The cerebellum in cognitive processes: supporting studies in children

Emergence of syntax and word prediction in an artificial neural circuit of the cerebellum

The cerebellum, interconnected with the cerebral neocortex, plays a vital role in human-characteristic cognition such as language processing, however, knowledge about the underlying circuit computation of the cerebellum remains very limited. To gain a better understanding of the computation underlying cerebellar language processing, we developed a biologically constrained cerebellar artificial neural network (cANN) model, which implements the recently identified cerebello-cerebellar recurrent pathway. We found that while cANN acquires prediction of future words, another function of syntactic recognition emerges in the middle layer of the prediction circuit. The recurrent pathway of the cANN was essential for the two language functions, whereas cANN variants with further biological constraints preserved these functions. Considering the uniform structure of cerebellar circuitry across all functional domains, the single-circuit computation, which is the common basis of the two language functions, can be generalized to fundamental cerebellar functions of prediction and grammar-like rule extraction from sequences, that underpin a wide range of cerebellar motor and cognitive functions. This is a pioneering study to understand the circuit computation of human-characteristic cognition using biologically-constrained ANNs.

B, Park K. Evaluation framework for facilitating the technology transfers of universities: Focusing on the perspective of technology donors

Technological innovation and preoccupation with new markets through technological innovation have become critical factors in achieving success in the global market. Currently, companies cannot develop and commercialize all technologies. Therefore, the importance of technology transfers is rapidly increasing. Technology transfer is a crucial strategy adopted by organizations to remain innovative and competitive. However, Korea's technology transfer rate is only 37.9%. In particular, the technology transfer rate from universities to companies is lower than that from government-funded research institutes in Korea. Although the fundamental approach for resolving barriers to technology transfer have been studied, previous research has been conducted from a narrow definition of technology transfer. Furthermore, previous research has focused on analyzing the success factors of technology transfer, presenting technology transfer processes, or conducting case studies. Therefore, it is necessary to develop a technology donor diagnosis framework based on CSFs (Critical Success Factors) to eliminate obstacles to technology transfers. To lower the barriers to technology transfers, it is necessary to develop a strategy for a successful technology transfer based on the diagnosis of technology donors. This study develops a diagnosis framework for universities from the perspective of technology donors, implements and tests the framework using case studies, and proposes strategies for each stage of technology transfer growth. The framework is able to assess multidimensional perspectives, because CSFs and PMs were extracted based on BSC. Furthermore, by comparing the perspectives score of technology donors in different universities, technology donors can identify the areas in which each university is lacking in its current situation. Multidimensional diagnosis and aggregation score of technology donors offer to extract optimal CSFs for technology transfer activation for each growth stage.

Differences between subclinical attention-deficit/hyperactivity and autistic traits in default mode, salience, and frontoparietal network connectivities in young adult Japanese

Attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are associated with attentional impairments, with both commonalities and differences in the nature of their attention deficits. This study aimed to investigate the neural correlates of ADHD and ASD traits in healthy individuals, focusing on the functional connectivity (FC) of attention-related large-scale brain networks (LSBNs). The participants were 61 healthy individuals (30 men; age, 21.9 ± 1.9 years). The Adult ADHD Self-Report Scale (ASRS) and Autism Spectrum Quotient (AQ) were administered as indicators of ADHD and ASD traits, respectively. Performance in the continuous performance test (CPT) was used as a behavioural measure of sustained attentional function. Functional magnetic resonance imaging scans were performed during the resting state (Rest) and auditory oddball task (Odd). Considering the critical role in attention processing, we focused our analyses on the default mode (DMN), frontoparietal (FPN), and salience (SN) networks. Region of interest (ROI)-to-ROI analyses (false discovery rate < 0.05) were performed to determine relationships between psychological measures with within-network FC (DMN, FPN, and SN) as well as with between-network FC (DMN-FPN, DMN-SN, and FPN-SN). ASRS scores, but not AQ scores, were correlated with less frequent commission errors and shorter reaction times in the CPT. During Odd, significant positive correlations with ASRS were demonstrated in multiple FCs within DMN, while significant positive correlations with AQ were demonstrated in multiple FCs within FPN. AQs were negatively correlated with FPN-SN FCs. During Rest, AQs were negatively and positively correlated with one FC within the SN and multiple FCs between the DMN and SN, respectively. These findings of the ROI-to-ROI analysis were only partially replicated in a split-half replication analysis, a replication analysis with open-access data sets, and a replication analysis with a structure-based atlas. The better CPT performance by individuals with subclinical ADHD traits suggests positive effects of these traits on sustained attention. Differential associations between LSBN FCs and ASD/ADHD traits corroborate the notion of differences in sustained and selective attention between clinical ADHD and ASD.

Distinct gray matter abnormalities in children/adolescents and adults with history of childhood maltreatment

Gray matter (GM) abnormalities have been reported in both adults and children/adolescents with histories of childhood maltreatment (CM). A comparison of effects in youth and adulthood may be informative regarding life-span effects of CM. Voxel-wise meta-analyses of whole-brain voxel-based morphometry studies were conducted in all datasets and age-based subgroups respectively, followed by a quantitative comparison of the subgroups. Thirty VBM studies (31 datasets) were included. The pooled meta-analysis revealed increased GM in left supplementary motor area, and reduced GM in bilateral cingulate/paracingulate gyri, left occipital lobe, and right middle frontal gyrus in maltreated individuals compared to the controls. Maltreatment-exposed youth showed less GM in the cerebellum, and greater GM in bilateral middle cingulate/paracingulate gyri and bilateral visual cortex than maltreated adults. Opposite GM alterations in bilateral middle cingulate/paracingulate gyri were found in maltreatment-exposed adults (decreased) and children/adolescents (increased). Our findings demonstrate different patterns of GM changes in youth closer to maltreatment events than those seen later in life, suggesting detrimental effects of CM on the developmental trajectory of brain structure.

Distinct multivariate structural brain profiles are related to variations in short- and long-delay memory consolidation across children and young adults

From early to middle childhood, brain regions that underlie memory consolidation undergo profound maturational changes. However, there is little empirical investigation that directly relates age-related differences in brain structural measures to memory consolidation processes. The present study examined memory consolidation of intentionally studied object-location associations after one night of sleep (short delay) and after two weeks (long delay) in normally developing 5-to-7-year-old children (n = 50) and young adults (n = 39). Behavioural differences in memory retention rate were related to structural brain measures. Our results showed that children, in comparison to young adults, retained correctly learnt object-location associations less robustly over short and long delay. Moreover, using partial least squares correlation method, a unique multivariate profile comprised of specific neocortical (prefrontal, parietal, and occipital), cerebellar, and hippocampal head and subfield structures in the body was found to be associated with variation in short-delay memory retention. A different multivariate profile comprised of a reduced set of brain structures, mainly consisting of neocortical (prefrontal, parietal, and occipital), hippocampal head, and selective hippocampal subfield structures (CA1-2 and subiculum) was associated with variation in long-delay memory retention. Taken together, the results suggest that multivariate structural pattern of unique sets of brain regions are related to variations in short- and long-delay memory consolidation across children and young adults.

Neuroimaging in cerebellar ataxia in childhood: A review

Ataxia is one of the most common pediatric movement disorders and can be caused by a large number of congenital and acquired diseases affecting the cerebellum or the vestibular or sensory system. It is mainly characterized by gait abnormalities, dysmetria, intention tremor, dysdiadochokinesia, dysarthria, and nystagmus. In young children, ataxia may manifest as the inability or refusal to walk. The diagnostic approach begins with a careful clinical history including the temporal evolution of ataxia and the inquiry of additional symptoms, is followed by a meticulous physical examination, and, depending on the results, is complemented by laboratory assays, electroencephalography, nerve conduction velocity, lumbar puncture, toxicology screening, genetic testing, and neuroimaging. Neuroimaging plays a pivotal role in either providing the final diagnosis, narrowing the differential diagnosis, or planning targeted further workup. In this review, we will focus on the most common form of ataxia in childhood, cerebellar ataxia (CA). We will discuss and summarize the neuroimaging findings of either the most common or the most important causes of CA in childhood or present causes of pediatric CA with pathognomonic findings on MRI. The various pediatric CAs will be categorized and presented according to (a) the cause of ataxia (acquired/disruptive vs. inherited/genetic) and (b) the temporal evolution of symptoms (acute/subacute, chronic, progressive, nonprogressive, and recurrent). In addition, several illustrative cases with their key imaging findings will be presented.

