True first-pass effect in basilar artery occlusions: First-pass complete reperfusion improves clinical outcome in stroke thrombectomy patients.

BACKGROUND: Complete reperfusion (mTICI 3) in anterior circulation ischemic stroke patients after a single mechanical thrombectomy (MT) pass has been identified as a predictor of favorable outcome (modified Rankin Score 0-2) and defined as true first-pass effect recently. This effect has not yet been demonstrated in posterior circulation ischemic stroke. We hypothesized a true first-pass effect for the subgroup of acute basilar artery occlusions (BAO). METHODS: Consecutive patients with acute thromboembolic occlusions in the posterior circulation, treated between 2010 and 2017, were screened and all BAO patients with complete angiographic reperfusion and known symptom onset included for unmatched and matched analysis after adjustment for multiple confounding factors (demographics, time intervals, stroke severity, posterior circulation Alberta Stroke Program early computed tomography Score and comorbidity. The primary objective was outcome at 90 days between matched cohorts of single pass vs. multi pass complete reperfusion patients. RESULTS: 90 MTs in BAO were analyzed, yielding 56 patients with known symptom onset, in whom we achieved complete reperfusion (mTICI 3), depending on whether complete reperfusion was achieved after a single pass (n = 28) or multiple passes (n = 28). Multivariable analysis of 56 non-matched patients revealed a significant association between first-pass complete reperfusion and favorable outcome (p < 0.01). In matched cohorts (n = 7 vs. n = 7), favorable outcome was only seen if complete reperfusion was achieved after a single pass (86% vs. 0%). CONCLUSION: Single pass complete reperfusion in acute basilar artery occlusion is an independent predictor of favorable outcome. Achieving complete reperfusion after multiple passes might impair favorable patient recovery.

[Estimation of prevalence and treatment needs of mental disorders. The problem of diagnostic thresholds]. / Abschätzung von Prävalenz und Behandlungsbedarf psychischer Störungen. Das Problem diagnostischer Schwellen.

BACKGROUND: Uncertainties in the context of threshold-based diagnostics represent a theoretically unsolved methodological problem that may require multidimensional solutions. Pragmatically, current research focuses on establishing reliable and valid operationalized criteria within the framework of diagnostic systems, such as the International Classification of Diseases (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders (DSM). AIM AND METHODS: By means of model calculations based on epidemiological data we show how exemplified changes in the disorder spectrum and diagnostic criteria influence case numbers. Furthermore, we investigate how threshold-based constructs, such as DSM-IV diagnoses, relate to the general criteria of illness and sickness. RESULTS: Variations in the disorder spectrum and thresholds lead to slight to moderate changes in case numbers. Regarding distress and impairment, mental disorders are associated with significantly reduced health-related quality of life and an increased number of days out of role (due to mental and/or physical problems). With increasing distress and impairment, the percentage of mental disorders increases significantly; in the 5 % of the general population with the highest distress and impairment, the proportion is nearly 80 %. DISCUSSION: Despite fuzzy boundaries, threshold-based diagnoses (DSM-IV) represent a satisfactory and reproducible disease classification (in terms of illness and sickness) for estimation of prevalence. There is a lack of definitions and instruments to assess treatment needs. It is still debated whether diagnostic symptom criteria always represent pathological disorders (i. e. disease).

[Neurocognitive disorders in DSM-5: pervasive changes in the diagnostics of dementia]. / Neurokognitive Störungen im DSM-5 : Durchgreifende Änderungen in der Demenzdiagnostik.

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) proposes an innovative chapter on neurocognitive disorders (NCD) as a substitute for the dementia, delirium and amnestic disorders chapter in DSM-IV. This NCD chapter promotes a most innovative change compared to DSM-IV. While the term delirium is preserved, the commonly used term dementia does not occur as a diagnostic entity. Neurocognitive disorders are more inclusive than dementias; they also cover early prodromal stages of dementias below the DSM-IV threshold. The diagnosis of NCDs requires essentially neuropsychological testing preferentially with standardized instruments. Special focus is given to etiological subtyping taking former diagnostic consensus processes by expert groups into consideration. The subsequent more extensive concept of NCD also allows the diagnosis of etiological-specific prodromal states of cognitive impairments. The changes from DSM-IV to DSM-5 are critically discussed.

External trial deep brain stimulation device for the application of desynchronizing stimulation techniques.

In the past decade deep brain stimulation (DBS)-the application of electrical stimulation to specific target structures via implanted depth electrodes-has become the standard treatment for medically refractory Parkinson's disease and essential tremor. These diseases are characterized by pathological synchronized neuronal activity in particular brain areas. We present an external trial DBS device capable of administering effectively desynchronizing stimulation techniques developed with methods from nonlinear dynamics and statistical physics according to a model-based approach. These techniques exploit either stochastic phase resetting principles or complex delayed-feedback mechanisms. We explain how these methods are implemented into a safe and user-friendly device.

Long-lasting desynchronization in rat hippocampal slice induced by coordinated reset stimulation.

In computational models it has been shown that appropriate stimulation protocols may reshape the connectivity pattern of neural or oscillator networks with synaptic plasticity in a way that the network learns or unlearns strong synchronization. The underlying mechanism is that a network is shifted from one attractor to another, so that long-lasting stimulation effects are caused which persist after the cessation of stimulation. Here we study long-lasting effects of multisite electrical stimulation in a rat hippocampal slice rendered epileptic by magnesium withdrawal. We show that desynchronizing coordinated reset stimulation causes a long-lasting desynchronization between hippocampal neuronal populations together with a widespread decrease in the amplitude of the epileptiform activity. In contrast, periodic stimulation induces a long-lasting increase in both synchronization and amplitude.