Muzika kod zdravog i obolelog mozga

Art and creativity originate in the brain and depend on normal brain functioning. Music is a multifacet phenomenon that exists as a universal heritage across all human societies and throughout the entire human history. There are numerous brain-based mechanisms involved in the cognitive processing of music, including music listening, performing, composing, reading, writing, as well as musical aesthetics and musical emotion. Music relates to many brain functions including perception, motor action, cognition, emotion, learning and memory. Various brain regions are associated with music processing and production, including the right anterior and posterior superior temporal lobe, the right inferior frontal cortex, the right prefrontal, bilateral premotor and bilateral parietal areas, the right anterior cerebellar lobe, language areas and limbic structures. In a diseased brain, after acquired brain injury, disorders in music perception or production have been described, although considered rare. Amusia or music-specific agnosia, a defective perception of music or its components is typically associated with temporal lobe lesions, and is more likely to occur with right-sided involvement. Etiology of acquired amusia comprise many diseases and conditions leading to brain injury, including traumatic brain injury, ischemic or hemorrhagic stroke, neoplasma, iatrogenic and epilepsy-related conditions, infections and degenerative diseases. Additionally, there are cases of congenital amusia, attributed to abnormality in neural networks for music, associated with structural variations in the frontal and temporal lobes.Umetnost i kreativnost potiču iz mozga i zavise od njegovog normalnog funkcionisanja. Muzika je multifacetni fenomen koji postoji kao univerzalno nasleđe u svim ljudskim društvima i kroz čitavu ljudsku istoriju. Postoje mnogobrojni moždani mehanizmi uključeni u kognitivnu obradu muzike, uključujući slušanje muzike, izvođenje, pisanje, čitanje, kao i muzičku estetiku i muzičke emocije. Muzika se odnosi na mnoge funkcije mozga, uključujući percepciju, motoriku, kogniciju, emocije, učenje i pamćenje. Različiti regioni mozga su povezani sa obradom i proizvodnjom muzike, uključujući prave prednje i zadnje superiorne temporalne režnje, desno inferiorni frontalni korteks, desno prefrontalni, bilateralni premotor i bilateralni parietalni prostori, desni anteriorni cerebelarni režanj, jezičke površine, limbičke strukture. U obolelom mozgu, nakon traume mozga, opisani su poremećaji u percepciji ili produkciji muzike, iako se smatraju retkim. Amuzija ili specifična muzička agnozija, narušena percepcija muzike ili njenih komponenti obično se povezuje sa lezijama temporalnog režnja i pretežno se javlja kod oštećenja desne polovine mozga. Etiologija stečene amusije obuhvata mnoge bolesti i stanja koji dovode do lezija mozga, uključujući traumatske povrede, ishemijski ili hemoragični moždani udar, neoplazme, jatrogena stanja, epilepsije, infekcije i degenerativne bolesti. Postoje i slučajevi kongenitalne amuzije, u vezi poremećaja neuronskih mreža za muziku, povezanih sa strukturnim varijacijama u frontalnom i temporalnom režnju

