Clinical Neuroscience

[Hungarian Epilepsy League]

SZUPERA Zoltán

JANUARY 30, 2006

Clinical Neuroscience - 2006;59(01-02)

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Clinical Neuroscience

[The potential role of spinal ketamine in multi-component antinociception]

JOÓ Gabriella

Clinical Neuroscience

[A NEURO-MECHANICAL TRANSDUCER MODEL FOR CONTROLLING JOINT ROTATIONS AND LIMB MOVEMENTS]

LACZKÓ József, KERRY Walton, RODOLFO Llinas

[Here we report on the development of an integrated general model for the control of limb movements. The model computes muscle forces and joint rotations as functions of activation signals from motoneuron pools. It models the relationship between neural signals, muscle forces and movement kinematics by taking into account how the discharge rates of motoneuron pools and the biomechanical characteristics of the musculoskeletal system affect the movement pattern that is produced. The lengths and inertial properties of limb segments, muscle attachment sites, the muscles’ force-length, force-frequency and force-velocity (of contraction) relationships, as well as a load parameter that simulates the effect of body weight are considered. There are a large number of possible ways to generate a planned joint rotation with muscle activation. We approach this “overcompleteness problem” by considering each joint to be controlled by a single flexor/extensor muscle pair and that only one of the two muscles is activated at a given time. Using this assumption, we have developed an inverse model that provides discharge rates of motoneuron pools that can produce an intended angular change in each joint. We studied the sensitivity of this inverse model to the muscle force-length relationship and to limb posture. The model could compute possible firing rates of motoneuron pools that would produce joint angle changes observed in rats during walking. It could also compare motoneuron activity patterns received for two different hypothetical force-length relations and show how the motoneuron pool activity would change if joints would be more flexed or extended during the entire movement.]

Clinical Neuroscience

[Hungarian Society of Clinical Neurophysiology]

SZUPERA Zoltán

Clinical Neuroscience

[COMPLEX TREMOR ANALYSIS FOR THE DIFFERENTIAL DIAGNOSIS OF ESSENTIAL TREMOR AND PARKINSON’S DISEASE]

FARKAS Zsuzsanna, CSILLIK Anita, PÁLVÖLGYI László, TAKÁCS Annamária, SZIRMAI Imre, KAMONDI Anita

[Objective - Tremor is the most common movement disorder which is most often either essential or caused by Parkinson’s disease. The differentiation of these disorders at the initial stage may be difficult. Objective assessment of the efficacy of tremor medications is only possible by instrumental measurements. The aim of this study was to determine whether the computer assisted tremor analysis system CATSYS 2000 can help in the differentiation of parkinsonian from essential tremor. Methods - The rhythmicity and maximal frequency of fast alternating hand and finger movements, simple reaction time and postural instability were recorded in healthy controls (n=18), patients with Parkinson’s disease (n=39) and essential tremor (n=37). Data were digitally converted and statistically analyzed. Results - Tremor intensity, median frequency and frequency distribution showed characteristic differences in the three groups. Performance in fast alternating movements of hands and fingers were significantly worse in both tremor groups compared to the healthy controls. Conclusions - The data also indicated that quantitative measurements of tremor parameters must be performed on both sides, because the presence of significant side differences support the diagnosis of Parkinson’s disease. The method presented can be used to objectively analyze tremor and performance in rhythmic movements. The results show that it helps to differentiate parkinsonian from essential tremor as well as to predict disease course and the effectiveness of therapy. Multivariate statistical analysis of tremor and movement performance also provides an opportunity to study the pathogenesis of human tremor.]

Clinical Neuroscience

[Hungarian Neurosurgical Society]

AZ Idegsebészeti Szakmai Kollégium

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Clinical Neuroscience

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

[Advanced Parkinson’s disease characteristics in clinical practice: Results from the OBSERVE-PD study and sub-analysis of the Hungarian data]

TAKÁTS Annamária, ASCHERMANN Zsuzsanna, VÉCSEI László, KLIVÉNYI Péter, DÉZSI Lívia, ZÁDORI Dénes, VALIKOVICS Attila, VARANNAI Lajos, ONUK Koray, KINCZEL Beatrix, KOVÁCS Norbert

