Repetitive transcranial magnetic stimulation in murine models of epilepsy: A systematic review of methodological aspects and outcomes.

OBJECTIVES: Clinical studies of repetitive transcranial magnetic stimulation (rTMS) do not provide consistent efficacy results, possibly due to variability in methodological parameters. Our aim is to systematically review preclinical rTMS protocols in murine models of epilepsy, offering insights from might facilitate the optimization of clinical trials. METHODS: We searched MEDLINE, SCOPUS and Web of Science from inception until December 2023, including English-written and peer-reviewed studies with clinical or electroencephalographic (EEG) outcomes. RESULTS: Among 480 search results, in the 23 eligible studies both mice and rats were used. Epilepsy induction methods included injections of pentylenetetrazole, kainic acid, picrotoxin and lithium-pilocarpine, electrical kindling (amygdala/ventral hippocampus), electroconvulsive shock and genetic models of absence and temporal lobe epilepsy. For motor threshold (MT) definition electromyography with motor evoked potentials and single-pulse TMS were used. Stimulation intensity ranged between 40 % and 200 % of MT or 0.125-2.5 T. High-frequency rTMS (≥5 Hz) demonstrated either no effect on seizure suppression or a rather facilitatory effect, promoting ictogenesis, with the exception of 20-Hz-rTMS coupling with lorazepam for status epilepticus cessation. Low-frequency rTMS (<5 Hz), primarily at 0.5 and 1 Hz, exerted an inhibitory effect on both clinical and EEG parameters on various epilepsy models in most studies and also significantly ameliorated performance in behavioral tests. CONCLUSIONS: rTMS holds potential for effective neuromodulation, that is critically dependent on stimulation frequency and epilepsy type. Translational knowledge gained from preclinical protocols may inform and optimize rTMS application for epilepsy management in future clinical trials.

Auditory processing in patients with temporal lobe epilepsy: A systematic review and meta-analysis.

BACKGROUND: Hearing efficiency is known to influence and interact with communication and mental health. Hearing impairment may be hidden when co-occurring with neurological disorders. PURPOSE: We performed a systematic review and meta-analysis in order to address the following questions: 1) which specific tools of auditory processing show clear deficits, separating Temporal Lobe Epilepsy (TLE) patients from normal controls,2) How well is TLE evaluated in terms of hearing and auditory processing? METHODS: The study inclusion criteria were: 1) patients diagnosed with temporal lobe epilepsy, 2) presence of a normal control group, 3) auditory processing assessment using auditory stimuli with behavioral tests and/or P300 or Mitch Match Negativity (MMN) latency and/or amplitude, 4) publications written in English, 5) publication date after 2000. 132 articles were retrieved and based on PRISMA & PICO criteria 23 articles were analyzed. RESULTS: Temporal resolution and processing as measured by the behavioral tests of Gaps-In-Noise (GIN) and Duration Pattern Test (DPT) document deficiencies in TLE patients and separate them from normal controls. Electrophysiology as measured by MMN & P300 shows statistically significant differences in TLE patients compared to controls with patients showing deficient auditory processing. A clear difference between studies with psychoacoustic assessment as opposed to electrophysiology ones may be due to lacking or incomplete evaluation of peripheral hearing by gold standard tools (76.9% in electrophysiology studies). CONCLUSION: Auditory processing is deficient in patients with TLE. There is a clear need to evaluate hearing efficiency before proceeding to auditory processing evaluation with behavioral or electrophysiological tests.

Usage and impact of patient-reported outcomes in epilepsy.

