Anatomical Brain Changes and Cognitive Abilities in Patients with Obstructive Sleep Apnea Syndrome and Nonalcoholic Fatty Liver Disease.

Obstructive sleep apnea (OSA) is characterized by repetitive complete or partial collapse of the upper airway and reduction of airflow during sleep. It is associated with significantly increased daytime muscle sympathetic nerve activity thought to result from the repetitive intermittent periods of hypoxemia during sleep and brain alterations that are likely to result. Different brain regions are affected by subsequent hypoxia/anoxia. Neurodegenerative processes result in measurable atrophy of cortical gray matter in the temporal lobes and posterior cingulate cortex, as well as in subcortical structures such as the hippocampus, amygdala, and thalamus. This study involved a group of firstly diagnosed, therapy-naive, nonalcoholic fatty liver disease (NAFLD) patients, out of which 144 (96 males and 48 females), aged 34-57 (mean 47.88 ± 6.07), satisfied the recruiting criteria for the study and control groups. All the patients underwent MRI scanning, polysomnography testing, and cognitive evaluation. Cognitively, worse results were obtained in the group with OSA (p < 0.05) and NAFLD (p=0.047). A significant decrease in volumes of cortical and subcortical structures was revealed (p < 0.001). In conclusion, brain deterioration followed by cognitive impairment is, most likely, the result of intermittent hypoxia and anoxia episodes that initiate the domino process of deteriorating biochemical reactions in the brain.

Cognitive Changes and Brain Volume Reduction in Patients with Nonalcoholic Fatty Liver Disease.

Studies of psychological condition of patients suffering from nonalcoholic fatty liver disease are rather equivocal about the results: while some claim that NAFLD patients suffer from anxiety and depression more than non-NAFLD controls, others do not withstand those findings. Lower cognitive potentials have also been reported, both in patient related and in animal model-based investigations, and correlated with assessed brain tissue changes. We hypothesized that NAFLD, as a condition, affects the brain tissue and, subsequently, the cognitive state. So we compared findings in 40 NAFLD positive and 36 NAFLD negative patients and correlated their brain tissue volumes with the results of Montreal Cognitive Assessment (MoCA) test. Binomial logistic regression verified the influence of NAFLD state leading to lower cognitive potentials: odds ratio 0.096; 95% confidence interval (CI) 0.032-0.289; p < 0.001. Patients with NAFLD had a greater risk to suffer from the cognitive impairment and depression: RR = 3.9; 95% CI 1.815-8.381; p = 0.0005 and RR = 1.65; 95% CI 1.16-2.36; p = 0.006. NAFLD significantly influenced the cognitive deficit and tissue volume reduction and patients suffering from NAFLD had about four times higher risk of having a cognitive impairment.

Current Use of mTOR Inhibitors for the Treatment of Subependymal Giant Cell Astrocytomas and Epilepsy in Patients with TSC.

The serine/threonine kinase mechanistic target of rapamycin (mTOR) is an important sensor of the cellular energy condition which, at the same time, represents a kind of master switch between anabolic and catabolic cellular processes. Tuberous sclerosis complex (TSC) is a genetic disease which is considered to be a prototype of a dysregulated mTOR signaling pathway. The dysregulated mTOR pathway in TSC leads to characteristic structural and physiologic abnormalities in multiple organs. In this review we focus on the pharmacological properties of mTOR inhibitors and clinical investigations of mTOR inhibitors for two important neurological TSC manifestations: subependymal giant cell astrocytomas (SEGAs) and epilepsy. Moreover, we present a safety profile of those agents and their current role in clinical practice.

THE REGULATION ROLE OF CAROTID BODY PERIPHERAL CHEMORECEPTORS IN PHYSIOLOGICAL AND PATHOPHYSIOLOGICAL CONDITIONS.

INTRODUCTION: The major oxygen sensors in the human body are peripheral chemoreceptors. also known as interoreceptors- as connected with internal organs, located in the aortic arch and in the body of the common carotid artery. Chemoreceptor function under physiological conditions. Stimulation of peripheral chemoreceptors during enviromental hypoxia causes a reflex-mediated increased ventilation, followed by the increase of the muscle sympatic activity, aiming to maintain tissue oxygen homeostatis, as well as glucosae, homeostatis. Besides that, peripheral chemoreceptors interact with central chemoreceptors. responsible for carbon dioxide changes . and they are able to modulate each other. Chemoreceptor function in pathophysiological conditions. Investigations of respiratory function in many pathological processes, such as hypertension, obstructive sleep apnea, congestive heart failure and many other diseases that are presented with enhanced peripheral chemosensitivity and impaired functional sy mpatholysis ultimately determine the peripheral chemorcceptor role and significance of peripheral chemoreceptors in the process of those pathological conditions development. Considering this, the presumed influence of peripheral chemoreceptors is important in patients having the above mentioned pathology. CONCLUSION: The importance and the role of peripheral chemoreceptors in the course of the breathing control is still controversial, despite many scientific attempts to solve this problem. The main objective of this review is to give the latest data on the peripheral chemoreceptor role and to highlight the importance of peripheral chemoreceptors for maintaining of oxygen homeostasis in pateints with hypoxia caused by either physiological or pathological conditions.