Vitamin D u svim dobima života

Vitamin D is a secosteroid hormon with pleiotrophic functions and essential for normal development and health throughout the entire life span. Vitamin D deficiency has epidemic proportions worldwide and interferes with important metabolic processes. Its prevalence is estimated in various populations of different etnicity and age from 50% up to 100% in certain groups. The main source of vitamin D for men is skin production by ultraviolet B radiation acting on 7-dehydrocholesterol. This is cholecalciferol or vitamin D3. Less than 20% is obtained from food. The active form, 1,25-dihydroxy-vitamin D (calcitriol) is synthesized in the kidney. Synthetic capacity declines with ageing. The main function of vitamin D is calcium homeostasis important for musculosceletal health, innate immunity, arterial integrity, endocrine function, antiinflamation, and various local processes (autocrine and epicrine functions) in more than 30 tissues where receptors exist. Vitamin D is also important for cognitive function, mainly executive in the frontal lobe. Normal vitamin D levels are above 75 nmol/L. Vitamin D deficiency is mostly due to the lack of sun exposure but can also be secondary to some individual characteristics. Deficiency during intrauterine development can lead to early and late negative consequences in bone growth, immune system, and cognition. The extreme deficiency causes rikets. In adults vitamin D deficiency has been suggested as a risk factor for infectious and autoimmune diseases, carcinomas (especially of the breast and colon), multiple sclerosis, falls, osteoporosis, bone fractures, cardiovacular and cerebrovascular diseases, diabetes mellitus type I and II, infertility, cognitive decline and dementia. Oral supplementation with serum level normalization can lead to reduction of these risks but even amelioration of some pathological states. Recomendation ranges form 400 IU of vitamin D in infants to 2000 IU in older population, but it should be guided by individual clinical circumstances.Vitamin D je sekosteroidni hormon sa pleotropnim funkcijama i presudan za pravilan razvoj i zdravlje kroz ceo životni vek. Nedostatak vitamina D ima razmere epidemije širom sveta i ometa važne metaboličke procese. Procene u različitim populacijama različitog etničkog porekla i starosti su od 50% do 100 % u pojedinim grupama. Glavni izvor vitamina D kod ljudi je sinteza u koži pod dejstvom ultraljubičastog B zračenja na 7- dehidrocholesterol. To je vitamin D3 ili holekalciferol. Manje od 20% se dobija iz hrane. Aktivni oblik, 1,25-dihidroksi- vitamin D (kalcitriol) se sintetiše u bubrezima. Sintetički kapaciteta opada sa starenjem. Glavna funkcija vitamina D je homeostaza kalcijuma, zdravlje muskuloskeletnog sistema, urođeni imunitet, integritet arterija, endokrine funkcije, antiinflamatorno dejstvo i različiti lokalni procesi (autokrine i epikrine funkcije) u više od 30 tkiva gde postoje receptori. Vitamin D je takođe važan za kognitivne funkcije, uglavnom egzekutivne u frontalnom režnju. Normalni nivoi vitamina D su iznad 75 nmol/L. Nedostatak vitamina D je uglavnom uzrokovan nedostatkom sunčeve svetlosti, ali i nekih individualnih karakteristika bolesnika. Nedostatak tokom intrauterinog razvoja može da dovede do ranih i kasnih negativnih posledica na rast kostiju, imuni sistem i kogniciju. Ekstremni nedostatak vitamin D izaziva rahitis. Kod odraslih je nedostatak vitamina D faktor rizika za infektivne i autoimune bolest, karcinome (naročito dojke i debelog creva), multiplu sklerozu, padove, osteoporozu, prelome kostiju, kardiovakularna i cerebrovaskularna oboljenja, dijabetes melitus tip I i II, neplodnost, kognitivni pad i demencije. Oralna suplementacija sa normalizacijom nivoa vitamina u serumu može da dovede do smanjenja ovih rizika ali čak i ublažavanje nekih patoloških stanja. Preporučene doze iznose od 400 IU vitamina D kod odojčadi do 2000 IU u starijoj populaciji, ali bi trebalo da se rukovodi individualnim kliničkim okolnostima

