Refined diagnostic criteria for the bipolar disorders: phase two of the AREDOC project

OBJECTIVE

As limitations exist across DSM criteria sets for defining and differentiating the bipolar disorders generally and their component bipolar I (BP-1) and bipolar II (BP-II) sub-types, we sought to generate empirically based criteria.

METHOD

We formed an international Task Force (TF) comprising members with bipolar disorder expertise, and who recruited 74 patients with a TF-diagnosed bipolar I and 104 with a bipolar II condition (with patients responding to definitional queries and symptom questionnaires), while 33 unipolar depressed patients recruited by the first author also completed the symptom questionnaire. A factor analysis sought to determine granular hypo/manic constructs.

RESULTS

The bipolar disorder subjects strongly affirmed a new general definition of a bipolar disorder (capturing both manic and hypomanic episodes). While DSM-5 requires impaired functioning, we established that a high percentage of individuals with a BP-I or a BP-II disorder reported improved functioning and therefore modified this criterion. Analyses identified syptoms with differential high rates in individuals with bipolar disorder and its sub-types (and thus not simply capturing happiness), while a factor analysis generated seven symptom constructs both linked with and differing from DSM-5 bipolar symptom criteria.

CONCLUSION

This second-stage report details a new set of criteria for differentiating the bipolar disorders from unipolar depressive conditions, while arguing for BP-I and BP-II disorders being differentiated principally by the respective presence or absence of psychotic features. Future studies will evaluate whether further modifications are required and examine for differential treatment benefits for those with a BP-I versus a BP-II condition.

Prediction of lithium response using clinical data

OBJECTIVE

Promptly establishing maintenance therapy could reduce morbidity and mortality in patients with bipolar disorder. Using a machine learning approach, we sought to evaluate whether lithium responsiveness (LR) is predictable using clinical markers.

METHOD

Our data are the largest existing sample of direct interview-based clinical data from lithium-treated patients (n = 1266, 34.7% responders), collected across seven sites, internationally. We trained a random forest model to classify LR-as defined by the previously validated Alda scale-against 180 clinical predictors.

RESULTS

Under appropriate cross-validation procedures, LR was predictable in the pooled sample with an area under the receiver operating characteristic curve of 0.80 (95% CI 0.78-0.82) and a Cohen kappa of 0.46 (0.4-0.51). The model demonstrated a particularly low false-positive rate (specificity 0.91 [0.88-0.92]). Features related to clinical course and the absence of rapid cycling appeared consistently informative.

CONCLUSION

Clinical data can inform out-of-sample LR prediction to a potentially clinically relevant degree. Despite the relevance of clinical course and the absence of rapid cycling, there was substantial between-site heterogeneity with respect to feature importance. Future work must focus on improving classification of true positives, better characterizing between- and within-site heterogeneity, and further testing such models on new external datasets.

Cerebellar parcellation in schizophrenia and bipolar disorder

OBJECTIVE

The cerebellum is involved in cognitive processing and emotion control. Cerebellar alterations could explain symptoms of schizophrenia spectrum disorder (SZ) and bipolar disorder (BD). In addition, literature suggests that lithium might influence cerebellar anatomy. Our aim was to study cerebellar anatomy in SZ and BD, and investigate the effect of lithium.

METHODS

Participants from 7 centers worldwide underwent a 3T MRI. We included 182 patients with SZ, 144 patients with BD, and 322 controls. We automatically segmented the cerebellum using the CERES pipeline. All outputs were visually inspected.

RESULTS

Patients with SZ showed a smaller global cerebellar gray matter volume compared to controls, with most of the changes located to the cognitive part of the cerebellum (Crus II and lobule VIIb). This decrease was present in the subgroup of patients with recent-onset SZ. We did not find any alterations in the cerebellum in patients with BD. However, patients medicated with lithium had a larger size of the anterior cerebellum, compared to patients not treated with lithium.

CONCLUSION

Our multicenter study supports a distinct pattern of cerebellar alterations in SZ and BD.