BACKGROUND: The use of patient-reported outcomes (PRO) in clinical practice is gaining increasing attention. This study aimed to provide a critical assessment of the current state-of-the-art and beliefs about the use of PRO in the management of people with epilepsy across some European countries. METHODS: Structured interviews were conducted with European experts to collect insights about (I) the personal experience with PRO; (II) the value and impact of PRO in the decision-making process at the national level; and (III) the interest for and use of PRO by national health authorities. RESULTS: Nine neurologists (Austria, Belgium, Czechia, Denmark, France, Greece, Italy, Poland, and United Kingdom), three health economists (Portugal, Romania, and Sweden), and one epidemiologist (Slovakia) participated. They all stated that PRO are collected at their own countries in the context of clinical trials and/or specific projects. During everyday clinical practice, PRO are collected routinely/almost routinely in Austria and Sweden and only at the discretion of the treating physicians in Czechia, Denmark, France, Greece, and Portugal. There was complete consensus about the favorable impact that the PRO can have in terms of clinical outcomes, healthcare resources utilization, and general patient satisfaction. Only participants from Portugal and Sweden answered that the PRO are perceived as very important by the National Health Authorities of their respective countries. CONCLUSIONS: Differences exist in attitudes and perspectives about PRO in epilepsy across Europe. An active plan is warranted to harmonize the measurement of PRO and ensure they can be relevant to people with epilepsy and health services.

Therapeutic Biomarkers in Friedreich's Ataxia: a Systematic Review and Meta-analysis.

Although a large array of biomarkers have been investigated in Friedreich's ataxia (FRDA) trials, the optimal biomarker for assessing disease progression or therapeutic benefit has yet to be identified. We searched PubMed, MEDLINE, and EMBASE databases up to June 2023 for any original study (with ≥ 5 participants and ≥ 2 months' follow-up) reporting the effect of therapeutic interventions on any clinical, cardiac, biochemical, patient-reported outcome measures, imaging, or neurophysiologic biomarker. We also explored the biomarkers' ability to detect subtle disease progression in untreated patients. The pooled standardized mean difference (SMD) was calculated using a random-effects model. The study's protocol was registered in PROSPERO (CRD42022319196). In total, 43 studies with 1409 FRDA patients were included in the qualitative synthesis. A statistically significant improvement was observed in Friedreich Ataxia Rating Scale scores [combining Friedreich Ataxia Rating Scale (FARS) and modified FARS (mFARS): SMD = - 0.32 (- 0.62 to - 0.02)] following drugs that augment mitochondrial function in a sensitivity analysis. Left ventricular mass index (LVMI) was improved significantly [SMD = - 0.34 (- 0.5 to - 0.18)] after 28.5 months of treatment with drugs that augment mitochondrial function. However, LVMI remained stable [SMD = 0.05 (- 0.3 to 0.41)] in untreated patients after 6-month follow-up. None of the remaining biomarkers changed significantly following any treatment intervention nor during the natural disease progression. Nevertheless, clinical implications of these results should be interpreted with caution because of low to very low quality of evidence. Further randomized controlled trials of at least 24 months' duration using a biomarker toolbox rather than a single biomarker are warranted.

The evolution of comprehensive genetic analysis in neurology: Implications for precision medicine.

Technological advancements have facilitated the availability of reliable and thorough genetic analysis in many medical fields, including neurology. In this review, we focus on the importance of selecting the appropriate genetic test to aid in the accurate identification of disease utilizing currently employed technologies for analyzing monogenic neurological disorders. Moreover, the applicability of comprehensive analysis via NGS for various genetically heterogeneous neurological disorders is reviewed, revealing its efficiency in clarifying a frequently cloudy diagnostic picture and delivering a conclusive and solid diagnosis that is essential for the proper management of the patient. The feasibility and effectiveness of medical genetics in neurology require interdisciplinary cooperation among several medical specialties and geneticists, to select and perform the most relevant test according to each patient's medical history, using the most appropriate technological tools. The prerequisites for a comprehensive genetic analysis are discussed, highlighting the utility of appropriate gene selection, variant annotation, and classification. Moreover, genetic counseling and interdisciplinary collaboration could improve diagnostic yield further. Additionally, a sub-analysis is conducted on the 1,502,769 variation records with submitted interpretations in the Clinical Variation (ClinVar) database, with a focus on neurology-related genes, to clarify the value of suitable variant categorization. Finally, we review the current applications of genetic analysis in the diagnosis and personalized management of neurological patients and the advances in the research and scientific knowledge of hereditary neurological disorders that are evolving the utility of genetic analysis towards the individualization of the treatment strategy.