The Predictive Value of Dynamic Intrinsic Local Metrics in Transient Ischemic Attack

BACKGROUND

Transient ischemic attack (TIA) is known as "small stroke." However, the diagnosis of TIA is currently difficult due to the transient symptoms. Therefore, objective and reliable biomarkers are urgently needed in clinical practice.

OBJECTIVE

The purpose of this study was to investigate whether dynamic alterations in resting-state local metrics could differentiate patients with TIA from healthy controls (HCs) using the support-vector machine (SVM) classification method.

METHODS

By analyzing resting-state functional MRI (rs-fMRI) data from 48 patients with and 41 demographically matched HCs, we compared the group differences in three dynamic local metrics: dynamic amplitude of low-frequency fluctuation (d-ALFF), dynamic fractional amplitude of low-frequency fluctuation (d-fALFF), and dynamic regional homogeneity (d-ReHo). Furthermore, we selected the observed alterations in three dynamic local metrics as classification features to distinguish patients with TIA from HCs through SVM classifier.

RESULTS

We found that TIA was associated with disruptions in dynamic local intrinsic brain activities. Compared with HCs, the patients with TIA exhibited increased d-fALFF, d-fALFF, and d-ReHo in vermis, right calcarine, right middle temporal gyrus, opercular part of right inferior frontal gyrus, left calcarine, left occipital, and left temporal and cerebellum. These alternations in the dynamic local metrics exhibited an accuracy of 80.90%, sensitivity of 77.08%, specificity of 85.37%, precision of 86.05%, and area under curve of 0.8501 for distinguishing the patients from HCs.

CONCLUSION

Our findings may provide important evidence for understanding the neuropathology underlying TIA and strong support for the hypothesis that these local metrics have potential value in clinical diagnosis.

Rhomboencephalosynapsis: Review of the literature

Rhombencephalosynapsis is a rare congenital anomaly, characterized by partial or total agenesis of the cerebellar vermis with midline fusion of the cerebellar hemispheres, dentate nuclei, and the superior cerebellar peduncles, creating the distinctive Keyhole appearance of the fourth ventricle. Rhombencephalosynapsis can be isolated or can occur in association with other congenital anomalies and syndromes such as Gómez-López-Hernández Syndrome (GLHS) or VACTERL; vertebral anomalies (V), anal atresia (A), cardiovascular defects (C), esophageal atresia and/or tracheo-esophageal fistula (TE), renal (R) and limb/radial (L) anomalies. Recent advances in prenatal imaging have resulted in an increasing rate of prenatal diagnosis of abnormalities of the posterior fossa including Rhombencephalosynapsis. Patients with rhombencephalosynapsis may present with motor developmental delay, ataxia, swallowing difficulties, muscular hypotonia, spastic quadriparesis, abnormal eye movements and a characteristic "figure-of-eight" head shaking. Cognitive outcome varies from severe intellectual disability to normal intellectual function. Rhombencephalosynapsis with VACTERL is often associated with severe cognitive disabilities, whereas patients with GLHS may have better cognitive function. The most common associated findings with rhombencephalosynapsis include hydrocephalus, mesencephalosynapsis, holoprosencephaly, pontocerebellar hypoplasia, corpus callosum dysgenesis and absence of septum pellucidum. Patients can be categorized into four groups: (1) Rhombencephalosynapsis associated with Gómez-López-Hernández syndrome; (2) Rhombencephalosynapsis with VACTERL; (3) Rhombencephalosynapsis with atypical holoprosencephaly, and (4) isolated rhomboencephalosynapsis. The etiology of rhombencephalosynapsis is unknown. Here, we discuss several hypotheses about its etiology.

Elucidating the neural correlates of emotion recognition in children with sub-clinical anxiety

BACKGROUND

The pervasiveness of subclinical anxiety in children, highlights the need to identify its neurobiological underpinnings to better inform interventions. Given the now well-established link between aberrant emotion processing and anxiety disorders and yet limited neurobiologically-informed research in this area, this study examined the neural correlates of emotion recognition (ER) in children with sub-clinical anxiety.

METHOD

Ninety children (aged 9-11 years) with sub-clinical anxiety, completed an emotion recognition task whilst undergoing functional magnetic resonance imaging. The ER task required participants to match shapes and match emotional faces in the context of shape distractors. Participants also completed the Spence Children's Anxiety Scale (SCAS).

RESULTS

Greater blood oxygenation level dependent (BOLD) changes associated with ER were observed in the lateral occipital cortex, middle frontal gyrus, superior middle frontal gyrus, inferior frontal gyrus, superior parietal lobule, inferior parietal lobule, superior temporal gyrus, and middle temporal gyrus symmetrically. The clusters also included posterior cingulate cortex, insula, hippocampus, amygdala and cerebellum during matching emotions than those matching shapes. Females showed greater BOLD changes associated with ER than males in the right middle frontal gyrus. The BOLD changes associated with ER in the right middle frontal gyrus and right insula were greater in children with SCAS subscale (physical injury fear) scores in the normal range than those with elevated scores.

DISCUSSION

The findings in this study implicate the right middle frontal gyrus and insula as key regions in the neurobiological underpinnings of sub-clinical anxiety as they relate to attention impairments in anxious children.

CONCLUSION

The results of this study indicate there are gender differences in young participants during emotion processing and provides a neurobiological target for attention impairments in anxious children.

Abnormal dendritic morphology in the cerebellum of cyclooxygenase-2- knockin mice

Prostaglandin E2 (PGE2) is a bioactive signalling molecule metabolized from the phospholipid membranes by the enzymatic activity of cycloxygenase-2 (COX-2). In the developing brain, COX-2 constitutively regulates the production of PGE2, which is important in neuronal development. However, abnormal COX-2/PGE2 signalling has been linked to neurodevelopmental disorders including autism spectrum disorders (ASDs). We have previously demonstrated that COX-2^- -KI mice show autism-related behaviours including social deficits, repetitive behaviours and anxious behaviours. COX-2-deficient mice also have deficits in pathways involved in synaptic transmission and dendritic spine formation. In this study, we use a Golgi-COX staining method to examine sex-dependent differences in dendritic and dendritic spine morphology in neurons of COX-2^- -KI mice cerebellum compared with wild-type (WT) matched controls at postnatal day 25 (P25). We show that COX-2^- -KI mice have increased dendritic arborization closer to the cell soma and increased dendritic looping. We also observed a sex-dependent effect of the COX-2^- -KI on dendritic thickness, dendritic spine density, dendritic spine morphology, and the expression of β-actin and the actin-binding protein spinophilin. Our findings show that changes in COX-2/PGE2 signalling lead to impaired morphology of dendrites and dendritic spines in a sex-dependant manner and may contribute the pathology of the cerebellum seen in individuals with ASD. This study provides further evidence that the COX-2^- -KI mouse model can be used to study a subset of ASD pathologies.

