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Clinical Neuroscience

SEPTEMBER 30, 2020

Neuroscience highlights: Main cell types underlying memory and spatial navigation

KRABOTH Zoltán, KÁLMÁN Bernadette

Interest in the hippocampal formation and its role in navigation and memory arose in the second part of the 20th century, at least in part due to the curious case of Henry G. Molaison, who underwent brain surgery for intractable epilepsy. The temporal association observed between the removal of his entorhinal cortex along with a significant part of hippocampus and the developing severe memory deficit inspired scientists to focus on these regions. The subsequent discovery of the so-called place cells in the hippocampus launched the description of many other functional cell types and neuronal networks throughout the Papez-circuit that has a key role in memory processes and spatial information coding (speed, head direction, border, grid, object-vector etc). Each of these cell types has its own unique characteristics, and together they form the so-called “Brain GPS”. The aim of this short survey is to highlight for practicing neurologists the types of cells and neuronal networks that represent the anatomical substrates and physiological correlates of pathological entities affecting the limbic system, especially in the temporal lobe. For that purpose, we survey early discoveries along with the most relevant neuroscience observations from the recent literature. By this brief survey, we highlight main cell types in the hippocampal formation, and describe their roles in spatial navigation and memory processes. In recent decades, an array of new and functionally unique neuron types has been recognized in the hippocampal formation, but likely more remain to be discovered. For a better understanding of the heterogeneous presentations of neurological disorders affecting this anatomical region, insights into the constantly evolving neuroscience behind may be helpful. The public health consequences of diseases that affect memory and spatial navigation are high, and grow as the population ages, prompting scientist to focus on further exploring this brain region.

Clinical Neuroscience

JANUARY 30, 2020

[Correction of the physiological artefacts at pre-surgical clinical functional MR]

KISS Máté, GÁL Andor Viktor, KOZÁK Lajos Rudolf, MARTOS János, NAGY Zoltán

[Introduction/aim of the study - Pre-surgical functional MRI (fMRI) is an important modality of examinations before brain surgery. There are several artefacts (e.g. motion, susceptibility) which may hinder the evaluation of fMRI data. Physiological artefacts (breathing, pulsation) also affect the sensitivity and specificity of anatomical localization. The aim of this study is to demonstrate the efficiency of physiological artefact identification and removal methods for presurgical evaluation. Materials and methods - Siemens Magnetom Verio 3T MRI scanner was used to collect data. The physiological parameters (breathing, pulse) were recorded with the MRI system’s built-in devices. Data from fourteen patients - with primary brain tumour - were evaluated with SPM12 utilizing the RETROICOR/RVHR tool to detect and decrease the effect of physiological artefacts. We compared the statistical maps obtained with and without the physiological correction using the Jaccard similarity coefficient, and ROI analyses. Results - Significant differences were found in the mean ROI values (p<0.0016) and the extensions of eloquent activations (p<0.0013), when using the physiological correction (RETORICOR/RVHR) based on convolution method. On the other hand, no significant differences were found between the ROIs’ standard deviations (F=0.28). The RETROICOR/ RVHR method helps to define the precise localisation of eloquent areas (p<0.009). The number of irrelevant (non-significant) voxels were increased (p<0.001). Conclusions - Minimising of physiological artefacts in fMRI data calculations, the (RETROICOR/RVHR) method based on convolution has been successfully adapted. This algorithm could be helpful before neurosurgical intervention. The activity pattern became more reliable. ]

Lege Artis Medicinae

JULY 20, 2019

[The red eye]

IMRE László

[Eye redness may be a sign of a variety of eye diseases with different severity. Most often redness is relatively harmless, such as conjunctivitis, but it can be a serious illness with visual impairment and even lasting consequences in the background of redness. It is therefore important for non-ophthalmologists to be informed and to know the basic types of redness of the eye and to recognize typical and characteristic forms of appearance. Based on these, they can decide whether the patient can be treated or forwarded to an ophthalmic institution. In the present continuing education article we try to summarize the causes of the red eye, primarily according to the characteristics of the redness of the eye and the anatomical localization. During the investigation of a patient with red eye, the type of the redness can be determined most by diffuse illumination and by naked eye inspection without any other means. It is important to know the principal features and causes of redness of conjunctival or ciliary or scleral origin, possible other recognizable differences (e.g. conjunctival papillae or follicles or conjunctival chemosis). We have attempted to illustrate these with a number of photographs, starting with a schematic representation of the characteristic features of redness. We tried to emphasize cases suitable for treating by non-ophthalmologists and tried to draw attention to the importance of referral un­clear or complicated cases.]

Clinical Neuroscience

SEPTEMBER 30, 2017

Title of the article: Bilateral acute angle-closure glaucoma induced by duloxetine

ATUM Mahmut, VILDAN Tunc, ENES Demiryurek, ALAGOZ Gursoy

Introduction - To present a rare case of bilateral acute angle-closure glaucoma secondary to duloxetine administered for the treatment of depression. Case presentation - A 46 year old woman developed bilateral closed angle glaucoma after 15 days of duloxetine usage. Intraocular pressures (IOP) were 52 and 55 mm Hg in right and left eyes respectively, with shallow anterior chamber and angle closure on gonioscopy. Discontinuing duloxetine treatment, initiation of antiglaucomatous treatment and bilateral Nd:YAG Laser iridotomy obtained normalized IOP and anterior chamber depth. Conclusion - Duloxetine, used in the treatment of depression can be responsible for acute angle-closure glaucoma by leading to mydriasis and ciliary effusion.