Frontalni sistem donošenja odluka

Frontal decision making system is both deliberative and automatic. Cognitive part of this system is mediated by prefrontal areas and emotive by limbic system and amygdala. Dopaminergic system is important in this function. The decision making process is constantly adjusted. Orbitofrontal cortex constantly evaluates the desirability of each action and adjusts decision-making strategy according to the current situation. If the environment is rapidly changing or is uncertain, the anterior cingulate cortex includes in decision-making. Interaction between prefrontal cortex and basal ganglia is necessary for decision-making. Autoactivation is mediated by medial prefrontal cortex and internal palidum. Apathy is a result of disruption of prefrontal decision-making system that consists of prefrontal cortex and prefrontal-subcortical neuronal circuits. Theory of mind (ToM) describes our ability to understand the mental state of others and to appreciate how it differs from our mental state and to predict their behavior. It is believed that the cellular level of ToM are mirror neurons. Impairment of the ToM leads to problems in social relations, providing adequate information, commenting on the conversation, thought disturbance and results in poor communication skills.Frontalni sistem donošenja odluka je i svesni i automatski. Kognitivni deo ovog sistema je posredovan prefrontalnim oblastima, a emotivni limbičkim sistemom i amigdalom. Dopaminergički sistem je važan za ovu funkciju. Proces donošenja odluka se neprestano prilagođava. Orbitofrontalna kora stalno ocenjuje poželjnost svake akcije i podešava strategiju odlučivanja prema trenutnoj situaciji. Ako se okruženje brzo menja, ili je neizvesno, prednja cingularna kora se uključuje u donošenje odluka. Interakcija između prefrontalnog korteksa i bazalnih ganglija je neophodna za donošenje odluka. Autoaktivacija je posredovana medijalnim prefrontalnim korteksom korteksom i unutrašnjim palidumom. Apatija je posledica prekida prefrontalnog sistema odlučivanja koji se sastoji od prefrontalni korteks i prefrontalni-subkortikalnim neuronskih kola. Teorija uma opisuje našu sposobnost da razumemo mentalno stanje drugih i da procenjujemo kako se razlikuje od našeg mentalnog stanja te da se predvidi njihovo ponašanje. Veruje se da je na ćelijskom nivou teorija uma posredovana ogledalskim neuronima. Poremećaj teorije uma dovodi do problema u društvenim odnosima, pružanja odgovarajućih informacija, komentarisanja konverzacije, poremećaja misli i dovodi do loših socijalnih veština

Hashimoto encephalopathy: Neurological and psychiatric perspective

Hashimoto encephalopathy (HE) is an autoimmune disease with neurological and neuropsychiatric manifestations and elevated titers of antithyroid antibodies in serum and cerebrospinal fluid. Patients are mostly women. Age varies from 8 to 86 years. Prevalence of HE is estimated to be 2.1/100,000. Neurological and/or psychiatric symptoms and signs constitute the clinical picture. The disease responds well to corticosteroid therapy, but sometimes other immunomodulatory therapies must be applied. Autoimmune mechanisms with antibodies against antigens in the brain cortex are suspected. The course of the disease can be acute, subacute, chronic, or relapsing/remitting. Some patients improve spontaneously, but a few died in spite of adequate therapy

The neuropsychology of hallucinations

Hallucinations are a psychopathological phenomenon with neuropsychological, neuroanatomical and pathophysiological correlates in specific brain areas. They can affect any of the senses, but auditory and visual hallucinations predominate. Verbal hallucinations reveal no gross organic lesions while visual hallucinations are connected to defined brain lesions. Functional neuroimaging shows impairments in modality specific sensory systems with the hyperactivity of the surrounding cerebral cortex. Disinhibition and expansion of the inner speech was noted with impaired internal monitoring in auditory verbal hallucinations. The subcortical areas and modal-specific associative cortex and cingulate cortex are essential for the occurrence of hallucinations

The Impact of Homocysteine, Vitamin B12, and Vitamin D Levels on Functional Outcome after First-Ever Ischaemic Stroke

We explored the relationship between acute ischaemic stroke (IS) early functional outcome and serum levels of homocysteine, vitamin B12, and D in a noninterventional prospective clinical study. We enrolled 50 patients with first-ever IS and performed laboratory tests and functional assessment at three time points: on admission and three and six months after stroke. Modified Rankin Scale (mRS), NIHSS scale, and Barthel index (BI) scores were assessed in all participants by trained examiner blinded to laboratory data. Patients did not receive treatment that might alter laboratory data. Admission NIHSS correlated with homocysteine levels (r = 0.304, p lt 0.05), B12 level (r = -0.410, p lt 0.01), and vitamin D levels (r = -0.465, p lt 0.01). Functional outcome measures (BI and mRS) did not significantly correlate with homocysteine and vitamin D3 levels at 3 and 6 months. However, a positive correlation with vitamin B12 levels was detected for BI both at 3 and 6 months and mRS at 6 months. Higher serum vitamin B12 levels were associated with better functional outcome at follow-up

