Distinct Subcortical Volume Alterations in Pediatric and Adult OCD: A Worldwide Meta- and Mega-Analysis

OBJECTIVE

Structural brain imaging studies in obsessive-compulsive disorder (OCD) have produced inconsistent findings. This may be partially due to limited statistical power from relatively small samples and clinical heterogeneity related to variation in illness profile and developmental stage. To address these limitations, the authors conducted meta- and mega-analyses of data from OCD sites worldwide.

METHOD

T1 images from 1,830 OCD patients and 1,759 control subjects were analyzed, using coordinated and standardized processing, to identify subcortical brain volumes that differ between OCD patients and healthy subjects. The authors performed a meta-analysis on the mean of the left and right hemisphere measures of each subcortical structure, and they performed a mega-analysis by pooling these volumetric measurements from each site. The authors additionally examined potential modulating effects of clinical characteristics on morphological differences in OCD patients.

RESULTS

The meta-analysis indicated that adult patients had significantly smaller hippocampal volumes (Cohen's d=-0.13; % difference=-2.80) and larger pallidum volumes (d=0.16; % difference=3.16) compared with adult controls. Both effects were stronger in medicated patients compared with controls (d=-0.29, % difference=-4.18, and d=0.29, % difference=4.38, respectively). Unmedicated pediatric patients had significantly larger thalamic volumes (d=0.38, % difference=3.08) compared with pediatric controls. None of these findings were mediated by sample characteristics, such as mean age or scanning field strength. The mega-analysis yielded similar results.

CONCLUSIONS

The results indicate different patterns of subcortical abnormalities in pediatric and adult OCD patients. The pallidum and hippocampus seem to be of importance in adult OCD, whereas the thalamus seems to be key in pediatric OCD. These findings highlight the potential importance of neurodevelopmental alterations in OCD and suggest that further research on neuroplasticity in OCD may be useful.

Accuracy of prenatal detection of tracheoesophageal fistula and oesophageal atresia

AIMS

This study aims to determine the rate of prenatal detection of tracheoesophageal fistula and oesophageal atresia (TOF/OA), by identifying a small or absent stomach bubble with or without polyhydramnios, on the prenatal ultrasound scans (USS).

METHODS

A retrospective study of prenatal ultrasound findings of babies with a prenatal and postnatal diagnosis of TOF/OA born between 1st January 2004 and 31st December 2013 was undertaken.

RESULTS

A total of 58 babies were born with TOF/OA. 40% of mothers had their prenatal investigations performed within our tertiary centre, and the remaining 60% had their antenatal care at their local district general hospital (DGH). The overall sensitivity for prenatal USS was 26%, with a specificity of 99% and a positive predictive value (PPV) of 35%. However, the sensitivity of the prenatal USS within the tertiary centre was significantly higher at 57%, while only 2 cases were detected prenatally in the DGHs. Polyhydramnios was seen in 67% of mothers that had a prenatal diagnosis of TOF/OA and its presence did significantly increase the positive predictive value of prenatal USS (from 35% to 63%). Of those that were postnatally diagnosed, 21% had prenatal polyhydramnios. There was no significant difference in postnatal outcomes between those that were prenatally diagnosed and those that were postnatally diagnosed.

CONCLUSION

Prenatal diagnosis of TOF/OA remains challenging. However within a specialist centre the accuracy of successful prenatal detection can be significantly improved. This is beneficial both for prenatal counselling of families and for planning appropriate perinatal and postnatal care for the baby.

Implicit learning on a probabilistic classification task in adults and adolescents with Bulimia Nervosa

BACKGROUND

Dysfunction in frontostriatal circuits likely contributes to impaired regulatory control in Bulimia Nervosa (BN), resulting in binge-eating and purging behaviors that resemble maladaptive habits. Less is known about the implicit learning processes of these circuits, which may contribute to habit formation.

METHODS

We compared 52 adolescent and adult females with BN to 55 healthy matched-controls during performance of a probabilistic classification learning task, one form of implicit learning. Groups were compared in accuracy and response times, using mixed-models with block, age, and diagnosis as predictors, corrected for multiple comparisons with confounds covaried.