Larger right inferior frontal gyrus volume and surface area in participants at genetic risk for bipolar disorders

BACKGROUND

Larger grey matter volume of the inferior frontal gyrus (IFG) is among the most replicated biomarkers of genetic risk for bipolar disorders (BD). However, the IFG is a heterogeneous prefrontal region, and volumetric findings can be attributable to changes in cortical thickness (CT), surface area (SA) or gyrification. Here, we investigated the morphometry of IFG in participants at genetic risk for BD.

METHODS

We quantified the IFG cortical grey matter volume in 29 affected, 32 unaffected relatives of BD probands, and 42 controls. We then examined SA, CT, and cortical folding in subregions of the IFG.

RESULTS

We found volumetric group differences in the right IFG, with the largest volumes in unaffected high-risk and smallest in control participants (F2,192 = 3.07, p = 0.01). The volume alterations were localized to the pars triangularis of the IFG (F2,97 = 4.05, p = 0.02), with no differences in pars opercularis or pars orbitalis. Pars triangularis volume was highly correlated with its SA [Pearson r(101) = 0.88, p < 0.001], which significantly differed between the groups (F2,97 = 4.45, p = 0.01). As with volume, the mean SA of the pars triangularis was greater in unaffected (corrected p = 0.02) and affected relatives (corrected p = 0.05) compared with controls. We did not find group differences in pars triangularis CT or gyrification.

CONCLUSIONS

These findings strengthen prior knowledge about the volumetric findings in this region and provide a new insight into the localization and topology of IFG alterations. The unique nature of rIFG morphology in BD, with larger volume and SA early in the course of illness, could have practical implications for detection of participants at risk for BD.

Identifying a neuroanatomical signature of schizophrenia, reproducible across sites and stages, using machine learning with structured sparsity

OBJECTIVE

Structural MRI (sMRI) increasingly offers insight into abnormalities inherent to schizophrenia. Previous machine learning applications suggest that individual classification is feasible and reliable and, however, is focused on the predictive performance of the clinical status in cross-sectional designs, which has limited biological perspectives. Moreover, most studies depend on relatively small cohorts or single recruiting site. Finally, no study controlled for disease stage or medication's effect. These elements cast doubt on previous findings' reproducibility.

METHOD

We propose a machine learning algorithm that provides an interpretable brain signature. Using large datasets collected from 4 sites (276 schizophrenia patients, 330 controls), we assessed cross-site prediction reproducibility and associated predictive signature. For the first time, we evaluated the predictive signature regarding medication and illness duration using an independent dataset of first-episode patients.

RESULTS

Machine learning classifiers based on neuroanatomical features yield significant intersite prediction accuracies (72%) together with an excellent predictive signature stability. This signature provides a neural score significantly correlated with symptom severity and the extent of cognitive impairments. Moreover, this signature demonstrates its efficiency on first-episode psychosis patients (73% accuracy).

CONCLUSION

These results highlight the existence of a common neuroanatomical signature for schizophrenia, shared by a majority of patients even from an early stage of the disorder.

Cortical abnormalities in bipolar disorder: an MRI analysis of 6503 individuals from the ENIGMA Bipolar Disorder Working Group

Despite decades of research, the pathophysiology of bipolar disorder (BD) is still not well understood. Structural brain differences have been associated with BD, but results from neuroimaging studies have been inconsistent. To address this, we performed the largest study to date of cortical gray matter thickness and surface area measures from brain magnetic resonance imaging scans of 6503 individuals including 1837 unrelated adults with BD and 2582 unrelated healthy controls for group differences while also examining the effects of commonly prescribed medications, age of illness onset, history of psychosis, mood state, age and sex differences on cortical regions. In BD, cortical gray matter was thinner in frontal, temporal and parietal regions of both brain hemispheres. BD had the strongest effects on left pars opercularis (Cohen's d=-0.293; P=1.71 × 10^-21), left fusiform gyrus (d=-0.288; P=8.25 × 10^-21) and left rostral middle frontal cortex (d=-0.276; P=2.99 × 10^-19). Longer duration of illness (after accounting for age at the time of scanning) was associated with reduced cortical thickness in frontal, medial parietal and occipital regions. We found that several commonly prescribed medications, including lithium, antiepileptic and antipsychotic treatment showed significant associations with cortical thickness and surface area, even after accounting for patients who received multiple medications. We found evidence of reduced cortical surface area associated with a history of psychosis but no associations with mood state at the time of scanning. Our analysis revealed previously undetected associations and provides an extensive analysis of potential confounding variables in neuroimaging studies of BD.