Biomarkers of therapeutic efficacy in adolescents and adults with 5q spinal muscular atrophy: a systematic review.

BACKGROUND: The therapeutic landscape of spinal muscular atrophy (SMA) was dramatically transformed with the introduction of three disease-modifying therapies (DMTs). A systematic review was performed to assess available evidence regarding quantitative therapeutic biomarkers used in SMA patients older than 11 years under treatment with DMTs. METHODS: Latest literature search in MEDLINE, EMBASE, Cochrane databases and gray literature resources was performed in June 2021. Studies reporting only motor function or muscle strength scales or pulmonary function tests were excluded. Primary outcome was the change from baseline score of any serum, cerebrospinal fluid (CSF) or neurophysiologic biomarker examined. RESULTS: Database and gray literature search yielded a total of 8050 records. We identified 14 records published from 2019 until 2021 examining 18 putative serum, CSF or neurophysiologic biomarkers along with routine CSF parameters in 295 SMA nusinersen-treated type 2-4 patients older than 11 years of age. There is evidence based on real-world observational studies suggesting that serum creatinine, creatine kinase activity levels along with CSF Αß42, glial fibrillary acidic protein concentration as well as ulnar compound motor action potential amplitude and single motor unit potential amplitude changes may depict therapeutic response in this population. CONCLUSION: This systematic review explored for the first-time biomarkers used to monitor therapeutic efficacy in SMA adolescents and adults treated with DMTs. Research in this area is in its early stages, and our systematic review can facilitate selection of quantitative therapeutic biomarkers that may be used as surrogate measures of treatment efficacy in future trials. PROTOCOL REGISTRATION: PROSPERO CRD42021245516.

Detailed measurements and simulations of electric field distribution of two TMS coils cleared for obsessive compulsive disorder in the brain and in specific regions associated with OCD.

The FDA cleared deep transcranial magnetic stimulation (Deep TMS) with the H7 coil for obsessive-compulsive disorder (OCD) treatment, following a double-blinded placebo-controlled multicenter trial. Two years later the FDA cleared TMS with the D-B80 coil on the basis of substantial equivalence. In order to investigate the induced electric field characteristics of the two coils, these were placed at the treatment position for OCD over the prefrontal cortex of a head phantom, and the field distribution was measured. Additionally, numerical simulations were performed in eight Population Head Model repository models with two sets of conductivity values and three Virtual Population anatomical head models and their homogeneous versions. The H7 was found to induce significantly higher maximal electric fields (p<0.0001, t = 11.08) and to stimulate two to five times larger volumes in the brain (p<0.0001, t = 6.71). The rate of decay of electric field with distance is significantly slower for the H7 coil (p < 0.0001, Wilcoxon matched-pairs test). The field at the scalp is 306% of the field at a 3 cm depth with the D-B80, and 155% with the H7 coil. The H7 induces significantly higher intensities in broader volumes within the brain and in specific brain regions known to be implicated in OCD (dorsal anterior cingulate cortex (dACC), dorsolateral prefrontal cortex (dlPFC), inferior frontal gyrus (IFG), orbitofrontal cortex (OFC) and pre-supplementary motor area (pre-SMA)) compared to the D-B80. Significant field ≥ 80 V/m is induced by the H7 (D-B80) in 15% (1%) of the dACC, 78% (29%) of the pre-SMA, 50% (20%) of the dlPFC, 30% (12%) of the OFC and 15% (1%) of the IFG. Considering the substantial differences between the two coils, the clinical efficacy in OCD should be tested and verified separately for each coil.