RESULTS

BN participants showed differences in performance on a probabilistic classification learning task that varied by age. Adolescents with BN initially performed as accurately as healthy adolescents, but showed poorer perseverance over time. Adults with BN initially performed less accurately than healthy adults, but improved to perform equivalently. Symptom severity was associated with poorer accuracy in both adults and adolescents with BN.

CONCLUSIONS

Frontostriatal dysfunction may underlie abnormalities in regulatory control and probabilistic classification learning in BN, likely contributing to the dysregulation of implicitly learned, maladaptive binge-eating and purging behaviors. Such dysfunction in BN may progress with increasing age, first manifesting in poor regulatory control over behaviors and then expanding to implicit learning processes that may underlie habitual behaviors.

Altered White Matter Microstructure in Adolescents and Adults with Bulimia Nervosa

Previous data suggest structural and functional deficits in frontal control circuits in adolescents and adults with bulimia nervosa (BN), but less is known about the microstructure of white matter in these circuits early in the course of the disorder. Diffusion tensor imaging (DTI) data were acquired from 28 female adolescents and adults with BN and 28 age- and BMI-matched healthy female participants. Tract-based spatial statistics (TBSS) was used to detect group differences in white matter microstructure and explore the differential effects of age on white matter microstructure across groups. Significant reductions in fractional anisotropy (FA) were detected in the BN compared with healthy control group in multiple tracts including forceps minor and major, superior longitudinal, inferior fronto-occipital, and uncinate fasciculi, anterior thalamic radiation, cingulum, and corticospinal tract. FA reductions in forceps and frontotemporal tracts correlated inversely with symptom severity and Stroop interference in the BN group. These findings suggest that white matter microstructure is abnormal in BN in tracts extending through frontal and temporoparietal cortices, especially in those with the most severe symptoms. Age-related differences in both FA and RD in these tracts in BN compared with healthy individuals may represent an abnormal trajectory of white matter development that contributes to the persistence of functional impairments in self-regulation in BN.

Adherence to guidelines regarding total hip replacement for fractured neck of femur

Introduction In 2011 the National Institute for Health and Care Excellence (NICE) published guidelines suggesting that clinicians offer total hip replacement (THR) to patients with displaced intracapsular hip fractures who could walk independently outside with no aids or one stick, who are not cognitively impaired and are ASA (American Society of Anesthesiologists) grade ≤2. They also stated that best practice is operating within 36 hours of presentation. This audit aimed to determine whether Scarborough Hospital was following these guidelines and compared the results with the national average. Methods Two years of data (January 2012 - December 2013) were collected retrospectively from Scarborough Hospital's hip fracture database on all patients presenting with an intracapsular hip fracture. Data were analysed to determine whether patients who had a THR fulfilled NICE criteria. Furthermore, patients with hemiarthroplasties who were eligible for THRs were identified. Finally, the time to surgery was calculated to examine whether patients receiving THRs waited longer than patients receiving hemiarthroplasties. Results In 2012, 48.6% of all eligible patients received a THR while in 2013 the figure was 55.9%. These percentages are much higher than the national average. However, 36 (53.7%) of the 67 patients who received a THR did not fulfil all the NICE criteria, mainly owing to high ASA grade. The mean time from presentation to theatre for THR was 8 hours and 37 minutes longer for THR patients than for hemiarthroplasty in 2012. This difference was reduced to 2 hours and 12 minutes in 2013. Conclusions Small general hospitals can meet and even exceed the standards regarding treatment strategies for hip factures. However, there is still room for improvement. Departmental training may be useful in achieving this aim. The anaesthetic team should be involved at the earliest opportunity, to help optimise patients preoperatively and determine whether patients listed for THR with higher ASA grades are suitable for this surgery.

