Neuropathologically informed imaging of cortical grey matter lesions in MS - A pilot study

Multiple sclerosis (MS) is frequently misdiagnosed based on MRI abnormalities detected in the brain white matter. Cortical lesions have been well described neuropathologically, but remain challenging to detect in clinical practice. Therefore, the ability to detect cortical lesions offers real potential to reduce misdiagnosis. Cortical lesions have been shown to have a predilection for regions with CSF stasis - such as the insula and cingulate gyrus. This pathological observation forms the basis of our current pilot MR imaging study, which successfully uses high spatial resolution imaging of these two anatomical regions to clearly identify cortical lesions in MS.

Structural brain signatures of frailty, defined as accumulation of self-reported health deficits in older adults

Background

Frailty in older adults has been associated with reduced brain health. However, structural brain signatures of frailty remain understudied. Our aims were: (1) Explore associations between a frailty index (FI) and brain structure on magnetic resonance imaging (MRI). (2) Identify the most important FI features driving the associations.

Methods

We designed a cross-sectional observational study from a population-based study (The Irish Longitudinal Study on Aging: TILDA). Participants aged ≥50 years who underwent the wave 3 MRI sub-study were included. We measured cortex, basal ganglia, and each of the Desikan-Killiany regional volumes. Age-and sex-adjusted correlations were performed with a 32-item self-reported FI that included conditions commonly tested for frailty in research and clinical settings. A graph theory analysis of the network composed by each FI item and cortex volume was performed. White matter fiber integrity was quantified using diffusion tensor imaging (DTI).

Results

In 523 participants (mean age 69, 49% men), lower cortex and thalamic volumes were independently associated with higher FI. Sensory and functional difficulties, diabetes, polypharmacy, knee pain, and self-reported health were the main FI associations with cortex volume. In the network analysis, cortex volume had a modest influence within the frailty network. Regionally, higher FI was significantly associated with lower volumes in both orbitofrontal and temporal cortices. DTI analyses revealed inverse associations between the FI and the integrity of some association bundles.

Conclusion

The FI used had a recognizable but subtle structural brain signature in this sample. Only some FI deficits were directly associated with cortex volume, suggesting scope for developing FIs that include metrics more specifically related with brain health in future aging neuroscience studies.

148 ORTHOSTATIC HEMODYNAMICS AND ACCELERATED BRAIN AGING

Background

Impaired recovery of blood pressure (BP) in response to standing up is a prevalent condition in older individuals. We evaluated the relationship between the recovery of hemodynamic responses to standing and brain health in adults over 50.

Methods

Participants from The Irish Longitudinal Study on Aging (TILDA) (n=418) performed an active stand challenge while BP and heart rate (HR) were continuously monitored. The recovery of these parameters was determined as the difference in measurements taken at 10 s and 20 s after standing, in relation to the baseline value. The difference between biological and chronological brain age was determined using BrainPAD, a novel validated measure of accelerated brain ageing. The data was fitted using linear regression models, using age, sex, weight, height, cardiac disease prevalence, antihypertensive and antidepressant use, smoking status, standing speed and pulse wave velocity as covariates.

Results

Adjusting for age and sex only, each additional year of BrainPAD was associated with a –0.35 mmHg (95% CI: –0.54 – –0.16, P<.001) change in orthostatic systolic BP recovery. In a fully adjusted model, the regression coefficient was estimated at –0.29 mmHg (95% CI: –0.48 – –0.10, P<.01). Similarly, a year increase in BrainPAD was associated with –0.21 mmHg (95% CI: –0.32– –0.10, P<0.001) and –0.14 mmHg (95% CI: –0.25– –0.04, P<.01) change in orthostatic diastolic BP recovery, for minimally and fully adjusted models respectively. HR recovery was not significantly associated with BrainPAD.

Conclusion

These results demonstrate that impaired systolic and diastolic BP recovery after standing is associated with accelerated brain aging in older individuals. This suggests that the BP response to standing, measured using beat-to-beat monitoring, has potential to be used as a marker of accelerated brain aging, relying on a simple procedure and devices that are easily accessible for clinical use.

Normalization of impaired emotion inhibition in bipolar disorder mediated by cholinergic neurotransmission in the cingulate cortex

