Intrathecal IgM synthesis as a diagnostic marker in patients with suspected CNS lymphoma.

For CNS lymphomas (CNSL), there is a high need for minimally invasive and easily obtainable diagnostic markers. Intrathecal IgM synthesis can easily be determined in routine CSF diagnostics. The aim of this study was to systematically investigate the diagnostic potential of intrathecal IgM synthesis in primary and secondary CNSL (PCNSL and SCNSL). In this retrospective study, patients with a biopsy-proven diagnosis of PCNSL or SCNSL were compared with patients with other neurological diseases in whom CNSL was initially the primary radiological differential diagnosis based on MRI. Sensitivity and specificity of intrathecal IgM synthesis were calculated using receiver operating characteristic curves. Seventy patients with CNSL were included (49 PCNSL and 21 SCNSL) and compared to 70 control patients. The sensitivity and specificity for the diagnosis of CNSL were 49% and 87%, respectively, for the entire patient population and 66% and 91% after selection for cases with tumor access to the CSF system and isolated intrathecal IgM synthesis. In cases with MRI-based radiological suspicion of CNSL, intrathecal IgM synthesis has good specificity but limited sensitivity. Because of its low-threshold availability, analysis of intrathecal IgM synthesis has the potential to lead to higher diagnostic accuracy, especially in resource-limited settings, and deserves further study.

COVID-19 and Intracranial Hemorrhage: A Multicenter Case Series, Systematic Review and Pooled Analysis.

INTRODUCTION: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) profoundly impacts hemostasis and microvasculature. In the light of the dilemma between thromboembolic and hemorrhagic complications, in the present paper, we systematically investigate the prevalence, mortality, radiological subtypes, and clinical characteristics of intracranial hemorrhage (ICH) in coronavirus disease (COVID-19) patients. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we performed a systematic review of the literature by screening the PubMed database and included patients diagnosed with COVID-19 and concomitant ICH. We performed a pooled analysis, including a prospectively collected cohort of critically ill COVID-19 patients with ICH, as part of the PANDEMIC registry (Pooled Analysis of Neurologic Disorders Manifesting in Intensive Care of COVID-19). RESULTS: Our literature review revealed a total of 217 citations. After the selection process, 79 studies and a total of 477 patients were included. The median age was 58.8 years. A total of 23.3% of patients experienced the critical stage of COVID-19, 62.7% of patients were on anticoagulation and 27.5% of the patients received ECMO. The prevalence of ICH was at 0.85% and the mortality at 52.18%, respectively. CONCLUSION: ICH in COVID-19 patients is rare, but it has a very poor prognosis. Different subtypes of ICH seen in COVID-19, support the assumption of heterogeneous and multifaceted pathomechanisms contributing to ICH in COVID-19. Further clinical and pathophysiological investigations are warranted to resolve the conflict between thromboembolic and hemorrhagic complications in the future.

Local Anesthetic-Induced Central Nervous System Toxicity during Interscalene Brachial Plexus Block: A Case Series Study of Three Patients.

Local anesthetics are commonly administered by nuchal infiltration to provide a temporary interscalene brachial plexus block (ISB) in a surgical setting. Although less commonly reported, local anesthetics can induce central nervous system toxicity. In this case study, we present three patients with acute central nervous system toxicity induced by local anesthetics applied during ISB with emphasis on neurological symptoms, key neuroradiological findings and functional outcome. Medical history, clinical and imaging findings, and outcome of three patients with local anesthetic-induced toxic left hemisphere syndrome during left ISB were analyzed. All patients were admitted to our neurological intensive care unit between November 2016 and September 2019. All three patients presented in poor clinical condition with impaired consciousness and left hemisphere syndrome. Electroencephalography revealed slow wave activity in the affected hemisphere of all patients. Seizure activity with progression to status epilepticus was observed in one patient. In two out of three patients, cortical FLAIR hyperintensities and restricted diffusion in the territory of the left internal carotid artery were observed in magnetic resonance imaging. Assessment of neurological severity scores revealed spontaneous partial reversibility of neurological symptoms. Local anesthetic-induced CNS toxicity during ISB can lead to severe neurological impairment and anatomically variable cerebral lesions.

Pulmonary embolism in neurocritical care-introduction of a novel grading system for risk stratification: the Frankfurt AMBOS score.

