Clinical Neuroscience

[Mechanism of the “dark” axonal degeneration in the central nervous system]

PÁL József, GALLYAS Ferenc

SEPTEMBER 30, 2014

Clinical Neuroscience - 2014;67(09-10)

[Background and purpose - In the central nervous tissue, two types of transsection-resulted axonal degeneration are generally accepted: “watery” and “dark”. The present paper deals with the assumption that the mechanism of this kind of “dark” axonal degeneration has a relationship with that of the “dark” neuronal degeneration. Methods - A minute stab wound is inflicted in the parietal cortex of the rat brain. From 1 h to 3 months postinjury, the resulted ultrastructural events in two distant regions of the corticospinal tract (internal capsule and C3 region of the corticospinal tract) are studied. Results - As a novel finding, the first morphological process of “dark” axonal degeneration was found to consists in a striking reduction of the distances between neighboring neurofilaments, which were readily distinguishable and apparently undamaged. This pattern (compacted ultrastructure) persisted for hours. By day 1 postinjury, the compacted axoplasmic elements aggregated into a homogenous and dense (“dark”) mass in which hardly any ultrastructural elements could be distinguished. Surrounded by apparently normal or mildly abnormal myelin sheat, this mass underwent a non-isotropic shrinkage during the next three months. Morphological signs of phagocytosis were insignificant. Conclusion - The ultrastructural events during the first day post-injury suggest a non-enzymatic mechanism as an alternative to the prevailing molecular-biological mechanism.]



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Clinical Neuroscience

[Grey matter atrophy in patients suffering from multiple sclerosis]

KINCSES Tamás Zsigmond, TÓTH Eszter, BANKÓ Nóra, VERÉB Dániel, SZABÓ Nikoletta, CSETE Gergő, FARAGÓ Péter, KIRÁLY András, BENCSIK Krisztina, VÉCSEI László

[White matter lesions are defining characteristics of multiple sclerosis (MS), whereas grey matter involvement is a less recognised attribute. Recent investigations using dedicated imaging approaches have made it possible to depict cortical lesions. Additionally, grey matter atrophy may be estimated using various methods. Several studies have suggested that grey matter atrophy closely correlates to clinical disability. In this review we have collected information on grey matter atrophy in MS and the effect of disease modifying therapies upon brain atrophy.]

Clinical Neuroscience

[The relevance of traumatic life events in schizophrenia spectrum disorders]


[The central goal of this manuscript was to review literature about the interconnections of traumatic life events and symptoms of schizophrenia spectrum of the last 15 years. First of all, the stress-diathesis model and the traumagenic neurodevelopmental model are shortly presented. Psychological effects of traumas and specific psychotic symptoms in connection with traumatic events are discussed. The course of the disease in patients affected by previous traumas and possible mediating factors are also addressed. Studies of both clinical and community samples are cited. It was also our aim to review literature about the neurobiological and neurocognitive processes in people affected by schizophrenia and/or traumatic life events. The role of prefrontal and medial temporal regions are explored with a special emphasis on contextual memory and hippocampal functioning. Finally, the possible effects of exploring traumatic life events on the treatment of schizophrenia are discussed.]

Clinical Neuroscience

[Complex approaches to study complex trait genetics in multiple sclerosis]


[Multiple sclerosis (MS) is a complex trait disorder defined by several genes and their interactions with environmental factors. A comprehensive exploration of the susceptibility variants had not been feasible until recently when new developments in biotechnology and bioinformatics made possible sequencing of the whole human genome, cataloguing of nucleotide variants and alignments of these variants in haplotypes. Earlier observations from epidemiological, candidate gene and linkage studies provided ample evidence to support a complex genetic determination of MS. New biotechnology and bioinformatics resources have been recently applied to further successful explorations of the disease. These efforts were paralleled by more careful and reliable ascertainments of disease phenotypes, collaborations among specialized centers to generate sufficient sample size and involvement of clinician-scientists capable of working both on the clinical and scientific study sides. Data obtained from the whole genome association studies (GWAS) elevated our understanding of MS genetics to a new level by identifying an extensive list of genetic determinants. Pathway analyses of MS-associated variants provided evidence to support the immune etiology of the disease. Future research will likely explore how environmental factors interact with the genome, and contribute to the abnormal immune activation and inflammation. This review summarizes the outcomes of MS genetic explorations including those of recent GWAS, and highlights practical consequences of genetic and genomic studies by pointing out as to how the derived data facilitate further elucidation of MS pathogenesis. A better understanding of disease processes is necessary for future advancements in therapeutics and the development of disease prevention strategies.]

Clinical Neuroscience

[P-wave dispersion doesn’t increase in patients with epilepsy]

SENOL Güney Mehmet, ÖZMEN Namik, YASAR Halit, TEKELI Hakan, ÖZDAG Fatih, SARACOGLU Mehmet

[Aim - Epileptic seizures have occasionally been associated with cardiac conditions as atrioventricular blocks, long QT syndrome etc. P-wave dispersion (PWD), which is the difference between the longest (P max) and shortest P-wave duration (P min), is considered as a forerunner of atrial fibrillation. In this study, we investigated P-wave dispersion (PWD) in epileptic patients; based on the hypothesis that microthromboembolism may occur in atrial fibrillation. Methods - Seventy five patients with mixed types of epilepsy and 50 age and sex matched healthy individuals were included into the study. P max, P min and PWD values were calculated for each subject from an ECG. Results - The mean age of subjects in the epilepsy group and control group were similar (p>0.05). P max in patients with epilepsy was 125.1±0.7 ms, P min was 67.3±10.3 ms, and PWD was 57.6±8.3 ms while these values in the control group were 116.8±11.0 ms, 66.5±5.5 ms and 46.8±7.1 ms, respectively. There were no statistically significant difference between two groups (p>0.05). Conclusions - PWD does not increase in patients with mixed types of epilepsy. Therefore we believe that microthromboembolism duo to atrial fibrillation can’t cause epileptic seizures in patients with no structural heart disease.]