The muscarinic-cholinergic system is involved in the pathophysiology of bipolar disorder (BD), and contributes to attention and the top-down and bottom-up cognitive and affective mechanisms of emotional processing, functionally altered in BD. Emotion processing can be assessed by the ability to inhibit a response when the content of the image is emotional. Impaired regulatory capacity of cholinergic neurotransmission conferred by reduced M₂-autoreceptor availability is hypothesized to play a role in elevated salience of negative emotional distractors in euthymic BD relative to individuals with no history of mood instability. Thirty-three euthymic BD type-I (DSM-V-TR) and 50 psychiatrically-healthy controls underwent functional magnetic resonance imaging (fMRI) and an emotion-inhibition paradigm before and after intravenous cholinergic challenge using the acetylcholinesterase inhibitor, physostigmine (1 mg), or placebo. Mood, accuracy, and reaction time on either recognizing or inhibiting a response associated with an image involving emotion and regional functional activation were examined for effects of cholinergic challenge physostigmine relative to placebo, prioritizing any interaction with the diagnostic group. Analyses revealed that (1) at baseline, impaired behavioral performance was associated with lower activation in the anterior cingulate cortex in BD relative to controls during emotion processing; (2) physostigmine (vs. placebo) affected behavioral performance during the inhibition of negative emotions, without altering mood, and increased activation in the posterior cingulate cortex in BD (vs. controls); (3) In BD, lower accuracy observed during emotion inhibition of negative emotions was remediated by physostigmine and was associated with cingulate cortex overactivation. Our findings implicate abnormal regulation of cholinergic neurotransmission in the cingulate cortices in BD, which may mediate exaggerated emotional salience processing, a core feature of BD.

Characteristics and outcomes of acute colitis diagnosed on cross-sectional imaging presenting via the emergency department in an Irish academic medical centre

BACKGROUND AND AIMS

A significant proportion of patients presenting to the Emergency Department with gastrointestinal symptoms that result in cross-sectional imaging receive a radiological diagnosis of colitis. We aimed to review the characteristics, outcomes, and final diagnoses of new emergency department presentations with colitis diagnosed on cross-sectional imaging.

METHODS

A radiology database was interrogated to identify patients admitted from the Emergency Department of St James's Hospital whose cross-sectional imaging demonstrated colitis. Baseline demographic data, information on inpatient investigations, final diagnoses, and outcomes were recorded. Adverse outcomes were defined as a requirement for surgery, intensive care unit (ICU) stay, or mortality RESULTS: A total of 118 patients, 67% female, were identified with a median age of 64 years (range 16.9-101.2). Median (range) admission duration was 10 days (1-241). Final colitis diagnoses were infectious (28%), undefined (27%), reactive (18%), inflammatory bowel disease (11%), ischaemic (9%), chemotherapy-associated (3%), diverticular (3%), and medication-associated (1%). Colonic perforation, colectomy, and mortality occurred in 1%, 5%, and 13% of the cohort respectively. On univariate analysis, low haemoglobin, low albumin, high lactate, and male gender were associated with adverse outcomes with the following odds ratios (OR) and 95% confidence intervals (95%CI) were low haemoglobin 1.49 [1.15-1.92] P = 0.002, low albumin 1.16 [1.07-1.25] P = 0.0002, lactate 1.65 [1.13-2.42] P = 0.009, and male gender 3.09 [1.23-7.77] P = 0.019. On multivariate analysis, male gender was associated with adverse outcomes.

CONCLUSION

Patients presenting to the Emergency Department with a colitis, requiring an abdominal CT are a heterogenous group with a proportion having concomitant intra-abdominal pathology resulting in critical illness. Hence their is a significant morbidity and mortality observed in this cohort which should not be extrapolated to a general population of patients presenting with colitis. In this cohort of patients, anaemia, hypoalbuminaemia, and elevated lactate in patients presenting to the ED with acute colitis are significantly associated with adverse outcomes. Early recognition of these prognostic factors may identify the cohort of patients who are best managed in a high-dependency setting.

Overactivation of the middle cingulate cortex and the caudate nucleus as neural correlates of the familial liability to major depressiive disorder

Introduction

Unaffected healthy 1st degree relatives of patients with major depressive disorder (MDD) are 3.6 times more liable to develop the disease themselves than the standard population without the history of the disorder. Neural correlates of this liability are of particular interest since the phenomenon does not always have behavioral manifestations and early detected can enhance quicker and better MDD prevention.

Objective

The objective of our study was to establish neuronal correlates of susceptibility MDD in unaffected healthy 1st degree relatives of patients with MDD. Inhibition of emotional information was examined in the present study.

Aims

The aim of the study was to better understand the development of MDD and the role of altered inhibition of emotional processing in it. That, in consequence, may contribute to establishing new methods of prevention and quicker detection of MDD liability.

Methods

Twenty-one unaffected healthy 1st degree relatives of patients with MDD and twenty-five matched healthy controls underwent a functional magnetic resonance imaging procedure with a task involving inhibition of emotional processing of positive, negative and neutral emotional information. 2 × 3 ANOVA was performed to establish if the two groups differed significantly in the inhibition of one of the three types of emotions.

Results

The unaffected healthy 1st degree relatives displayed an increased neural activation during the inhibition of negative emotional information in the bilateral middle cingulate cortex (MCC) and the left caudate nucleus (p< 0.05, family wise error).