Sex-specific neural activity when resolving cognitive interference in individuals with or without prior internalizing disorders

The processing of cognitive interference is a self-regulatory capacity that is impaired in persons with internalizing disorders. This investigation was to assess sex differences in the neural correlates of cognitive interference in individuals with and without an illness history of an internalizing disorder. We compared functional magnetic resonance imaging blood-oxygenation-level-dependent responses in both males (n=63) and females (n=80) with and without this illness history during performance of the Simon task. Females deactivated superior frontal gyrus, inferior parietal lobe, and posterior cingulate cortex to a greater extent than males. Females with a prior history of internalizing disorder also deactivated these regions more compared to males with that history, and they additionally demonstrated greater activation of right inferior frontal gyrus. These group differences were represented in a significant sex-by-illness interaction in these regions. These deactivated regions compose a task-negative or default mode network, whereas the inferior frontal gyrus usually activates when performing an attention-demanding task and is a key component of a task-positive network. Our findings suggest that a prior history of internalizing disorders disproportionately influences functioning of the default mode network and is associated with an accompanying activation of the task-positive network in females during the resolution of cognitive interference.

SapC-DOPS-induced lysosomal cell death synergizes with TMZ in glioblastoma

SapC-DOPS is a novel nanotherapeutic that has been shown to target and induce cell death in a variety of cancers, including glioblastoma (GBM). GBM is a primary brain tumor known to frequently demonstrate resistance to apoptosis-inducing therapeutics. Here we explore the mode of action for SapC-DOPS in GBM, a treatment being developed by Bexion Pharmaceuticals for clinical testing in patients. SapC-DOPS treatment was observed to induce lysosomal dysfunction of GBM cells characterized by decreased glycosylation of LAMP1 and altered proteolytic processing of cathepsin D independent of apoptosis and autophagic cell death. We observed that SapC-DOPS induced lysosomal membrane permeability (LMP) as shown by LysoTracker Red and Acridine Orange staining along with an increase of sphingosine, a known inducer of LMP. Additionally, SapC-DOPS displayed strong synergistic interactions with the apoptosis-inducing agent TMZ. Collectively our data suggest that SapC-DOPS induces lysosomal cell death in GBM cells, providing a new approach for treating tumors resistant to traditional apoptosis-inducing agents.

Reward-based spatial learning in unmedicated adults with obsessive-compulsive disorder

OBJECTIVE

The authors assessed the functioning of mesolimbic and striatal areas involved in reward-based spatial learning in unmedicated adults with obsessive-compulsive disorder (OCD).

METHOD

Functional MRI blood-oxygen-level-dependent response was compared in 33 unmedicated adults with OCD and 33 healthy, age-matched comparison subjects during a reward-based learning task that required learning to use extramaze cues to navigate a virtual eight-arm radial maze to find hidden rewards. The groups were compared in their patterns of brain activation associated with reward-based spatial learning versus a control condition in which rewards were unexpected because they were allotted pseudorandomly to experimentally prevent learning.

RESULTS

Both groups learned to navigate the maze to find hidden rewards, but group differences in neural activity during navigation and reward processing were detected in mesolimbic and striatal areas. During navigation, the OCD group, unlike the healthy comparison group, exhibited activation in the left posterior hippocampus. Unlike healthy subjects, participants in the OCD group did not show activation in the left ventral putamen and amygdala when anticipating rewards or in the left hippocampus, amygdala, and ventral putamen when receiving unexpected rewards (control condition). Signal in these regions decreased relative to baseline during unexpected reward receipt among those in the OCD group, and the degree of activation was inversely associated with doubt/checking symptoms.

CONCLUSIONS

Participants in the OCD group displayed abnormal recruitment of mesolimbic and ventral striatal circuitry during reward-based spatial learning. Whereas healthy comparison subjects exhibited activation in this circuitry in response to the violation of reward expectations, unmedicated OCD participants did not and instead over-relied on the posterior hippocampus during learning. Thus, dopaminergic innervation of reward circuitry may be altered, and future study of anterior/posterior hippocampal dysfunction in OCD is warranted.

Reducing risk of overdose with midazolam injection in adults: an evaluation of change in clinical practice to improve patient safety in England

RATIONALE AIMS AND OBJECTIVES

This study sought to evaluate potential reductions in risk associated with midazolam injection, a sedating medication, following a UK National Patient Safety Alert. This alert, 'Reducing risk of overdose with midazolam injection in adults', was sent to all National Health Service organizations as a Rapid Response Report detailing actions services should take to minimize risks.