Lege Artis Medicinae

APRIL 20, 2016

[What does the „whole”-ness of patients with diabetes mellitus mean?]

VÁLYI Péter

[Diabetes mellitus is a chronic, progressive disease, characterized by elevated levels of blood glucose, can lead to many complications and can increase the overall risk of early disability and dying prematurely. The newest guidelines on management of patients with diabetes mellitus give a full description of diagnostic criteria, prevention, lifestyle and pharmacological treatment, complications, age-related characteristics. However, in everyday care of patients with diabetes mellitus little attention is paid to severity of anatomical and functional impairment related to disease, how and in what extent those limit everyday activities, restricts filling the social role, the importance of interrelationship of a human being and environment, to personal factors. The aims of this publication is: to present how diabetes mellitus influences the entirety, the “whole”-ness of a human; to show tools of objective estimation of impairments and changes of functionality; to call attention to importance of development of residual abilities, of shaping supportive environment, of assessment of needs, of positive influences of personal characteristics; to demonstrate how all these measures improve quality of life and compliance of patient with diabetes mellitus. The holistic approach of “human’s whole-ness” can contribute to success of preventive, curative and rehabilitative measures in patients with diabetes mellitus.]

Lege Artis Medicinae

DECEMBER 15, 2015

[„Disease sffair”, „health affair” or „whole-ness affair” in everyday medical practice?]

VÁLYI Péter

[In everyday medical practice the diagnostics and treatment of diseases, and the patient’s rehabilitation are in focus. There are not considered in details the personal elements, how disease affects the completeness of human life, in what extent impairs the whole-person anatomical and functional condition, alters abilities, limits activities of daily living, restricts filling the social role. Human personal characteristics are disregarded, environmental factors (that can support and restrict the everyday activities) are leaved out of consideration. Based on the contemporary ideas of human being and health, the aim of this article is facilitating the consideration of human completeness, “whole”-ness at all stages of patient care. Focusing on human wholeness can contribute to better physician-patient interrelationship. An important condition for wholeness-centred approach is the “precurabilitation” view that means the unity and simultaneity of prevention, curing and rehabilitation. ]

Clinical Neuroscience

OCTOBER 05, 2013

[Occurence and molecular pathology of high grade gliomas]

MURNYÁK Balázs, CSONKA Tamás, HEGYI Katalin, MÉHES Gábor, KLEKNER Álmos, HORTOBÁGYI Tibor

[Background - Glial tumours represent the most frequent type of primary brain cancers. Gliomas are characterized by heterogeneity that makes the diagnosis, histological classification and the choosing of correct therapy more difficult. Despite the advances in developing therapeutic strategies patients with malignant gliomas have a poor prognosis; therefore glial tumours represent one of the most important areas of cancer research. There are no detailed data on the epidemiology of gliomas in Hungary. Methods - In the first section of our publication, we analysed the histological diagnosed cases between 2007 and 2011 at the Institute of Pathology, University of Debrecen Medical and Health Science Centre. We analyzed the incidence of 214 high-grade gliomas by tumor grades, gender, age, and the anatomical localization. Results - The majority of cases were glioblastoma (182 cases), and the remaining 32 cases were anaplastic gliomas. The mean age of patients was 57 years (±16.4), and the male:female ratio was 1.1:1. The most frequent area of tumors was the frontal lobe followed by the temporal, parietal and occipital lobe. We include new findings published recently about glioma patogenesis, molecular pathways, mutant genes and chromosomal regions. We explain briefly the role of selected important genes in glioma genesis and give an update on knowledge provided by modern molecular methods, which could beneficially influence future therapy and the diagnosis of gliomas.]

Clinical Neuroscience

JANUARY 25, 2013

[The significance of high-resolution ultrasonography in the diagnosis of peripheral nerve disorders]

SCHEIDL Erika, JOSEF Böhm, FARBAKY Zsófia, DEBRECZENI Róbert, BERECZKI Dániel, ARÁNYI Zsuzsanna

[High resolution ultrasonography is an emerging technique for the investigation of peripheral nerves and is increasingly used worldwide in the diagnosis of peripheral nerve disorders, however, until now it is not widespread in Hungary. According to the literature this method is especially useful in entrapment neuropathies, traumatic peripheral nerve injuries, tumors of the peripheral nerves and sonographically guided interventions. Ultrasonography allows precise morphological analysis and quantitative measurements of the nerves providing useful complementary information to electrodiagnostic data. In entrapment neuropathies ultrasound shows nerve swelling mainly proximal to the sites of compression and a focal change of echotexture. On longitudinal scan, an abrupt caliber change and spindle-like swelling of the compressed nerve segment can be seen. Evaluation of the anatomical background and visualisation of the postoperative and posttraumatic changes provide useful information for planning of the therapy. Ultrasound may be of significant help in localizing the pathological nerve segment when it is at an electrophysiologically inaccessible site or when substantial secondary axonal loss precludes precise electrophysiological localization and it might even show pathological changes when nerve conduction studies are normal. Contrary to electrophysiological investigation ultrasonography might discover neurotmesis in the akute phase of traumatic nerve injuries indicating the necessity of surgical intervention. We provide a summary of the main indications and further application areas of this method.]