Mijalgični encefalomijelitis - enigma na raskršću medicine

Myalgic encephalomyelitis is a complex, multisystem disease with chronic course significantly affecting patients' quality of life. Physical and mental exertion intolerability, muscle pain, and sleep problems are the main features accompanied often with cognitive inefficacy and vegetative symptoms. Prevalence is 7-3000 per 100,000 adults. It is estimated that 90% of the patients are misdiagnosed. Pathogenesis is still only speculative but current research points to disturbances in the immunological system, inflammatory pathways, autonomic and central nervous system, muscle and mitochondria, as well as alterations of gut microbiota and gut permeability. The onset is typically acute, following an infectious disease. Exertional intolerance lasting for more than six months is an important diagnostic factor. The core features must be moderate to severe and present at least 50% of the time. Diagnostic criteria should be fulfilled and differential diagnosis should be made to exclude other potential pathological conditions or to diagnose comorbidities. Brain magnetic resonance imaging morphometry has shown gray matter atrophy in occipital lobes bilaterally, right angular gyrus, and the posterior division of the left parahippocampal gyrus, consistent with memory problems and potentially with impairment of visual processing. Treatment is still symptomatic and of partial benefit. Symptomatic treatment can include medications for controlling pain and sleep problems, graded exercise and cognitive behavioral therapy. Larger controlled trials are needed to shed more light on this challenging condition.Mijalgični encefalomijelitis je složeno, multisistemsko oboljenje sa hroničnim tokom koje značajno utiče na kvalitet života bolesnika. Slaba tolerancija na fizički i mentalni napor, bolovi u mišićima i problemi sa spavanjem glavne su odlike i često su praćene kognitivnom neefikasnošću i vegetativnim simptomima. Prevalencija je 7-3000 na 100.000 odraslih. Procenjuje se da je 90% ovih bolesnika pogrešno dijagnostikovano. Patogeneza je i dalje samo spekulativna, ali trenutna istraživanja ukazuju na poremećaje u imunološkom sistemu, inflamatornom odgovoru, autonomnom i centralnom nervnom sistemu, mišićima i mitohondrijama, kao i promene mikrobiote i propustljivosti creva. Početak bolesti je tipično akutan i prati infektivnu bolest. Netolerancija napora koja traje duže od šest meseci važan je dijagnostički kriterijum. Osnovne karakteristike moraju biti umerene do teške i prisutne najmanje 50% vremena. Isključivanje drugih mogućih patoloških stanja ili komorbiditetnih dijagnoza zahteva zadovoljavanje dijagnostičkih kriterijuma i diferencijalno dijagnostičko sagledavanje. Morfometrijska snimanja mozga magnetnom rezonancom pokazala su atrofiju sive mase u okcipitalnim režnjevima bilateralno, desnom angularnom girusu i posteriornom levom parahipokampalnom girusu, što može dovesti do problema sa pamćenjem i oštećenja vizuelne obrade informacija. Lečenje je i dalje simptomatsko i samo delimično uspešno. Simptomatski tretman može da uključuje lekove za kontrolu bola i problema sa spavanjem, doziranu fizičku aktivnost i kognitivno-bihevioralnu terapiju. Potrebne su veće studije da bi se razjasnilo ovo medicinsko stanje

Vitamin a and the nervous system

Vitamin A is essential for the early development and normal functioning of the brain throughout life. A deficiency of vitamin A is one of the leading causes of morbidity and mortality in developing countries, and subclinical deficiency is probably present worldwide. The main active molecule in vitamin A is retinoic acid, which is involved in vision, the immune system, skin health, olfaction and cognition (learning, memory, spatial functions, olfaction, etc.) through processes of neuroplasticity and neurogenesis. Vitamin A is involved in the regulation of about one-sixth of the human genome. It has non-genomic actions in protein translation and paracrine actions. Retinal vitamin A aldehyde is crucial for day and night vision. The best-known manifestation of hypovitaminosis A is night blindness but in more severe cases, it causes blindness. In the hypothalamus, vitamin A, with information from the retina, acts in circadian and seasonal regulation. Increased retinoic acid levels in the blood are associated with increased risk of depression, and lower levels have been connected with Alzheimer's disease, Parkinson's disease, cerebral ischemia, autistic spectrum disorders and schizophrenia. Higher doses and longer periods of treatment pose the threat of hypervitaminosis A. Vitamin A and its analogs are a promising new class of therapeutic agents in a wide spectrum of disorders, albeit with a narrow therapeutic window

