Rainer Dziewas

Universitätsklinikum Münster, Muenster, North Rhine-Westphalia, Germany

Are you Rainer Dziewas?

Claim your profile

Publications (161)462.02 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Although early identification of patients at risk for dysphagia is crucial in acute stroke care, predicting whether a particular patient is likely to have swallowing problems based on the brain scan is difficult because a comprehensive model of swallowing control is missing. In this study whether stroke location is associated with dysphagia incidence, severity and the occurrence of penetration or aspiration was systematically evaluated relying on a voxel-based imaging analysis approach. Two hundred acute stroke patients were investigated applying fiberoptic endoscopic evaluation of swallowing within 96 h from admission. Lesion masks were obtained from each patient's brain scan and registered to standard space. The percentage of lesioned volume of 137 atlas-based brain regions was determined in each case. Region-specific odds ratios were afterwards calculated with respect to presence of dysphagia, its severity and occurrence of penetration or aspiration. In all, 165 patients were diagnosed with dysphagia, 80 of whom had severe swallow impairment. For each investigated item there were significant differences of regional percentage infarction in distinct brain areas between affected patients and those who did not present with that specific dysfunction. In particular, right hemispheric lesions of the pre- and post-central gyri, opercular region, supramarginal gyrus and respective subcortical white matter tracts were related to dysphagia, with post-central lesions being especially associated with severe swallowing impairment. Distinct brain lesion locations are related to the incidence, severity and pattern of swallowing dysfunction. © 2015 EAN.
    European Journal of Neurology 05/2015; 22(5):832-8. DOI:10.1111/ene.12670 · 3.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose: To prove the tissue-protecting effect of mechanical recanalization, we assessed the CT perfusion-based tissue outcome ("TO") and correlated this imaging parameter with the 3-month clinical outcome ("CO"). Materials and Methods: 159 patients with large intracranial artery occlusions revealing mechanical recanalization were investigated by CCT, CT angiography (CTA) and CT perfusion (CTP) upon admission. For the final infarct volume, native CCT was repeated after 24 h. The "TO" ("percentage mismatch loss" = %ML) was defined as the difference between initial penumbral tissue on CTP and final infarct volume on follow-up CCT. We monitored the three-month modified Rankin Scale (mRS), age, bleeding occurrence, time to recanalization, TICI score and collateralization grade, infarct growth and final infarct volume. Spearman's correlation and nominal regression analysis were used to evaluate the impact of these parameters on mRS. Results: Significant correlations were found for %ML and mRS (c = 0.48, p < 0.001), for final infarct volume and mRS (c = 0.52, p < 0.001), for TICI score and mRS (c = - 0.35, p < 0.001), for initial infarct core and mRS (c = 0.14, p = 0.039) as well as for age and mRS (c = 0.37, p < 0.001). According to the regression analysis, %ML predicted the classification of mRS correctly in 38.5 % of cases. The subclasses mRS 1 and 6 could be predicted by %ML with 86.4 % and 60.9 % reliability, respectively. No correlations were found for time to recanalization and mRS, for collateralization grade and mRS, and for post-interventional bleeding and mRS. Conclusion: Better than the TICI score, CT-based TO predicts the clinical success of mechanical recanalization, showing that not recanalization, but reperfusion should be regarded as a surrogate parameter for stroke therapy. Key Points: • %ML as well as the final infarct volume can make a direct point about the immediate effect of successful mechanical recanalization.• The clinical outcomes after mechanical recanalization are reliably predicted by %ML, reflecting the benefit of escalation therapy including interventional reopening of parent vessel occlusions.• Not recanalization but rather reperfusion should be regarded as a surrogate parameter for successful stroke therapy. Citation Format: • Drewer-Gutland F, Kemmling A, Ligges S et al. CTP-Based Tissue Outcome: Promising Tool to Prove the Beneficial Effect of Mechanical Recanalization in Acute Ischemic Stroke. Fortschr Röntgenstr 2015; DOI: 10.1055/s-0034-1399189. © Georg Thieme Verlag KG Stuttgart · New York.
