with fMRI during an event-related probabilistic reversal task.

RESULTS

Pediatric BD participants had significantly greater neural activity than controls in fronto-parietal regions during the reversal phase, particularly in response to punished reversal errors (p < 0.05 corrected for multiple comparisons).

CONCLUSIONS

Our current study suggests that during reversal learning, BD youths inefficiently recruit regions associated with processing response conflict and implementing alternative responses, including subdivisions of the frontal cortex and the parietal cortex. Such deficits are present in euthymic BD youth. Further work is necessary to evaluate the specificity of such alterations.

Neurological soft signs in juvenile patients with Asperger syndrome, early-onset psychosis, and healthy controls

AIM

The study of neurological soft signs (NSS) in patients with Asperger syndrome may help us to elucidate the neurological basis of this disorder and to clarify its relationship with other neurodevelopmental disorders. The goal of this study was to compare the prevalence of NSS in a sample of patients with Asperger syndrome, early-onset psychosis and healthy controls.

METHOD

NSS were assessed by means of the Neurological Evaluation Scale in a sample of 29 patients with Asperger syndrome (mean age = 12.86 ± 2.58 years), 30 patients with first-episode early-onset psychoses (mean age 14.17 ± 1.02 years) and 30 healthy controls (mean age 12.33 ± 2.69 years).

RESULTS

Significant group differences were found between Asperger syndrome patients and healthy controls both in all the Neurological Evaluation Scale subscales and in the Neurological Evaluation Scale total score. There were no significant differences between both groups of patients in any of the Neurological Evaluation Scale scores.

CONCLUSIONS

NSS are more prevalent in Asperger syndrome than in healthy controls. The NSS profile was not disorder-specific in our samples of patients with Asperger syndrome and early-onset psychoses.

Emotion processing influences working memory circuits in pediatric bipolar disorder and attention-deficit/hyperactivity disorder

OBJECTIVE

This functional magnetic resonance imaging (fMRI) study examined how working memory circuits are affected by face emotion processing in pediatric bipolar disorder (PBD) and attention-deficit/hyperactivity disorder (ADHD).

METHODS

A total of 23 patients with PBD, 14 patients with ADHD, and 19 healthy control (HC) subjects (mean age, 13.36 ± 2.55 years) underwent an affective, two-back fMRI task with blocks of happy, angry, and neutral faces.

RESULTS

For angry versus neutral faces PBD patients, relative to ADHD patients, exhibited increased activation in the subgenual anterior cingulate cortex (ACC) and orbitofrontal cortex, and reduced activation in the dorsolateral prefrontal cortex (DLPFC) and premotor cortex. Relative to the HC group, the PBD group showed no increased activation and reduced activation at the junction of DLPFC and ventrolateral prefrontal cortex (VLPFC). Relative to HC, the ADHD patients exhibited greater activation in the DLPFC and reduced activation in the ventral and medial PFC, pregenual ACC, striatum, and temporo-parietal regions. For happy versus neutral faces, relative to the ADHD group, the PBD group exhibited greater activation in the bilateral caudate, and relative to the HC group the ADHD group showed increased activation in the DLPFC, striatal, and parietal regions, and no reduced activation. The ADHD group, compared with the HC group, showed no reduced activation and increased activation in regions that were underactive for the angry face condition.

CONCLUSIONS

Relative to the ADHD group, the PBD group exhibited greater deployment of the emotion-processing circuitry and reduced deployment of working memory circuitry. Commonalities across PBD and ADHD patients, relative to the HC individuals, entailed cortico-subcortical activity that was reduced under negative emotional challenge and increased under positive emotional challenge.

Genetics and intermediate phenotypes of the schizophrenia--bipolar disorder boundary

Categorization of psychotic illnesses into schizophrenic and affective psychoses remains an ongoing controversy. Although Kraepelinian subtyping of psychosis was historically beneficial, modern genetic and neurophysiological studies do not support dichotomous conceptualization of psychosis. Evidence suggests that schizophrenia and bipolar disorder rather present a clinical continuum with partially overlapping symptom dimensions, neurophysiology, genetics and treatment responses. Recent large scale genetic studies have produced inconsistent findings and exposed an urgent need for re-thinking phenomenology-based approach in psychiatric research. Epidemiological, linkage and molecular genetic studies, as well as studies in intermediate phenotypes (neurocognitive, neurophysiological and anatomical imaging) in schizophrenia and bipolar disorders are reviewed in order to support a dimensional conceptualization of psychosis. Overlapping and unique genetic and intermediate phenotypic signatures of the two psychoses are comprehensively recapitulated. Alternative strategies which may be implicated into genetic research are discussed.