Pulmonary embolism (PE) due to deep vein thrombosis is a complication with severe morbidity and mortality rates. Neurocritical care patients constitute an inhomogeneous cohort with often strict contraindications to conventional embolism treatment. The aim of the present study is to identify risk factors for pulmonary embolism for intensified risk stratification in this demanding cohort. In this retrospective analysis, 387 neurocritical care patients received computed tomography for clinical suspicion of PE (304 neurosurgical and 83 neurological patients). Analysed parameters included age, gender, disease pattern, the presence of deep vein thrombosis, resuscitation, in-hospital mortality, present anticoagulation, coronary artery disease, diabetes mellitus, smoking status, hypertension and ABO blood type. Computed tomography confirmed 165 cases of pulmonary embolism among 387 patients with clinical suspicion of pulmonary embolism (42%). Younger age (p < 0.0001), female gender (p < 0.006), neurooncological disease (p < 0.002), non-O blood type (p < 0.002) and the absence of Marcumar therapy (p < 0.003) were identified as significant risk factors for pulmonary embolism. On the basis of the identified risk factors, the AMBOS score system is introduced. Neurocritical care patients with high AMBOS score are at elevated risk for PE and should therefore be put under intensified monitoring for cardiovascular events in neurocritical care units.

Tick-borne encephalitis virus (TBEV) infection in pregnancy: Absence of virus transmission to the fetuses despite severe maternal disease - A case study.

Tick-borne encephalitis (TBE) is an emerging infectious disease in large parts of Europe and Asia. Whereas other members of the Flaviviridae family can harm fetal development, there are only very few reports on TBE virus (TBEV) infections during pregnancy. Thus, the implications for fetal health remain largely unknown. In this study, we present detailed pre- and postnatal health assessment of three children in the context of severe maternal TBEV infection during pregnancy. Following acute TBEV infection of the mothers, intrauterine growth and development of all children were assessed by repetitive prenatal ultrasound. Postnatal examinations included clinical and virological analyses over a follow-up period of 18 months. Prenatally, no signs of intrauterine growth restrictions were observed. All neonates were delivered at term. Umbilical cord blood of the newborns tested negative for TBEV RNA. Virus-specific IgG antibodies were positive at birth but negative at 9 and 11 months of age. Importantly, IgM antibodies remained negative throughout the period of observation. Taken together, these clinical and virological data strongly suggest that fetal TBEV infection did not occur, despite severe manifestations in the mothers.

Therapeutic Options for Patients with Refractory Status Epilepticus in Palliative Settings or with a Limitation of Life-Sustaining Therapies: A Systematic Review.

BACKGROUND: Refractory status epilepticus (RSE) represents a serious medical condition requiring early and targeted therapy. Given the increasing number of elderly or multimorbid patients with a limitation of life-sustaining therapy (LOT) or within a palliative care setting (PCS), guidelines-oriented therapy escalation options for RSE have to be omitted frequently. OBJECTIVES: This systematic review sought to summarize the evidence for fourth-line antiseizure drugs (ASDs) and other minimally or non-invasive therapeutic options beyond guideline recommendations in patients with RSE to elaborate on possible treatment options for patients undergoing LOT or in a PCS. METHODS: A systematic review of the literature in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, focusing on fourth-line ASDs or other minimally or non-invasive therapeutic options was performed in February and June 2020 using the MEDLINE, EMBASE and Cochrane databases. The search terminology was constructed using the name of the specific ASD or therapy option and the term 'status epilepticus' with the use of Boolean operators, e.g. "(brivaracetam) AND (status epilepticus)". The respective Medical Subject Headings (MeSH) and Emtree terms were used, if available. RESULTS: There is currently no level 1, grade A evidence for the use of ASDs in RSE. The best evidence was found for the use of lacosamide and topiramate (level 3, grade C), followed by brivaracetam, perampanel (each level 4, grade D) and stiripentol, oxcarbazepine and zonisamide (each level 5, grade D). Regarding non-medicinal options, there is little evidence for the use of the ketogenic diet (level 4, grade D) and magnesium sulfate (level 5, grade D) in RSE. The broad use of immunomodulatory or immunosuppressive treatment options in the absence of a presumed autoimmune etiology cannot be recommended; however, if an autoimmune etiology is assumed, steroid pulse, intravenous immunoglobulins and plasma exchange/plasmapheresis should be considered (level 4, grade D). Even if several studies suggested that the use of neurosteroids (level 5, grade D) is beneficial in RSE, the current data situation indicates that there is formal evidence against it. CONCLUSIONS: RSE in patients undergoing LOT or in a PCS represents a challenge for modern clinicians and epileptologists. The evidence for the use of ASDs in RSE beyond that in current guidelines is low, but several effective and well-tolerated options are available that should be considered in this patient population. More so than in any other population, advance care planning, advance directives, and medical ethical aspects have to be considered carefully before and during therapy.