Omega 3 fatty acids in psychiatry: Myth and reality

Omega 3 fatty acids are long-chain polyunsaturated fatty acids (LC-PUFAs). The basic molecule is the Alpha-linolenic acid (ALA) from which LC-PUFAs are formed: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). DHA is the predominant fatty acid in the brain especially in synaptic membranes, astrocytes, myelin and organelle membranes. LC-PUFAs lead to increased membrane fluidity and permeability, and most of the positive effects depend on immunomodulatory activities, via mechanisms of gene expression, cell signaling, and membrane organization. Previous studies in animal models have shown that LC-PUFAs are essential for normal dopaminergic, glutamatergic and serotonergic neurotransmission. Preclinical and clinical studies have demonstrated the role of PUFAs as an effective adjuvant therapy for unipolar and bipolar depression. Lack of omega 3 fatty acids plays a role in the onset of anxiety and aggression. Low omega 3 fatty acids in the prefrontal cortex of people with schizophrenia reduce dopaminergic neurotransmission, contributing to negative and neurocognitive symptoms, while subsequent disinhibition in the limbic system causes positive symptoms. Some evidence suggests that LC-PUFA may delay or even prevent the progression of particular psychotic disorders in high-risk children and adolescents. Epidemiological studies have shown a positive correlation between the relatively high intake of DHA and EPA and the lower relative risk of mild cognitive impairment and dementia or their progression. The recommended daily intake of EPA and DHA varies significantly: 300-500 mg/day as recommended by the World Health Organization (WHO), up to 1-2 grams/day in Norway. Daily intakes of EPA and DHA up to 3 grams are generally recognized as safe. EPA and DHA at doses greater than 3 grams per day can have side effects: an increase in bleeding frequency, oxidation of n-3PUFAs with the formation of biologically active oxidation products, and more.Omega 3 masne kiseline su polinezasićene masne kiseline dugih lanaca (LC-PUFAs). Osnovni molekul je alfa-linolenska kiselina (ALA) od koje nastaju LC-PUFA: eikosapentaenoična kiselina (EPA) i dokosaheksaenoička kiselina (DHA). DHA je dominantna masna kiselina u mozgu naročito u sinaptičkim membranama, astrocitima, mijelinu i membranama organela. LC-PUFAs dovode do povećane fluidnosti i permeabilnosti membrana, a većina pozitivnih efekata zavisi od imunomodulacionih aktivnosti, preko mehanizama ekspresije gena, ćelijske signalizacije i organizacije membrane. Dosadašnjim istrazivanjima na animalnim modelima pokazano je da su LC-PUFAs neophodne za normalnu dopaminergičku, glutamatergičku i serotonergičku neurotransmisiju. Prekliničke i kliničke studije su pokazale ulogu PUFAs kao efikasne adjuvantne terapije unipolarne i bipolarne depresije. Nedostatak omega 3 masnih kiselina ima ulogu u nastanku anksioznosti i agresivnosti. Niske omega 3 masne kiseline u prefrontalnoj kori mozga u osoba sa shizofrenijom smanjuju dopaminergičku neurotransmisiju, doprinoseći negativnim i neurokognitivnim simptomima dok posledična dezinhibicija u limbičkom sistemu izaziva pozitivne simptome. Neki dokazi ukazuju da LC-PUFA može da odloži ili čak spreči napredovanje pojedinih psihotičnih poremećaja u visoko rizične dece i adolescenata. Epidemiološke studije su pokazale pozitivnu korelaciju između relativno visokog unosa DHA i EPA i nižeg relativnog rizika od pojave blagog kognitivnog poremećaja i demencije ili njihovog napredovanja. Preporučeni dnevni unos EPA i DHA značajno varira: 300-500 mg/dan kako Svetska zdravstvena organizacija (SZO) preporučuje, pa sve do 1-2 grama/dan u Norveškoj. Dnevni unos EPA i DHA do 3 grama je generalno priznat kao siguran. EPA i DHA u dozama većim od 3 grama dnevno može da da neželjene efekte: povećanje učestalosti krvarenja, oksidaciju n-3PUFAs sa nastankom biološki aktivnih oksidacionih produkata i drugo