Volumetric, cortical thickness and white matter integrity alterations in bipolar disorder type I and II

BACKGROUND

Bipolar disorder (BD) is a debilitating psychiatric disorder affecting millions of people worldwide with mean time to diagnosis estimated to be at least 10 years. Whilst many brain imaging studies have compared those with BD to controls, few have attempted to investigate differences between BD Type I and II and matched controls.

METHODS

Thirty-one patients with BD (16 Type I and 15 Type II) and 31 matched healthy controls were MRI brain scanned with conventional T1-weighted and diffusion tensor imaging methods.

RESULTS

There was significantly reduced regional brain volume and thickness among the BD subjects, but also between BD Type I when compared to Type II. White matter integrity also differed between the groups and BD severity correlated significantly with regional brain volume and thickness.

LIMITATIONS

Future investigations will consider length of time each BD patient had been diagnosed with BD, as well as assessing controls for family history of psychiatric illness, specifically BD. Similarly, genetic assessment will be conducted as well.

CONCLUSIONS

These findings suggest that there are not only regional brain volumetric, thickness and white matter integrity differences between BD and matched controls, but also between those with BD Type I and Type II, such that reduced regional brain volume may underlie BD Type I whereas white matter integrity is more altered in BD Type II.

Cingulate Cortex in Schizophrenia: its relation with negative symptoms and psychotic onset. A review study

OBJECTIVE

The cingulate cortex is a functionally heterogeneous region involved in diverse cognitive and emotional processes. It is a region of special interest to investigate the neurological substrate of schizophrenia. The aim of this paper is to review all the studies that investigated the relation between the cingulate cortex and two of the most important and little known areas of this disease: the psychotic onset and the negative symptoms.

MATERIAL AND METHODS

Relevant literature was identified through a search in PubMed, Web of Science, and Cochrane database. Search terms included negative symptoms, cingulate cortex, cingulate gyrus, schizophrenia, PET, SPECT, MRI, fMRI, BOLD, deficit schizophrenia, early-onset schizophrenia, psychotic onset, psychosis.

RESULTS

9 studies evidenced a link between negative symptoms and hypoactivity of cingulate cortex, whereas 7 studies did not. A positive relationship between anterior cingulate cortex gray matter thinning and high risk for schizophrenia is well characterized in literature.

CONCLUSIONS

In a large portion of patients hypoactivity of cingulate cortex underlie the presence of negative symptoms. In particular, ACC (anterior cingulated cortex) thinning seems to be related to the increasing social withdrawal that is characteristic of the psychosis prodrome. New therapies focused on the brain stimulation of the cingulate cortex could represent an important aid for patients with this kind of symptoms.

A review of the role of female gender in autism spectrum disorders

This paper reviews the literature exploring gender differences associated with the clinical presentation of autism spectrum disorders (ASD). The potentially mediating effect of comorbid psychopathology, biological and neurodevelopmental implications on these gender differences is also discussed. A vastly heterogeneous condition, while females on the lower-functioning end of the spectrum appear to be more severely affected, an altered clinical manifestation of the disorder among high-functioning females may consequently result in many being un- or mis-diagnosed. To date, there is strong bias in the literature towards the clinical presentation of ASD in males. It is imperative that future research explores gender differences across the autism spectrum, in order to improve researchers', clinicians' and the public's understanding of this debilitating disorder.

Impact of comorbid anxiety disorders and obsessive-compulsive disorder on 24-month clinical outcomes of bipolar I disorder

BACKGROUND

This study investigated the impact of comorbid obsessive-compulsive disorder (OCD) and four anxiety disorders [panic disorder (PD), agoraphobia, social anxiety disorder (SAD), and generalized anxiety disorder (GAD)] on the clinical outcomes of bipolar disorder.

METHODS

This study analysed data of 174 patients with bipolar I disorder who participated in the prospective observational study. Participants were assessed every 3 months for 24 months. The primary outcome measure was the achievement of symptomatic remission, defined by a total score on the Young Mania Rating Scale (YMRS) of ≤12 and a total score on the 21-item Hamilton Depression Rating Scale (HAMD-21) of ≤8.