Treatment of refractory and superrefractory status epilepticus with topiramate: A cohort study of 106 patients and a review of the literature.

OBJECTIVE: Novel treatments are needed to control treatment-resistant status epilepticus (SE). We present a summary of clinical cases where oral topiramate (TPM) was used in refractory SE (RSE) and superrefractory SE (SRSE). METHODS: A review of medical records was carried out to detect TPM administration in SE patients treated in Frankfurt and Marburg between 2011 and 2016. The primary outcome question concerned SE resolution after TPM initiation. RESULTS: In total, TPM was used in 106 of 854 patients having a mean age of 67.4 ± 18.1 years, 61 of whom were female (57.5%). The median latency from SE onset to TPM initiation was 8.5 days. Patients with SE had previously failed a median of five other antiepileptic drugs. The median initial TPM dose was 100 mg/d, which was uptitrated to a median maintenance dose of 400 mg/d. Treatment with TPM was continued for a median time of 12 days. TPM was the last drug provided to 42 of 106 (39.6%) patients, with a resultant response attributed to TPM observed in 29 of 106 (27.4%) patients. A response was attributed to TPM in 21 (31.8%) of 66 RSE cases and eight (20%) of 40 SRSE cases. Treatment-emergent adverse events were attributed to TPM usage in two patients, one each with pancreatitis and hyperchloremic acidosis, and in 38 patients (35.8%), hyperammonemia was seen. Thirty-four of these patients received a combination of TPM and valproate and/or phenobarbital. The intrahospital mortality rate was 22.6% (n = 24). SIGNIFICANCE: The rate of SE cessation attributed to TPM treatment (27.4%) represents a relevant response given the late treatment position of TPM and the treatment latency of more than 8 days. Based on these results and in line with the findings of other case series, TPM can be considered an alternative option for treating RSE and SRSE.

Introducing the New 3.5/28 Microstent Retriever for Recanalization of Distal Cerebral Arteries in Acute Stroke: Preliminary Results.

BACKGROUND AND PURPOSE: To describe our first experience using a small stent retriever specifically designed for thrombectomy in cerebral arteries with a small caliber (Acandis APERIO® 3.5/28) in patients with acute ischemic stroke. MATERIALS AND METHODS: All patients with an acute ischemic stroke, who underwent endovascular recanalization using the APERIO® thrombectomy device with a diameter of 3.5 mm, were identified in retrospect and included in the present analysis. Demographic and clinical data as well as data on the procedures performed were collected (patient sex, mean age, NIHSS, mRS, TICI score, and complications). RESULTS: Stent retriever-based thrombectomy with the Aperio® 3.5/28 alone (n = 10 vessels) or in combination with other devices (n = 13 vessels) was performed in 22 acute stroke patients with embolic occlusions of distal branches of the anterior and posterior circulations (median NIHSS = 8.5). For vessels treated with the Aperio® 3.5/28, we achieved a TICI 2b/3 reperfusion rate of 73.9%. One patient suffered a symptomatic intracerebral hemorrhage after thrombectomy; otherwise, no procedure-related complications were seen. CONCLUSION: Our data suggest that mechanical thrombectomy of distal cerebral artery occlusions with the Aperio® 3.5/28 is feasible and in general safe, thus offering a promising option for endovascular stroke therapy. However, multicentric studies with larger patient cohorts are necessary to evaluate the clinical benefit.

Costs and cost-driving factors for acute treatment of adults with status epilepticus: A multicenter cohort study from Germany.