Pathophysiology of NSS in ADHD

Attention deficit/hyperactivity disorder (ADHD) is the behavioural disorder most commonly diagnosed in childhood. In addition to the main symptoms of inattention, impulsiveness and hyperactivity, neurological soft signs (NSS) are often associated with ADHD. NSS are discrete motor and sensory disorders that cannot be linked to specific cerebral lesions. We review all the scientific contributions on NSS in ADHD. The conclusions support the presence of an alteration in the neural networks for motor control inhibition, at the base of the pathophysiology of NSS in children with ADHD, as well as a possible central role of dopamine in these neural circuits.

Neural correlates of response inhibition in pediatric bipolar disorder and attention deficit hyperactivity disorder

Impulsivity, inattention and poor behavioral inhibition are common deficits in pediatric bipolar disorder (PBD) and attention deficit hyperactivity disorder (ADHD). This study aimed to identify similarities and differences in the neural substrate of response inhibition deficits that are associated with these disorders. A functional magnetic resonance imaging (fMRI) study was conducted on 15 unmedicated PBD patients (Type I, manic/mixed), 11 unmedicated ADHD patients, and 15 healthy controls (HC) (mean age = 13.5 years; S.D. = 3.5). A response inhibition task examined the ability to inhibit a motor response to a target when a stop cue appeared shortly after. The PBD and ADHD groups did not differ on behavioral performance, although both groups were less accurate than the HC group. fMRI findings showed that for trials requiring response inhibition, the ADHD group, relative to the PBD and HC groups, demonstrated reduced activation in both ventrolateral (VLPFC) and dorsolateral (DLPFC) prefrontal cortex, and increased bilateral caudate activation compared with HC. The PBD group, relative to HC, showed decreased activation in the left VLPFC, at the junction of the inferior and middle frontal gyri, and in the right anterior cingulate cortex (ACC). Prefrontal dysfunction was observed in both the ADHD and PBD groups relative to HC, although it was more extensive and accompanied by subcortical overactivity in ADHD.

White matter abnormalities in bipolar disorder: insights from diffusion tensor imaging studies

Diffusion tensor imaging (DTI) is a neuroimaging technique with the potential to elucidate white matter abnormalities. Recently, it has been applied to help in better understanding of the pathophysiology of bipolar disorder (BD). This review sought to synthesise existing literature on DTI studies in BD, summarise current findings and highlight brain regions that have consistently been implicated in BD, as well as posit possible future directions for DTI research in BD. The extant findings from this review suggest loss of white matter network connectivity as a possible phenomenon associated with bipolar disorder, involving prefrontal and frontal regions, projection, associative and commissural fibres, with sparse and less consistent evidence implicating the subcortical and non-frontal lobes of the brain. There are some differences in the direction of changes observed in white matter indices, and these may be attributed to factors including sample heterogeneity and limitations of DTI techniques. The possible roles of the parietal, temporal and occipital lobes and subcortical regions in BD await further investigation. Studies of bipolar disorder using DTI lag behind other neuropsychiatric diseases such as schizophrenia, but DTI research in BD is fast gaining pace. The emerging trends from these DTI findings underscore the importance of further research to unravel the underlying neural mechanisms and clinico-anatomical correlations involving white matter in BD.

Differential engagement of cognitive and affective neural systems in pediatric bipolar disorder and attention deficit hyperactivity disorder

This fMRI study investigates the neural bases of cognitive control of emotion processing in pediatric bipolar disorder (PBD) and attention deficit hyperactivity disorder (ADHD). Seventeen un-medicated PBD patients, 15 un-medicated ADHD patients, and 14 healthy controls (HC) (mean age = 13.78 +/- 2.47) performed an emotional valence Stroop Task, requiring them to match the color of an emotionally valenced word to the color of either of two adjacent circles. Both patient groups responded significantly slower than HC, but there were no group differences in accuracy. A voxel-wise analysis of variance on brain activation revealed a significant interaction of group by word valence [F(2,41) = 4.44; p = .02]. Similar group differences were found for negative and positive words. For negative versus neutral words, both patient groups exhibited greater activation in dorsolateral prefrontal cortex (DLPFC) and parietal cortex relative to HC. The PBD group exhibited greater activation in ventrolateral prefrontal cortex (VLPFC) and anterior cingulate cortex (ACC) relative to HC. The ADHD group exhibited decreased VLPFC activation relative to HC and the PBD group. During cognitive control of emotion processing, PBD patients deployed the VLPFC to a greater extent than HC. The ADHD patients showed decreased VLPFC engagement relative to both HC and PBD patients.