Conclusions

The overactivation of the MCC and caudate nucleus can be a marker of MDD liability

Occulomotor Neural Integrator Dysfunction in Multiple Sclerosis: Insights From Neuroimaging

Background: Magnetic resonance imaging is a key diagnostic and monitoring tool in multiple Sclerosis (MS). While the substrates of motor and neuropsychological symptoms in MS have been extensively investigated, nystagmus-associated imaging signatures are relatively under studied. Accordingly, the objective of this study is the comprehensive characterisation of cortical, subcortical, and brainstem involvement in a cohort of MS patients with gaze-evoked nystagmus.

Methods: Patients were recruited from a specialist MS clinic and underwent multimodal neuroimaging including high-resolution structural and diffusion tensor data acquisitions. Morphometric analyses were carried out to evaluate patterns of cortical, subcortical, brainstem, and cerebellar gray matter pathology. Volumetric analyses were also performed to further characterize subcortical gray matter degeneration. White matter integrity was evaluated using axial-, mean-, and radial diffusivity as well as fractional anisotropy.

Results: Whole-brain morphometry highlighted considerable brainstem and cerebellar gray matter atrophy, and the tract-wise evaluation of white matter metrics revealed widespread pathology in frontotemporal and parietal regions. Nystagmus-associated gray matter degeneration was identified in medial cerebellar, posterior medullar, central pontine, and superior collicular regions. Volume reductions were identified in the putamen, thalamus and hippocampus.

Conclusions: Multiple sclerosis is associated with widespread gray matter pathology which is not limited to cortical regions but involves striatal, thalamic, cerebellar, and hippocampal foci. The imaging signature of gaze-evoked nystagmus in MS confirms the degeneration of key structures of the neural integrator network.

Childhood-Diagnosed ADHD, Symptom Progression, and Reversal Learning in Adulthood

OBJECTIVE

ADHD persists in up to 60% into adulthood, and the reasons for persistence are not fully understood. The objective of this study was to characterize the neurofunctional basis of decision making in those with a childhood diagnosis of ADHD with either persistent or remitted symptoms in adulthood versus healthy control participants.

METHOD

Thirty-two adults diagnosed with ADHD as children were split into persistent ( n = 18) or remitted ( n = 14) ADHD groups. Their neural activity and neurofunctional connectivity during a probabilistic reversal learning task were compared with 32 healthy controls.

RESULTS

Remitters showed significantly higher neural connectivity in final reversal error and probabilistic error conditions, and persisters depict higher neural connectivity in reversal errors than controls at a family-wise error (FWE) corrected whole-brain corrected threshold.

CONCLUSION

Remitters may have utilized higher neural connectivity than controls to make successful decisions. Also, remitters may have utilized compensatory strategies to override any potential underlying ADHD deficits.

Single-Nucleotide Polymorphism of the FKBP5 Gene and Childhood Maltreatment as Predictors of Structural Changes in Brain Areas Involved in Emotional Processing in Depression

The gene expressing the FK506 binding protein 51 (FKBP5) is involved in the regulation of glucocorticoid receptor sensitivity. The rs1360780 SNP in this gene (T allele vs C homozygous) has been found to be associated with major depressive disorder (MDD). The aim of our study was to investigate whether this polymorphism might be associated with altered brain structure and function in a cohort of 40 patients with MDD and 43 healthy controls. A functional magnetic resonance imaging (fMRI) emotional attention task was employed. Diffusion tensor imaging (DTI) was also conducted, extracting mean diffusivity (MD) and fractional anisotropy (FA) from brain areas that showed functional differences between patients expressing the two alleles of the rs1360780 SNP. Finally, the effect of the interaction of childhood adversity as measured by the Childhood trauma Questionnaire (CTQ) and rs1360780 allele status was analyzed in relation to DTI measures using a general linear model. All results presented are family-wise error (FWE) corrected. Functional interactions were found between genotype and diagnosis (p<0.01). Patients carrying the high-risk allele, compared with patients not carrying it, showed reduced activity in the rolandic operculum, Heschl gyrus, insula, parahippocampal gyrus, posterior cingulate cortex, inferior frontal gyrus (p<0.05 for all measures); and increased MD and reduced FA measures in many of these regions (p<0.05). An interaction between CTQ scores and allele status was associated with DTI changes in the insula, rolandic operculum, and inferior frontal gyrus. Here, the presence of both the high-risk allele and higher CTQ scores was associated with higher MD and lower FA values (p<0.05). In conclusion, MDD patients expressing the T allele of rs1360780, compared with C homozygous patients, exhibit functional and structural differences in areas involved in emotional perception and inhibition. The interaction between the T allele and childhood maltreatment explained our structural findings in these regions, suggesting that their altered maturation and function might be influenced by early chronic stress in the presence of this genetic trait.

DNA methylation of the serotonin transporter gene (SLC6A4) is associated with brain function involved in processing emotional stimuli

BACKGROUND

The aim of the present study was to investigate the association of fMRI blood oxygen-level dependent (BOLD) reactivity with the level of epigenetic methylation of SLC6A4 in blood DNA from a sample of healthy participants and patients with major depressive disorder (MDD).