OBJECTIVE: To provide first data on inpatient costs and cost-driving factors due to nonrefractory status epilepticus (NSE), refractory status epilepticus (RSE), and super-refractory status epilepticus (SRSE). METHODS: In 2013 and 2014, all adult patients treated due to status epilepticus (SE) at the university hospitals in Frankfurt, Greifswald, and Marburg were analyzed for healthcare utilization. RESULTS: We evaluated 341 admissions in 316 patients (65.7 ± [standard deviation]18.2 years; 135 male) treated for SE. Mean costs of hospital treatment were €14,946 (median €5,278, range €776-€152,911, €787 per treatment day) per patient per admission, with a mean length of stay (LOS) of 19.0 days (median 14.0, range 1-118). Course of SE had a significant impact on mean costs, with €8,314 in NSE (n = 137, median €4,597, €687 per treatment day, 22.3% of total inpatient costs due to SE), €13,399 in RSE (n = 171, median €7,203, €638/day, 45.0% of total costs, p < 0.001), and €50,488 in SRSE (n = 33, median €46,223, €1,365/day, 32.7% of total costs, p < 0.001). Independent cost-driving factors were SRSE, ventilation, and LOS of >14 days. Overall mortality at discharge was 14.4% and significantly higher in RSE/SRSE (20.1%) than in NSE (5.8%). SIGNIFICANCE: Acute treatment of SE, and particularly SRSE and ventilation, are associated with high hospital costs and prolonged LOS. Extrapolation to the whole of Germany indicates that SE causes hospital costs of >€200 million per year. Along with the demographic change, incidence of SE will increase and costs for hospital treatment and sequelae of SE will rise.

Addition of Anti-Angiogenetic Therapy with Bevacizumab to Chemo- and Radiotherapy for Leptomeningeal Metastases in Primary Brain Tumors.

Leptomeningeal dissemination of a primary brain tumor is a condition which is challenging to treat, as it often occurs in rather late disease stages in highly pretreated patients. Its prognosis is dismal and there is still no accepted standard of care. We report here a good clinical effect with a partial response in three out of nine patients and a stable disease with improvement on symptoms in two more patients following systemic anti-angiogenic treatment with bevacizumab (BEV) alone or in combination with chemo- and/or radiotherapy in a series of patients with leptomeningeal dissemination from primary brain tumors (diffuse astrocytoma WHO°II, anaplastic astrocytoma WHO°III, anaplastic oligodendroglioma WHO°III, primitive neuroectodermal tumor and glioblastoma, both WHO°IV). This translated into effective symptom control in five out of nine patients, but only moderate progression-free and overall survival times were reached. Partial responses as assessed by RANO criteria were observed in three patients (each one with anaplastic oligodendroglioma, primitive neuroectodermal tumor and glioblastoma). In these patients progression-free survival (PFS) intervals of 17, 10 and 20 weeks were achieved. In three patients (each one with diffuse astrocytoma, anaplastic astrocytoma and primitive neuroectodermal tumor) stable disease was observed with PFS of 13, 30 and 8 weeks. Another three patients (all with glioblastoma) were primary non-responders and deteriorated rapidly with PFS of 3 to 4 weeks. No severe adverse events were seen. These experiences suggest that the combination of BEV with more conventional therapy schemes with chemo- and/or radiotherapy may be a palliative treatment option for patients with leptomeningeal dissemination of brain tumors.

Breakdown of long-range temporal dependence in default mode and attention networks during deep sleep.

The integration of segregated brain functional modules is a prerequisite for conscious awareness during wakeful rest. Here, we test the hypothesis that temporal integration, measured as long-term memory in the history of neural activity, is another important quality underlying conscious awareness. For this aim, we study the temporal memory of blood oxygen level-dependent signals across the human nonrapid eye movement sleep cycle. Results reveal that this property gradually decreases from wakefulness to deep nonrapid eye movement sleep and that such decreases affect areas identified with default mode and attention networks. Although blood oxygen level-dependent spontaneous fluctuations exhibit nontrivial spatial organization, even during deep sleep, they also display a decreased temporal complexity in specific brain regions. Conversely, this result suggests that long-range temporal dependence might be an attribute of the spontaneous conscious mentation performed during wakeful rest.

Large-scale brain functional modularity is reflected in slow electroencephalographic rhythms across the human non-rapid eye movement sleep cycle.