    RöFo - Fortschritte auf dem Gebiet der R 04/2015; DOI:10.1055/s-0034-1399189 · 1.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: An increasing number of stroke patients have to be supported by mechanical ventilation in intensive care units (ICU), with a relevant proportion of them requiring gradual withdrawal from a respirator. To date, weaning studies have focused merely on mixed patient groups, COPD patients or patients after cardiac surgery. Therefore, the best weaning strategy for stroke patients remains to be determined. Here, we designed a prospective randomized controlled study comparing adaptive support ventilation (ASV), a continuous weaning strategy, with biphasic positive airway pressure (BIPAP) in combination with spontaneous breathing trials, a discontinuous technique, in the treatment of stroke patients. The primary endpoint was the duration of the weaning process. Only the 40 (out of 54) patients failing in an initial spontaneous breathing trial (T-piece test) were included into the study; the failure proportion is considerably larger compared to previous studies. Eligible patients were pseudo-randomly assigned to one of the two weaning groups. Both groups did not differ regarding age, gender, and severity of stroke. The results showed that the median weaning duration was 10.7 days (±SD 7.0) in the discontinuous weaning group, and 8 days (±SD 4.5) in the continuous weaning group (p < 0.05). To the best of our knowledge, this is the first clinical study to show that continuous weaning is significantly more effective compared to discontinuous weaning in mechanically ventilated stroke patients. We suppose that the reason for the superiority of continuous weaning using ASV as well as the bad performance of our patients in the 2 h T-piece test is caused by the patients' compliance. Compared to patients on surgical and medical ICUs, neurological patients more often suffer from reduced vigilance, lack of adverse-effects reflexes, dysphagia, and cerebral dysfunction. Therefore, stroke patients may profit from a more gradual withdrawal of weaning. © 2015 S. Karger AG, Basel.
    Cerebrovascular Diseases 04/2015; 39(5-6):269-277. DOI:10.1159/000381222 · 3.70 Impact Factor
  • P Muhle, R Wirth, J Glahn, R Dziewas
    [Show abstract] [Hide abstract]
    ABSTRACT: The term presbyphagia refers to all changes of swallowing physiology that are manifested with increasing age. Alterations in the pattern of deglutition that are part of healthy aging are called primary presbyphagia. Primary presbyphagia is not an illness in itself but contributes to a more pervasive naturally diminished functional reserve, making older adults more susceptible to dysphagia. If disorders in swallowing occur in the elderly as a comorbidity of a specific disease, for example stroke or neurodegenerative disorders, this is called secondary presbyphagia. Increasing age has an impact on each stage of deglutition. In the oral preparatory phase a diminished input for smell and taste as well as a usually multifactorial cause of dry mouth are the most important influencing factors. Sarcopenia, the degenerative loss of skeletal muscle mass, strength and quality associated with aging, interferes in particular with the oropharyngeal phase. A decreased sensory feedback from the oropharyngeal mucosa leads to a delayed triggering of the swallowing reflex. Finally, a reduction in connective tissue elasticity and changes of the axial skeleton lead to various modifications of the swallowing pattern with advanced age.
    Der Nervenarzt 04/2015; DOI:10.1007/s00115-014-4183-7 · 0.86 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The act of swallowing is a complex neuromuscular function that is processed in a distributed network involving cortical, subcortical and brainstem structures. Difficulty in swallowing arises from a variety of neurologic diseases for which therapeutic options are currently limited. Pharyngeal electrical stimulation (PES) is a novel intervention designed to promote plastic changes in the pharyngeal motor cortex to aid dysphagia rehabilitation. In the present study we evaluate the effect of PES on cortical swallowing network activity and associated changes in swallowing performance.
    NeuroImage 01/2015; 104. DOI:10.1016/j.neuroimage.2014.10.016 · 6.13 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Eligibility criteria are a key factor for the feasibility and validity of clinical trials. We aimed to develop an online tool to assess the potential effect of inclusion and exclusion criteria on the proportion of patients eligible for an acute stroke trial.
