Modulating Visuomotor Sequence Learning by Repetitive Transcranial Magnetic Stimulation: What Do We Know So Far?

Predictive processes and numerous cognitive, motor, and social skills depend heavily on sequence learning. The visuomotor Serial Reaction Time Task (SRTT) can measure this fundamental cognitive process. To comprehend the neural underpinnings of the SRTT, non-invasive brain stimulation stands out as one of the most effective methodologies. Nevertheless, a systematic list of considerations for the design of such interventional studies is currently lacking. To address this gap, this review aimed to investigate whether repetitive transcranial magnetic stimulation (rTMS) is a viable method of modulating visuomotor sequence learning and to identify the factors that mediate its efficacy. We systematically analyzed the eligible records (n = 17) that attempted to modulate the performance of the SRTT with rTMS. The purpose of the analysis was to determine how the following factors affected SRTT performance: (1) stimulated brain regions, (2) rTMS protocols, (3) stimulated hemisphere, (4) timing of the stimulation, (5) SRTT sequence properties, and (6) other methodological features. The primary motor cortex (M1) and the dorsolateral prefrontal cortex (DLPFC) were found to be the most promising stimulation targets. Low-frequency protocols over M1 usually weaken performance, but the results are less consistent for the DLPFC. This review provides a comprehensive discussion about the behavioral effects of six factors that are crucial in designing future studies to modulate sequence learning with rTMS. Future studies may preferentially and synergistically combine functional neuroimaging with rTMS to adequately link the rTMS-induced network effects with behavioral findings, which are crucial to develop a unified cognitive model of visuomotor sequence learning.

[Isolated IgG4 hypertrophic pachymeningitis with cranial nerve involvement].

IgG4-related (IgG4-RD) disease is a relatively newly identified, chronic autoimmune disorder that can affect any organ system. The disease is relatively rare. It has mostly systemic presentation, however it can also appear in isolated form in one single organ. In our report, we demonstrate an elderly male patient's case with IgG4-RD presented in the form of diffuse meningeal inflammation and hypertrophic pachymeningitis with one-sided cranial nerve and intraventricular involvement.

[Follow up examination of multiple sclerosis patients treated with alemtuzumab in Multiple Sclerosis Centre, Szeged]. / Alemtuzumabterápiával kezelt sclerosis multiplexes betegek követéses vizsgálata a szegedi Sclerosis Multiplex Centrumban.

Background and purpose: Therapeutic strategy of relapse-remitting multiple sclerosis has changed significantly during the past decade. While earlier escalating therapy was widely applied, recently, in case of high disease activity, induction therapy has become available. Methods: In our study, we processed the data of our alemtuzumab treated patients from our register. Alte-ra-tions in relapse rate and MRI activity due to the treatment were determined. These data were compared in patients treated with alemtuzumab as an escalating and as an induction therapy. We noted the observed side effects. Results: The 49 patients observed in the study had undergone two cycles of alemtuzumab therapy. The drug was applied as an induction therapy in 9 cases. Average relapse rate during the two years was 1.4±1.0, which decreased to 0.1±0.3 in the two years following the therapy. The average EDSS before therapy was 2.7±2.2 in the induction therapy group and 2.7±1.7 in the escalating therapy group. After the treatment, this score decreased to 1.6±0.6 and 2.5±1.8 in the induction and the escalating therapy group, respectively. We found clinical and MRI progression in case of 4 patients. As regards to side effects, cytokine release was detected in 51.0% of the patients following the first cycle, and 24.5% of the patients following the second cycle of the therapy. Infection related to the therapy was observed in 28.6%, while autoimmune thyreoiditis was diagnosed in 18.3% of the patients. Conclusion: The tight follow-up of the treated patients and the precise documentation of the register enable the comparison of results yielded by placebo controlled clinical studies with daily practice, as well as to gain information on the benefits of induction therapy as a paradigm shift in treating MS patients.

The safety and efficacy of fingolimod: Real-world data from a long-term, non-interventional study on the treatment of RRMS patients spanning up to 5 years from Hungary.