RESULTS

Comorbidity was associated with decreased likelihood of remission. However, the impact of individual disorders on outcome differed according to clinical and treatment situations. Most comorbid anxiety disorders and OCD had a negative effect on remission during the first year of evaluation, as measured by the HAMD-21, and in patients taking a conventional mood stabilizer alone. However, the association with poorer outcome was observed only for a few specific comorbid disorders in the second year (GAD and OCD), as measured by YMRS-defined remission (OCD), and in patients with olanzapine therapy (GAD and OCD).

LIMITATIONS

Follow-up evaluation of comorbid disorders was lacking.

CONCLUSIONS

Comorbid anxiety disorders and OCD negatively influenced the clinical course of bipolar disorder. Specifically, OCD had a consistently negative impact on the outcome of bipolar I disorder regardless of clinical situation. Effective strategies for the control of these comorbidities are required to achieve better treatment outcomes.

A negative pilot study of daily bimodal transcranial direct current stimulation in schizophrenia

BACKGROUND

A small number of studies conducted to date have suggested that transcranial direct current stimulation (tDCS) applied to the temporoparietal cortex may reduce auditory hallucinations in patients with schizophrenia. Prefrontal brain stimulation with other methods, has also been shown to potentially improve the negative symptoms of this disorder.

OBJECTIVE

To investigate the therapeutic potential of daily bimodal tDCS: anodal stimulation to the prefrontal cortex and cathodal stimulation to the temporoparietal junction in patients with persistent hallucinations and negative symptoms of schizophrenia.

METHODS

We conducted two small randomized double-blind controlled trials comparing bimodal tDCS to sham stimulation. In one study, stimulation was provided unilaterally, in the second study it was provided bilaterally.

RESULTS

Neither unilateral nor bilateral tDCS resulted in a substantial change in either hallucinations or negative symptoms. Stimulation was well tolerated without side-effects.

CONCLUSION

Daily tDCS does not appear to have substantial potential in the treatment of hallucinations or negative symptoms and further research should investigate higher doses of stimulation or more frequently applied treatment schedules.

Acute motor, neurocognitive and neurophysiological change following concussion injury in Australian amateur football. A prospective multimodal investigation

OBJECTIVES

This multimodal study investigated the motor, neurocognitive and neurophysiological responses following a sports related concussion injury in the acute-phase (up to 10 days) in sub-elite Australian football players.

DESIGN

Between-group, repeated measures.

METHODS

Over the course of one season (six months), 43 male players from one football club (25.1 ± 4.5 years) were assessed for fine motor dexterity, visuomotor reaction time, implicit learning and attention. Motor cortex excitability and inhibition were assessed using transcranial magnetic stimulation.

RESULTS

Of the 43 players, eight suffered concussion injuries, and were compared to 15 non-concussed players (active control) who returned for follow up testing. Post-concussion assessments using the aforementioned tests were carried out at 48 and 96 h, and 10 days. Compared to the non-concussed players, those who suffered concussion showed slowed fine dexterity (P = 0.02), response (P = 0.02) and movement times (P = 0.01) 48 h post-concussion. Similarly, attentional performance was reduced in the concussed group at all time points (48 h: P < 0.01; 96 h: P < 0.01; and 10 days: P = 0.02) post-concussion. TMS revealed significantly increased corticospinal inhibition at 48 (P = 0.04) and 96 h post concussion (P = 0.02) with significant correlations between increased corticospinal inhibition and response (r = 0.48; P < 0.01), movement time (r = 0.42; P = 0.02), and attention performance (r = 0.44; P = 0.01).

CONCLUSIONS

This study has demonstrated that acutely concussed Australian football players show abnormalities in motor, cognitive and neurophysiological measures with variable rates of recovery. These findings suggest that measuring the recovery of concussed athletes should incorporate a range of testing modalities rather than relying on one area of measurement in determining return to play.