    Stroke 11/2014; 46(1). DOI:10.1161/STROKEAHA.114.007124 · 6.02 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: PurposeA prospective, epidemiologic study was conducted to assess whether the 2009 pandemic influenza A(H1N1) vaccination in Germany almost exclusively using an AS03-adjuvanted vaccine (Pandemrix) impacts the risk of Guillain–Barré syndrome (GBS) and its variant Fisher syndrome (FS).Methods Potential cases of GBS/FS were reported by 351 participating hospitals throughout Germany. The self-controlled case series methodology was applied to all GBS/FS cases fulfilling the Brighton Collaboration (BC) case definition (levels 1–3 of diagnostic certainty) with symptom onset between 1 November 2009 and 30 September 2010 reported until end of December 2010.ResultsOut of 676 GBS/FS reports, in 30 cases, GBS/FS (BC levels 1–3) occurred within 150 days following influenza A(H1N1) vaccination. The relative incidence of GBS/FS within the primary risk period (days 5–42 post-vaccination) compared with the control period (days 43–150 post-vaccination) was 4.65 (95%CI [2.17, 9.98]). Similar results were found when stratifying for infections within 3 weeks prior to onset of GBS/FS and when excluding cases with additional seasonal influenza vaccination. The overall result of temporally adjusted analyses supported the primary finding of an increased relative incidence of GBS/FS following influenza A(H1N1) vaccination.Conclusions The results indicate an increased risk of GBS/FS in temporal association with pandemic influenza A(H1N1) vaccination in Germany. © 2014 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 11/2014; 23(11). DOI:10.1002/pds.3638 · 3.17 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Purpose/Aim Cerebrovascular events (CVE) in HIV infected patients have become an increasingly relevant neurological complication. Data about the prevalence and clinical features of CVE in HIV infected patients since the introduction of combined Anti-Retroviral Therapy (cART) are rare. Methods A retrospective study of HIV-infected patients with a CVE was performed from 2002-2011. During this time period 3203 HIV-infected patients were admitted to the University hospital of Muenster, Germany. All patients had access to regular and long term treatment with cART. The clinical features were analyzed and the prevalence of ischemic stroke (IS), transient ischemic attack (TIA) and intracerebral bleeding (ICB) was calculated. Results The total prevalence of all CVE was at 0.6% (95% CI: 0.3, 0.8) (0.4% for IS (95% CI: 0.2, 0.6), 0.2% for TIA (95% CI: 0.0, 0.3) and 0.1% for ICB (95% CI: 0.0, 0.2)) and the crude annual incidence rate at 59 per 100.000 for all events. The median CD4 cell count was 405/μl (25(th) to 75(th) percentile: 251-568). The majority of patients had AIDS. The median age was at 49 years (25(th) to 75(th) percentile: 40-69). Some events were associated with HIV-associated vasculopathy or viral co-infections. Most patients presented with multiple vascular risk factors. Conclusion The study confirms that CVE occur in HIV-infected patients with a good immune status and at a young age. HIV infection has to be considered in young stroke patients. The rate of CVE in this study was constant when comparing to the pre-cART era. HIV associated vasculopathy and viral co-infections need to be considered in the diagnostics of stroke.
    International Journal of Neuroscience 08/2014; DOI:10.3109/00207454.2014.956870 · 1.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Neurogenic dysphagia is one of the most frequent and prognostically relevant neurological deficits in a variety of disorders, such as stroke, parkinsonism and advanced neuromuscular diseases. Flexible endoscopic evaluation of swallowing (FEES) is now probably the most frequently used tool for objective dysphagia assessment in Germany. It allows evaluation of the efficacy and safety of swallowing, determination of appropriate feeding strategies and assessment of the efficacy of different swallowing manoeuvres. The literature furthermore indicates that FEES is a safe and well-tolerated procedure. In spite of the huge demand for qualified dysphagia diagnostics in neurology, a systematic FEES education has yet not been established. The structured training curriculum presented in this article aims to close this gap and intends to enforce a robust and qualified FEES service. As management of neurogenic dysphagia is not confined to neurologists, this educational program is applicable to other clinicians and speech language therapists with expertise in dysphagia as well.
