Miloslav Kopecek

Brain structural signature of familial predisposition for bipolar disorder: replicable evidence for involvement of the right inferior frontal gyrus.

BACKGROUND To translate our knowledge about neuroanatomy of bipolar disorder (BD) into a diagnostic tool, it is necessary to identify the neural signature of predisposition for BD and separate it from effects of long-standing illness and treatment. Thus, we examined the associations among genetic risk, illness burden, lithium treatment, and brain structure in BD. METHODS This is a two-center, replication-design, structural magnetic resonance imaging study. First, we investigated neuroanatomic markers of familial predisposition by comparing 50 unaffected and 36 affected relatives of BD probands as well as 49 control subjects using modulated voxel-based morphometry. Second, we investigated effects of long-standing illness and treatment on the identified markers in 19 young participants early in the course of BD, 29 subjects with substantial burden of long-lasting BD and either minimal lifetime (n = 12), or long-term ongoing (n = 17) lithium treatment. RESULTS Five groups, including the unaffected and affected relatives of BD probands from each center as well as participants early in the course of BD showed larger right inferior frontal gyrus (rIFG) volumes than control subjects (corrected p < .001). The rIFG volume correlated negatively with illness duration (corrected p < .01) and, relative to the controls, was smaller among BD individuals with long-term illness burden and minimal lifetime lithium exposure (corrected p < .001). Li-treated subjects had normal rIFG volumes despite substantial illness burden. CONCLUSIONS Brain structural changes in BD may result from interplay between illness burden and compensatory processes, which may be enhanced by lithium treatment. The rIFG volume could aid in identification of subjects at risk for BD even before any behavioral manifestations.

Amygdala volumes in mood disorders — Meta-analysis of magnetic resonance volumetry studies

BACKGROUND The amygdala plays an important role in the regulation of emotions and has been implicated in the pathophysiology of mood disorders. Studies of amygdala volumes in mood disorders have been conflicting, with findings of increased, decreased and unchanged amygdala volumes in patients relative to controls. We present the largest meta-analysis of amygdala volumes in mood disorders and the first one to investigate modifying effects of clinical, demographic and methodological variables. METHODS We reviewed 40 magnetic resonance imaging studies investigating amygdala volumes in patients with unipolar or bipolar disorders. For meta-analysis we used standardized differences in means (SDM) and random effect models. In the search for sources of heterogeneity, we subdivided the studies based on diagnosis, setting, age, medication status, sex, duration of illness, slice thickness, interrater reliability of tracing and anatomical definitions used. RESULTS The volumes of the left and right amygdala in bipolar (N=215) or unipolar (N=409) patients were comparable to controls. Bipolar children and adolescents had significantly smaller left amygdala volumes relative to controls (SDM=-0.34, 95%CI=-0.65; -0.04, z=-2.20, p=0.03), whereas bipolar adults showed a trend for left amygdala volume increases (SDM=0.46, 95%CI=-0.03; 0.96, z=1.83, p=0.07). Unipolar inpatients had significantly larger left (SDM=0.35, 95%CI=0.03; 0.67, z=-2.17, p=0.03) amygdala volumes than controls, with no significant amygdala volume changes in unipolar outpatients. LIMITATIONS Heterogeneity of included studies. CONCLUSIONS The absence of overall differences in amygdala volumes, in the presence of significant and sometimes mirror changes in patient subgroups, demonstrates marked heterogeneity among mood disorders. Amygdala volume abnormalities may not be associated with mood disorders per se, but rather may underlie only some dimensions of illness or represent artifacts of medication or comorbid conditions.

Smaller hippocampal volumes in patients with bipolar disorder are masked by exposure to lithium: a meta-analysis.