Abnormal Cerebellar Development in Autism Spectrum Disorders

Autism spectrum disorders (ASD) comprise a group of heterogeneous neurodevelopmental conditions characterized by impaired social interactions and repetitive behaviors with symptom onset in early infancy. The genetic risks for ASD have long been appreciated: concordance of ASD diagnosis may be as high as 90% for monozygotic twins and 30% for dizygotic twins, and hundreds of mutations in single genes have been associated with ASD. Nevertheless, only 5-30% of ASD cases can be explained by a known genetic cause, suggesting that genetics is not the only factor at play. More recently, several studies reported that up to 40% of infants with cerebellar hemorrhages and lesions are diagnosed with ASD. These hemorrhages are overrepresented in severely premature infants, who are born during a period of highly dynamic cerebellar development that encompasses an approximately 5-fold size expansion, an increase in structural complexity, and remarkable rearrangements of local neural circuits. The incidence of ASD-causing cerebellar hemorrhages during this window supports the hypothesis that abnormal cerebellar development may be a primary risk factor for ASD. However, the links between developmental deficits in the cerebellum and the neurological dysfunctions underlying ASD are not completely understood. Here, we discuss key processes in cerebellar development, what happens to the cerebellar circuit when development is interrupted, and how impaired cerebellar function leads to social and cognitive impairments. We explore a central question: Is cerebellar development important for the generation of the social and cognitive brain or is the cerebellum part of the social and cognitive brain itself?

Neural basis of working memory in ADHD: Load versus complexity

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Working memory (WM).

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Load versus Complexity.

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ADHD.

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FMRI.

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Working Memory Striatum and Cerebellum.

Working memory (WM) deficits are key in attention deficit hyperactivity disorder (ADHD). Nevertheless, WM is not universally impaired in ADHD. Additionally, the neural basis for WM deficits in ADHD has not been conclusively established, with regions including the prefrontal cortex, cerebellum, and caudate being implicated. These contradictions may be related to conceptualizations of WM capacity, such as load (amount of information) versus operational-complexity (maintenance-recall or manipulation). For instance, relative to neurotypical (NT) individuals, complex WM operations could be impaired in ADHD, while simpler operations are spared. Alternatively, all operations may be impaired at higher loads. Here, we compared the impact of these two components of WM capacity: load and operational-complexity, between ADHD and NT, behaviorally and neurally. We hypothesized that the impact of WM load would be greater in ADHD, and the neural activation would be altered. Participants (age-range 12–23 years; 50 ADHD (18 females); 82 NT (41 females)) recalled three or four objects (load) in forward or backward order (operational-complexity) during functional magnetic resonance imaging scanning. The effects of diagnosis and task were compared on performance and neural engagement. Behaviorally, we found significant interactions between diagnosis and load, and between diagnosis, load, and complexity. Neurally, we found an interaction between diagnosis and load in the right striatum, and between diagnosis and complexity in the right cerebellum and left occipital gyrus. The ADHD group displayed hypo-activation compared to NT group during higher load and greater complexity. This informs mechanisms of functional problems related to WM in adolescents and young adults with ADHD (e.g., academic performance) and remedial interventions (e.g., WM-training).

Aberrant Resting-State Cerebellar-Cerebral Functional Connectivity in Unmedicated Patients With Obsessive-Compulsive Disorder

Background: Although abnormality of cerebellar-cerebral functional connectivity at rest in obsessive-compulsive disorder (OCD) has been hypothesized, only a few studies have investigated the neural mechanism. To verify the findings of previous studies, a large sample of patients with OCD was studied because OCD shows possible heterogeneity. Methods: Forty-seven medication-free patients with OCD and 62 healthy controls (HCs) underwent resting-state functional magnetic imaging scans. Seed-based connectivity was examined to investigate differences in cerebellar-cerebral functional connectivity in OCD patients compared with HCs. Correlations between functional connectivity and the severity of obsessive-compulsive symptoms were analyzed. Results: In OCD, we found significantly increased functional connectivity between the right lobule VI and the left precuneus, which is a component of the default mode network (DMN), compared to HCs. However, there was no correlation between the connectivity of the right lobule VI-left precuneus and obsessive-compulsive severity. Conclusions: These findings suggest that altered functional connectivity between the cerebellum and DMN might cause changes in intrinsic large-scale brain networks related to the traits of OCD.

The role of cerebellum in the child neuropsychological functioning

This chapter proposes a review of neuropsychologic and behavior findings in pediatric pathologies of the cerebellum, including cerebellar malformations, pediatric ataxias, cerebellar tumors, and other acquired cerebellar injuries during childhood. The chapter also contains reviews of the cerebellar mutism/posterior fossa syndrome, reported cognitive associations with the development of the cerebellum in typically developing children and subjects born preterm, and the role of the cerebellum in neurodevelopmental disorders such as autism spectrum disorders and developmental dyslexia. Cognitive findings in pediatric cerebellar disorders are considered in the context of known cerebellocerebral connections, internal cellular organization of the cerebellum, the idea of a universal cerebellar transform and computational internal models, and the role of the cerebellum in specific cognitive and motor functions, such as working memory, language, timing, or control of eye movements. The chapter closes with a discussion of the strengths and weaknesses of the cognitive affective syndrome as it has been described in children and some conclusions and perspectives.

Working Memory Impairments in Cerebellar Disorders of Childhood

The cerebellum is a crucial center for motor control and integration. Increasing evidence supports the notion that the cerebellum is also involved in nonmotor functions. Along these lines, multiple cerebellar disorders of childhood and adulthood are associated with behavioral and cognitive symptoms, including impairments in memory. One form of memory commonly affected in cerebellar disorders is working memory, which uses attention to manipulate information that is immediately available to execute cognitive tasks. This article reviews the literature illustrating that working memory impairments are frequently observed in acquired, congenital, and genetic/developmental cerebellar disorders of childhood. Functional neuroimaging studies demonstrate that working memory tasks engage many posterior regions of the cerebellar hemispheres and vermis. Thus, the cerebellum acts as one important node in the working memory circuit, and when the cerebellum is involved in childhood disorders, deficits in working memory commonly occur.

Acute coordinative exercise ameliorates general and food-cue related cognitive function in obese adolescents

Whether the acute coordinative exercise could affect the inhibitory control and food-cue related attention in obese adolescents remains understudied. Therefore, this study used the Stroop test and the food-cue related Stroop test to explore the impacts of 20 min of acute coordinative exercise on the cognitive tests involving inhibitory control and attentional bias towards food-cue related stimuli, respectively, in obese adolescents. Thirty-eight obese adolescents (mean age = 14.63 ± 0.69 years) were equally divided into exercise and control groups. The cognitive tests (i.e., the Stroop test and the food-cue related Stroop test) and hunger scores were conducted and assessed before and after an intervention. The exercise group had significantly larger negative pre-post response time difference in the congruent (-1.04 ± 0.29 ms) and incongruent (-5.76 ± 1.66 ms) conditions of the Stroop test than the control group (ps < 0.01), and a smaller post-interference (1.13 ± 0.14) than the pre-interference (1.31 ± 0.14, p = 0.04). Moreover, a significantly larger negative pre-post response time difference on the food-cue related Stroop test was observed in the exercise group (-4.42 ± 7.20 ms) than the control group (1.76 ± 8.37 ms, p = 0.02). Collectively, an acute coordinative exercise session could induce superior inhibitory control and less attentional bias towards food-cue related stimuli in obese adolescents.

The Cerebellar Cognitive Affective/Schmahmann Syndrome: a Task Force Paper

Sporadically advocated over the last two centuries, a cerebellar role in cognition and affect has been rigorously established in the past few decades. In the clinical domain, such progress is epitomized by the "cerebellar cognitive affective syndrome" ("CCAS") or "Schmahmann syndrome." Introduced in the late 1990s, CCAS reflects a constellation of cerebellar-induced sequelae, comprising deficits in executive function, visuospatial cognition, emotion-affect, and language, over and above speech. The CCAS thus offers excellent grounds to investigate the functional topography of the cerebellum, and, ultimately, illustrate the precise mechanisms by which the cerebellum modulates cognition and affect. The primary objective of this task force paper is thus to stimulate further research in this area. After providing an up-to-date overview of the fundamental findings on cerebellar neurocognition, the paper substantiates the concept of CCAS with recent evidence from different scientific angles, promotes awareness of the CCAS as a clinical entity, and examines our current insight into the therapeutic options available. The paper finally identifies topics of divergence and outstanding questions for further research.