Clinical Neuroscience

SEPTEMBER 30, 2012

[Role of the intraoperative electrical brain stimulation in conserving the speech and language function in neurosurgical operations of awake patients]

ERÕSS Loránd, FEKETE Gábor, ENTZ László, FABÓ Dániel, BORBÉLY Csaba, KOZÁK Lajos Rudolf, ANDREJKOVICS Mónika, CZIRJÁK Sándor, FEDORCSÁK Imre, NOVÁK László, BOGNÁR László

[Aim of the study - To summarize the results gained with awake craniotomies, which were performed in either low grade glioma patients or epilepsy surgical patients whose tumor or epileptogenic zone, was in the vicinity of eloquent, mostly language, cortices. Patient selection and methods - In our retrospective study we selected 16 patients who were operated awake between 1999-2011 at the Neurosurgical Department of MÁV Kórház Budapest, or at the National Institute of Neurosciences in Budapest, or at the Neurosurgical Department of the University of Debrecen in Debrecen. In the presurgical evaluation if it was possible we performed functional magnetic resonance imaging, tractography and detailed neuropsychological testing. At the National Institute of Neurosciences all patients were operated with the aid of MR guided neuronavigation. Results - Anesthesia was carried out without complications in all of the 16 cases. Monitoring of sleep deepness has significantly contributed to the safety of anesthesia during the superficial anesthezied states of the operation. The intraoperative neuropsychological tasks used for testing language were sensitive enough to judge the little disturbances in speech during stimulation. Stimulation evoked seizures could be adequately managed during surgery and did not influence the outcome of the procedures. The use of neuronavigation helped significantly by planning the optimal place for the craniotomy and by intraoperative orientation. Conclusions - Awake craniotomies require well practiced surgical teams, which requires the cooperation of neuro-anesthesiologits, neurosurgeons, neuropsychologist and electrophysiologists. It has two goals, first to reduce the time of surgery to minimize surgical complications, secondly the detailed intraoperative mapping of cognitive and motor functions to avoid any neurological deficit. The intraoperative anatomical data provided by the neuronavigation and the functional data provided by awake intraoperative stimulation of the patient together serve the safety of the patient which is essential in the neurologically minimal invasive neurosurgical approach of the 21st century.]

Clinical Neuroscience

JULY 30, 2012

[Endoscopic, posterior transseptal pituitary surgery - Learning curve of the surgical technique and equipment in 61 operations]

BELLA Zsolt, FÜLÖP Béla, CSAJBÓK Éva, MAGONY Sándor, VALKUSZ Zsuzsa, HERCZEGH Szilvia, JÓRI József, BODOSI Mihály, CZIGNER Jenő, BARZÓ Pál

[Introduction - The removal of hypophyseal tumor by transsphenoidal pituitary surgery using microsurgical instruments was first performed over 100 years ago. Operating techniques for this surgery are constantly being renewed, first by using a microscope and later on with the use of an endoscop. The authors provide an overview of the minimal invasive posterior transseptal-transsphenoidal aproach with the combined utilization of classical techniques with the assistance of the endoscop. Method - Sixty-one patients (33 female, 28 male, 21-84 yrs) were treated for sellar region tumor resection using an endonasal transsphenoidal aproach with the help of an endoscop. Follow ups were performed within 2-21 months. Results - Total tumor resection was successful in 91.8%, and partial resection in 8.2% of the patients. The rate of complications using the endoscop method was not higher compared to that of the classical microscopic method. There was no major bleeding in any of the cases. Adverse events such as minor epistaxis occurred in 4.9%, transitional diabetes insipidus in 6.5%, inraoperative CSF leak in 16.67%, postoperative CSF leak in 11.5% and meningitis in 8.2% of the patients. After the operation the pathological hormonal production stoped in all patients except in two patients who were acromegalic. However their GH level normalized and they did not require further treatment, the IGF-1 still remained high. Conclusion - The success of the surgical treatment is based on both, the proficient pre- and postoperative endocrinological care, and the minimal invasive surgical technique. The endoscop was used partially or continuously during the operation for better visualization of the operation field in multiple angles (30°, 45°). It was useful in differentiating between normal and tumorous glandular tissue, and also offered an enhanced view of the intrasellar (via hydroscopy) and parasellar region. Moreover the endoscopic method is able to decrease the operating time, reduce blood loss. In different stages of the surgery, depending on the anatomical and pathological situation, switching back and forth from microscope to endoscop technique, gives us the benefit of a clearer view in each situation.]