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

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

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

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 Closing-in phenomenon: intricate aspect of constructional apraxia

Fenomen približavanja modelu odnosi se na tendenciju da se zadati model kopira njemu veoma blizu ili preko njega. Ovaj fenomen klasično se shvata kao vid konstrukcione apraksije koji se javlja pri zadacima grafomotornog kopiranja ili pri gestualnim imitacijama. Njegovo ispoljavanje na neuropsihološkim testovima uzima se kao neurokognitivni indikator demencija, a najčešće kao indikator Alchajmerove demencije. Međutim, iako visoko specifičan znak za ovu vrstu demencije, savremena literatura upućuje na zaključak da ovaj fenomen svakako nije patognomoničan za Alchajmerovu bolest, već da se javlja u širokom spektru neurokognitivnih poremećaja sa ili bez demencije. Iako je naša stručna javnost upoznata sa fenomenom približavanja modelu, do sada se o njemu nije na sistematičan način izlagalo. Iz tog razloga, osim diskusije o značaju približavanja modelu u kliničkoj praksi, rad objedinjuje i kritički analizira dosadašnja saznanja u vezi sa fenomenom. U radu autori diskutuju: (1) Istorijski razvoj i konceptualizacija fenomena; (2) Neuroanatomski korelati fenomena; (3) Hipoteza o kompenzaciji; (4) Hipoteza o atrakciji.The closing-in phenomenon occurs when a drawing is reproduced close to or superimposed on the original model. This phenomenon is classically understood as a type of constructional apraxia that occurs during graphomotor copying tasks or gestural imitations. Its manifestation on neuropsychological tests is taken as a neurocognitive indicator of dementia, most often as an indicator of Alzheimer's disease. Although a highly specific sign for this dementia type, current literature suggests that it is certainly not pathognomonic for Alzheimer's dementia, but occurs in a wide range of neurocognitive disorders with or without dementia. Although the Serbian academic circles are familiar with this phenomenon, thus far it hasn’t been sistematically explored. For this reason, in addition to discussing the significance of this phenomenon in clinical practice, in this paper we also summarize and critically analyze current knowledge regarding closing-in phenomenon. In this paper we discuss: (1) Historical development and conceptualization; (2) Neuroanatomical correlates of the phenomenon; (3) Compensation hypothesis; (4) Attraction hypothesis

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

The Closing-in phenomenon: intricate aspect of constructional apraxia

Fenomen približavanja modelu odnosi se na tendenciju da se zadati model kopira njemu veoma blizu ili preko njega. Ovaj fenomen klasično se shvata kao vid konstrukcione apraksije koji se javlja pri zadacima grafomotornog kopiranja ili pri gestualnim imitacijama. Njegovo ispoljavanje na neuropsihološkim testovima uzima se kao neurokognitivni indikator demencija, a najčešće kao indikator Alchajmerove demencije. Međutim, iako visoko specifičan znak za ovu vrstu demencije, savremena literatura upućuje na zaključak da ovaj fenomen svakako nije patognomoničan za Alchajmerovu bolest, već da se javlja u širokom spektru neurokognitivnih poremećaja sa ili bez demencije. Iako je naša stručna javnost upoznata sa fenomenom približavanja modelu, do sada se o njemu nije na sistematičan način izlagalo. Iz tog razloga, osim diskusije o značaju približavanja modelu u kliničkoj praksi, rad objedinjuje i kritički analizira dosadašnja saznanja u vezi sa fenomenom. U radu autori diskutuju: (1) Istorijski razvoj i konceptualizacija fenomena; (2) Neuroanatomski korelati fenomena; (3) Hipoteza o kompenzaciji; (4) Hipoteza o atrakciji.The closing-in phenomenon occurs when a drawing is reproduced close to or superimposed on the original model. This phenomenon is classically understood as a type of constructional apraxia that occurs during graphomotor copying tasks or gestural imitations. Its manifestation on neuropsychological tests is taken as a neurocognitive indicator of dementia, most often as an indicator of Alzheimer's disease. Although a highly specific sign for this dementia type, current literature suggests that it is certainly not pathognomonic for Alzheimer's dementia, but occurs in a wide range of neurocognitive disorders with or without dementia. Although the Serbian academic circles are familiar with this phenomenon, thus far it hasn’t been sistematically explored. For this reason, in addition to discussing the significance of this phenomenon in clinical practice, in this paper we also summarize and critically analyze current knowledge regarding closing-in phenomenon. In this paper we discuss: (1) Historical development and conceptualization; (2) Neuroanatomical correlates of the phenomenon; (3) Compensation hypothesis; (4) Attraction hypothesis