Molecular causes of sex-specific deficits in rodent models of neurodevelopmental disorders

Neurodevelopmental disorders (NDDs) such as intellectual disability and autism spectrum disorder consistently show a male bias in prevalence, but it remains unclear why males and females are affected with different frequency. While many behavioral studies of transgenic NDD models have focused only on males, the requirement by the National Institutes of Health to consider sex as a biological variable has promoted the comparison of male and female performance in wild-type and mutant animals. Here, we review examples of rodent models of NDDs in which sex-specific deficits were identified in molecular, physiological, and/or behavioral responses, showing sex differences in susceptibility to disruption of genes mutated in NDDs. Haploinsufficiency in genes involved in mechanisms such as synaptic function (GABRB3 and NRXN1), chromatin remodeling (CHD8, EMHT1, and ADNP), and intracellular signaling (CC2D1A and ERK1) lead to more severe behavioral outcomes in males. However, in the absence of behavioral deficits, females can still present with cellular and electrophysiological changes that could be due to compensatory mechanisms or differential allocation of molecular and cellular functions in the two sexes. By contrasting these findings with mouse models where females are more severely affected (MTHFR and AMBRA1), we propose a framework to approach the study of sex-specific deficits possibly leading to sex bias in NDDs.

Functional Outcomes of Cerebellar Malformations

The cerebellum is well-established as a primary center for controlling sensorimotor functions. However, recent experiments have demonstrated additional roles for the cerebellum in higher-order cognitive functions such as language, emotion, reward, social behavior, and working memory. Based on the diversity of behaviors that it can influence, it is therefore not surprising that cerebellar dysfunction is linked to motor diseases such as ataxia, dystonia, tremor, and Parkinson's disease as well to non-motor disorders including autism spectrum disorders (ASD), schizophrenia, depression, and anxiety. Regardless of the condition, there is a growing consensus that developmental disturbances of the cerebellum may be a central culprit in triggering a number of distinct pathophysiological processes. Here, we consider how cerebellar malformations and neuronal circuit wiring impact brain function and behavior during development. We use the cerebellum as a model to discuss the expanding view that local integrated brain circuits function within the context of distributed global networks to communicate the computations that drive complex behavior. We highlight growing concerns that neurological and neuropsychiatric diseases with severe behavioral outcomes originate from developmental insults to the cerebellum.

The Cerebellar Cognitive Affective/Schmahmann Syndrome: a Task Force Paper

Sporadically advocated over the last two centuries, a cerebellar role in cognition and affect has been rigorously established in the past few decades. In the clinical domain, such progress is epitomized by the "cerebellar cognitive affective syndrome" ("CCAS") or "Schmahmann syndrome." Introduced in the late 1990s, CCAS reflects a constellation of cerebellar-induced sequelae, comprising deficits in executive function, visuospatial cognition, emotion-affect, and language, over and above speech. The CCAS thus offers excellent grounds to investigate the functional topography of the cerebellum, and, ultimately, illustrate the precise mechanisms by which the cerebellum modulates cognition and affect. The primary objective of this task force paper is thus to stimulate further research in this area. After providing an up-to-date overview of the fundamental findings on cerebellar neurocognition, the paper substantiates the concept of CCAS with recent evidence from different scientific angles, promotes awareness of the CCAS as a clinical entity, and examines our current insight into the therapeutic options available. The paper finally identifies topics of divergence and outstanding questions for further research.

Cerebellar Functional Connectivity in Term- and Very Preterm-Born Infants

Cortical resting state networks have been consistently identified in infants using resting state-functional connectivity magnetic resonance imaging (rs-fMRI). Comparable studies in adults have demonstrated cerebellar components of well-established cerebral networks. However, there has been limited investigation of early cerebellar functional connectivity. We acquired non-sedated rs-fMRI data in the first week of life in 57 healthy, term-born infants and at term-equivalent postmenstrual age in 20 very preterm infants (mean birth gestational age 27 ± 2 weeks) without significant cerebral or cerebellar injury. Seed correlation analyses were performed using regions of interests spanning the cortical and subcortical gray matter and cerebellum. Parallel analyses were performed using rs-fMRI data acquired in 100 healthy adults. Our results demonstrate that cortico-cerebellar functional connectivity is well-established by term. Intra- and cortico-cerebellar functional connectivity were largely similar in infants and adults. However, infants showed more functional connectivity structure within the cerebellum, including stronger homotopic correlations and more robust anterior-posterior anticorrelations. Prematurity was associated with reduced correlation magnitudes, but no alterations in intra- and cortico-cerebellar functional connectivity topography. These results add to the growing evidence that the cerebellum plays an important role in shaping early brain development during infancy.

Genetic deletion of genes in the cerebellar rhombic lip lineage can stimulate compensation through adaptive reprogramming of ventricular zone-derived progenitors

BACKGROUND

The cerebellum is a foliated posterior brain structure involved in coordination of motor movements and cognition. The cerebellum undergoes rapid growth postnataly due to Sonic Hedgehog (SHH) signaling-dependent proliferation of ATOH1+ granule cell precursors (GCPs) in the external granule cell layer (EGL), a key step for generating cerebellar foliation and the correct number of granule cells. Due to its late development, the cerebellum is particularly vulnerable to injury from preterm birth and stress around birth. We recently uncovered an intrinsic capacity of the developing cerebellum to replenish ablated GCPs via adaptive reprogramming of Nestin-expressing progenitors (NEPs). However, whether this compensation mechanism occurs in mouse mutants affecting the developing cerebellum and could lead to mis-interpretation of phenotypes was not known.

METHODS

We used two different approaches to remove the main SHH signaling activator GLI2 in GCPs: 1) Our mosaic mutant analysis with spatial and temporal control of recombination (MASTR) technique to delete Gli2 in a small subset of GCPs; 2) An Atoh1-Cre transgene to delete Gli2 in most of the EGL. Genetic Inducible Fate Mapping (GIFM) and live imaging were used to analyze the behavior of NEPs after Gli2 deletion.

RESULTS

Mosaic analysis demonstrated that SHH-GLI2 signaling is critical for generating the correct pool of granule cells by maintaining GCPs in an undifferentiated proliferative state and promoting their survival. Despite this, inactivation of GLI2 in a large proportion of GCPs in the embryo did not lead to the expected dramatic reduction in the size of the adult cerebellum. GIFM uncovered that NEPs do indeed replenish GCPs in Gli2 conditional mutants, and then expand and partially restore the production of granule cells. Furthermore, the SHH signaling-dependent NEP compensation requires Gli2, demonstrating that the activator side of the pathway is involved.

CONCLUSION

We demonstrate that a mouse conditional mutation that results in loss of SHH signaling in GCPs is not sufficient to induce long term severe cerebellum hypoplasia. The ability of the neonatal cerebellum to regenerate after loss of cells via a response by NEPs must therefore be considered when interpreting the phenotypes of Atoh1-Cre conditional mutants affecting GCPs.

Chiari Type I Malformation Associated With Verbal Fluency Impairment

PURPOSE

Chiari malformation (CM) Type I is a rare disorder that implies an anomaly in the craniocervical junction, where one or both cerebellar tonsils are displaced below the foramen magnum into the cervical spinal channel. Research carried out regarding cognitive symptoms such as verbal fluency is scarce. The aim of this study was to investigate whether verbal fluency is impaired in a CM clinical group compared to a group of healthy control individuals while controlling for depression and anxiety symptomatology.

METHOD

For this purpose, 101 individuals were enrolled to take part in the study (51 CM, 50 healthy controls). The Controlled Oral Word Association Test (Benton, de Hamsher, & Sivan, 1983) and the Hospital Anxiety and Depression Scale (Zigmond & Snaith, 1983) were administered.

RESULTS

Results showed significantly lower scores for the CM group in verbal fluency compared to the control group (p < .005). After performing an analysis of covariance to eliminate depression and anxiety symptomatology tendencies, it was observed that verbal fluency could not be predicted by this variable (p > .005).

