EEG microstates show different features in focal epilepsy and psychogenic nonepileptic seizures.

OBJECTIVE: Electroencephalography (EEG) microstate analysis seeks to cluster the scalp's electric field into semistable topographical EEG activity maps at different time points. Our study aimed to investigate the features of EEG microstates in subjects with focal epilepsy and psychogenic nonepileptic seizures (PNES). METHODS: We included 62 adult subjects with focal epilepsy or PNES who received video-EEG monitoring at the epilepsy monitoring unit. The subjects (mean age = 42.8 ± 21.2 years) were distributed equally between epilepsy and PNES groups. We extracted microstates from a 4.4 ± 1.0-min, 21-channel resting-state EEG. We excluded subjects with interictal epileptiform discharges during resting-state EEGs. After preprocessing, we derived five main EEG microstates-MS1 to MS5-for the full frequency band (1-30 Hz) and frequency subbands (delta, 1-4 Hz; theta, 4-8 Hz; alpha, 8-12 Hz; beta, 12-30 Hz), using the MATLAB-based EEGLAB toolkit. Statistical features of microstates (duration, occurrence, contribution, global field power [GFP]) were compared between the groups, using logistic regression corrected for age and sex. RESULTS: We detected no differences in microstate parameters in the full frequency band. We found a longer duration (delta: B = -7.680, p = .046; theta: B = -16.200, p = .043) and a higher contribution (delta: B = -7.414, p = .035; theta: B = -7.509, p = .031) of MS4 in lower frequency bands in the epilepsy group. The PNES group showed a higher occurrence of MS5 in the delta subband (B = 3.283, p = .032). In the theta subband, a higher GFP of MS1 was associated with the PNES group (B = 5.674, p = .025), whereas a higher GFP of MS2 was associated with the epilepsy group (B = -6.579, p = .026). SIGNIFICANCE: Microstate features show differences between patients with focal epilepsy and PNES. EEG microstates could be a promising parameter, helping to understand changes in brain dynamics in subjects with epilepsy, and should be explored as a potential biomarker.

Assessing 72 h vs. 24 h of long-term video-EEG monitoring to confirm the diagnosis of epilepsy: a retrospective observational study.

Introduction: Paroxysmal seizure-like events can be a diagnostic challenge. Inpatient video-electroencephalography (EEG) monitoring (VEM) can be a valuable diagnostic tool, but recommendations for the minimal duration of VEM to confirm or rule out epilepsy are inconsistent. In this study, we aim to determine whether VEM of 48 or 72 h was superior to 24 h. Methods: In this monocentric, retrospective study, we included 111 patients with paroxysmal, seizure-like events who underwent at least 72 h of VEM. Inclusion criteria were as follows: (1) Preliminary workup was inconclusive; (2) VEM admission occurred to confirm a diagnosis; (3) At discharge, the diagnosis of epilepsy was conclusively established. We analyzed the VEM recordings to determine the exact time point of the first occurrence of epileptic abnormalities (EAs; defined as interictal epileptiform discharges or electrographic seizures). Subgroup analyses were performed for epilepsy types and treatment status. Results: In our study population, 69.4% (77/111) of patients displayed EAs during VEM. In this group, the first occurrence of EAs was observed within 24 h in 92.2% (71/77) of patients and within 24-72 h in 7.8% (6/77). There was no statistically significant difference in the incidence of EA between medicated and non-medicated patients or between focal, generalized epilepsies and epilepsies of unknown type. Of the 19 recorded spontaneous electroclinical seizures, 6 (31.6%) occurred after 24 h. Discussion: A VEM of 24 h may be sufficient in the diagnostic workup of paroxysmal seizure-like events under most circumstances. Considering the few cases of first EA in the timeframe between 24 and 72 h, a prolonged VEM may be useful in cases with a high probability of epilepsy or where other strategies like sleep-EEG or ambulatory EEG show inconclusive results. Prolonged VEM increases the chance of recording spontaneous seizures. Our study also highlights a high share of subjects with epilepsy that do not exhibit EAs during 72 h of VEM.

The role of creatine kinase in distinguishing generalized tonic-clonic seizures from psychogenic non-epileptic seizures (PNES) and syncope: a retrospective study and meta-analysis of 1300 patients.