BACKGROUND: Fingolimod was approved and reimbursed by the healthcare provider in Hungary for the treatment of highly active relapsing-remitting multiple sclerosis (RRMS) in 2012. The present study aimed to assess the effectiveness, safety profile, and persistence to fingolimod in a real-life setting in Hungary in RRMS patients who were either therapy naïve before enrollment or have changed to fingolimod from another disease-modifying therapy (DMT) for any reason. METHODS: This cross-sectional, observational study with prospective data collection was performed nationwide at 21 sites across Hungary. To avoid selection bias, sites were asked to document eligible patients in consecutive chronological order. Demographic, clinical, safety and efficacy data were analysed for up to 5 years from 570 consenting adult patients with RRMS who had received treatment with fingolimod for at least one year. RESULTS: 69.6% of patients remained free from relapses for the whole study duration; in the first year, 85.1% of patients did not experience a relapse, which rose to 94.6% seen in the 5th year. Compared to baseline at study end, 28.2% had higher, and 9.1% had lower, meanwhile, 62.7% of the patients had stable EDSS scores. Overall, the annualized relapse rate decreased from 0.804 observed at baseline to 0.185, 0.149, 0.122, 0.091, and 0.097 (77.0%, 82.1%, 85.2%, 89.7%, and 89.0% relative reduction, respectively) after 1, 2, 3, 4, and 5 years of treatment. The greatest reduction rate was seen in the group of therapy naïve patients. Treatment persistence on fingolimod after 60 months was 73.4%. CONCLUSION: In this nationwide Hungarian cohort, most patients under fingolimod treatment were free from relapses and disability progression. In addition, fingolimod has proven to be a well-tolerated DMT that has sustained its manageable safety profile, high efficacy, and positive benefit/risk ratio for up to 5 years in a real-life setting.

Emerging Biomarkers of Multiple Sclerosis in the Blood and the CSF: A Focus on Neurofilaments and Therapeutic Considerations.

INTRODUCTION: Multiple Sclerosis (MS) is the most common immune-mediated chronic neurodegenerative disease of the central nervous system (CNS) affecting young people. This is due to the permanent disability, cognitive impairment, and the enormous detrimental impact MS can exert on a patient's health-related quality of life. It is of great importance to recognise it in time and commence adequate treatment at an early stage. The currently used disease-modifying therapies (DMT) aim to reduce disease activity and thus halt disability development, which in current clinical practice are monitored by clinical and imaging parameters but not by biomarkers found in blood and/or the cerebrospinal fluid (CSF). Both clinical and radiological measures routinely used to monitor disease activity lack information on the fundamental pathophysiological features and mechanisms of MS. Furthermore, they lag behind the disease process itself. By the time a clinical relapse becomes evident or a new lesion appears on the MRI scan, potentially irreversible damage has already occurred in the CNS. In recent years, several biomarkers that previously have been linked to other neurological and immunological diseases have received increased attention in MS. Additionally, other novel, potential biomarkers with prognostic and diagnostic properties have been detected in the CSF and blood of MS patients. AREAS COVERED: In this review, we summarise the most up-to-date knowledge and research conducted on the already known and most promising new biomarker candidates found in the CSF and blood of MS patients. DISCUSSION: the current diagnostic criteria of MS relies on three pillars: MRI imaging, clinical events, and the presence of oligoclonal bands in the CSF (which was reinstated into the diagnostic criteria by the most recent revision). Even though the most recent McDonald criteria made the diagnosis of MS faster than the prior iteration, it is still not an infallible diagnostic toolset, especially at the very early stage of the clinically isolated syndrome. Together with the gold standard MRI and clinical measures, ancillary blood and CSF biomarkers may not just improve diagnostic accuracy and speed but very well may become agents to monitor therapeutic efficacy and make even more personalised treatment in MS a reality in the near future. The major disadvantage of these biomarkers in the past has been the need to obtain CSF to measure them. However, the recent advances in extremely sensitive immunoassays made their measurement possible from peripheral blood even when present only in minuscule concentrations. This should mark the beginning of a new biomarker research and utilisation era in MS.

Genetic epidemiological characteristics of a Hungarian subpopulation of patients with Huntington's disease.

BACKGROUND: Recent advances in therapeutic options may prevent deterioration related to Huntington's disease (HD), even at the pre-symptomatic stage. Be that as it may, a well-characterized patient population is essential for screening and monitoring outcome. Accordingly, the aim of this study was to describe the characteristics of a Hungarian subpopulation of HD patients and mutation carriers diagnosed at the University of Szeged. METHODS: We conducted a search for International Classification of Diseases (ICD) code G10H0 in the local medical database for the period of 1 January 1998 to 31 December 2018. RESULTS: We identified 90 HD cases (male: 45, female: 45) and 34 asymptomatic carriers (male: 15, female: 19). The median age of onset was 45 years (range: 16-79). There were 3 cases of juvenile onset (3.3%), and 7 of late disease onset (7.8%). The median repeat length was 43 (range: 36-70) for the pathological and 19 for the non-pathological alleles (range: 9-35). 17.5% of the pathological alleles were in the decreased penetrance range, while 7% of non-pathological alleles were intermediate. CONCLUSIONS: The genetic and clinical features of the population examined in the present study were in line with the previous Hungarian study, as well as with international literature. The exceptions were the higher ratio of reduced penetrance and intermediate alleles.