The long-term effects of sports concussion on retired Australian football players: a study using transcranial magnetic stimulation

This study investigated corticomotor excitability and inhibition, cognitive functioning, and fine motor dexterity in retired elite and amateur Australian football (AF) players who had sustained concussions during their playing careers. Forty male AF players who played at the elite level (n=20; mean age 49.7±5.7 years) or amateur level (n=20; mean age 48.4±6.9 years), and had sustained on average 3.2 concussions 21.9 years previously, were compared with 20 healthy age-matched male controls (mean age 47.56±6.85 years). All participants completed assessments of fine dexterity, visuomotor reaction time, spatial working memory (SWM), and associative learning (AL). Transcranial magnetic stimulation (TMS) was used to measure corticospinal excitability: stimulus-response (SR) curves and motor evoked potential (MEP) 125% of active motor threshold (aMT); and intracortical inhibition: cortical silent period (cSP), short-interval intracortical inhibition (SICI), and long-interval intracortical inhibition (LICI). Healthy participants performed better in dexterity (p=0.003), reaction (p=0.003), and movement time (p=0.037) than did both AF groups. Differences between AF groups were found in AL (p=0.027) and SWM (p=0.024). TMS measures revealed that both AF groups showed reduced cSP duration at 125% aMT (p>0.001) and differences in SR curves (p>0.001) than did healthy controls. Similarly, SICI (p=0.012) and LICI (p=0.009) were reduced in both AF groups compared with controls. Regression analyses revealed a significant contribution to differences in motor outcomes with the three measures of intracortical inhibition. The measures of inhibition differed, however, in terms of which performance measure they had a significant and unique predictive relationship with, reflecting the variety of participant concussion injuries. This study is the first to demonstrate differences in motor control and intracortical inhibition in AF players who had sustained concussions during their playing career two decades previously.

Cortical inhibition, excitation, and connectivity in schizophrenia: a review of insights from transcranial magnetic stimulation

Schizophrenia (SCZ) is a debilitating mental illness with an elusive pathophysiology. Over the last decade, theories emphasizing cortical dysfunction have received increasing attention to explain the heterogeneous symptoms experienced in SCZ. Transcranial magnetic stimulation (TMS) is a noninvasive form of brain stimulation that is particularly suited to probing the fidelity of specific excitatory and inhibitory neuronal populations in conscious humans. In this study, we review the contribution of TMS in assessing inhibitory and excitatory neuronal populations and their long-range connections in SCZ. In addition, we discuss insights from combined TMS and electroencephalography into the functional consequences of impaired excitation/inhibition on cortical oscillations in SCZ.

Occipital bending in depression

There are reports of differences in occipital lobe asymmetry within psychiatric populations when compared with healthy control subjects. Anecdotal evidence and enlarged lateral ventricles suggests that there may also be a different pattern of curvature whereby one occipital lobe wraps around the other, termed 'occipital bending'. We investigated the prevalence of occipital bending in 51 patients with major depressive disorder (males mean age = 41.96 ± 14.00 years, females mean age = 40.71 ± 12.41 years) and 48 age- and sex-matched healthy control subjects (males mean age = 40.29 ± 10.23 years, females mean age = 42.47 ± 14.25 years) and found the prevalence to be three times higher among patients with major depressive disorder (18/51, 35.3%) when compared with control subjects (6/48, 12.5%). The results suggest that occipital bending is more common among patients with major depressive disorder than healthy subjects, and that occipital asymmetry and occipital bending are separate phenomena. Incomplete neural pruning may lead to the cranial space available for brain growth being restricted, or ventricular enlargement may exacerbate the natural occipital curvature patterns, subsequently causing the brain to become squashed and forced to 'wrap' around the other occipital lobe. Although the clinical implications of these results are unclear, they provide an impetus for further research into the relevance of occipital bending in major depression disorder.

Magnetic seizure therapy in an adolescent with refractory bipolar depression: a case report

Magnetic seizure therapy (MST) has shown efficacy in adult patients with treatment-resistant depression with limited impairment in memory. To date, the use of MST in adolescent depression has not been reported. Here we describe the first successful use of MST in the treatment of an adolescent patient with refractory bipolar depression. This patient received MST in an ongoing open-label study for treatment-resistant major depression. Treatments employed a twin-coil MST apparatus, with the center of each coil placed over the frontal cortex (ie, each coil centered over F3 and F4). MST was applied at 100 Hz and 100% machine output at progressively increasing train durations. Depressive symptoms were assessed using the 24-item Hamilton Depression Rating Scale and cognitive function was assessed with a comprehensive neuropsychological battery. This adolescent patient achieved full remission of clinical symptoms after an acute course of 18 MST treatments and had no apparent cognitive decline, other than some autobiographical memory impairment that may or may not be related to the MST treatment. This case report suggests that MST may be a safe and well tolerated intervention for adolescents with treatment-resistant bipolar depression. Pilot studies to further evaluate the effectiveness and safety of MST in adolescents warrant consideration.