BACKGROUND/AIM: As the clinical differentiation between epileptic seizures, psychogenic non-epileptic seizures (PNES), and syncope depends mainly on a detailed report of the event, which may not be available, an objective assessment of a potential biochemical analysis is needed. We aimed to investigate whether serum creatine kinase (CK) could be used to differentiate epileptic seizure from PNES and syncope and to assess the strength of evidence present. METHODS: We directed a retrospective cohort study coupled with a systematic review and meta-analysis of studies that measured CK in patients with epilepsy, PNES, syncope, and healthy controls. RESULTS: The cohort study, which traced 202 patients, showed that the CK level was significantly higher 48 h after the event in the epilepsy group versus patients with syncope (p < 0.01) Along with 1086 patients obtained through a database search for meta-analysis, CK level compared to different types of seizures from PNES was higher in epileptic seizure patients with a mean difference of 568.966 mIU/ml (95% CI 166.864, 971.067). The subgroup analysis of CK showed that it was higher in GTCS compared to syncope with a mean difference of 125.39 mIU/ml (95% CI 45.25, 205.52). DISCUSSION: Increased serum levels of CK have been associated mainly with epileptic seizures in relation to non-epileptic events. However, further studies would try to explore the variation in measurements and any other potential diagnostic marker. CONCLUSION: The cohort study shows that the CK level in epilepsy seizures is higher after 48 h from the event compared to syncope. Moreover, the meta-analysis results show the present diagnostic utility of CK and its importance to be used in accordance with a detailed report of the event.

Left atrial appendage thrombus in acute stroke: diagnostic accuracy of CT angiography compared to transesophageal echocardiography.

OBJECTIVES: To evaluate the value of an extended emergency computed tomography angiography (CTA) including cardiac imaging in patients with acute ischemic stroke for the detection of left atrial appendage (LAA) thrombus compared to transesophageal echocardiography (TEE) as a reference standard. MATERIALS AND METHODS: We conducted a retrospective case-control study of patients with presumed acute ischemic stroke who had undergone non-ECG-gated CTA for the craniocervical vessels with an extended coverage including the heart in the context of emergency stroke evaluation and for whom TEE was available as part of the routine stroke diagnostic. We selected cases with evidence of LAA thrombus in TEE and controls without LAA thrombus in TEE in a 1:3 ratio. Two independent observers analyzed CTA images for presence of LAA thrombus and were blinded to the presence of thrombus in TEE. RESULTS: Twenty-two patients with LAA thrombus in TEE, and 66 patients without LAA thrombus in TEE were included. The detection of LAA thrombus using CTA showed a sensitivity of 63.6%, a specificity of 81.8%, a positive predictive value of 53.9% and a negative predicted value of 87.1%. Interobserver agreement was only moderate (Cohen´s κ = 0.43). CONCLUSIONS: An extended emergency CTA including cardiac imaging can be helpful in early risk stratification in patients with stroke of cardioembolic origin. However, our data show that a standard CTA of craniocervical vessels with extended coverage of the heart is of limited value when compared to TEE, the standard method of detecting LAA thrombi.

[Cerebral venous sinus thrombosis : An overview of causes, diagnostics and treatment]. / Sinus- und Hirnvenenthrombose : Ein Überblick über Ursachen, Diagnostik und Therapie.

In some cases, cerebral venous sinus thrombosis shows a fulminant progress but with an incidence of 1.32 cases per 100,000 person-years it is relatively rare. Nevertheless, the disease is responsible for around 0.5-1% of all stroke cases. The neurological examination often reveals nonspecific findings but especially in younger patients with acute to subacute position-dependent headaches, this differential diagnosis should definitely be considered. This article presents the most common causes, including a digression on vaccine-induced immune thrombotic thrombocytopenia (VITT) as well as recommendations for clinical, laboratory testing and imaging diagnostics. In addition, relevant complications with particular reference to epileptic seizures within the framework of the disease entity and guideline-based acute treatment and secondary prophylaxis are presented.

Reduced REM sleep: a potential biomarker for epilepsy - a retrospective case-control study.