Clinical Neuroscience

[Retinal ganglion cell layer and visual function in patients with progressive external ophthalmoplegia caused by common mtDNA deletion]

FARZANEH Naghizadeh, VARGA Edina Tímea, MOLNÁR Mária Judit, HOLLÓ Gábor

[Aim - Mitochondrial (mt) disorders are metabolic conditions with multiorgan involvement, which often cause neuroophtalmological symptoms. The aim of the study was to investigate the relation between progressive external ophthalmoplegia (PEO), visual pathway and mitochondrial DNA (mtDNA) mutations in patients younger than 55 years of age. Methods - Five female patients (35 to 53 years of age) with mithochondrial disease were investigated. Automated threshold perimetry (Octopus G2 test), scanning laser polarimetry (GDx-VCC and GDx-ECC) and Fourier-domain optical coherence tomography (RTVue-100 OCT) were used in addition to detailed ophthalmological examination and evaluation of visually evoked potentials (VEP). Frequent mutations of the mtDNA were investigated in the patients’ blood and muscle samples. Results - PEO of various severity levels was found in all patients, using clinical tests. Genetic testing showed “common deletion” of mtDNA in all cases. For both eyes of 4 patients functional and structural ophthalmic tests had normal results. In one patient decreased visual acuity, reduced retinal nerve fiber layer thickness and prolonged L3 VEP latency time were found without optic disc damage and visual field deterioration. Conclusion - In 4 of our 5 patients with PEO due to common deletion of mtDNA retinal ganglion cells and visual function remained normal for a long period of life.]

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Clinical Neuroscience


ARÁNYI Zsuzsanna

[Transcranial magnetic stimulation (TMS) is a relatively new technique that allows painless activation of cortical motor neurons. In the clinical setting, TMS is primarily used for the investigation of the corticospinal tract in various neurological diseases, being especially useful in the detection of subclinical dysfunction. In addition to the motor cortex, TMS can be applied to examine other structures inaccessible to electrical stimulation, such as the canalicular portion of the facial nerve. In healthy individuals, TMS can be utilized to monitor excitability changes of the motor system in various situations and muscles, providing valuable information to the understanding of the physiology of motor control. Furthermore, TMS can be used to explore interhemispheric connections as well as intracortical inhibitory and excitatory processes both in health and disease. Finally, with the help of TMS cortical maps of the representation areas of muscles can be constructed, giving insight to both short and long-term cortical plasticity and to the reorganisation of the motor cortex following damage to the brain or acquisition of new motor skills]

Clinical Neuroscience

[What happens to vertiginous population after emission from the Emergency Department?]

MAIHOUB Stefani, MOLNÁR András, CSIKÓS András, KANIZSAI Péter, TAMÁS László, SZIRMAI Ágnes

[Background – Dizziness is one of the most frequent complaints when a patient is searching for medical care and resolution. This can be a problematic presentation in the emergency department, both from a diagnostic and a management standpoint. Purpose – The aim of our study is to clarify what happens to patients after leaving the emergency department. Methods – 879 patients were examined at the Semmel­weis University Emergency Department with vertigo and dizziness. We sent a questionnaire to these patients and we had 308 completed papers back (110 male, 198 female patients, mean age 61.8 ± 12.31 SD), which we further analyzed. Results – Based on the emergency department diagnosis we had the following results: central vestibular lesion (n = 71), dizziness or giddiness (n = 64) and BPPV (n = 51) were among the most frequent diagnosis. Clarification of the final post-examination diagnosis took several days (28.8%), and weeks (24.2%). It was also noticed that 24.02% of this population never received a proper diagnosis. Among the population only 80 patients (25.8%) got proper diagnosis of their complaints, which was supported by qualitative statistical analysis (Cohen Kappa test) result (κ = 0.560). Discussion – The correlation between our emergency department diagnosis and final diagnosis given to patients is low, a phenomenon that is also observable in other countries. Therefore, patient follow-up is an important issue, including the importance of neurotology and possibly neurological examination. Conclusion – Emergency diagnosis of vertigo is a great challenge, but despite of difficulties the targeted and quick case history and exact examination can evaluate the central or peripheral cause of the balance disorder. Therefore, to prevent declination of the quality of life the importance of further investigation is high.]

Lege Artis Medicinae

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[Nonsteroidal antiinflammatory drugs (NSAIDs) are among the most frequently used pharmaceuticals. Nevertheless, a number of studies emphasized that NSAIDs were damaging not only the gastrointestinal (GI), but also the cardiovascular (CV) system, could increase the blood pressure, the frequency of coronary events (angina, myocardial infarction) and stroke incidence, as well as they might deterio­rate renal functions. The National Institute for Health and Care Excellence (NICE) did not find evidence that administering NSAIDs could increase the risk of developing COVID-19 or worsened the condition of COVID-19 patients. However, unwanted effects of specific drugs differ substantially in their occurrence and seriousness as well. It seemed to be for a long time that the NSAIDs provoked higher GI-risk was closely related to the COX1/COX2 selectivity, like the cardiovascular (CV) risk to the COX2/COX1 selectivity, however, the recent data did not prove it clearly. Based on the available literature while pondering the gastrointestinal and cardiovascular adverse events, among all NSAIDs the aceclofenac profile seemed to be the most favourable.]

Lege Artis Medicinae

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