[The majority of patients with advanced Parkinson’s disease are treated at specialized movement disorder centers. Currently, there is no clear consensus on how to define the stages of Parkinson’s disease; the proportion of Parkinson’s patients with advanced Parkinson’s disease, the referral process, and the clinical features used to characterize advanced Parkinson’s disease are not well delineated. The primary objective of this observational study was to evaluate the proportion of Parkinson’s patients identified as advanced patients according to physician’s judgment in all participating movement disorder centers across the study. Here we evaluate the Hungarian subset of the participating patients. The study was conducted in a cross-sectional, non-interventional, multi-country, multi-center format in 18 countries. Data were collected during a single patient visit. Current Parkinson’s disease status was assessed with Unified Parkinson’s Disease Rating Scale (UPDRS) parts II, III, IV, and V (modified Hoehn and Yahr staging). Non-motor symptoms were assessed using the PD Non-motor Symptoms Scale (NMSS); quality of life was assessed with the PD 8-item Quality-of-Life Questionnaire (PDQ-8). Parkinson’s disease was classified as advanced versus non-advanced based on physician assessment and on questions developed by the Delphi method. Overall, 2627 patients with Parkinson’s disease from 126 sites were documented. In Hungary, 100 patients with Parkinson’s disease were documented in four movement disorder centers, and, according to the physician assessment, 50% of these patients had advanced Parkinson’s disease. Their mean scores showed significantly higher impairment in those with, versus without advanced Parkinson’s disease: UPDRS II (14.1 vs. 9.2), UPDRS IV Q32 (1.1 vs. 0.0) and Q39 (1.1 vs. 0.5), UPDRS V (2.8 vs. 2.0) and PDQ-8 (29.1 vs. 18.9). Physicians in Hungarian movement disorder centers assessed that half of the Parkinson’s patients had advanced disease, with worse motor and non-motor symptom severity and worse QoL than those without advanced Parkinson’s disease. Despite being classified as eligible for invasive/device-aided treatment, that treatment had not been initiated in 25% of these patients.]

Clinical Neuroscience

[Zonisamide: one of the first-line antiepileptic drugs in focal epilepsy ]

JANSZKY József, HORVÁTH Réka, KOMOLY Sámuel

[Chronic administration of antiepileptic drugs without history of unprovoked epileptic seizures are not recommended for epilepsy prophylaxis. Conversely, if the patient suffered the first unprovoked seizure, then the presence of epileptiform discharges on the EEG, focal neurological signs, and the presence of epileptogenic lesion on the MRI are risk factors for a second seizure (such as for the development of epilepsy). Without these risk factors, the chance of a second seizure is about 25-30%, while the presence of these risk factors (for example signs of previous stroke, neurotrauma, or encephalitis on the MRI) can predict >70% seizure recurrence. Thus the International League Against Epilepsy (ILAE) re-defined the term ’epilepsy’ which can be diagnosed even after the first seizure, if the risk of seizure recurrence is high. According to this definition, we can start antiepileptic drug therapy after a single unprovoked seizure. There are four antiepileptic drugs which has the highest evidence (level „A”) as first-line initial monotherapy for treating newly diagnosed epilepsy. These are: carbamazepine, phenytoin, levetiracetam, and zonisamide (ZNS). The present review focuses on the ZNS. Beacuse ZNS can be administrated once a day, it is an optimal drug for maintaining patient’s compliance and for those patients who have a high risk for developing a non-compliance (for example teenagers and young adults). Due to the low interaction potential, ZNS treatment is safe and effective in treating epilepsy of elderly people. ZNS is an ideal drug in epilepsy accompanied by obesity, because ZNS has a weight loss effect, especially in obese patients.]

Clinical Neuroscience

Effects of valproate, carbamazepine and levetiracetam on Tp-e interval, Tp-e/QT and Tp-e/QTc ratio

YASAR Altun, ERDOGAN Yasar

Aim - To evaluate P-wave dispersion before and after antiepileptic drug (AED) treatment as well as to investigate the risk of ventricular repolarization using the Tpeak-Tend (Tp-e) interval and Tp-e/QT ratio in patients with epileptic disorder. Methods - A total of 63 patients receiving AED therapy and 35 healthy adults were included. ECG recordings were obtained before and 3 months after anti-epileptic treatment among patients with epilepsy. For both groups, Tp-e and Tp-e/QT ratio were measured using a 12-lead ECG device. Results - Tp-e interval, Tpe/QT and Tp-e/QTc ratios were found to be higher in the patient group than in the control group (p<0.05, for all), while QTmax ratio was significantly lower in the patient group. After 3 months of AED therapy, significant increases in QT max, QTc max, QTcd, Tp-e, Tp-e/QT, and Tp-e/QTc were found among the patients (p<0.05). When the arrhythmic effects of the drugs before and after treatment were compared, especially in the valproic acid group, there were significant increases in Tp-e interval, Tp-e/QT and Tp-e/QTc values after three months of treatment (p<0.05). Carbamazepine and levetiracetam groups were not statistically significant in terms of pre- and post-treatment values. Conclusions - It was concluded that an arrhythmogenic environment may be associated with the disease, and patients who received AED monotherapy may need to be followed up more closely for arrhythmia.

Lege Artis Medicinae

[Thiazide- or thiazide-like diuretics should be used in the treatment of patients with hypertension? Particularities of the situation in Hungary]

VÁLYI Péter

[Diuretics have remained the cornerstone of the antihypertensive treatment since their widespreading in the 1960s. According to the 2018 ESC/ESH Guidelines for the management of arterial hypertension, in the absence of evidence from direct comparator trials and recognizing that many of the approved single-pill combinations are based on hydrochlorothiazide, this drug and thiazide-like indapamide can be considered suitable antihypertensive agents. In the 2018 Hungarian guidelines indapamide is named as the most efficacious diuretic in the treatment of patients with hypertension. The aim of the publication is redefining thiazide- and thiazide-like diuretic use in the treatment of hypertensive patients, with particular attention to presently available hydrochlorothia­zide and indapamide, and their combination drugs in Hungary.]