OBJECTIVE: Establishing the diagnosis of epilepsy can be challenging if interictal epileptic discharges (IEDs) or seizures are undetectable. Many individuals with epilepsy experience sleep disturbances. A reduced percentage of REM sleep (REM%) has been observed following seizures. We aimed to assess differences of REM% in individuals with epilepsy in comparison with differential diagnoses. METHODS: We performed a retrospective, monocentric, two-armed case-control study with 128 age-matched individuals who underwent ≥72 hours of continuous video-EEG monitoring at our epilepsy monitoring unit (EMU) for diagnostic evaluation. We assessed REM% on the first and last night of EMU admission. Logistic regressions models were used to evaluate the predictive value of REM%. RESULTS: We included 64 individuals diagnosed with epilepsy and 64 with a differential diagnosis. REM% in the epilepsy group was significantly lower [12.2% (±4.7) vs. 17.2% (±5.2), p<0.001]. We found no significant influence of sex, age, anti-seizure, or other medications. A REM%-based and an IED and seizure-based regression model were not significantly different [area under the curve (AUC) 0.791 (95% confidence interval (CI): 0.713-0.870) vs. 0.853 (95% CI: 0.788-0.919), p=0.23]. A combined model, based on IEDs, seizures, and REM%, was superior to the IED model alone [0.933 (0.891-0.975), p<0.01]. INTERPRETATION: Our study shows significantly reduced REM% in individuals with epilepsy. REM%-based models show a good predictive performance. REM% assessment could improve diagnostic accuracy - especially for challenging cases, e.g., when IEDs or seizures are absent and patient history and semiology appear ambiguous. REM% as a biomarker should be evaluated in prospective, multicentric trials.

Decline in the number of patients with meningitis in German hospitals during the COVID-19 pandemic.

BACKGROUND AND OBJECTIVES: In 2020, a wide range of hygiene measures was implemented to mitigate infections caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In consequence, pulmonary infections due to other respiratory pathogens also decreased. Here, we evaluated the number of bacterial and viral meningitis and encephalitis cases during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: In a multicentre retrospective analysis of data from January 2016 until December 2020, numbers of patients diagnosed with bacterial meningitis and other types of CNS infections (such as viral meningitis and encephalitis) at 26 German hospitals were studied. Furthermore, the number of common meningitis-preceding ear-nose-throat infections (sinusitis, mastoiditis and otitis media) was evaluated. RESULTS: Compared to the previous years, the total number of patients diagnosed with pneumococcal meningitis was reduced (n = 64 patients/year in 2020 vs. n = 87 to 120 patients/year between 2016 and 2019, all p < 0.05). Additionally, the total number of patients diagnosed with otolaryngological infections was significantly lower (n = 1181 patients/year in 2020 vs. n = 1525 to 1754 patients/year between 2016 and 2019, all p < 0.001). We also observed a decline in viral meningitis and especially enterovirus meningitis (n = 25 patients/year in 2020 vs. n = 97 to 181 patients/year between 2016 and 2019, all p < 0.001). DISCUSSION: This multicentre retrospective analysis demonstrates a decline in the number of patients treated for viral and pneumococcal meningitis as well as otolaryngological infections in 2020 compared to previous years. Since the latter often precedes pneumococcal meningitis, this may point to the significance of the direct spread of pneumococci from an otolaryngological focus such as mastoiditis to the brain as one important pathophysiological route in the development of pneumococcal meningitis.

Early postictal serum lactate concentrations are superior to serum creatine kinase concentrations in distinguishing generalized tonic-clonic seizures from syncopes.

Concentrations of serum creatine kinase (CK) and serum lactate are frequently measured to help differentiate between generalized tonic-clonic seizures (GTCS) and syncope. The aim of this prospective cohort study was to systematically compare these two markers. The primary outcome is the measurement of serum lactate and CK in blood samples drawn within 2 h of the event in patients admitted with either a GTCS (n = 49) or a syncope (n = 36). Furthermore, the specificity and sensitivity of serum lactate and CK are determined as diagnostic markers in distinguishing between GTCS and syncope. GTCS patients have significantly higher serum lactate levels compared to syncope patients (p < 0.001). In contrast, CK does not differ between groups at admission. Regarding the first hour after the seizure, we identify a cut-off for serum lactate of 2.45 mmol/l for diagnosing GTCS as the cause of an impairment of consciousness with a sensitivity of 0.94 and a specificity of 0.93 (AUC: 0.97; 95% CI 0.94-1.0). In the second hour after the event, the ROC analysis yields similar results (AUC: 0.94; 95% CI 0.85-1.0). Serum lactate is a sensitive and specific diagnostic marker to discriminate GTCS from syncope and is superior to CK early after admission to the emergency department.