METHOD

To evaluate any potential changes arising from this alert, a number of data sources were explored including reported incidents to a national reporting system for health care error, clinician survey and audit data, pharmaceutical purchasing patterns and feedback from National Health Service managers.

RESULTS

Prior to the Rapid Response Report, 498 incidents were received by the National Patient Safety Agency including three deaths. Post-implementation of the Rapid Response Report (June 2009), no incidents resulting in death or severe harm had been received. All organizations reported having completed the Rapid Response Report actions. Purchase and use of risk-prone, high-strength sedating midazolam by health care organizations decreased significantly as did the increased use of safer, lower strength doses (as recommended in the Rapid Response Report).

CONCLUSIONS

Organizations can achieve safer medication practices, better knowledge, awareness and implementation of national safer practice recommendations. Risks from inadvertent overdose of midazolam injection were reduced post-implementation of national recommendations. Ongoing monitoring of this particular adverse event will be required with a sustained patient safety message to health services to maintain awareness of the issue and reduction in the number of midazolam-related errors.

Frontostriatal circuits and the development of bulimia nervosa

Bulimia nervosa (BN) is characterized by both recurrent episodes of binge eating that are, in part, defined by a sense of loss of control and compensatory behaviors to avoid weight gain. Impulsive behaviors are also common in individuals with BN, indicating more pervasive difficulties in behavioral self-regulation. Findings from functional and anatomical neuroimaging studies of individuals with BN suggest dysfunction in the dorsal frontostriatal circuits that support self-regulatory capacities and habit learning and in overlapping ventral circuits that support reward processing and reward-based learning. In this review, we describe the normal development of frontostriatal circuits and then present behavioral and neuroimaging data from adolescents and adults with BN. These data suggest that the abnormal maturation of frontostriatal circuits may contribute to the habitual binge-eating and purging behaviors of BN. Future longitudinal imaging studies will improve understanding of how these circuits contribute to the developmental trajectory of BN and will inform novel interventions that could target or prevent the impulsive and habit-like features of this disorder.

Changes in corticostriatal connectivity during reinforcement learning in humans

Many computational models assume that reinforcement learning relies on changes in synaptic efficacy between cortical regions representing stimuli and striatal regions involved in response selection, but this assumption has thus far lacked empirical support in humans. We recorded hemodynamic signals with fMRI while participants navigated a virtual maze to find hidden rewards. We fitted a reinforcement-learning algorithm to participants' choice behavior and evaluated the neural activity and the changes in functional connectivity related to trial-by-trial learning variables. Activity in the posterior putamen during choice periods increased progressively during learning. Furthermore, the functional connections between the sensorimotor cortex and the posterior putamen strengthened progressively as participants learned the task. These changes in corticostriatal connectivity differentiated participants who learned the task from those who did not. These findings provide a direct link between changes in corticostriatal connectivity and learning, thereby supporting a central assumption common to several computational models of reinforcement learning.

Annual research review: The neurobehavioral development of multiple memory systems--implications for childhood and adolescent psychiatric disorders

Extensive evidence indicates that mammalian memory is organized into multiple brains systems, including a 'cognitive' memory system that depends on the hippocampus and a stimulus-response 'habit' memory system that depends on the dorsolateral striatum. Dorsal striatal-dependent habit memory may in part influence the development and expression of some human psychopathologies, particularly those characterized by strong habit-like behavioral features. The present review considers this hypothesis as it pertains to psychopathologies that typically emerge during childhood and adolescence. These disorders include Tourette syndrome, attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, eating disorders, and autism spectrum disorders. Human and nonhuman animal research shows that the typical development of memory systems comprises the early maturation of striatal-dependent habit memory and the relatively late maturation of hippocampal-dependent cognitive memory. We speculate that the differing rates of development of these memory systems may in part contribute to the early emergence of habit-like symptoms in childhood and adolescence. In addition, abnormalities in hippocampal and striatal brain regions have been observed consistently in youth with these disorders, suggesting that the aberrant development of memory systems may also contribute to the emergence of habit-like symptoms as core pathological features of these illnesses. Considering these disorders within the context of multiple memory systems may help elucidate the pathogenesis of habit-like symptoms in childhood and adolescence, and lead to novel treatments that lessen the habit-like behavioral features of these disorders.