Dziewas et al. Neurological Research and Practice (2021) 3:23 Neurological Research https://doi.org/10.1186/s42466-021-00122-3 and Practice GUIDELINES Open Access Diagnosis and treatment of neurogenic dysphagia – S1 guideline of the German Society of Neurology Rainer Dziewas1,2* , Hans-Dieter Allescher3, Ilia Aroyo4, Gudrun Bartolome5, Ulrike Beilenhoff6, Jörg Bohlender7, Helga Breitbach-Snowdon8, Klemens Fheodoroff9, Jörg Glahn10, Hans-Jürgen Heppner11, Karl Hörmann12, Christian Ledl13, Christoph Lücking14, Peter Pokieser15, Joerg C. Schefold16, Heidrun Schröter-Morasch17, Kathi Schweikert18, Roland Sparing19, Michaela Trapl-Grundschober20, Claus Wallesch21, Tobias Warnecke1, Cornelius J. Werner22, Johannes Weßling23, Rainer Wirth24 and Christina Pflug25 Abstract Introduction: Neurogenic dysphagia defines swallowing disorders caused by diseases of the central and peripheral nervous system, neuromuscular transmission, or muscles. Neurogenic dysphagia is one of the most common and at the same time most dangerous symptoms of many neurological diseases. Its most important sequelae include aspiration pneumonia, malnutrition and dehydration, and affected patients more often require long-term care and are exposed to an increased mortality. Based on a systematic pubmed research of related original papers, review articles, international guidelines and surveys about the diagnostics and treatment of neurogenic dysphagia, a consensus process was initiated, which included dysphagia experts from 27 medical societies. Recommendations: This guideline consists of 53 recommendations covering in its first part the whole diagnostic spectrum from the dysphagia specific medical history, initial dysphagia screening and clinical assessment, to more refined instrumental procedures, such as flexible endoscopic evaluation of swallowing, the videofluoroscopic swallowing study and high-resolution manometry. In addition, specific clinical scenarios are captured, among others the management of patients with nasogastric and tracheotomy tubes. The second part of this guideline is dedicated to the treatment of neurogenic dysphagia. Apart from dietary interventions and behavioral swallowing treatment, interventions to improve oral hygiene, pharmacological treatment options, different modalities of neurostimulation as well as minimally invasive and surgical therapies are dealt with. Conclusions: The diagnosis and treatment of neurogenic dysphagia is challenging and requires a joined effort of different medical professions. While the evidence supporting the implementation of dysphagia screening is rather convincing, further trials are needed to improve the quality of evidence for more refined methods of dysphagia diagnostics and, in particular, the different treatment options of neurogenic dysphagia. The present article is an abridged and translated version of the guideline recently published online (https://www.awmf.org/uploads/tx_ szleitlinien/030-111l_Neurogene-Dysphagie_2020-05.pdf). * Correspondence: [email protected] 1Klinik für Neurologie, Universitätsklinik Münster, 48149 Münster, Germany 2Klinik für Neurologie und Neurologische Frührehabilitation, Klinikum Osnabrück, Am Finkenhügel 1, 49076 Osnabrück, Germany Full list of author information is available at the end of the article © The Author(s). 2021 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Dziewas et al. Neurological Research and Practice (2021) 3:23 Page 2 of 30 Introduction mortality [11]. Patients with inflammatory muscle disor- The present article is an abridged and translated version ders are also often subject to swallowing impairment. of the guideline recently published online (https://www. The frequency is approximately 20 % in dermatomyo- awmf.org/uploads/tx_szleitlinien/030-111l_Neurogene- sitis, 30–60 % in polymyositis, and between 65 and 86 % Dysphagie_2020-05.pdf). The act of swallowing is a in inclusion body myositis [12]. Finally, dysphagia is also highly complex neuromuscular process that requires a major diagnostic and therapeutic challenge in the in- precise bilateral coordination of more than 25 muscle tensive care unit [13]. Regardless of the primary illness, pairs. Using different imaging techniques, numerous 70–80 % of patients requiring prolonged mechanical physiological studies have consistently demonstrated ventilation present, at least temporarily, with