CONCLUSIONS

From the results of this study, it can be concluded that people suffering from CM exhibit less verbal fluency than healthy control individuals and that this difference is not caused by depression or anxiety.

Age-dependent dormant resident progenitors are stimulated by injury to regenerate Purkinje neurons

Outside of the neurogenic niches of the brain, postmitotic neurons have not been found to undergo efficient regeneration. We demonstrate that mouse Purkinje cells (PCs), which are born at midgestation and are crucial for development and function of cerebellar circuits, are rapidly and fully regenerated following their ablation at birth. New PCs are produced from immature FOXP2+ Purkinje cell precursors (iPCs) that are able to enter the cell cycle and support normal cerebellum development. The number of iPCs and their regenerative capacity, however, diminish soon after birth and consequently PCs are poorly replenished when ablated at postnatal day five. Nevertheless, the PC-depleted cerebella reach a normal size by increasing cell size, but scaling of neuron types is disrupted and cerebellar function is impaired. Our findings provide a new paradigm in the field of neuron regeneration by identifying a population of immature neurons that buffers against perinatal brain injury in a stage-dependent process.

Nonprogressive congenital ataxias

The terminology of nonprogressive congenital ataxia (NPCA) refers to a clinically and genetically heterogeneous group of disorders characterized by congenital or early-onset ataxia, but no progression or even improvement on follow-up. Ataxia is preceded by muscular hypotonia and delayed motor (and usually language) milestones. We exclude children with prenatal, perinatal, and postnatal acquired diseases, malformations other than cerebellar hypoplasia, and defined syndromic disorders. Patients with NPCA have a high prevalence of cognitive and language impairments, in addition to increased occurrence of seizures, ocular signs (nystagmus, strabismus), behavior changes, and microcephaly. Neuroimaging is variable, ranging from normal cerebellar anatomy to reduced cerebellar volume (hypoplasia in the proper sense), and enlarged interfolial spaces, potentially mimicking atrophy. The latter appearance is often called "hypoplasia" as well, in view of the static clinical course. Some patients had progressive enlargement of cerebellar fissures, but a nonprogressive course. There is no imaging-clinical-genetic correlation. Dominant, recessive, and X-linked inheritance is documented for NPCA. Here, we focus on the still rather short list of dominant and recessive genes associated with NPCA, identified in the last few years. With future advances in genetics, we expect a rapid expansion of knowledge in this field.

Cerebellar granule cell replenishment postinjury by adaptive reprogramming of Nestin+ progenitors

Regeneration of several organs involves adaptive reprogramming of progenitors, however, the intrinsic capacity of the developing brain to replenish lost cells remains largely unknown. In this study, we discovered that the developing cerebellum has unappreciated progenitor plasticity, since it undergoes near full growth and functional recovery following acute depletion of granule cells, the most plentiful neuron population in the brain. We demonstrate that following postnatal ablation of granule cell progenitors, Nestin-expressing progenitors (NEPs) specified during mid-embryogenesis to produce astroglia and interneurons, switch their fate and generate granule neurons in mice. Moreover, Hedgehog-signaling in two NEP populations is crucial not only for the compensatory replenishment of granule neurons but also to scale interneuron and astrocyte numbers. Thus we provide insights into the mechanisms underlying robustness of circuit formation in the cerebellum, and speculate that adaptive reprogramming of progenitors in other brain regions plays a greater role than appreciated in developmental regeneration.

Associations between motor proficiency in children with history of maltreatment and living in social economically vulnerability

Maltreatment and living in poor socioeconomic conditions during childhood may implicate in deficits on motor proficiency, nevertheless, the literature on this issue is still scarce. The goal of the study was to investigate the possible associations among manual dexterity, aiming and catching tasks, and balance tasks for children who suffers maltreatment and lived in social vulnerability. Eighty-two (82) children (08-09 years old) participated in the study. Forty-one (41) belong to the (SEV-M Group) children living in social economic vulnerability and were previously maltreated (lived in foster homes as results of parental neglect and domestic violence), and 41 belong to the (SEV Group) children living in social economical vulnerability with no history of childhood maltreatment. Children were assessed using the Movement Assessment Battery for Children -2nd Edition. Structural Equation Modeling was used to analyze the data. The results suggest the existence of a variety of motor difficulties in the group of children who suffered from neglect and domestic violence. The statistics model showed a negative effect for children in at-risk environments (regression coefficient=-0.30) and only showed a significant effect (p=0.04) for balance abilities. Traumatic experiences may have a negative effect on children' balance proficiency.

Neuropsychological phenotypes of 76 individuals with Joubert syndrome evaluated at a single center

Joubert syndrome (JS) is a genetically heterogeneous ciliopathy characterized by hypo-dysplasia of the cerebellar vermis, a distinct hindbrain/midbrain malformation (molar tooth sign), and intellectual disability. We evaluated the neuropsychological profiles of 76 participants with JS in the context of molecular genetics and clinical covariates. Evaluations included neuropsychological testing, structured parental interviews, DNA sequencing, brain magnetic resonance imaging (MRI), electroencephalography (EEG), ophthalmologic examination, and assessment for renal and hepatic disease. On average, participants manifested Full Scale Intelligence Quotients (FSIQ) in the moderately to profoundly low range (M = 64.3 ± 15.3). Of the Wechsler index scores, verbal comprehension was least affected and processing speed was most affected. Receptive language was rated as better than expressive language on the Vineland Adaptive Behavior Scales-Second Edition. Those with abnormal EEG had a significantly lower FSIQ (n = 15; M = 50.7 ± 12.9) compared to participants with normal EEG (n = 39; M = 64.7 ± 16.3; p = .004). Participants taking psychiatric medications manifested a lower FSIQ (n = 20; M = 54.8 ± 13.2) than those not taking them (n = 42; M = 65.0 ± 17.2; p = .022). These correlations were also present in the TMEM67-related JS sub-cohort (n = 14). Based on parental assessment, psychiatric and behavioral problems were significantly more common than in the general population for all measures (p < .004 for all). The majority (65%) of individuals with JS have some degree of intellectual disability. Abnormal EEG is associated with lower neuropsychological function. Processing speed is a weakness, while verbal comprehension and receptive language are relative strengths. These findings may guide parents, teachers, therapists, and doctors to determine appropriate therapies, accommodations, and academic goals for individuals with JS.

Sexual dimorphism of the cerebellar vermis in schizophrenia

Converging lines of evidence implicate structural and functional abnormalities in the cerebellum in schizophrenia (SCZ). The cerebellar vermis is of particular interest given its association with clinical symptoms and cognitive deficits in SCZ and its known connections with cortical regions such as the prefrontal cortex. Prior neuroimaging studies have shown structural and functional abnormalities in the vermis in SCZ. In this study, we examined the cerebellar vermis in 50 individuals with SCZ and 54 healthy controls (HC) using a quantitative volumetric approach. All participants underwent high-resolution structural magnetic resonance imaging (MRI). The vermis was manually traced for each participant, and vermis volumes were computed using semiautomated methods. Volumes for total vermis and vermis subregions (anterior and posterior vermis) were analyzed in the SCZ and HC groups. Significant diagnosis-by-sex interaction effects were found in total vermis and vermis subregion analyses. These effects appeared to be driven by significantly decreased posterior vermis volumes in males with SCZ. Exploratory analyses did not reveal significant effects of clinical variables (FEP status, illness duration, and BPRS total score and subscores) on vermis volumes. The findings herein highlight the presence of neural sex differences in SCZ and the need for considering sex-related factors in studying the disorder.