    Der Nervenarzt 07/2014; 85(8). DOI:10.1007/s00115-014-4114-7 · 0.86 Impact Factor
  • Parkinsonism & Related Disorders 06/2014; 20(9). DOI:10.1016/j.parkreldis.2014.06.016 · 4.13 Impact Factor
  • Aktuelle Ernährungsmedizin 05/2014; 39(03):174-186. DOI:10.1055/s-0033-1343218
  • Gastrointestinal Endoscopy 05/2014; 79(5):AB515. DOI:10.1016/j.gie.2014.02.815 · 4.90 Impact Factor
  • Der Nervenarzt 04/2014; 85(4):482-4. · 0.86 Impact Factor
  • Parkinsonism & Related Disorders 04/2014; 20(4). DOI:10.1016/j.parkreldis.2014.01.007 · 4.13 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Current neuroimaging research on functional disturbances provides growing evidence for objective neuronal correlates of allegedly psychogenic symptoms, thereby shifting the disease concept from a psychological towards a neurobiological model. Functional dysphagia is such a rare condition, whose pathogenetic mechanism is largely unknown. In the absence of any organic reason for a patient's persistent swallowing complaints, sensorimotor processing abnormalities involving central neural pathways constitute a potential etiology. In this pilot study we measured cortical swallow-related activation in 5 patients diagnosed with functional dysphagia and a matched group of healthy subjects applying magnetoencephalography. Source localization of cortical activation was done with synthetic aperture magnetometry. To test for significant differences in cortical swallowing processing between groups, a non-parametric permutation test was afterwards performed on individual source localization maps. Swallowing task performance was comparable between groups. In relation to control subjects, in whom activation was symmetrically distributed in rostro-medial parts of the sensorimotor cortices of both hemispheres, patients showed prominent activation of the right insula, dorsolateral prefrontal cortex and lateral premotor, motor as well as inferolateral parietal cortex. Furthermore, activation was markedly reduced in the left medial primary sensory cortex as well as right medial sensorimotor cortex and adjacent supplementary motor area (p<0.01). Functional dysphagia - a condition with assumed normal brain function - seems to be associated with distinctive changes of the swallow-related cortical activation pattern. Alterations may reflect exaggerated activation of a widely distributed vigilance, self-monitoring and salience rating network that interferes with down-stream deglutition sensorimotor control.
    PLoS ONE 02/2014; 9(2):e89665. DOI:10.1371/journal.pone.0089665 · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Stroke is regularly accompanied by dysphagia and other factors associated with decreased nutritional intake. Dysphagia with aspiration pneumonia and insufficient nutritional intake lead to worse outcome after stroke.This guideline is the first chapter of the guideline "Clinical Nutrition in Neurology" of the German Society for Clinical Nutrition (DGEM) which itself is one part of a comprehensive guideline about all areas of Clinical Nutrition. The thirty-one recommendations of the guideline are based on a systematic literature search and review, last updated December 31, 2011. All recommendations were discussed and consented at several consensus conferences with the entire DGEM guideline group. The recommendations underline the importance of an early screening and assessment of dysphagia and give advice for an evidence based and comprehensive nutritional management to avoid aspiration, malnutrition and dehydration.