METHODS

We investigated patients with MDD and healthy controls using fMRI and an emotional attention-shifting task. We assessed site-specific DNA methylation of a previously characterized SLC6A4 region in peripheral blood DNA using pyrosequencing.

RESULTS

Our study involved 25 patients with MDD and 35 healthy controls. Activation in the anterior insula elicited by negative emotional content was significantly positively associated with the degree of SLC6A4 methylation. Significantly negative associations were observed between activation in the posterior insula and the degree of SLC6A4 methylation when judging the geometry of pictures after seeing negative in contrast to positive emotional stimuli. Healthy controls with a high degree of SLC6A4 methylation depicted significantly more activity elicited by positive stimuli in limbic regions and more activity elicited by negative stimuli in limbic as well as cognitive control regions than those with a low degree of SLC6A4 methylation.

LIMITATIONS

It is impossible to measure methylation directly in the brain and thus we assessed peripheral methylation of SLC6A4. Since the association was cross-sectional, no conclusion about cause and effect can be drawn.

CONCLUSION

Our study provides further support to the hypothesis that particular DNA methylation states that are associated with brain function during emotion processing are detectable in the periphery.

Impaired reward processing in the human prefrontal cortex distinguishes between persistent and remittent attention deficit hyperactivity disorder

Symptoms of attention deficit hyperactivity disorder (ADHD) in children often persist into adulthood and can lead to severe antisocial behavior. However, to-date it remains unclear whether neuro-functional abnormalities cause ADHD, which in turn can then provide a marker of persistent ADHD. Using event-related functional magnetic resonance imaging (fMRI), we measured blood oxygenation level dependent (BOLD) signal changes in subjects during a reversal learning task in which choice of the correct stimulus led to a probabilistically determined 'monetary' reward or punishment. Participants were diagnosed with ADHD during their childhood (N=32) and were paired with age, gender, and education matched healthy controls (N=32). Reassessment of the ADHD group as adults resulted in a split between either persistent (persisters, N=17) or remitted ADHDs (remitters, N=15). All three groups showed significantly decreased activation in the medial prefrontal cortex (PFC) and the left striatum during punished correct responses, however only remitters and controls presented significant psycho-physiological interaction between these fronto-striatal reward and outcome valence networks. Comparing persisters to remitters and controls showed significantly inverted responses to punishment (P<0.05, family-wise error corrected) in left PFC region. Interestingly, the decreased activation shown after punishment was located in different areas of the PFC for remitters compared with controls, suggesting that remitters might have learned compensation strategies to overcome their ADHD symptoms. Thus, fMRI helps understanding the neuro-functional basis of ADHD related behavior differences and differentiates between persistent and remittent ADHD.

Effect of childhood maltreatment on brain structure in adult patients with major depressive disorder and healthy participants

BACKGROUND

Childhood maltreatment has been found to play a crucial role in the development of psychiatric disorders. However, whether childhood maltreatment is associated with structural brain changes described for major depressive disorder (MDD) is still a matter of debate. The aim of this study was to investigate whether patients with MDD and a history of childhood maltreatment display more structural changes than patients without childhood maltreatment or healthy controls.

METHODS

Patients with MDD and healthy controls with and without childhood maltreatment experience were investigated using high-resolution magnetic resonance imaging (MRI), and data were analyzed using voxel-based morphometry.

RESULTS

We studied 37 patients with MDD and 46 controls. Grey matter volume was significantly decreased in the hippocampus and significantly increased in the dorsomedial prefrontal cortex (DMPFC) and the orbitofrontal cortex (OFC) in participants who had experienced childhood maltreatment compared with those who had not. Patients displayed smaller left OFC and left DMPFC volumes than controls. No significant difference in hippocampal volume was evident between patients with MDD and healthy controls. In regression analyses, despite effects from depression, age and sex on the DMPFC, OFC and hippocampus, childhood maltreatment was found to independently affect these regions.

LIMITATIONS

The retrospective assessment of childhood maltreatment; the natural problem that patients experienced more childhood maltreatment than controls; and the restrictions, owing to sample size, to investigating higher order interactions among factors are discussed as limitations.

CONCLUSION

These results suggest that early childhood maltreatment is associated with brain structural changes irrespective of sex, age and a history of depression.Thus, the study highlights the importance of childhood maltreatment when investigating brain structures.

Attention network hypoconnectivity with default and affective network hyperconnectivity in adults diagnosed with attention-deficit/hyperactivity disorder in childhood

IMPORTANCE

The neurobiological underpinnings of attention-deficit/hyperactivity disorder (ADHD) and particularly those associated with the persistence of ADHD into adulthood are not yet well understood. The correlation patterns in spontaneous neural fluctuations at rest are known as resting-state functional connectivity (RSFC) and could characterize ADHD-specific connectivity changes.

