Dissociation of motor control from motor awareness in awake sleepwalkers: An EEG study in virtual reality.

Recent behavioral evidence from a virtual reality (VR) study indicates that awake sleepwalkers show dissociation of motor control and motor awareness. This dissociation resembles the nocturnal disintegration of motor awareness and movement during episodes of sleepwalking. Here, we set out to examine the neural underpinnings of altered motor awareness in sleepwalkers by measuring EEG modulation during redirected walking in VR. To this end, we measured scalp EEG during ongoing motor behavior to provide information on motor processing and its modulation in VR. Using this approach, we discovered distinct EEG patterns associated to dual tasking and sub-threshold motor control in sleepwalkers compared to control subjects. These observations provide further electrophysiological evidence for the proposed brain-body dissociation in awake sleepwalkers. This study shows proof-of-principle that EEG biomarkers of movement in a VR setting add to the understanding of altered motor awareness in sleepwalkers. In a broader perspective, we confirm the feasibility of using the additional dimensionality in VR providing novel diagnostic biomarkers not accessible to conventional clinical investigations. In future studies, this approach could contribute to the diagnostic work-up of patients with a broad spectrum of neurological diseases.

Predictive value of EEG in postanoxic encephalopathy: A quantitative model-based approach.

INTRODUCTION: The majority of comatose patients after cardiac arrest do not regain consciousness due to severe postanoxic encephalopathy. Early and accurate outcome prediction is therefore essential in determining further therapeutic interventions. The electroencephalogram is a standardized and commonly available tool used to estimate prognosis in postanoxic patients. The identification of pathological EEG patterns with poor prognosis relies however primarily on visual EEG scoring by experts. We introduced a model-based approach of EEG analysis (state space model) that allows for an objective and quantitative description of spectral EEG variability. METHODS: We retrospectively analyzed standard EEG recordings in 83 comatose patients after cardiac arrest between 2005 and 2013 in the intensive care unit of the University Hospital Zürich. Neurological outcome was assessed one month after cardiac arrest using the Cerebral Performance Category. For a dynamic and quantitative EEG analysis, we implemented a model-based approach (state space analysis) to quantify EEG background variability independent from visual scoring of EEG epochs. Spectral variability was compared between groups and correlated with clinical outcome parameters and visual EEG patterns. RESULTS: Quantitative assessment of spectral EEG variability (state space velocity) revealed significant differences between patients with poor and good outcome after cardiac arrest: Lower mean velocity in temporal electrodes (T4 and T5) was significantly associated with poor prognostic outcome (p<0.005) and correlated with independently identified visual EEG patterns such as generalized periodic discharges (p<0.02). Receiver operating characteristic (ROC) analysis confirmed the predictive value of lower state space velocity for poor clinical outcome after cardiac arrest (AUC 80.8, 70% sensitivity, 15% false positive rate). CONCLUSION: Model-based quantitative EEG analysis (state space analysis) provides a novel, complementary marker for prognosis in postanoxic encephalopathy.

Cognitive impairment is not a predictor of failure to adhere to anticoagulation of stroke patients with atrial fibrillation.

BACKGROUND: Oral anticoagulation (OAC) with vitamin K antagonists (VKA) or direct oral anticoagulants (DOAC) is an effective strategy that is used for stroke prevention in patients with atrial fibrillation (AF). However, OAC is underused particularly in elderly patients, who are often physically disabled or cognitively impaired. We aimed at evaluating the effect of cognitive status and disability on OAC adherence 1 year after stroke or TIA. METHODS: In this prospective, single-center, observational study patients with ischemic stroke or TIA were consecutively included between 3/2011 and 9/2012. The detailed medical history, basic demographic variables, cardiovascular risk factors, stroke severity according to the National Institutes of Health Stroke Scale (NIHSS), medication including OAC were all recorded. Cognitive performance was measured using the Montreal Cognitive Assessment (MoCA) score at baseline. The functional status was assessed by recording activities and instrumental activities of daily living, respectively (ADL, IADL). After 12 months, patients had a follow-up visit to reassess the cognitive and functional status (MoCA, ADL and IADL) and to document the current use of OAC. RESULTS: In total, 12 months after the ischemic stroke or TIA AF had been diagnosed in 160/586 (27.3%). Of these, 151 patients (94.4%) were treated with OAC. OAC was performed using VKA in 79/151 (52.3%) and DOACs in 72/151 (47.7%). Cognitive impairment at 12 months follow-up was not associated with the absence of OAC treatment. However, regression analysis revealed that patients with AF with physical (ADL) and functional disability (IADL) were less likely to be treated with OAC (p = 0.08 and p = 0.04, respectively) 12 months after a stroke. None of these two factors, however, was independently associated with nonadherence to OAC 12 months after stroke. Although cognitive performance was similar in patients receiving VKA and direct anticoagulants (DOAC), adherence to VKA tended to be lower (82.6 vs. 94.6%, p = 0.12). CONCLUSIONS: In stroke and TIA patients with AF, the multifactorial medical and functional constellation rather than cognitive impairment specifically can be an obstacle for long-term OAC.

Renal failure caused by malakoplakia lesions of the urinary bladder.

Μalakoplakia is a rare inflammatory condition of the urogenital tract. The most frequently affected organ is urinary bladder. This condition has features of a granulomatous inflammation, the pathogenesis of which is not well understood. In this study, we presented a case of urinary bladder malakoplakia associated with advanced obstructive uropathy and renal failure.