Neural networks related to pro-saccades and anti-saccades revealed by independent component analysis

The saccadic eye movement system provides an excellent model for investigating basic cognitive processes and flexible control over behaviour. While the mechanism of pro-saccades (PS) is well known, in the case of the anti-saccade task (AS) it is still not clear which brain regions play a role in the inhibition of reflexive saccade to the target, nor what is the exact mechanism of vector inversion (i.e. orienting in the opposite direction). Independent component analysis (ICA) is one of the methods being used to establish temporally coherent brain regions, i.e. neural networks related to the task. In the present study ICA was applied to fMRI data from PS and AS experiments. The study revealed separate networks responsible for saccade generation into the desired direction, the inhibition of automatic responses, as well as vector inversion. The first function is accomplished by the eye fields network. The inhibition of automatic responses is associated with the executive control network. Vector inversion seems to be accomplished by the network comprising a large set of areas, including intraparietal sulcus, precuneus/posterior cingulate cortices, retrosplenial and parahippocampal. Those regions are associated with the parieto-medial temporal pathway, so far linked only to navigation. These results provide a new insight into understanding of the processes of the inhibition and vector inversion.     

Bilateral SUNCT-like headache in a patient with prolactinoma responsive to lamotrigine

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) syndrome is a rare trigeminal autonomic cephalalgia. The cases of SUNCT with attacks that affected both sides simultaneously have only rarely been reported and some of them had underlying pathology. We have reported a case of bilateral SUNCT-like headache secondary to a prolactinoma and responsive to lamotrigine treatment.     

Clinical Risk Factors for Early Complications After High-Dose-Rate Endobronchial Brachytherapy in the Palliative Treatment of Lung Cancer

PurposeThis study sought to identify the rate of complications and clinical risk factors for early complications of high-dose-rate endobronchial brachytherapy (HDR-EBBT). The identification of these risk factors could result in a decrease or avoidance of complications.Patients and MethodsWe analyzed risk factors for complications in 761 patients with advanced-stage lung cancer who were treated with HDR-EBBT as a part of the multimodality therapy. We reviewed patient, radiology, and bronchology charts for complications of HDR-EBBT. Complications were defined as severe hypoxemia, global respiratory failure, cardiac arrhythmia requiring additional treatment, hemoptysis, pneumothorax, pneumomediastinum, pulmonary edema, tracheoesophageal fistulae, and death. Risk factors were defined as acute myocardial infarction ≥ 6 months previously, stabilized hypertension, arrhythmia, chronic obstructive pulmonary disease (COPD), stabilized cardiomyopathy, previous external-beam radiation therapy, chemotherapy, and interventional pulmonology treatment. Age, sex, tumor histology, and tumor localization were also subjected to multivariate analyses.ResultsThe rate of complications was 5.4%. Statistically significant (P = .001) risk factors for complications of HDR-EBBT included stabilized hypertension, controlled chronic cardiac arrhythmias, COPD, and stabilized cardiomyopathy. We found a significant correlation between age and number of risk factors, and the occurrence of complications (P = .001).ConclusionOur results indicate that closer monitoring of patients with identified risk factors is advisable. Such monitoring should be performed both before and after treatment, to avoid complications.     

Impact of early-life stress on the medial prefrontal cortex functions – a search for the pathomechanisms of anxiety and mood disorders

Although anxiety and mood disorders (MDs) are the most common mental diseases, the etiologies and mechanisms of these psychopathologies are still a matter of debate. The medial prefrontal cortex (mPFC) is a brain structure that is strongly implicated in the pathophysiology of these disorders. Agrowing number of epidemiological and clinical studies show that early-life stress (ELS) during the critical period of brain development may increase the risk for anxiety and MDs. Neuroimaging analyses in humans and numerous reports from animal models clearly demonstrate that ELS affects behaviors that are dependent on the mPFC, as well as neuronal activity and synaptic plasticity within the mPFC. The mechanisms engaged in ELS-induced changes in mPFC function involve alterations in the developmental trajectory of the mPFC and may be responsible for the emergence of both early-onset (during childhood and adolescence) and adulthood-onset anxiety and MDs. ELS-evoked changes in mPFC synaptic plasticity may constitute an example of metaplasticity. ELS may program brain functions by affecting glucocorticoid levels. On the molecular level, ELS-induced programming is registered by epigenetic mechanisms, such as changes in DNAmethylation pattern, histone acetylation and microRNA expression. Vulnerability and resilience to ELS-related anxiety and MDs depend on the interaction between individual genetic predispositions, early-life experiences and later-life environment. In conclusion, ELS may constitute a significant etiological factor for anxiety and MDs, whereas animal models of ELS are helpful tools for understanding the pathomechanisms of these disorders.