OBJECTIVE

To determine the specific location of possible ADHD-related differences in RSFC between adults diagnosed as having ADHD in childhood and control subjects. DESIGN Using resting-state functional magnetic resonance imaging, we calculated and compared functional connectivity from attention, affective, default, and cognitive control networks involved in the psychopathology of ADHD between the ADHD and control groups. SETTING University psychiatric service and magnetic resonance imaging research center.

PARTICIPANTS

Sixteen drug-free adults (5 women and 11 men; mean age, 24.5 years) diagnosed with combined-type ADHD in childhood and 16 healthy controls matched for age (mean age, 24.4 years), sex, handedness, and educational level recruited from the community.

INTERVENTION

Functional magnetic resonance imaging.

MAIN OUTCOMES AND MEASURES

Connectivity data from ventral and dorsal attention, affective, default, and cognitive control networks and ADHD symptoms derived from ADHD-specific rating instruments.

RESULTS

Adults with ADHD showed significantly decreased RSFC within the attention networks and increased RSFC within the affective and default mode and the right lateralized cognitive control networks compared with healthy controls (P < .01, familywise error for whole-brain cluster correction). Lower RSFC in the ventral and dorsal attention network was significantly correlated with higher levels of ADHD symptoms (P < .001).

CONCLUSIONS AND RELEVANCE

These RSFC findings might underpin a biological basis for adult ADHD and are functionally related to persistent inattention, disturbance in cognitive control, and emotional dysregulation in adults with ADHD. These findings need to be understood in the context of all aspects of brain function in ADHD.

Recruitment of the left hemispheric emotional attention neural network in risk for and protection from depression

BACKGROUND

Family history of major depressive disorder (MDD) increases individuals' vulnerability to depression and alters the way depression manifests itself. Emotion processing and attention shifting are functions altered by MDD and family history of the disease; therefore, it is important to recognize the neural correlates of these functions in association with both factors.

METHODS

Our study determines neural correlates of emotion processing and attention shifting for healthy individuals and patients with MDD with and without family history of depression. We compared the performance and neural activity in a functional magnetic resonance imaging experiment examining emotion processing and attention shifting in all participants.

RESULTS

Our sample included 4 study groups: healthy controls without family history of depression (n = 25), patients with MDD without family history of the disease (n = 20), unaffected healthy first-degree relatives of patients with MDD (n = 21) and patients with MDD with family history of MDD (n = 30). Compared with healthy controls, unaffected first-degree relatives overactivate the somatosensory cortex and the attention controlling areas during both emotion processing and attention shifting. Patients with family history of MDD have stronger neural activation in subcortical areas during shifting attention from negative stimuli. Patients without family history of MDD have less activation in the paralimbic regions and more activation in core limbic areas, especially during emotion processing.

LIMITATIONS

The conclusions about the intergroup differences in activation can be drawn only about neural areas engaged in the task.

CONCLUSION

Unaffected first-degree relatives of patients with MDD overreact to external emotional cues and compensate for the vulnerability with increased involvement of executive control. Patients with a family history of MDD have less executive control over their attentional shifts in the face of negative stimuli. Patients without a family history of MDD process emotional stimuli in a more visceral way than controls.

Early life adversity is associated with brain changes in subjects at family risk for depression

OBJECTIVE

The interplay of genetic and early environmental factors is recognized as an important factor in the aetiology of major depressive disorder (MDD). The aim of the present study was to examine whether reduced volume of hippocampus and frontal brain regions involved in emotional regulation are already present in unaffected healthy individuals at genetic risk of suffering MDD and to investigate whether early life adversity is a relevant factor interacting with these reduced brain structures.

METHOD

Twenty unaffected first-degree relatives of patients with MDD (FHP: family history positive) and 20 healthy controls (FHN: family history negative) underwent high-resolution magnetic resonance imaging. Manual tracing of hippocampal sub-regions and voxel-based morphometry was used to compare groups and find association to early life adversity.

RESULTS

FHP subjects with history of emotional abuse had significantly smaller left and right hippocampal heads. VBM also showed smaller dorsolateral prefrontal cortices (DLPFC), medial prefrontal cortices (MPFC) and anterior cortex cinguli in FHP who had a previous history of emotional abuse.

CONCLUSION

High risk individuals for depression have reduced volume of brain regions related to emotional processing in particular when they additionally suffered childhood abuse, indicating that genetic and environmental factors like early life adversity influence brain structure possibly via epigenetic mechanisms and thus structural anomalies may precede the onset of the illness.