Cognitive rehabilitation in a child with Joubert Syndrome: Developmental trends and adaptive changes in a single case report

We report the clinical and rehabilitative follow up of M, a female child carrying a compound heterozygous pathogenic mutations in the TCTN1 gene and affected by Joubert Syndrome (JS). JS is a congenital cerebellar ataxia characterized by "the molar tooth sign" on axial MRI, a pathognomonic neuroradiological malformation involving the cerebellum and brainstem. JS presents with high phenotypic/cognitive variability, and little is known about cognitive rehabilitation programs. We describe the therapeutic settings, intensive rehabilitation targets and outcome indexes in M's cognitive development. Using a single case evidence-based approach, we attempt to distinguish the effectiveness of the intervention from the overall developmental trend. We assume that an adequate amount of focused, goal directed treatment in a relative short period of time can be at least as effective as one provided in longer time, and much less interfering with the child's everyday life. We conclude by discussing specific issues in cognitive development and rehabilitation in JS and, more broadly, in cerebellar malformations.

The neurological outcomes of cerebellar injury in premature infants

AIM

Cerebellar injury is a characteristic injury associated with preterm infants. However, the impact of cerebellar injury on the development of preterm infants is unclear.

METHOD

We reviewed magnetic resonance image studies of preterm infants with cerebral palsy retrospectively and evaluated the developmental outcomes.

RESULTS

Cerebellar injury was recognized in 9 (2.4%) of 381 patients with cerebral palsy who were born preterm. The median gestational age was 26 (range 23-32) weeks and the median birth weight was 938 (range 492-1450) g. Seven of the nine patients had severe symmetric injuries to the inferior cerebellar hemispheres, resulting in a pancake-like appearance of the residual upper cerebellum. Supratentorial lesions were also recognized: periventricular leukomalacia in seven; atrophy of the basal ganglia in two; and intraventricular hemorrhage in two. Importantly, the motor dysfunction was related to the reduction in the white matter volume and severity of basal ganglia atrophy, but not to the cerebellar injury. Four of the nine patients could walk without limitations despite extensive cerebellar disruption. Only four patients could speak meaningful words during the study and only one spoke two-word sentences.

INTERPRETATION

The patients with cerebellar injury might have a communication handicap, rather than altered motor function. Prematurity-related cerebellar complications require more attention in terms of cognitive and speech function, in addition to neuromotor development.

A systematic review of neuropsychological outcomes following posterior fossa tumor surgery in children

PURPOSE

Central nervous system tumors are the most common solid tumors in the pediatric population. As children with central nervous system (CNS) tumors are surviving into adolescence and adulthood, more research is being focused on the long-term cognitive outcomes of the survivors. This review examines the literature on different cognitive outcomes of survivors of different childhood posterior fossa CNS tumor types.

METHODS

The authors reviewed the literature for articles published from 2000 to 2012 about long-term neuropsychological outcomes of children diagnosed with posterior fossa brain tumors before the age of 18, which distinguished between histological tumor types, and had a minimum follow-up of 3 years.

RESULTS

The literature search returned 13 articles, and a descriptive analysis was performed comparing intelligence quotient (IQ), attention/executive function, and memory components of 456 survivors of childhood posterior fossa tumors. Four articles directly compared astrocytoma and medulloblastoma survivors and showed medulloblastoma survivors fared worse in IQ, attention/executive function, and memory measurements. Five articles reporting medulloblastomas found IQ, attention, and memory scores to be significantly below the standardized means. Articles examining astrocytoma survivors found IQ scores within the normal range for the population. Survivors of ependymomas reported 2/23 survivors impaired on IQ scores, while a second study reported a significant number of ependymoma survivors lower than the expected population norm.

CONCLUSIONS

Tumor histopathology and the type of postoperative adjuvant therapy seem to have a significant impact on the long-term neuropsychological complications of pediatric posterior fossa CNS tumor survivors. Age at diagnosis and treatment factors are important variables that affect the outcomes of the survivors.

Theory-of-mind in individuals with Alström syndrome is related to executive functions, and verbal ability

Objective: This study focuses on cognitive prerequisites for the development of theory-of-mind (ToM), the ability to impute mental states to self and others in young adults with Alström syndrome (AS). AS is a rare and quite recently described recessively inherited ciliopathic disorder which causes progressive sensorineural hearing loss and juvenile blindness, as well as many other organ dysfunctions. Two cognitive abilities were considered; Phonological working memory (WM) and executive functions (EF), both of importance in speech development.

Methods: Ten individuals (18–37 years) diagnosed with AS, and 20 individuals with no known impairment matched for age, gender, and educational level participated. Sensory functions were measured. Information about motor functions and communicative skills was obtained from responses to a questionnaire. ToM was assessed using Happés strange stories, verbal ability by a vocabulary test, phonological WM by means of an auditory presented non-word serial recall task and EF by tests of updating and inhibition.

Results: The AS group performed at a significantly lower level than the control group in both the ToM task and the EF tasks. A significant correlation was observed between recall of non-words and EF in the AS group. Updating, but not inhibition, correlated significantly with verbal ability, whereas both updating and inhibition were significantly related to the ability to initiate and sustain communication. Poorer performance in the ToM and EF tasks were related to language perseverance and motor mannerisms.

Conclusion: The AS group displayed a delayed ToM as well as reduced phonological WM, EF, and verbal ability. A significant association between ToM and EF, suggests a compensatory role of EF. This association may reflect the importance of EF to perceive and process input from the social environment when the social interaction is challenged by dual sensory loss. We argue that limitations in EF capacity in individuals with AS, to some extent, may be related to early blindness and progressive hearing loss, but maybe also to gene specific abnormalities.

Building an adaptive brain across development: targets for neurorehabilitation must begin in infancy

Much progress has been made toward behavioral and pharmacological intervention in intellectual disability, which was once thought too difficult to treat. Down syndrome (DS) research has shown rapid advances, and clinical trials are currently underway, with more on the horizon. Here, we review the literature on the emergent profile of cognitive development in DS, emphasizing that treatment approaches must consider how some "end state" impairments, such as language deficits, may develop from early alterations in neural systems beginning in infancy. Specifically, we highlight evidence suggesting that there are pre- and early postnatal alterations in brain structure and function in DS, resulting in disturbed network function across development. We stress that these early alterations are likely amplified by Alzheimer's disease (AD) progression and poor sleep. Focusing on three network hubs (prefrontal cortex, hippocampus, and cerebellum), we discuss how these regions may relate to evolving deficits in cognitive function in individuals with DS, and to their language profile in particular.

Functional and clinical insights from neuroimaging studies in childhood-onset schizophrenia

Childhood-onset schizophrenia is a rare pediatric onset psychiatric disorder continuous with and typically more severe than its adult counterpart. Neuroimaging research conducted on this population has revealed similarly severe neural abnormalities. When taken as a whole, neuroimaging research in this population shows generally decreased cortical gray matter coupled with white matter connectivity abnormalities, suggesting an anatomical basis for deficits in executive function. Subcortical abnormalities are pronounced in limbic structures, where volumetric deficits are likely related to social skill deficits, and cerebellar deficits that have been correlated to cognitive abnormalities. Structures relevant to motor processing also show a significant alteration, with volumetric increase in basal ganglia structures likely due to antipsychotic administration. Neuroimaging of this disorder shows an important clinical image of exaggerated cortical loss, altered white matter connectivity, and differences in structural development of subcortical areas during the course of development and provides important background to the disease state.

The role of ionotropic glutamate receptors in childhood neurodevelopmental disorders: autism spectrum disorders and fragile x syndrome

Autism spectrum disorder (ASD) and Fragile X syndrome (FXS) are relatively common childhood neurodevelopmental disorders with increasing incidence in recent years. They are currently accepted as disorders of the synapse with alterations in different forms of synaptic communication and neuronal network connectivity. The major excitatory neurotransmitter system in brain, the glutamatergic system, is implicated in learning and memory, synaptic plasticity, neuronal development. While much attention is attributed to the role of metabotropic glutamate receptors in ASD and FXS, studies indicate that the ionotropic glutamate receptors (iGluRs) and their regulatory proteins are also altered in several brain regions. Role of iGluRs in the neurobiology of ASD and FXS is supported by a weight of evidence that ranges from human genetics to in vitro cultured neurons. In this review we will discuss clinical, molecular, cellular and functional changes in NMDA, AMPA and kainate receptors and the synaptic proteins that regulate them in the context of ASD and FXS. We will also discuss the significance for the development of translational biomarkers and treatments for the core symptoms of ASD and FXS.