Stepwise occlusion of the carotid arteries of the rat: MRI assessment of the effect of donepezil and hypoperfusion-induced brain atrophy and white matter microstructural changes.

Bilateral common carotid artery occlusion (BCCAo) in the rat is a widely used animal model of vascular dementia and a valuable tool for preclinical pharmacological drug testing, although the varying degrees of acute focal ischemic lesions it induces could interfere with its translational value. Recently, a modification to the BCCAo model, the stepwise occlusion of the two carotid arteries, has been introduced. To acquire objective translatable measures, we used longitudinal multimodal magnetic resonance imaging (MRI) to assess the effects of semi-chronic (8 days) donepezil treatment in this model, with half of the Wistar rats receiving the treatment one week after the stepwise BCCAo. With an ultrahigh field MRI, we measured high-resolution anatomy, diffusion tensor imaging, cerebral blood flow measurements and functional MRI in response to whisker stimulation, to evaluate both the structural and functional effects of the donepezil treatment and stepwise BCCAo up to 5 weeks post-occlusion. While no large ischemic lesions were detected, atrophy in the striatum and in the neocortex, along with widespread white matter microstructural changes, were found. Donepezil ameliorated the transient drop in the somatosensory BOLD response in distant cortical areas, as detected 2 weeks after the occlusion but the drug had no effect on the long term structural changes. Our results demonstrate a measurable functional MRI effect of the donepezil treatment and the importance of diffusion MRI and voxel based morphometry (VBM) analysis in the translational evaluation of the rat BCCAo model.

Task-related temporal and topographical changes of cortical activity during ultra-rapid visual categorization.

The aim of our study was to provide electrophysiological evidence about the modulation of the categorization process by task requirements in the human brain. Event-related potentials (ERP) were recorded during three different categorization tasks using matched stimulus sets. In all cases, the subjects were required to differentiate between "animal" and "non-animal" stimuli. In the first task (two-choice task), they were asked to press corresponding buttons to each stimulus types. The second task was a go/no-go paradigm, only animal stimuli required motor response. The third task was a counting task; participants had to count the animal stimuli without any motor response. The reaction times in the go/no-go paradigm were significantly shorter. ERP differences between animal and non-animal pictures in the go/no-go task also appeared earlier and were localized at more posterior scalp positions compared to the two-choice task. Comparing animal responses in the two-choice task and in the go/no-go paradigm, we found a significant difference in the 130- to 170-ms time window over the fronto-central, centro-parietal regions. Similar differences were found between the responses to animal pictures in the two-choice task and in the counting paradigm. We used brain electric source analysis (BESA) algorithm on difference waves to localize the best fitting dipoles and determine the localization of brain areas contributing to scalp potential differences. The results show that different task requirements evoke different activity in the medial part of the temporal pole. The data we provided here draw attention to the careful handling of results obtained from categorization experiments, because different task requirements can affect the early categorization process itself.

Lactate infusion fails to improve semantic categorization in Alzheimer's disease.

Impaired neuronal energy metabolism, oxidative changes and microvascular abnormalities lead to altered lactate levels in Alzheimer's dementia. The aim of the present study was to assess whether intravenous sodium-lactate, a metabolic alternative and vasodilator that is thought to improve cognition, advances the cognitive performance of Alzheimer patients. Semantic categorization paradigm was used to present the electrophysiological correlates of natural scene categorization of Alzheimer patients before and after intravenous saline or sodium-lactate infusion. Mean amplitudes of event-related potentials (ERPs) were measured in two time windows before and after the treatments; two negative components (N1 between 150 and 250 ms and N2 between 400 and 600 ms) and one positive component (P2 between 250 and 400 ms) were identified. The negative components were more negative for the non-animal trials than for the animal trials while the positive component was similar for both categories. After the lactate treatment the amplitudes of the negative components became more negative mainly for the non-animal trials while the amplitude of the positive component turned more positive for the animal trials, however these changes were not significant. No changes have been observed after normal saline infusion. These results suggest that, contrary to its anticipated beneficial effects, sodium-lactate fails to significantly improve semantic categorization processes in Alzheimer's disease and this enhancement can be detected by recording ERPs. The effect of sodium-lactate to slightly improve semantic memory might be based on its positive effect on cardio- and cerebro-vascular function and neuronal metabolism.