Effect of genetic variant in BICC1 on functional and structural brain changes in depression

Genes and early-life adversity (ELA) interactively increase the risk of developing major depressive disorder (MDD). A recent genome-wide association study suggests that the minor T-allele of single-nucleotide polymorphisms in the bicaudal C homolog 1 gene (BICC1) has a protective role against MDD. The aims of the study were to investigate whether the minor T-allele of BICC1 is protective against hippocampal structural brain changes, whether it is associated with increased functional brain activity in the emotion regulation system, and how ELA would modify this association. Forty-four patients with MDD and 44 healthy controls were investigated using structural magnetic resonance imaging (MRI) and functional MRI with an emotion inhibition task. Analysis of a single-nucleotide polymorphism in the BICC1-1 (rs999845) gene was performed. Right hippocampal bodies of patients and controls without a history of ELA and who carry the protective T-allele of BICC1 were significantly larger compared with those participants homozygous for the major C-allele of BICC1. However, MDD patients with ELA, who carry the T-allele, had smaller hippocampal head volumes compared with MDD patients without ELA. FMRI showed that patients and controls carrying the protective T-allele of BICC1 activate the emotion regulation system significantly more compared with those participants homozygous for the major C-allele (p<0.05, family wise error corrected). These results are suggestive that the minor T-allele of BICC1 has a protective role against MDD and its known structural and functional brain changes. However, this protective effect seems to be lost in the case of co-occurrence of ELA.

Neurotrophic tyrosine kinase polymorphism impacts white matter connections in patients with major depressive disorder

BACKGROUND

Polymorphisms in the brain-derived neurotrophic factor (BDNF) gene and its receptor neurotrophic tyrosine kinase receptor type 2 (NTRK2) have been implicated in mood disorders. The aim of this study was to examine whether the NTRK2 and BDNF polymorphisms impact brain white matter connections in major depressive disorder and whether they may also have an interactive effect with environmental stress in the form of early life adversity.

METHODS

The study group comprised 45 depressed patients and 45 age- and gender-matched control subjects. High angular resolution diffusion images were obtained and analyzed using tract-based spatial statistics. Analysis of a single nucleotide polymorphism in the BDNF (rs6265/Valine66Methionine) and NTRK2 (rs11140714) genes was performed.

RESULTS

An interactive effect was found between NTRK2 and depression diagnosis maximally affecting the cingulum. Depressed patients homozygous for the A allele of NTRK2 showed significantly reduced fractional anisotropy compared with depressed patients with at least one copy of the G allele or control subjects with either the A/A or G carrier genotypes in the left and right corona radiata, left uncinate fasciculus, left inferior fronto-occipital fasciculus, left cerebral peduncle, posterior thalamic radiation, and middle cerebral peduncle. Significantly smaller gray matter volume was seen in frontal lobe regions in patients homozygous for the A allele.

CONCLUSIONS

Polymorphisms in NTRK2 gene increase risk of architectural changes in several brain regions involved in emotional regulation.

Reduced expression of glucocorticoid-inducible genes GILZ and SGK-1: high IL-6 levels are associated with reduced hippocampal volumes in major depressive disorder

Neuroplasticity may have a core role in the pathophysiology of major depressive disorder (MDD), a concept supported by experimental studies that found that excessive cortisol secretion and/or excessive production of inflammatory cytokines impairs neuronal plasticity and neurogenesis in the hippocampus. The objective of this study was to examine how changes in the glucocorticoid and inflammatory systems may affect hippocampal volumes in MDD. A multimodal approach with structural neuroimaging of hippocampus and amygdala, measurement of peripheral inflammatory proteins interleukin (IL)-6 and C-reactive protein (CRP), glucocorticoid receptor (GR) mRNA expression, and expression of glucocorticoid-inducible genes (glucocorticoid-inducible genes Leucin Zipper (GILZ) and glucocorticoid-inducible kinase-1 (SGK-1)) was used in 40 patients with MDD and 43 healthy controls (HC). Patients with MDD showed smaller hippocampal volumes and increased inflammatory proteins IL-6 and CRP compared with HC. Childhood maltreatment was associated with increased CRP. Patients with MDD, who had less expression of the glucocorticoid-inducible genes GILZ or SGK-1 had smaller hippocampal volumes. Regression analysis showed a strong positive effect of GILZ and SGK-1 mRNA expression, and further inverse effects of IL-6 concentration, on hippocampal volumes. These findings suggest that childhood maltreatment, peripheral inflammatory and glucocorticoid markers and hippocampal volume are interrelated factors in the pathophysiology of MDD. Glucocorticoid-inducible genes GILZ and SGK-1 might be promising candidate markers for hippocampal volume changes relevant for diseases like MDD. Further studies need to explore the possible clinical usefulness of such a blood biomarker, for example, for diagnosis or prediction of therapy response.

Tracheoesophageal compression associated with substernal goitre. Correlation of symptoms with cross-sectional imaging findings

Objective: The aim of this study was to compare the subjective tracheoesophageal pressure symptoms associated with substernal goitres with objective cross-sectional radiographic measurements.

Design: Patients with substernal goitre were questioned regarding tracheoesophageal compression symptoms and these data were analysed for correlation with radiographic and intra-operative findings.