Motor function may differentiate attention deficit hyperactivity disorder from early onset bipolar disorder

BACKGROUND

Differentiating between bipolar spectrum disorder (BD) and attention deficit hyperactivity disorder (ADHD) in childhood and adolescence is difficult because the clinical presentation is influenced by ongoing neural development, causing considerable symptom overlap. Motor problems and neurological soft signs have been associated with ADHD for decades. Little is known about motor skills in BD. Here we assess the diagnostic accuracy of neuromotor deviations in differentiating ADHD from BD in clinical practice. We also investigate if these deviations exist in concurrent ADHD and BD, thus indicating true comorbidity

METHODS

64 patients 6-18 years (31 girls, 33 boys) fulfilling the diagnostic criteria of BD, ADHD combined subtype (ADHD-C) or comorbid BD and ADHD-C, were compared using an age-standardized neuromotor test; NUBU. Categorical variables were analyzed using cross table with two-tailed chi square test or Fisher's exact test when appropriate. Continuous variables were analyzed by Kruskal-Wallis test and, if significant, Mann-Whitney U test and ROC plots.

RESULTS

The ADHD-C group and the comorbid ADHD-C and BD group both showed significantly more neurological soft signs (p less than 0.01) and lower mean static coordination percentile (p less than 0.01) than the BD group. The positive predictive value of NUBU in the diagnosis of ADHD-C with or without concurrent BD was 89% (80-95) for total soft signs and 87% (79-95) for static coordination below the 7.5 percentile.

CONCLUSION

An age-standardized neuromotor test battery may promote diagnostic accuracy in differentiating ADHD from BD in clinical practice, and help evaluating whether symptoms of ADHD in children who have BD reflect symptom overlap or real comorbidity. This may have important implications for everyday diagnostic work.

Magnetic resonance imaging studies in early onset bipolar disorder: an updated review

Over the past 5-10 years, advances in neuroimaging methods and study designs have begun to appear in the literature of early-onset bipolar disorder (onset before 18 years of age). This article contains an updated review of the literature regarding neuroimaging in youths with bipolar disorder (BPD), highlighting important new study designs and techniques. Overall, structural, functional (fMRI) and magnetic resonance spectroscopy (MRS) report consistent abnormalities in regions of the frontal lobe and limbic structures. Functional MRI and MRS studies also frequently report striatal and thalamic abnormalities in early-onset BPD. Future neuroimaging studies in youths with BPD should include longitudinal studies incorporating multimodal neuroimaging techniques.

Cerebellar ataxia in youths at risk for bipolar disorder

OBJECTIVE

Structural, biochemical, and functional cerebellar abnormalities occur in individuals with or at-risk for developing bipolar disorder (BD), but the clinical implications of these abnormalities are unknown. The present study examined cerebellar function in youths who were at familial risk for BD by comparing ataxia battery scores of youths with a bipolar parent to those of healthy youths.

METHODS

Trained raters administered an ataxia battery, consisting of three tasks, to children (aged 8-12 years) with at least one parent with BD type I (BDI) who themselves did not have BDI (at-risk or AR group, n = 21) and healthy comparison children (aged 8-12 years) with parents free of DSM-IV Axis I psychopathology (HC group, n = 23).

RESULTS

AR youths performed worse than HC youths on the Sharpened Romberg test (subjects standing heel-to-toe) and standing on one foot with eyes open (p < 0.02).

CONCLUSIONS

The results indicate that youths at familial risk for BD have more difficulty performing a Sharpened Romberg test than a HC group, suggesting that midline cerebellar dysfunction may be a biomarker for the future development of BD. Further studies examining the relationships among youths at risk for BD, coordination abnormalities, and cerebellar dysfunction are needed.