    Experimental and Translational Stroke Medicine 12/2013; 5(1):14. DOI:10.1186/2040-7378-5-14
  • Sonja Suntrup, Rainer Dziewas
    [Show abstract] [Hide abstract]
    ABSTRACT: Swallowing is an essential part of life, whose central neural processing has increasingly been explored over the last two decades. Besides the well-known significance of medullary structures, involvement of a bilateral, widely distributed cortical and subcortical network has been shown. Moreover, the role of distinct brain areas could be related to specific aspects of swallowing control. Stroke is the most frequent reason for swallowing dysfunction. Dysphagia in stroke has a reported incidence of approximately 50% and is associated with increased mortality due to aspiration pneumonia. While 15% of patients suffer from persistent dysphagia, the majority shows fast recovery of swallow function within days to weeks. Thus, stroke constitutes a convenient lesion model to evaluate functional recovery due to spontaneous neuronal plasticity and following therapeutic interventions. The remarkable recovery of stroke-related dysphagia depends on compensatory reorganization in the undamaged hemisphere. The focus of treatment studies is therefore shifting from exercise-based manipulation of swallowing biomechanics towards approaches that modulate the underlying neural systems. By influencing cortical excitability and activity levels these methods are said to promote structural and functional reorganization resulting in clinical improvement. Techniques include those applied to the cortex like transcranial magnetic or direct current stimulation, but also those applied to the periphery, such as pharyngeal electrical stimulation. Some of these techniques have reached a stage of development that makes future use in clinical practice conceivable. Increasing the effect size and duration by further optimizing stimulation protocols will be a crucial issue.
    Klinische Neurophysiologie 11/2013; 44(04):247-256. DOI:10.1055/s-0033-1357208 · 0.33 Impact Factor
  • Aktuelle Ernährungsmedizin 08/2013; 38(04):e49-e89. DOI:10.1055/s-0033-1343317
  • Der Nervenarzt 08/2013; 84(8):1003. DOI:10.1007/s00115-013-3855-z · 0.86 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: : Decisions regarding tracheostomy tube removal after mechanical ventilation often depend on the physician's individual experience because evidence-based practice guidelines are still scarce, especially for critically ill neurologic patients. In these patients, the prevalence of aspiration is high and regarded as an important contributor to decannulation failure. The presence of severe neurological deficits may, however, give clinicians the subjective impression that a tracheostomy tube is still necessary although decannulation may actually be safe. It is therefore crucial to test swallowing function reliably prior to decannulation in this patient population. : Prospective observational study. : University hospital, neurological ICU. : One hundred tracheostomized patients with acute neurologic disease completely weaned from mechanical ventilation. : An endoscopic protocol evaluating readiness for decannulation and a conventional clinical swallowing examination were carried out by separate, experienced practitioners blinded to each other's decisions. Patient management always followed the decision made with endoscopy. : Practitioners' decannulation decisions (yes/no) reached with both assessments were compared. Decannulated patients were monitored throughout their stay for complications related to tube removal. Endoscopy was performed successfully in all subjects without any complications. Following the protocol, the tracheostomy tube was successfully removed in 54 patients, whereas according to the clinical swallowing examination, only 29 patients would have been decannulated at that point. Only one patient needed recannulation due to respiratory problems, resulting in a failure rate of 1.9%. : In neurologic patients, speech-language pathologists' impressions about the patient's state when clinically assessing indirect variables of swallowing function often lead to the unnecessary prolongation of cannulation time. Endoscopic evaluation has the advantage of objectively visualizing the patient's ability to manage secretions directly and allows for faster but, nonetheless, safe decannulation. The endoscopic protocol proposed here is a safe, efficient, and objective bedside tool to guide decannulation decisions.
    Critical care medicine 07/2013; 41(7):1728-32. DOI:10.1097/CCM.0b013e31828a4626 · 6.15 Impact Factor

Publication Stats

1k Citations
462.02 Total Impact Points


  • 2001–2015
    • Universitätsklinikum Münster
      • Klinik und Poliklinik für Neurologie
      Muenster, North Rhine-Westphalia, Germany
    • University of Münster
      • • Department of Neurology
      • • Institute of Biomagnetism and Biosignalanalysis
      Muenster, North Rhine-Westphalia, Germany
  • 2013
    • University Hospital Essen
      • Institute of Diagnostic and Interventional Radiology and Neuroradiology
      Essen, North Rhine-Westphalia, Germany
  • 2012
    • Universität Heidelberg
      • Clinik of Neurology
      Heidelberg, Baden-Wuerttemberg, Germany
  • 2003–2005
    • University of Toronto
      • Rotman Research Institute
      Toronto, Ontario, Canada