Results: Twenty-six patients were included. Patients with airway symptoms including dyspnoea, stridor and coughing were more likely to have significant tracheal narrowing on pre-operative computed tomography (CT) imaging. There was also a significant correlation between the perceived severity of lump sensation in the throat and the presence of tracheal and oesophageal displacement and retrotracheal extension of the thyroid mass.

Conclusion: Pre-operative CT measurements of tracheal and oesophageal displacement, retrotracheal extension and the degree of tracheal compression correlate well with the presence and severity of tracheoesophageal pressure symptoms. None of the radiographic findings that are exclusive to substernal goitre (percentage of substernal mass, goitre size at the level of the thoracic inlet, ratio of goitre size to the vertebral body at the thoracic inlet and retrosternal isthmus size) had any correlation with clinical symptoms in this study.

Phase II pilot study of neoadjuvant cetuximab in combination with cisplatin and gemcitabine in patients with resectable IB-IIIA non small cell lung cancer

17107

Background: Adjuvant and neoadjuvant chemotherapy play a role in optimising long term outcome of patients with resectable non small cell lung cancer (NSCLC). The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase which is overexpressed NSCLC. Cetuximab is a monoclonal antibody which attaches to the extracellular domain of the EGFR preventing ligand binding. Preclinical data and phase II evidence in advanced NSCLC suggest cetuximab potentiates the effect of conventional cytotoxic agents. Methods: Patients with histologically confirmed resectable stage IB-IIIA NSCLC and adequate end-organ function, giving informed written consent are eligible. Three weekly cycles of cisplatin 80 mg/m2 D1, gemcitabine 1250 mg/m2 D1,D8 and cetuximab loading dose of 400 mg/m2 on first infusion, thereafter weekly 250 mg/m2 are used. The primary endpoint is response rate (radiological and pathological). Secondary endpoints are safety and tolerability of the combination, resection rate following therapy, overall survival and relapse free survival. In addition, molecular prognostic and predictive biomarkers of response are being assessed. Sequential samples of tissue, plasma, serum and white blood cells are being collected before, during and after therapy on all patients. Results: 16 patients have been recruited to date. (10 men, 6 women). Median age 66 (range 29–76). 3 patients stage I, 4 patients, stage II, 9 patients stage III. 11 have completed treatment. Response (RECIST guidelines); PR - 6 patients, SD - 4 patients, PD - 1 patient. The most common toxicity was skin rash (100%). Grade 3/4 toxicities were neutropenia (73%), thrombocytopenia (45%). There were 2 grade 3 and 2 grade 4 cardiovascular toxicities in patients with significant co-morbid cardiovascular histories. Conclusion: The response rate is consistent with that established for neoadjuvant chemotherapy. Ongoing biomarker studies may identify those patients most likely to benefit from induction treatment.

No significant financial relationships to disclose.

The Role of a Right Fronto-Parietal Network in Cognitive Control

Seemingly distinct cognitive tasks often activate similar anatomical networks. For example, the right fronto-parietal cortex is active across a wide variety of paradigms suggesting that these regions may subserve a general cognitive function. We utilized fMRI and a GO/NOGO task consisting of two conditions, one with intermittent unpredictive “cues-to-attend” and the other without any “cues-to-attend,” in order to investigate areas involved in inhibition of a prepotent response and top-down attentional control. Sixteen subjects (5 male, ages ranging from 20 to 30 years) responded to an alternating sequence of the letters X and Y and withheld responding when the alternating sequence was broken (e.g., when X followed an X). Cues were rare stimulus font-color changes, which were linked to a simple instruction to attend to the task at hand. We hypothesized that inhibitions and cues, despite requiring quite different responses from subjects, might engage similar top-down attentional control processes and would thus share a common network of anatomical substrates. Although inhibitions and cues activated a number of distinct brain regions, a similar network of right dorsolateral prefrontal and inferior parietal regions was active for both. These results suggest that this network, commonly activated for response inhibition, may subserve a more general cognitive control process involved in allocating top-down attentional resources.

Cannonball metastases with favourable prognosis

BACKGROUND

Secondary 'cannonball' metastases to the lung are frequent and usually associated with disseminated malignancy and poor prognosis.

AIM

To report the case of a patient with metastatic pulmonary endometrial stromal sarcoma who had a previous hysterectomy for benign uterine fibroids and no past history of malignancy.

RESULT

A 70-year-old female presented with cannonball metastases in her lung. Four years previously she had a hysterectomy for 'fibroids'. Review of the original histology revealed endometrial stromal sarcoma, similar to the lung metastasis. She currently has a good prognosis.

CONCLUSION

A patient with 'cannonball' metastases can have a favourable prognosis. A female patient with a previous hysterectomy for uterine fibroids, should be considered to have metastatic sarcoma until proven otherwise.