Classification of first-episode schizophrenia spectrum disorders and controls from whole brain white matter fractional anisotropy using machine learning

Background

Schizophrenia is a chronic disorder with an early onset and high disease burden in terms of life disability. Its early recognition may delay the resulting brain structural/functional alterations and improve treatment outcomes. Unlike conventional group-statistics, machine-learning techniques made it possible to classify patients and controls based on the disease patterns on an individual level. Diagnostic classification in first-episode schizophrenia to date was mostly performed on sMRI or fMRI data. DTI modalities have not gained comparable attention.

Methods

We performed the classification of 77 FES patients and 77 healthy controls matched by age and sex from fractional anisotropy data from using linear support-vector machine (SVM). We further analyzed the effect of medication and symptoms on the classification performance using standard statistical measures (t-test, linear regression) and machine learning (Kernel–Ridge regression).

Results

The SVM distinguished between patients and controls with significant accuracy of 62.34% (P = 0.005). There was no association between the classification performance and medication nor symptoms. Group level statistical analysis yielded brain-wide significant differences in FA.

Conclusion

The SVM in combination with brain white-matter fractional anisotropy might help differentiate FES from HC. The performance of our classification model was not associated with symptoms or medications and therefore reflects trait markers in the early course of the disease.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Subcortical volumetric abnormalities in bipolar disorder

Considerable uncertainty exists about the defining brain changes associated with bipolar disorder (BD). Understanding and quantifying the sources of uncertainty can help generate novel clinical hypotheses about etiology and assist in the development of biomarkers for indexing disease progression and prognosis. Here we were interested in quantifying case-control differences in intracranial volume (ICV) and each of eight subcortical brain measures: nucleus accumbens, amygdala, caudate, hippocampus, globus pallidus, putamen, thalamus, lateral ventricles. In a large study of 1710 BD patients and 2594 healthy controls, we found consistent volumetric reductions in BD patients for mean hippocampus (Cohen's d=-0.232; P=3.50 × 10-7) and thalamus (d=-0.148; P=4.27 × 10-3) and enlarged lateral ventricles (d=-0.260; P=3.93 × 10-5) in patients. No significant effect of age at illness onset was detected. Stratifying patients based on clinical subtype (BD type I or type II) revealed that BDI patients had significantly larger lateral ventricles and smaller hippocampus and amygdala than controls. However, when comparing BDI and BDII patients directly, we did not detect any significant differences in brain volume. This likely represents similar etiology between BD subtype classifications. Exploratory analyses revealed significantly larger thalamic volumes in patients taking lithium compared with patients not taking lithium. We detected no significant differences between BDII patients and controls in the largest such comparison to date. Findings in this study should be interpreted with caution and with careful consideration of the limitations inherent to meta-analyzed neuroimaging comparisons.

Connectivity of the anterior insula differentiates participants with first-episode schizophrenia spectrum disorders from controls: a machine-learning study

BACKGROUND

Early diagnosis of schizophrenia could improve the outcomes and limit the negative effects of untreated illness. Although participants with schizophrenia show aberrant functional connectivity in brain networks, these between-group differences have a limited diagnostic utility. Novel methods of magnetic resonance imaging (MRI) analyses, such as machine learning (ML), may help bring neuroimaging from the bench to the bedside. Here, we used ML to differentiate participants with a first episode of schizophrenia-spectrum disorder (FES) from healthy controls based on resting-state functional connectivity (rsFC).