Emotion recognition of static and dynamic faces in autism spectrum disorder

There is substantial evidence for facial emotion recognition (FER) deficits in autism spectrum disorder (ASD). The extent of this impairment, however, remains unclear, and there is some suggestion that clinical groups might benefit from the use of dynamic rather than static images. High-functioning individuals with ASD (n = 36) and typically developing controls (n = 36) completed a computerised FER task involving static and dynamic expressions of the six basic emotions. The ASD group showed poorer overall performance in identifying anger and disgust and were disadvantaged by dynamic (relative to static) stimuli when presented with sad expressions. Among both groups, however, dynamic stimuli appeared to improve recognition of anger. This research provides further evidence of specific impairment in the recognition of negative emotions in ASD, but argues against any broad advantages associated with the use of dynamic displays.

Neurocognitive deficits, craving, and abstinence among alcohol-dependent individuals following detoxification

Alcohol dependence, a chronic relapsing disorder, is characterized by an impaired ability to regulate compulsive urges to consume alcohol. Very few empirical studies have examined the presence of these executive deficits, how they relate to craving, and the enduring nature of these deficits during abstinence. As such, the current study aimed to characterize these cognitive deficits within a sample of 24 alcohol-dependent participants post-detoxification and 23 non-alcohol-dependent participants. Participants were administered the Sustained Attention to Response Task to measure response inhibition and sustained attention and the Random Number Generation Task to examine executive deficits. Correlations between cognitive performance and clinical measures of alcohol dependence were examined. As predicted, the alcohol-dependent group exhibited poorer performance across the domains of response inhibition, executive function, and attentional control. Cognitive performance was related to clinical measures of craving and years of alcohol consumption, whereas the duration of abstinence was not associated with improved cognitive performance. These findings highlight the need for therapeutic strategies to target these enduring neurocognitive deficits in improving the treatment of alcohol dependence.

Can sleep disturbance in depression predict repetitive transcranial magnetic stimulation (rTMS) treatment response?

Treatment for depression is not effective in all patients and it is therefore important to identify factors that can be used to tailor treatments. One potential factor is insomnia. Several repetitive transcranial magnetic stimulation (rTMS) studies have reported on this symptom, however, they did not take into account the presence of hypersomnia or that insomnia was related to their outcome measure. Our aim was to investigate whether baseline sleep disruption was related to rTMS treatment response. We pooled data from four clinical trials using rTMS to treat depression, including 139 subjects in data analysis. Insomnia was measured using the Hamilton Depression Rating Scale (HamD) sleep questions and hypersomnia from the Beck Depression Inventory (BDI). To reduce the possible impact of insomnia on our treatment response outcome we created an adjusted HamD score which omitted sleep items. Sleep disturbances were common in our study: 66% had insomnia and 38% hypersomnia. Using regression analysis with our adjusted HamD score we found no relation between baseline insomnia or hypersomnia and rTMS treatment response. Our data are consistent with previous studies; however, this is the first rTMS study to our knowledge that has attempted to dissociate baseline insomnia from the HamD outcome measure and to report no relationship between hypersomnia and rTMS outcome.

Improvement in quality of life with left prefrontal transcranial magnetic stimulation in patients with pharmacoresistant major depression: acute and six month outcomes

BACKGROUND

Transcranial magnetic stimulation (TMS) is a safe and effective treatment for major depression. We describe quality of life (QOL) outcomes from acute treatment with TMS, and describe the durability of benefit across 24-weeks.

METHODS

Three hundred and one medication-free patients with pharmacoresistant major depression were randomized to active or sham TMS in a 6-week controlled trial. Nonresponders to the 6-week blinded phase of the study were enrolled in a 6-week open-label study without unblinding the prior treatment assignment. Responders and partial responders to both the blinded (active or sham treatment) or open acute treatment phases were tapered off TMS over three weeks, while initiating maintenance antidepressant medication monotherapy. These subjects entered the 24-week study to examine the durability of response to TMS. The Medical Outcomes Study-36 Item Short Form (SF-36) and the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q) were used to measure overall function and QOL. During the 24-week durability of effect study, QOL assessments were done at study entry and at the end of 24-weeks.