Dietary regulation of the renal sodium-phosphate (Na+/Pi) transporter during early ontogeny in the rat

Phosphates are necessary for proper skeletal growth and function, as well as for growth and development of cells. Phosphate repletion depends partly on the function of the renal sodium-phosphate (Na+/Pi) transport system that functions to recover filtered urinary phosphate. It has been suggested that in order to meet the higher phosphate requirement of the developing animal, the weanling rat would have a greater adaptive response to chronic phosphate deprivation than the adolescent rat. The current study sought to characterize the adaptive response to dietary phosphate deprivation in terms of Na+/Pi transporter activity, and mRNA and immunoreactive protein levels. Weanling and adolescent rats were pair fed either a low-phosphate diet (LPD) or a control-phosphate diet (CPD) for 1 week. Maximal rates of transport (Vmax) were not different in weanling or adolescent rats on CPD (weanling 2.13 +/- 0.29 nmol/mg protein/10 sec, and adolescent 1.41 +/- 0.036 nmol/mg protein/10 sec, n = 3). K(m) values were not different in either group on CPD (weanling 0.15 +/- 0.08 mM Pi, and adolescent 0.22 +/- 0.13 mM Pi). There were no difference in mRNA abundance (Na+/Pi transporter/1B15 = 0.194 +/- 0.12 for weanling and 0.230 +/- 0.03 for adolescents, n = 3) or immunoreactive protein levels (Na+/Pi transporter/beta-actin = 0.232 +/- 0.01 for weanlings and 0.300 +/- 0.05 for adolescents, n = 3) in the two groups when fed CPD. After chronic Pi deprivation, the weanling rat showed a greater adaptive response than the adolescent as measured by Vmax values (weanling LPD/CPD = 2.01, P < 0.01; adolescent LPD/CPD not different; n = 3), mRNA signal intensity (weanling LPD/CPD = 1.86, P < 0.05; adolescent LPD/CPD not different; n = 3), and protein signal intensity (weanling LPD/CPD = 3.63, P < 0.01, and adolescent LPD/CPD 1.91, P < 0.05; n = 3). K(m) values were not affected by LPD. Immunohistochemical analysis of kidney cortex showed greater apical staining in both groups on LPD, with the increase being noticeably greater in the weanlings. Furthermore, two-way analysis of variance demonstrates a significant adaptive response in the weanling period in regard to maximum transport capacity (Vmax) and immunoreactive protein (Western), suggesting a synergistic effect between the developmental stage and low-phosphate diet. Therefore, it appears that the adaptive response is greater in the more rapidly developing animal (the weanling), and these results suggest a compensatory mechanism to conserve phosphate during periods of rapid growth.

MRI in the investigation of Morton's neuroma: which sequences?

Morton's 'neuroma' is a painful focus of peri-neural fibrosis, which may affect the interdigital nerves of the feet. Clinical diagnosis and localization may be inaccurate. Computed tomography (CT), ultrasound and magnetic resonance imaging (MRI) have been used to confirm the diagnosis pre-operatively. Recently, MRI using T1-weighted sequences with fat saturation after i.v. Gadolinium DTPA has been suggested as the most effective MR sequence for depiction of Morton's neuroma of the neuroma of the forefoot. Our results show that T1-weighted axial and coronal images with an axial FSE T2-weighted sequence detect neuromata more consistently than an enhanced T1 fat suppressed sequence.

Epigenetic factors controlling the development of avian Purkinje neurons

Using a unique protocol, we have developed an avian neuron culture system in which a high yield of Purkinje neurons is obtained more readily than with pre-existing methods. Purkinje neurons were identified in vitro using the specific antibodies calbindin and cyclic GMP-kinase. Survival of Purkinje neurons was dependent on astrocyte contact and enhanced by astrocytic factors supplied to the medium by a monolayer of astrocytes grown on coated membranes suspended in the culture wells but not in contact with the neurons. The age of the cerebellum from which astrocytes were obtained was shown to affect the morphological development of the Purkinje neurons suggesting the developmentally-regulated expression of growth factors. However, in the presence of the astrocytes, Purkinje neurons could only progress to a limited stage of development based on morphological criteria. The addition to the culture of cerebellar granule neurons at a time of Purkinje neuron development that they would expect to encounter them in vivo resulted in a shift of Purkinje neurons to a mature phenotype. This maturation effect was increased in response to increasing levels of granule neurons, but was independent of the granule neuron ages used. This system offers significant advantages over other Purkinje neuron culture systems and will be useful for studying the extrinsic factors involved in Purkinje neuron development and histogenesis.

Intraosseous lipomas

Intraosseous lipomas are considered to be rare tumours. We describe four cases and discuss their appearances and diagnosis. It is likely with the increasing frequency of computed tomography and magnetic resonance examinations of the lumbar spine that many more asymptomatic lesions will present to the radiologist and that these tumours are not as rare as the literature would suggest.