Primary Sjögren's Syndrome Presenting with Rapidly Progressive Dementia: A Case Report.

BACKGROUND: Rapidly progressive dementias (RPDs) are dementias that progress subacutely over a time period of weeks to months. Primary Sjögren's syndrome (pSS) is an autoimmune disease that can affect any organ system and may present with a wide range of clinical features that may mimic a plethora of medical conditions and, in rare cases, may manifest as RPD. We describe a unique case of pSS, in which rapidly progressive dementia (RPD) was the first disease manifestation, and the patient's radiological and electroencephalogram findings were compatible with Creutzfeldt- Jakob disease (CJD). CASE PRESENTATION: Here, we report a 58-year-old woman who presented with cognitive impairment rapidly deteriorating over the last 6 months prior to admission. Brain MRI and EEG were indicative of CJD. However, CSF 14-3-3 and tau/phospho tau ratio were within normal limits and therefore alternative diagnoses were considered. Blood tests were significant for positive antinuclear antibodies, anti-ENA, and anti-SSA and a lip biopsy was consistent with pSS. The patient was started on intravenous steroids followed by oral prednisone taper, which prevented further deterioration. CONCLUSION: This rare case expands the spectrum of neurological manifestations in pSS and highlights the importance of considering pSS in the differential diagnosis of RPDs in order to avoid misdiagnosis and provide appropriate treatment in a timely fashion.

Removing artifacts from TMS-evoked EEG: A methods review and a unifying theoretical framework.

Transcranial magnetic stimulation (TMS) combined with electroencephalography (EEG) is a technique for studying cortical excitability and connectivity in health and disease, allowing basic research and potential clinical applications. A major methodological issue, severely limiting the applicability of TMS-EEG, relates to the contamination of EEG signals by artifacts of biologic or non-biologic origin. To solve this problem, several methods, based on independent component analysis (ICA), principal component analysis (PCA), signal space projection (SSP), and other approaches, have been developed over the last decade. This article is divided into two parts. In the first part, we review the theoretical background of the currently available TMS-EEG artifact removal methods. In the second part, we formally introduce the mathematics underpinnings of the cleaning methods. We classify them into spatial and temporal filters based on their properties. Since the most frequently used TMS-EEG cleaning approach are spatial filter methods, we focus on them and introduce beamforming as a unified framework of the most popular spatial filtering techniques. This unifying approach enables the comparative assessment of these methods by highlighting their differences in terms of assumptions, challenges, and applicability for different types of artifacts and data. The different properties and challenges of the methods discussed are illustrated with both simulated and recorded data. This article targets non-mathematical and mathematical audiences. Accordingly, those readers interested in essential background information on these methods can focus on Section 2. Whereas theory-oriented readers may find Section 3 helpful for making informed decisions between existing methods and developing the methodology further.

EEG Recordings as Biomarkers of Pain Perception: Where Do We Stand and Where to Go?

INTRODUCTION: The universality and complexity of pain, which is highly prevalent, yield its significance to both patients and researchers. Developing a non-invasive tool that can objectively measure pain is of the utmost importance for clinical and research purposes. Traditionally electroencephalography (EEG) has been mostly used in epilepsy; however, over the recent years EEG has become an important non-invasive clinical tool that has helped increase our understanding of brain network complexities and for the identification of areas of dysfunction. This review aimed to investigate the role of EEG recordings as potential biomarkers of pain perception. METHODS: A systematic search of the PubMed database led to the identification of 938 papers, of which 919 were excluded as a result of not meeting the eligibility criteria, and one article was identified through screening of the reference lists of the 19 eligible studies. Ultimately, 20 papers were included in this systematic review. RESULTS: Changes of the cortical activation have potential, though the described changes are not always consistent. The most consistent finding is the increase in the delta and gamma power activity. Only a limited number of studies have looked into brain networks encoding pain perception. CONCLUSION: Although no robust EEG biomarkers of pain perception have been identified yet, EEG has potential and future research should be attempted. Designing strong research protocols, controlling for potential risk of biases, as well as investigating brain networks rather than isolated cortical changes will be crucial in this attempt.