BACKGROUND Smaller hippocampal volumes relative to controls are among the most replicated neuroimaging findings in individuals with unipolar but not bipolar depression. Preserved hippocampal volumes in most studies of participants with bipolar disorder may reflect potential neuroprotective effects of lithium (Li). METHODS To investigate hippocampal volumes in patients with bipolar disorder while controlling for Li exposure, we performed a meta-analysis of neuroimaging studies that subdivided patients based on the presence or absence of current Li treatment. To achieve the best coverage of literature, we categorized studies based on whether all or a majority, or whether no or a minority of patients were treated with Li. Hippocampal volumes were compared by combining standardized differences between means (Cohen d) from individual studies using random-effects models. RESULTS Overall, we analyzed data from 101 patients with bipolar disorder in the Li group, 245 patients in the non-Li group and 456 control participants from 16 studies. Both the left and right hippocampal volumes were significantly larger in the Li group than in controls (Cohen d = 0.53, 95% confidence interval [CI] 0.18 to 0.88; Cohen d = 0.51, 95% CI 0.21 to 0.81, respectively) or the non-Li group (Cohen d = 0.93, 95% CI 0.56 to 1.31; Cohen d = 1.07, 95% CI 0.70 to 1.45, respectively), which had smaller left and right hippocampal volumes than the control group (Cohen d = -0.36, 95% CI -0.55 to -0.17; Cohen d = -0.38, 95% CI -0.63 to -0.13, respectively). There was no evidence of publication bias. LIMITATIONS Missing information about the illness burden or lifetime exposure to Li and polypharmacy in some studies may have contributed to statistical heterogeneity in some analyses. CONCLUSION When exposure to Li was minimized, patients with bipolar disorder showed smaller hippocampal volumes than controls or Li-treated patients. Our findings provide indirect support for the negative effects of bipolar disorder on hippocampal volumes and are consistent with the putative neuroprotective effects of Li. The preserved hippocampal volumes among patients with bipolar disorder in most individual studies and all previous meta-analyses may have been related to the inclusion of Li-treated participants.

Reduced hippocampal volumes in healthy carriers of brain-derived neurotrophic factor Val66Met polymorphism: meta-analysis.

Abstract Objectives. Converging evidence suggests that the brain-derived neurotrophic factor (BDNF) gene Val66Met polymorphism affects brain structure. Yet the majority of studies have shown no effect of this polymorphism on hippocampal volumes, perhaps due to small effect size. Methods. We performed a meta-analysis of studies investigating the association between Val66Met BDNF polymorphism and hippocampal volumes in healthy subjects by combining standardized differences between means (SDM) from individual studies using random effect models. Results. Data from 399 healthy subjects (255 Val-BDNF homozygotes and 144 carriers of at least one Met-BDNF allele) in seven studies were meta-analysed. Both the left and right hippocampi were significantly larger in Val-BDNF homozygotes than in carriers of at least one Met-BDNF allele (SDM = 0.41, 95% Confidence Interval = 0.20; 0.62, z = 3.86, P = 0.0001; SDM = 0.41; 95% Confidence Interval = 0.20; 0.61, z = 3.81, P = 0.0001, respectively), with no evidence of publication bias. Conclusions. Healthy carriers of BDNF gene Val66Met polymorphism show bilateral hippocampal volume reduction. The effect size was small, but the same direction of effect was seen in all meta-analyzed studies. The association with the BDNF gene Val66Met polymorphism makes hippocampal volume a potential candidate for an endophenotype of disorders presenting with reduced hippocampal volumes.

Hippocampal volumes in bipolar disorders: opposing effects of illness burden and lithium treatment

Hajek T, Cullis J, Novak T, Kopecek M, Höschl C, Blagdon R, O’Donovan C, Bauer M, Young L T, MacQueen G, Alda M. Hippocampal volumes in bipolar disorders: opposing effects of illness burden and lithium treatment. 
Bipolar Disord 2012: 14: 261–270.

The change of prefrontal QEEG theta cordance as a predictor of response to bupropion treatment in patients who had failed to respond to previous antidepressant treatments

UNLABELLED The aim of the study was to examine whether the reduction of theta prefrontal quantitative EEG (QEEG) cordance after one week of bupropion administration is a predictor of response to a 4-week treatment in patients that had failed to respond to previous antidepressant treatments. METHOD EEG data of 18 inpatients were monitored at baseline and after one week. QEEG cordance was computed at 3 frontal electrodes (Fp1, Fp2, Fz). Response to treatment was defined as a >/=50% reduction of MADRS score. RESULTS Nine of the eleven responders and one of the seven non-responders showed decreased prefrontal cordance value after the first week of treatment (p=0.01). Positive and negative predictive values of cordance reduction for the prediction of response to the treatment were 0.9 and 0.75, respectively. CONCLUSION Similar to other antidepressants, the reduction of prefrontal QEEG cordance might be helpful in the prediction of the acute outcome of bupropion treatment.

Low frequency (1-Hz), right prefrontal repetitive transcranial magnetic stimulation (rTMS) compared with venlafaxine ER in the treatment of resistant depression: a double-blind, single-centre, randomized study.