RESULTS

Statistically significant improvement in both functional status and QOL outcomes was observed in patients treated with active TMS compared with sham TMS during the acute phase of the randomized, sham-controlled trial. Similar benefits were observed in patients who entered the open-label extension study. These improvements were sustained across the 24-week follow up study.

CONCLUSIONS

Acute treatment with TMS improved functional status and QOL outcomes in patients with major depression. This clinical effect was durable in long-term follow up.

A transcranial magnetic stimulation study of the effect of visual orientation on the putative human mirror neuron system

Mirror neurons are a class of motor neuron that are active during both the performance and observation of behavior, and have been implicated in interpersonal understanding. There is evidence to suggest that the mirror response is modulated by the perspective from which an action is presented (e.g., egocentric or allocentric). Most human research, however, has only examined this when presenting intransitive actions. Twenty-three healthy adult participants completed a transcranial magnetic stimulation experiment that assessed corticospinal excitability whilst viewing transitive hand gestures from both egocentric (i.e., self) and allocentric (i.e., other) viewpoints. Although action observation was associated with increases in corticospinal excitability (reflecting putative human mirror neuron activity), there was no effect of visual perspective. These findings are discussed in the context of contemporary theories of mirror neuron ontogeny, including models concerning associative learning and evolutionary adaptation.

Hippocampal sulcal cavities in depression and healthy individuals

BACKGROUND

A literature review suggested age and cognitive problems to be related to an increased prevalence of small areas of signal variation within the hippocampus observed on MRI, described as hippocampal sulcal cavities (HSCs; (Maller et al., 2011)). The current study aimed to describe the prevalence of HSCs in patients with treatment-resistant depression (TRD) and healthy controls over a large age-range.

METHODS

115 TRD patients and 86 controls underwent MRI brain scanning. Right and left HSCs were rated separately for prevalence and length.

RESULTS

HSCs were observed in 73.04% of those with TRD, statistically more prevalent (p=0.001) than amongst controls (51.16%). These findings are consistent with our review (66% prevalence in memory disorders and 47% in healthy controls). Furthermore, HSC presence and length was associated with aging.

LIMITATIONS

The study was cross-sectional so its implications for aging are tentative. A larger sample scanned longitudinally will allow for more sophisticated statistical methods by which to investigate the relationship between HSCs, aging, and TRD.

CONCLUSIONS

Although their clinical significance remains uncertain, the results of the current study suggest that HSCs are related with age and those with TRD have more aged brains than their peers.

To a broader concept of remission: rating the health-related quality of life in bipolar disorder

BACKGROUND

The relationship between remission and quality of life in bipolar disorder is incompletely understood. This study aimed to determine cut-points on the 36-item Short-Form Health Survey (SF-36) and the European Quality of Life Index (EQ-5D) that corresponded with an objective clinical measure of remission in bipolar disorder patients.

METHODS

Data from a 2-year prospective observational study of bipolar and schizoaffective patients were analysed. Concordant with previous research, the Clinical Global Impression-Bipolar Version (CGI-BP) was used as an index of remission, specifically the severity scores of 1 (normal, not at all ill) and 2 (borderline mentally ill). The mean SF-36 standardized mental component (SMC) and standardized physical component (SPC) total scores as well as the EQ-5D index score that corresponded with a CGI-BP severity score of 1 or 2 were determined.

RESULTS

The mean SF-36 score that corresponded with a CGI-BP severity score of 1 or 2, was below 50 for the SPC (49.3) and below 49 for the SMC (48.3). The mean EQ-5D score that corresponded with a CGI-BP severity score of 1 or 2 was below 0.88 (0.87).

LIMITATIONS

Although the initial sample is sufficiently large (n=240), 49 patients scored 1 and 2 on the CGI-S, of which 12 had schizoaffective disorder.

CONCLUSIONS

This study suggests that a cut-off score of ≥50 for the SPC and ≥49 for the SMC of the SF-36 and ≥0.88 for the EQ-5D index approximates a CGI-BP definition of remission.