Motor outcomes in children exposed to early psychosocial deprivation

OBJECTIVES

To determine the effect of psychosocial deprivation early in life on motor development, assess the impact of a foster care intervention on improving motor development, and assess the association between motor and cognitive outcomes in children with a history of institutional care.

STUDY DESIGN

In a randomized controlled trial, children living in Romanian institutions were randomly assigned to care as usual in the institution or placed in family-centered foster care as part of the Bucharest Early Intervention Project. The average age at placement into foster care was 23 months. At age 8 years, the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition, Short Form (BOT2-SF) was applied to assess the motor proficiency of children in both groups, as well as a never-institutionalized group from the Romanian community.

RESULTS

Children in the never-institutionalized group did significantly better on the BOT2-SF than children who had ever been institutionalized (P < .001). There was no significant difference in performance between children in the care as usual group and the foster care group. This finding also held true for all individual items on the BOT2-SF except sit-ups. Regression analyses revealed that the between-group and within-group differences in BOT2-SF scores were largely mediated by IQ.

CONCLUSION

Early deprivation had a negative effect on motor development that was not resolved by placement in foster care. This effect was predominantly mediated by IQ. This study highlights the importance of monitoring for and addressing motor delays in children with a history of institutionalization, particularly those children with low IQ.

Consensus paper: pathological role of the cerebellum in autism

There has been significant advancement in various aspects of scientific knowledge concerning the role of cerebellum in the etiopathogenesis of autism. In the current consensus paper, we will observe the diversity of opinions regarding the involvement of this important site in the pathology of autism. Recent emergent findings in literature related to cerebellar involvement in autism are discussed, including: cerebellar pathology, cerebellar imaging and symptom expression in autism, cerebellar genetics, cerebellar immune function, oxidative stress and mitochondrial dysfunction, GABAergic and glutamatergic systems, cholinergic, dopaminergic, serotonergic, and oxytocin-related changes in autism, motor control and cognitive deficits, cerebellar coordination of movements and cognition, gene-environment interactions, therapeutics in autism, and relevant animal models of autism. Points of consensus include presence of abnormal cerebellar anatomy, abnormal neurotransmitter systems, oxidative stress, cerebellar motor and cognitive deficits, and neuroinflammation in subjects with autism. Undefined areas or areas requiring further investigation include lack of treatment options for core symptoms of autism, vermal hypoplasia, and other vermal abnormalities as a consistent feature of autism, mechanisms underlying cerebellar contributions to cognition, and unknown mechanisms underlying neuroinflammation.

Patterns of cognitive and fine motor deficits in a case of Dandy-Walker continuum

Cerebellar vermian hypoplasia in the context of Dandy-Walker complex is a relatively common disorder associated with a variety of cognitive and behavioral deficits in addition to impairment in motor control. Few studies, however, have examined the neuropsychological profiles of children with isolated hypoplasias of the cerebellum. Herein, we report a 6-year-old girl with Dandy-Walker continuum presenting with mild mental retardation and an inability to produce intelligible speech, despite adequate comprehension of single items and simple instructions. She was able to articulate vowels but not consonants, and fine motor function was deficient. Visual memory was intact for single items but not for multiple items, and visuospatial perception was impaired. An inability to form intelligible speech is not typically reported in cases of isolated vermian hypoplasia. The case extends our knowledge of the phenotypes associated with cerebellar hypoplasia and its relation to fine motor and articulatory control.

Fronto-striato-cerebellar dysregulation in adolescents with depression during motivated attention

BACKGROUND

Pediatric major depressive disorder (MDD) is associated with deficits in sustained attention, thought to be related to underlying motivation deficits. This hypothesis, however, has never directly been tested using functional magnetic resonance imaging. In this study, we investigated the neurofunctional correlates of the interplay between attention and motivation in medication-naive pediatric MDD using a rewarded sustained attention task.

METHODS

Functional magnetic resonance imaging was used to compare brain activation between 20 medication-naïve, noncomorbid, first-episode adolescents with MDD aged 13 to 18 years and 21 gender-, age-, and IQ-matched healthy adolescents. Participants performed a sustained attention task with and without a monetary reward to assess the impact of reward on sustained attention networks.

RESULTS

During nonrewarded sustained attention, adolescents with MDD showed reduced activation compared with healthy control subjects in occipital cortex. When sustained attention was rewarded, however, the underactivation in adolescents with MDD was in an extensive right hemispheric network of inferior fronto-striato-thalamic attention and limbic hippocampus-anterior cingulate reward processing areas. Major depressive disorder patients showed increased activation in cerebellum, which correlated with reduced frontal activation and depressive symptoms, suggesting compensatory response. Further analysis showed that reward upregulated fronto-striatal and hippocampal/temporal activation in control subjects but deactivated these regions in MDD, with opposite effects in the cerebellum.

CONCLUSIONS

Medication-naïve MDD adolescents show abnormalities in the regulation in fronto-striato-cerebellar brain regions involved in attention and reward during motivated but not unmotivated attention. This suggests a dysfunctional interplay between motivation and cognition in pediatric MDD, where motivation appears less capable of upregulating attention networks relative to healthy youths.

Training-induced neuroanatomical plasticity in ADHD: a tensor-based morphometric study

Experience-based neuroplasticity has typically been associated with functional changes, but growing evidence indicates that training can also render dynamic structural alterations in the brain. Although research on training-induced morphological plasticity has consistently demonstrated rapid increases of gray matter volume in task-related regions, no studies have examined if local volumetric reductions in gray matter associated with certain psychiatric disorders may be reversible by adequate training. We aimed to assess whether a training program applied to ADHD patients can contravene some of the associated neuroanatomical alterations. High-resolution anatomical scans were acquired before and after the training period, and a whole-brain tensor-based morphometric approach was applied to extract a voxel-wise estimation of longitudinal changes in regional gray matter volume. Our results show focal volumetric gray matter increases in bilateral middle frontal cortex and right inferior-posterior cerebellum after cognitive training compared with the ADHD control group. The extent of gray matter volume increase in the inferior-posterior cerebellum was associated with attentional performance. These findings illustrate the capacity of the nervous system for rapid morphological adjustments in response to environmental triggers. Moreover, the dorsolateral prefrontal cortex and cerebellum are commonly considered sites of volumetric reduction in ADHD, and the inferior-posterior lobule of the cerebellum is associated with progressive symptom-related volume loss. Hence, the clusters of volumetric change observed in our study were confined to structures typically characterized by volume reduction in ADHD patients, providing preliminary indications that cognitive training may contravene some of the neuroanatomical deficits associated with the disorder.

Cerebellar development in childhood onset schizophrenia and non-psychotic siblings

We explored regional and total volumetric cerebellar differences in probands and their unaffected full siblings relative to typically developing participants. Participants included 94 (51 males) patients diagnosed with childhood onset schizophrenia (COS), 80 related non-psychotic siblings (37 males) and 110 (64 males) typically developing participants scanned longitudinally. The sample mean age was 16.87(S.D.=4.7; range 6.5 to 29). We performed mixed model regressions to examine group differences in trajectory and volume. The COS group had smaller bilateral anterior lobes and anterior and total vermis volumes than controls. The COS group diverged from controls over time in total, left, right, and bilateral posterior inferior cerebellum. Siblings did not have any fixed volumetric differences relative to controls but differed from controls in developmental trajectories of total and right cerebellum, left inferior posterior, left superior posterior, and superior vermis. Results are consistent with previous COS findings and several reports of decreased cerebellar volume in adult onset schizophrenia. Sibling trajectories may represent a trait marker, although the effect size for volumetric differences in early adulthood may be small.

Long-term sequelae after acquired pediatric hemorrhagic cerebellar lesions

PURPOSE

The aim of the present study was to assess cognitive, affective, and motor long-term sequelae after acquired focal pediatric cerebellar lesions.