BACKGROUND Previous studies have shown effectiveness of repetitive transcranial magnetic stimulation (rTMS) in the treatment of depression. This double-blind study compared efficacy of l Hz rTMS over the right prefrontal dorsolateral cortex with venlafaxine ER in the treatment of resistant depression. METHODS A total of 60 inpatients with depressive disorder (DSM-IV criteria), who previously did not respond to at least one antidepressant treatment, were randomly assigned to 1 Hz rTMS with placebo and venlafaxine ER with sham rTMS for 4 weeks. The primary outcome measure was score change in the Montgomery-Asberg Depression Rating Scale (MADRS). We also used Clinical Global Impression (CGI) and Beck Depressive. Inventory-Short Form (BDI-SF). The response was defined as a >or=50% reduction of MADRS score. RESULTS There were no significant differences between treatment groups in MADRS (p=0.38), BDI-SF (p=0.56) and CGI (p=0.17) scores from baseline to endpoint. Response rates for rTMS (33%) and venlafaxine (39%) as well as remission (MADRS score<or=10 points) rates (19% vs. 23%) and drop-out rate did not differ between treatment groups. There were significant reductions of MADRS, CGI and BDI-SF scores in both groups. LIMITATIONS Small sample size. No placebo arm was included for ethical reasons, because both treatments have previously been reported to be more effective than placebo. Relatively short duration of antidepressant treatment. CONCLUSION The findings of this study suggest that, at least in the acute treatment, the right sided rTMS produces clinically relevant reduction of depressive symptomatology in patients with resistant depression comparable to venlafaxine ER. Larger sample sizes are required to confirm these results.

The Malleability of Working Memory and Visuospatial Skills: A Randomized Controlled Study in Older Adults

There is accumulating evidence that training on working memory (WM) generalizes to other nontrained domains, and there are reports of transfer effects extending as far as to measures of fluid intelligence. Although there have been several demonstrations of such transfer effects in young adults and children, they have been difficult to demonstrate in older adults. In this study, we investigated the generalizing effects of an adaptive WM intervention on nontrained measures of WM and visuospatial skills. We randomly assigned healthy older adults to train on a verbal n-back task over the course of a month for either 10 or 20 sessions. Their performance change was compared with that of a control group. Our results revealed reliable group effects in nontrained standard clinical measures of WM and visuospatial skills in that both training groups outperformed the control group. We also observed a dose-response effect, that is, a positive relationship between training frequency and the gain in visuospatial skills; this finding was further confirmed by a positive correlation between training improvement and transfer. The improvements in visuospatial skills emerged even though the intervention was restricted to the verbal domain. Our work has important implications in that our data provide further evidence for plasticity of cognitive functions in old age.

Montreal cognitive assessment (MoCA): Normative data for old and very old Czech adults

ABSTRACT The principal aim of our study was to present norms for old and very old Czech adults on the Czech version of the Montreal Cognitive Assessment (MoCA) and investigate the influence of social and demographic factors on MoCA performance. We analyzed 540 adults aged ≥ 60 years (5-year age categories; nationally representative sample in terms of sex and educational level), who met strict inclusion criteria for the absence of neurodegenerative disorders and performed within normal range in neuropsychological assessment. Using multiple regression model, we found that MoCA performance was affected by age and education (both p < .001) but not sex. The study provides normed percentile estimates for MoCA performance stratified by age (60–74 years; ≥ 75 years) and education lower versus higher. We also present percentile equivalents for the MoCA and Mini-Mental State Examination (MMSE) for use in clinical practice. We found age- and education-related effects on MoCA performance which support the use of culturally adapted normative data.

White matter hyperintensities in affected and unaffected late teenage and early adulthood offspring of bipolar parents: A two-center high-risk study

BACKGROUND White matter hyperintensities (WMHs) are among the most replicated neuroimaging findings in bipolar disorder (BD). It is not clear whether these lesions are an artifact of comorbid conditions, or whether they are directly associated with the disorder, or even represent biological risk factor for BD. METHODS To test whether WMHs meet criteria for an endophenotype of BD, we conducted a high-risk design study and recruited 35 affected, 44 unaffected relatives of bipolar probands (age range 15-30 years), matched by age and sex with 49 healthy controls without any personal or family history of psychiatric disorders. The presence of WMHs was determined from Fluid Attenuated Inversion Recovery (FLAIR) scans acquired on a 1.5 Tesla scanner using a validated semi-quantitative scale. RESULTS We found mostly low grade WMHs in all groups. The proportion of WMH-positive subjects was comparable between the unaffected high-risk, affected familial and control groups. CONCLUSION White matter hyperintensities did not meet criteria for an endophenotype of BD. Bipolar disorder in young subjects without comorbid conditions was not associated with increased rate of WMHs.