significant that apart from the well-established role of the brain swallowing impairment and aspiration after successful stem, different cortical areas are involved in the modula- weaning, probably due to a critical illness polyneurop- tion of swallowing. Based on these findings, athy and structural changes caused by the artificial air- reorganization mechanisms have been further explored way like edema of the arytenoids [14]. This impairment and form the neuroscientific basis for treatment ap- not only necessitates prolonged artificial nutrition, but is proaches using different neurostimulation modalities. also linked to serious complications, such as pneumonia Neurogenic dysphagia defines swallowing disorders and the necessity for reintubation and is in addition an caused by diseases of the CNS, PNS, neuromuscular independent predictor of increased mortality [13]. transmission, or muscles. In contrast to this uniformity Regardless of the underlying diseases, the risk of devel- suggestive term, swallowing disorders caused by specific oping a swallowing disorder increases significantly with diseases differ considerably in terms of their clinical age. Thus, dysphagia is found in 30-40% of independently presentation, the respective therapeutic options, and the living older people [15], while more than 50% of nursing prognosis. Dysphagia is one of the most common and at home residents [16] and approximately 70% of all geriatric the same time most dangerous symptoms of many in-patients are affected by this disorder [17]. As with other neurological diseases. Impaired deglutition is initially patient groups, in geriatric patients dysphagia increases found in at least 50% of all patients with ischemic or the risk of pneumonia and malnutrition [18] with the crit- hemorrhagic stroke [1]. Affected patients have a 4 times ical consequences of reduced physical and mental capabil- increased risk of aspiration pneumonia, suffer more ities and, ultimately, increased frailty [19]. often from a long-lasting severe disability, are more Finally swallowing disorders can also occur as a side often discharged to nursing homes, and also show sig- effect of pharmacotherapy or at least be critically wors- nificantly increased mortality [2]. Comparable numbers ened [20]. First of all, both typical and atypical neurolep- have been published for traumatic brain injury with a re- tics may cause dysphagia which may occur as either ported incidence of clinically relevant dysphagia in about bradykinetic or dyskinetic form [21]. As shown in a re- 60% of patients [3]. In this patient collective, the pres- cent systematic review, there is a dose-response relation- ence of dysphagia is associated with a significantly ex- ship between the dosage of neuroleptic medication and tended time on mechanical ventilation and a longer the risk of pneumonia [22]. Also, treatment with benzo- need for artificial nutrition. In all Parkinson syndromes, diazepine receptor agonists is associated with an in- neurogenic dysphagia is also a major risk factor for creased risk of pneumonia, although the pneumonia, which is the leading cause of death in these pathophysiological link with a possible drug-induced patients [4, 5]. Furthermore, swallowing disorders in dysphagia for this group of substances is not clearly doc- these patients are associated with a reduced quality of umented [20]. Finally, experimental studies have shown life, insufficient drug effects, and malnutrition [6, 7]. 20- that intravenously injection of opiates is associated with 30% of patients with dementia have severe dysphagia an acute deterioration of pharyngeal swallowing function with silent aspiration that goes unnoticed by the patients and an increased risk of aspiration [23]. However, the [8]. Dysphagia is also a prominent clinical feature in clinical significance of this finding is still unclear, since various neuromuscular diseases. Up to 30% of patients in recently extubated intensive care patients, for ex- with amyotrophic lateral sclerosis present with impaired ample, the occurrence of silent aspirations did not cor- swallowing at diagnosis [9] and practically all of them relate with the cumulative opiate dose [24]. develop dysphagia as the disease progresses. Myasthenia This guideline addresses general issues regarding diag- Gravis manifests itself in 15% of cases with swallowing nosis