Autonomic dysfunction in amyotrophic lateral sclerosis: A neurophysiological and neurosonology study.

BACKGROUND AND PURPOSE: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder affecting upper and lower motor neurons. Some ALS patients exhibit concomitant nonmotor signs, and thus ALS is considered a multisystem disorder. The aim of this study is to investigate autonomous nervous system involvement in ALS. METHODS: We investigated 21 ALS patients and 28 age-matched controls. ALS patients were assessed for disease severity with the Revised-ALS Functional Rating Scale (ALSFSR) and for the presence of autonomic symptoms with the Composite Autonomic Symptom Score scale. Sympathetic nervous system was evaluated by sympathetic skin response (SSR) and parasympathetic nervous system by ultrasonography of vagus nerve (VN) at the level of the thyroid gland. RESULTS: SSR latencies were shorter and SSR amplitudes were higher in controls compared to ALS patients. The cross-sectional area (CSA) of the VN was significantly smaller in ALS patients (mean CSA right/left: 1.73±0.62 mm2 /1.47±0.53 mm2 ) compared to controls (mean CSA right/left: 2.91±0.79 mm2 /2.30±0.80 mm2 ), right: p <. 001, left: p <. 001. There was a significant negative correlation between disease duration and CSA of left-VN (r = -0.493, p = .023). This correlation was attenuated between disease duration and CSA of right-VN (r = -0.419, p = .059). ALSFSR-R was positively correlated to CSA of right-VN (p = .006, r = 0.590). CSA of VN did not correlate with bulbar involvement. CONCLUSIONS: This study confirms the presence of autonomic dysfunction in ALS patients and provides evidence of VN atrophy that correlates with disease severity and duration and is independent of bulbar involvement. Degeneration of dorsal nucleus neurons of the VN is hypothesized.

Biomarkers of disease progression in adolescents and adults with 5q spinal muscular atrophy: a systematic review and meta-analysis.

Since the introduction of disease modifying treatments there is an unmet need to identify biomarkers of spinal muscular atrophy (SMA) natural history. We performed a systematic review and meta-analysis to summarize available evidence. We searched MEDLINE, Embase, Cochrane Library and gray literature until February 2021. The primary outcome was biomarkers longitudinal course in adolescents and adults. The secondary outcome was the discrimination of patients from controls. We included 42 records examining 606 patients from 19 population cohorts over a maximum follow-up of 17-years. Lung function and serum biomarkers could not depict disease progression. We identified potential biomarkers of disease activity [SMA functional rating scale, MoviPlate, pinch strength, compound muscle action potential (CMAP), motor unit number estimation (MUNE)] that require further investigation. Data regarding Hammersmith functional motor scale expanded, Revised upper limb module, 6-minute walk test were contradictory impeding any pooled estimate. The pooled analysis regarding our secondary outcome revealed that upper limb CMAP amplitudes and MUNE mean values differed significantly between SMA patients and controls [mean difference -3.63(-6.2, -1.06), -119.74(-153.93, -85.56) respectively]. Given the lack of natural history data on this population, our qualitative synthesis and meta-analysis could provide valuable evidence and identify promising predictive biomarkers requiring further longitudinal examination. PROSPERO Registration: CRD42021235605.

Nusinersen in Adults with 5q Spinal Muscular Atrophy: a Systematic Review and Meta-analysis.