METHODS

Eight patients with a history of isolated acquired hemorrhagic cerebellar lesions before the age of 13 participated in this study. All participants underwent a neurologic examination, including the Zurich Neuromotor Assessment (ZNA) and the International Cooperative Ataxia Rating Scale (ICARS). Cognitive functions have been evaluated with a general cognitive assessment and an extensive neuropsychological battery. Furthermore, patients and parents filled in questionnaires about quality of life and possible behavioral or emotional problems.

RESULTS

The results revealed that all patients exhibited motor problems (ZNA). Most participants had further restricted oculomotor movements (ICARS). Age at injury and the full scale IQ were significantly positively correlated (Pearson correlation 0.779; p = 0.023). Conversely, no overall neuropsychological profile could be identified except for marginally reduced reaction times and susceptibility to interference. In addition, borderline results in semantic and phonemic word fluency tasks were apparent. A dysexecutive syndrome was diagnosed in one patient. However, verbal performance and reading abilities were non-pathologic in all participants. The patients reported having a good quality of life without major physical restrictions.

CONCLUSIONS

Emotional disturbances and the presence of a mild cerebellar cognitive affective syndrome (as frequently described in adult patients) could only be confirmed in adolescents with vermis lesions. Nevertheless, in laboratory conditions, neuropsychological impairments were present in all patients. Heterogeneity of age at injury and exact lesion site may have led to interpersonal differences in neuropsychological outcome.

A review of fronto-striatal and fronto-cortical brain abnormalities in children and adults with Attention Deficit Hyperactivity Disorder (ADHD) and new evidence for dysfunction in adults with ADHD during motivation and attention

Attention Deficit Hyperactivity Disorder (ADHD) has long been associated with abnormalities in frontal brain regions. In this paper we review the current structural and functional imaging evidence for abnormalities in children and adults with ADHD in fronto-striatal, fronto-parieto-temporal, fronto-cerebellar and fronto-limbic regions and networks. While the imaging studies in children with ADHD are more numerous and consistent, an increasing number of studies suggests that these structural and functional abnormalities in fronto-cortical and fronto-subcortical networks persist into adulthood, despite a relative symptomatic improvement in the adult form of the disorder. We furthermore present new data that support the notion of a persistence of neurofunctional deficits in adults with ADHD during attention and motivation functions. We show that a group of medication-naïve young adults with ADHD behaviours who were followed up 20 years from a childhood ADHD diagnosis show dysfunctions in lateral fronto-striato-parietal regions relative to controls during sustained attention, as well as in ventromedial orbitofrontal regions during reward, suggesting dysfunctions in cognitive-attentional as well as motivational neural networks. The lateral fronto-striatal deficit findings, furthermore, were strikingly similar to those we have previously observed in children with ADHD during the same task, reinforcing the notion of persistence of fronto-striatal dysfunctions in adult ADHD. The ventromedial orbitofrontal deficits, however, were associated with comorbid conduct disorder (CD), highlighting the potential confound of comorbid antisocial conditions on paralimbic brain deficits in ADHD. Our review supported by the new data therefore suggest that both adult and childhood ADHD are associated with brain abnormalities in fronto-cortical and fronto-subcortical systems that mediate the control of cognition and motivation. The brain deficits in ADHD therefore appear to be multi-systemic and to persist throughout the lifespan.

Slowing down: age-related neurobiological predictors of processing speed

Processing speed, or the rate at which tasks can be performed, is a robust predictor of age-related cognitive decline and an indicator of independence among older adults. This review examines evidence for neurobiological predictors of age-related changes in processing speed, which is guided in part by our source based morphometry findings that unique patterns of frontal and cerebellar gray matter predict age-related variation in processing speed. These results, together with the extant literature on morphological predictors of age-related changes in processing speed, suggest that specific neural systems undergo declines and as a result slow processing speed. Future studies of processing speed – dependent neural systems will be important for identifying the etiologies for processing speed change and the development of interventions that mitigate gradual age-related declines in cognitive functioning and enhance healthy cognitive aging.

Cerebellum structure differences and relationship to speech in boys and girls with nonsyndromic cleft of the lip and/or palate

OBJECTIVE

To identify regional cerebellar structural differences in boys and girls with nonsyndromic cleft of the lip and/or palate and determine whether these differences are related to speech impairment.

DESIGN

Between 2003 and 2007, measures on cerebellar volume were obtained on 43 children with nonsyndromic cleft of the lip and/or palate and 43 age- and sex-matched, healthy controls. Children with the cleft condition also received speech evaluations. Children with nonsyndromic cleft of the lip and/or palate were recruited from clinic records, and controls (screened for medical, psychiatric, speech/language, and behavioral concerns) were recruited from the local community. All tests were administered at a large midwestern hospital. Boys and girls with nonsyndromic cleft of the lip and/or palate were compared with the healthy controls on global and regional measures of cerebellar volume. Areas of significant difference were then correlated with measures of speech to assess relationships in children with nonsyndromic cleft of the lip and/or palate.

RESULTS

Boys with nonsyndromic cleft of the lip and/or palate had smaller cerebellums than controls (p = .002); whereas, for girls, only regional reductions in size reached significance (corpus medullare, p = .040). Cerebellum size was correlated with articulation for boys (p = .045).

CONCLUSIONS

These findings lend support to previous research documenting abnormal brain structure in children with nonsyndromic cleft of the lip and/or palate and suggest that the cerebellum may play a role in speech deficits along with other structural causes, at least in boys.

Enhanced neural activity in frontal and cerebellar circuits after cognitive training in children with attention-deficit/hyperactivity disorder

The brain is a plastic entity that can undergo dynamic changes throughout the lifespan as a result of training. Attention-deficit/hyperactivity disorder (ADHD) is commonly treated with psychostimulant medication, and the prevalence of ADHD medication prescription is a topic of heated scientific debate. In addition, cognitive training is frequently provided to patients with ADHD. Although psychostimulant effects have been thoroughly investigated, no previous studies have assessed the neural effects of cognitive training in ADHD. We applied fMRI-paradigms of response inhibition and selective attention to chart the effects of a 10-day cognitive training program in 19 unmedicated ADHD children receiving either cognitive or control training. The two resulting longitudinal datasets were analyzed using whole-brain random-effects general linear models. Although we observed no increases of activity in the control group, both fMRI-datasets revealed enhanced activity after cognitive training in neural structures closely related to ADHD pathophysiology. On the inhibition paradigm, our results indicated increases in orbitofrontal, superior frontal, middle temporal, and inferior frontal cortex. The attentional task was characterized by increased activity in the cerebellum, which correlated with improvement on in-scanner measures of attention. Our findings provide preliminary evidence that cognitive training enhances activity in neural structures typically affected by the disorder. Similar results have been obtained following methylphenidate administration, suggesting that training of cognitive functions may mimic the effects of psychostimulant medication on the brain. These findings postulate a neural account for the potency of cognitive training in ADHD, and hold clinical implications, supporting the inclusion of training programs in standard ADHD-treatment.

Age-related changes in processing speed: unique contributions of cerebellar and prefrontal cortex

Age-related declines in processing speed are hypothesized to underlie the widespread changes in cognition experienced by older adults. We used a structural covariance approach to identify putative neural networks that underlie age-related structural changes associated with processing speed for 42 adults ranging in age from 19 to 79 years. To characterize a potential mechanism by which age-related gray matter changes lead to slower processing speed, we examined the extent to which cerebral small vessel disease influenced the association between age-related gray matter changes and processing speed. A frontal pattern of gray matter and white matter variation that was related to cerebral small vessel disease, as well as a cerebellar pattern of gray matter and white matter variation were uniquely related to age-related declines in processing speed. These results demonstrate that at least two distinct factors affect age-related changes in processing speed, which might be slowed by mitigating cerebral small vessel disease and factors affecting declines in cerebellar morphology.