METHOD

We acquired resting-state functional MRI data from 63 patients with FES who were individually matched by age and sex to 63 healthy controls. We applied linear kernel support vector machines (SVM) to rsFC within the default mode network, the salience network and the central executive network.

RESULTS

The SVM applied to the rsFC within the salience network distinguished the FES from the control participants with an accuracy of 73.0% (p = 0.001), specificity of 71.4% and sensitivity of 74.6%. The classification accuracy was not significantly affected by medication dose, or by the presence of psychotic symptoms. The functional connectivity within the default mode or the central executive networks did not yield classification accuracies above chance level.

CONCLUSIONS

Seed-based functional connectivity maps can be utilized for diagnostic classification, even early in the course of schizophrenia. The classification was probably based on trait rather than state markers, as symptoms or medications were not significantly associated with classification accuracy. Our results support the role of the anterior insula/salience network in the pathophysiology of FES.

Neuroprotective effect of lithium on hippocampal volumes in bipolar disorder independent of long-term treatment response

BACKGROUND

Neuroimaging studies have demonstrated an association between lithium (Li) treatment and brain structure in human subjects. A crucial unresolved question is whether this association reflects direct neurochemical effects of Li or indirect effects secondary to treatment or prevention of episodes of bipolar disorder (BD).

METHOD

To address this knowledge gap, we compared manually traced hippocampal volumes in 37 BD patients with at least 2 years of Li treatment (Li group), 19 BD patients with <3 months of lifetime Li exposure over 2 years ago (non-Li group) and 50 healthy controls. All BD participants were followed prospectively and had at least 10 years of illness and a minimum of five episodes. We established illness course and long-term treatment response to Li using National Institute of Mental Health (NIMH) life charts.

RESULTS

The non-Li group had smaller hippocampal volumes than the controls or the Li group (F 2,102 = 4.97, p = 0.009). However, the time spent in a mood episode on the current mood stabilizer was more than three times longer in the Li than in the non-Li group (t(51) = 2.00, p = 0.05). Even Li-treated patients with BD episodes while on Li had hippocampal volumes comparable to healthy controls and significantly larger than non-Li patients (t(43) = 2.62, corrected p = 0.02).

CONCLUSIONS

Our findings support the neuroprotective effects of Li. The association between Li treatment and hippocampal volume seems to be independent of long-term treatment response and occurred even in subjects with episodes of BD while on Li. Consequently, these effects of Li on brain structure may generalize to patients with neuropsychiatric illnesses other than BD.

Are minimized perfusion circuits the better heart lung machines? Final results of a prospective randomized multicentre study

Introduction: Minimized perfusion circuits (MPCs), although aiming at minimizing the adverse effects of cardiopulmonary bypass, have not yet gained popularity. This can be attributed to concerns regarding their safety, as well as lack of sufficient evidence of their benefit.

Methods: Described is a randomized, multicentre study comparing the MPC - ROCsafeRX to standard cardiopulmonary bypass in patients undergoing elective coronary artery bypass grafting and/ or aortic valve replacement.

Results: Five hundred patients were included in the study (252 randomized to the ROCsafeRX group and 248 to standard cardiopulmonary bypass). Both groups were well matched for demographic characteristics and type of surgery. No operative mortality and no device-related complications were encountered.

Transfusion requirement (333 ± 603 vs. 587 ± 1010 ml; p=0.001), incidence of atrial fibrillation (16.3% vs. 24.2%; p=0.03) and the incidence of major adverse events (9.1% vs. 16.5%; p=0.02) were all in favour of the MPC group.

Conclusion: These results confirm both the safety and efficacy of the ROCsafeRX MPC for a large variety of cardiac patients. Minimized perfusion circuits should, therefore, play a greater role in daily practice so that as many patients as possible can benefit from their advantages.

Lithium response across generations

OBJECTIVE

To describe and integrate observations from bipolar patients responsive to lithium stabilization and their children.