Evidence for nusinersen administration in adult 5q spinal muscular atrophy (5q-SMA) patients is scarce and based on real-world observational data. The present systematic review and meta-analysis aimed to explore the efficacy and safety of nusinersen in patients older than 12 years of age with 5q-SMA. We searched MEDLINE, EMBASE, the Cochrane Library, and grey literature through April 2021. Cross-sectional studies, case reports, review articles, and studies with follow-up less than 6 months were excluded. We included 12 records (seven case-series, five cohorts) representing 11 population cohorts and enrolling 428 SMA patients. We observed statistically significant improvements on motor function Hammersmith Functional Motor Scale Expanded (HFMSE) and Revised Upper Limb Module (RULM) scores at the longest follow-up assessments [SMD = 0.17(95% CI 0.01-0.33), SMD = 0.22(95% CI 0.06-0.38), respectively]. HFMSE and RULM significant improvements were also detected at the subgroup analysis during 10 and 14 months. HFMSE and RULM amelioration occurred earlier in patients with SMA type 3 or 4 during short-term analysis (≤ 6 months). 6-min walk tests (6MWT) and pulmonary function tests did not change. Minimal clinically important differences in HFMSE and RULM were observed in 43.3% (95% CI 34.5-52.3) and 38.9% (95% CI 27.7-50.7), respectively. Severe adverse events were reported in 2% (95% CI 0-5.8). Treatment withdrawal rate was 3% (95% CI 0.5-6.6). Despite the low quality of evidence and the unmet need for randomized data to establish the safety and efficacy of nusinersen in adults, our meta-analysis confirms that nusinersen is a valuable treatment option for older patients with longer-disease duration.Trial registration: PROSPERO database CRD42020223109.

Bridging the gap: TMS-EEG from lab to clinic.

The combination of transcranial magnetic stimulation (TMS) and electroencephalography (EEG) has reached technological maturity and has been an object of significant scientific interest for over two decades. Ιn parallel, accumulating evidence highlights the potential of TMS-EEG as a useful tool in the field of clinical neurosciences. Nevertheless, its clinical utility has not yet been established, partly because technical and methodological limitations have created a gap between an evolving scientific tool and standard clinical practice. Here we review some of the identified gaps that still prevent TMS-EEG moving from science laboratories to clinical practice. The principal and partly overlapping gaps include: 1) complex and laborious application, 2) difficulty in obtaining high-quality signals, 3) suboptimal accuracy and reliability, and 4) insufficient understanding of the neurobiological substrate of the responses. All these four aspects need to be satisfactorily addressed for the method to become clinically applicable and enter the diagnostic and therapeutic arena. In the current review, we identify steps that might be taken to address these issues and discuss promising recent studies providing tools to aid bridging the gaps.

TMS-induced brain connectivity modulation in Genetic Generalized Epilepsy.

OBJECTIVE: In epilepsy patients, Transcranial Magnetic Stimulation (TMS) may result in the induction and modulation of epileptiform discharges (EDs). We hereby investigate the modulatory effects of TMS on brain connectivity in Genetic Generalized Epilepsy (GGE) and explore their potential as a diagnostic biomarker in GGE. METHODS: Patients with GGE (n=18) and healthy controls (n=11) were investigated with a paired-pulse TMS-EEG protocol. The brain network was studied at local and at global levels using Coherence as an EEG connectivity measure. Comparison of patients vs controls was performed in a time-resolved manner by analyzing comparatively pre- vs post-TMS brain networks. RESULTS: There was statistically significant TMS-induced modulation of connectivity at specific frequency bands within groups and difference in TMS-induced modulation between the two groups. The most significant difference between patients and controls related to connectivity modulation in the γ band at 1-3 sec post-TMS (p=0.004). CONCLUSIONS: TMS modulates the healthy and epileptic brain connectivity in different ways. Our results indicate that TMS-EEG connectivity analysis can be a basis for a diagnostic biomarker of GGE. SIGNIFICANCE: The analysis identifies specific time periods and frequency bands of interest of TMS-induced connectivity modulation and elucidates the effect of TMS on the healthy and epileptic brain connectivity.