Large-scale brain functional networks (measured with functional magnetic resonance imaging, fMRI) are organized into separated but interacting modules, an architecture supporting the integration of distinct dynamical processes. In this work we study how the aforementioned modular architecture changes with the progressive loss of vigilance occurring in the descent to deep sleep and we examine the relationship between the ensuing slow electroencephalographic rhythms and large-scale network modularity as measured with fMRI. Graph theoretical methods are used to analyze functional connectivity graphs obtained from fifty-five participants at wakefulness, light and deep sleep. Network modularity (a measure of functional segregation) was found to increase during deeper sleep stages but not in light sleep. By endowing functional networks with dynamical properties, we found a direct link between increased electroencephalographic (EEG) delta power (1-4 Hz) and a breakdown of inter-modular connectivity. Both EEG slowing and increased network modularity were found to quickly decrease during awakenings from deep sleep to wakefulness, in a highly coordinated fashion. Studying the modular structure itself by means of a permutation test, we revealed different module memberships when deep sleep was compared to wakefulness. Analysis of node roles in the modular structure revealed an increase in the number of locally well-connected nodes and a decrease in the number of globally well-connected hubs, which hinders interactions between separated functional modules. Our results reveal a well-defined sequence of changes in brain modular organization occurring during the descent to sleep and establish a close parallel between modularity alterations in large-scale functional networks (accessible through whole brain fMRI recordings) and the slowing of scalp oscillations (visible on EEG). The observed re-arrangement of connectivity might play an important role in the processes underlying loss of vigilance and sensory awareness during deep sleep.

The impact of acamprosate on cue reactivity in alcohol dependent individuals: a functional magnetic resonance imaging study.

Alcohol cue-induced brain activation has been studied extensively in alcoholics. However, little is known about the impact of standard treatment protocols on this phenomenon. The current study aimed at investigating the impact of the anticraving substance acamprosate on alcohol cue-related brain activity. Patients underwent a functional magnetic resonance imaging investigation before the beginning of medication with acamprosate or placebo (T0) and 2 weeks later (T1). All patients also received psychiatric inpatient treatment including psychotherapeutic interventions. Twenty-nine patients were included in the T0 analysis and 22 patients in the T1 analysis. At T0, a cluster in the left and right posterior cingulate cortex, covering parts of the retrosplenial cortex, was significantly associated with alcohol versus neutral cue exposure. At T1, no significant cluster was found for the alcohol-versus-neutral contrast. The analysis of the impact of acamprosate on cue-related activity in the posterior cingulate cortex cluster revealed no significant difference to placebo. These results provide further evidence for the involvement of the posterior cingulate cortex in alcohol cue exposure. However, in comparison with psychiatric inpatient treatment alone, there was no additional effect of acamprosate on cue-related brain activity.

Automatic sleep staging using fMRI functional connectivity data.

Recent EEG-fMRI studies have shown that different stages of sleep are associated with changes in both brain activity and functional connectivity. These results raise the concern that lack of vigilance measures in resting state experiments may introduce confounds and contamination due to subjects falling asleep inside the scanner. In this study we present a method to perform automatic sleep staging using only fMRI functional connectivity data, thus providing vigilance information while circumventing the technical demands of simultaneous recording of EEG, the gold standard for sleep scoring. The features to classify are the linear correlation values between 20 cortical regions identified using independent component analysis and two regions in the bilateral thalamus. The method is based on the construction of binary support vector machine classifiers discriminating between all pairs of sleep stages and the subsequent combination of them into multiclass classifiers. Different multiclass schemes and kernels are explored. After parameter optimization through 5-fold cross validation we achieve accuracies over 0.8 in the binary problem with functional connectivities obtained for epochs as short as 60s. The multiclass classifier generalizes well to two independent datasets (accuracies over 0.8 in both sets) and can be efficiently applied to any dataset using a sliding window procedure. Modeling vigilance states in resting state analysis will avoid confounded inferences and facilitate the study of vigilance states themselves. We thus consider the method introduced in this study a novel and practical contribution for monitoring vigilance levels inside an MRI scanner without the need of extra recordings other than fMRI BOLD signals.

To wake or not to wake? The two-sided nature of the human K-complex.

Sleep fosters performance but likewise renders creatures insensitive to environmental threat. The brain balances between sleep promotion and protection during light sleep. One associated electrophysiological hallmark is the K-complex (KC), the sleep promoting versus arousal inducing role of which is under debate. We examined 37 subjects using EEG-combined fMRI and found KC-associated positive BOLD signal changes in subcortical (brainstem, thalamus), sensory and motor, midline and regions which form part of the default mode network, and negative changes in the anterior insula. Connectivity analysis revealed the primary auditory cortex as the first region to be influenced during the KC and that midline regions activated successively from front to back in association with the sleep protecting part of the KC. Our findings support thalamic involvement in KC mediation and an association of KCs with subcortical arousal mechanisms: activations in sensory areas suggest the existence of low level information processing during KC limited by anterior insula disengagement suggesting a two-sided nature of the KC: it embodies an arousal with subsequent sleep-guarding counteraction that might on the one hand serve periodical monitoring of the environment with basic information processing and on the other hand protect the continuity of sleep and thus its restoring effect.