METHOD

Selected findings are described from the clinical and biological investigations of adults meeting research criteria for bipolar disorder and for responsiveness to lithium stabilization; and from prospective studies of the children of lithium responders and non-responders.

RESULTS

Response to prophylactic lithium identifies a valid subtype of bipolar disorder, however the search for biological markers of lithium response, while promising, has so far remained inconclusive. Adult responders to lithium stabilization exhibit definable clinical features which are also observable in their affected children. In prospective studies the children of bipolar parents develop symptoms earlier than reported previously, with marked differences between the offspring of lithium responders and non-responders. The illness evolves in predictable clinical stages, first from non-specific sleep and anxiety disorders to mood symptoms and then, often starting in adolescence, major depressive and later activated episodes.

CONCLUSION

Investigating and comparing unequivocal responders and non-responders to long-term lithium treatment and their offspring is a fertile research strategy for addressing a multitude of clinical and research questions.

Beneficial effects of modern perfusion concepts in aortic valve and aortic root surgery

Minimized perfusion circuits (MPC) were found to reduce side effects of standard extracorporeal circulation (ECC). We evaluated the safety and efficacy of the ROCsafe™ MPC for aortic valve and aortic root surgery. One hundred and seventy patients were randomized for surgery using either MPC [n = 85, 30 female/55 male, mean age: 69.8 ± 11.8 years; aortic valve replacement (AVR): n = 40; AVR + coronary artery bypass graft (CABG): n = 31; David operation: n = 3; aortic root replacement (ARR): n = 11] or ECC [n = 85, 29 female/56 male, mean age: 67.7 ± 9.5 years; AVR: n = 39; AVR+CABG: n = 35, David operation: n = 2; ARR: n = 9]. Neurological status, length of ICU stay, C-reactive protein (CRP), blood count, transfusion requirements and bleeding volume were analyzed. The MPC system provided ultrasound-controlled de-airing. A small roller pump and a flexible reservoir were used for left ventricular venting. As a control, we used a standard ECC with cardiotomy suction and hard-shell reservoir. Cross-clamp time (MPC: 76.5 ± 29.5; ECC: 79.0 ± 34.0 min) and bypass time (MPC: 103.0 ± 37.9; ECC: 106.9 ± 44.9 min) were comparable between groups. Transfusion requirements (red blood cells: MPC: 1.5 ± 1.5 vs. ECC: 2.2 ± 2.1 units [p = 0.05], frozen plasma: MPC: 1.2 ± 1.8 vs. ECC: 1.9 ± 2.4 units [p = 0.03]), postoperative bleeding (MPC: 521 ± 283 vs. ECC: 615 ± 326 ml/24 h, p = 0.09) were lower using MPC. ICU stay was shorter with MPC (1.6 ± 1.6 days) compared to ECC (2.4 ± 2.8 days, p = 0.001). One stroke occurred in each group. The ROCsafe™ MPC provides safe circulatory support for a wide range of aortic valve surgeries. Transfusion requirements, postoperative bleeding and length of ICU stay were markedly reduced compared to standard extracorporeal perfusion.

Tumor markers in pleural effusions

AIM

The aim of this study was to determine the diagnostic capabilities of tumor markers in pleural effusion and their importance for assessment of the etiology of pleural effusions.

PATIENTS AND METHODS

In pleural effusions from 166 patients hospitalized during the period 2003-2005 at the Department of Oncology and Radiotherapy, Faculty Hospital in Pilsen, the following tumor markers were determined: thymidine kinase (TK), neuron-specific enolase (NSE), cytokeratins [tissue polypeptide antigen (TPA), tissue polypeptide-specific antigen (TPS) and cytokeratin fragment 19 (CYFRA 21-1)], carcinoembryonic antigen (CEA) and mucinous markers (CA 15-3, CA 19-9, CA 125). The inflammatory marker procalcitonin-PCT was also assessed.

RESULTS

Tumor markers CA 125, TPA, TPS were significantly elevated in exudates, irrespective of the etiology, as a non-specific reaction in mesothelial cells. TK had a sensitivity of over 80% for all the types of cancer examined, while CA 15-3 had a sensitivity of over 90%.

CONCLUSION

Significant positivity of PCT and CA 15-3 in pleural effusions indicate a suspicion of inflammatory disease. Positivity of TK and CA 15-3 indicate a strong suspicion of malignant exudates.

The phenotypes of bipolar disorder: relevance for genetic investigations

The search for susceptibility genes for bipolar disorder (BD) depends on appropriate definitions of the phenotype. In this paper, we review data on diagnosis and clinical features of BD that could be used in genetic studies to better characterize patients or to define homogeneous subgroups. Clinical symptoms, long-term course, comorbid conditions, and response to prophylactic treatment may define groups associated with more or less specific loci. One such group is characterized by symptoms of psychosis and linkage to 13q and 22q. A second group includes mainly bipolar II patients with comorbid panic disorder, rapid mood switching, and evidence of chromosome 18 linkage. A third group comprises typical BD with an episodic course and favourable response to lithium prophylaxis. Reproducibility of cognitive deficits across studies raises the possibility of using cognitive profiles as endophenotypes of BD, with deficits in verbal explicit memory and executive function commonly reported. Brain imaging provides a more ambiguous data set consistent with heterogeneity of the illness.

On-pump cardiac surgery in a conscious patient using a thoracic epidural anesthesia--an ultra fast track method

OBJECTIVE

To demonstrate the applicability and efficacy of spontaneous ventilation during cardiac surgery.

METHODS

From March 1999 through December 2002, 129 awake patients were operated on; 90 on-pump and 39 off-pump. A thoracic epidural space blockage was performed one hour prior to an incision being made at the Th 2-Th 4 level. Medial approach was used and the hanging drop method was routinely employed for epidural space detection.

RESULTS

There were 82 male and 47 female patients with a mean age of 64.5 years. Forty two cases were aortic valve replacement, 32 patients underwent on-pump coronary artery bypass grafting (CABG), 12 underwent mitral valve replacement, 27 patients were indicated for sternal wound reexploration, 12 for off-pump CABG, one for aortic valve replacement with aortic arch reconstruction and aortic valve replacement together with CABG was performed three times. There were ten conversions to general anesthesia and there was no death. Mean duration of the stay in the intensive care unit was 7.2 hours and in the hospital 5.1 days. We did not observe low cardiac output syndrome, stroke, renal insufficiency or pulmonary dysfunction in patients who sufficiently underwent thoracic epidural anesthesia. Less pain at assessments was demonstrated (Visual Analgetic Score=3.3).

CONCLUSION

The recent interest in rapid recovery and early out-patient care of patients after cardiac surgery has prompted investigations into the use of neuraxial analgesia for these procedures. The above mentioned technique would be beneficial for patients with preoperative pulmonary dysfunction and may be particularly useful in endoscopic cardiac surgery. (Tab. 1, Fig. 2, Ref. 18.)

Hippocampal damage mediated by corticosteroids--a neuropsychiatric research challenge

There is an increasing evidence that corticosteroids damage the hippocampus in rodents and in primates. Hippocampal atrophy induced by corticosteroids may play an important role in the pathogenesis of a range of neuropsychiatric disorders. Hippocampus is necessary for short-term memory consolidation and HPA axis regulation. Signs of hippocampal damage (HPA dysregulation in combination with memory impairment) are found in affective disorders, Alzheimer's disease and in posttraumatic stress disorder. MRI volumetry reveals reduced hippocampal volume in these diseases. Evidence supporting the "glucocorticoid hypothesis" of psychiatric disorders is reviewed in the first part of the paper. Unresolved questions concerning temporary aspects of neurodegeneration, causality, reversibility, type of damage, factors increasing hippocampal vulnerability, and both pharmacological (CRH antagonists, antiglucocorticoid drugs, GABA-ergic, serotonergic, glutamatergic agents) and non-pharmacological (psychotherapy) treatment approaches are discussed in the second part.