Stephanie K. Daniels

Aspiration in patients with acute stroke

OBJECTIVES To determine the frequency and clinical predictors of aspiration within 5 days of acute stroke. DESIGN Case series. SETTING Tertiary care center. PATIENTS Consecutive stroke patients (n = 55) with new neurologic deficit evaluated within 5 days of acute stroke. MAIN OUTCOME MEASURES Comparison of features identified on clinical swallowing and oromotor examinations and occurrence of aspiration (silent or overt) evident on videofluoroscopic swallow study (VSS). RESULTS Aspiration occurred in 21 of 55 patients (38%). Whereas 7 of 21 patients (33%) aspirated overtly, 14 (67%) aspirated silently on VSS. Chi-square analyses revealed that dysphonia, dysarthria, abnormal gag reflex, abnormal volitional cough, cough after swallow, and voice change after swallow were significantly related to aspiration and were predictors of the subset of patients with silent aspiration. Logistic regression revealed that abnormal volitional cough and cough with swallow, in conjunction, predicted aspiration with 78% accuracy. CONCLUSIONS Silent aspiration appears to be a significant problem in acute stroke patients because silent aspiration occurred in two thirds of the patients who aspirated. The prediction of patients at risk for aspiration was significantly improved by the presence of concurrent findings of abnormal volitional cough and cough with swallow on clinical examination.

The role of the insular cortex in dysphagia.

Abstract. Recent data indicate that dysphagia may occur following unilateral cortical stroke; however, the elucidation of specific cytoarchitectonic sites that produce deglutition disorders remains unclear. In a previous study of unilateral cortical stroke patients with dysphagia, Daniels et al. [8] proposed that the insula may be important in swallowing as it was the most common lesion site in the patients studied. Therefore, 4 unilateral stroke patients with discrete lesions of the insular cortex were studied to further facilitate understanding of the role of the insula in swallowing. Dysphagia, as confirmed by videofluoroscopy, was evident in 3 of the 4 patients; all had lesions that involved the anterior insula, whereas the only patient without dysphagia had a lesion restricted to the posterior insula. These data suggest that the anterior insula may be an important cortical substrate in swallowing. The anterior insula has connections to the primary and supplementary motor cortices, the ventroposterior medial nucleus of the thalamus, and to the nucleus tractus solitarius, all of which are important regions in the mediation of oropharyngeal swallowing. Therefore, discrete lesions of the anterior insula may disrupt these connections and, thereby, produce dysphagia.

Clinical Assessment of Swallowing and Prediction of Dysphagia Severity

Dysphagia with aspiration is prevalent in acute stroke; however, noninvasive clinical screening assessments to identify patients at risk of developing aspiration are limited. This study was underta...

Valid Items for Screening Dysphagia Risk in Patients With Stroke A Systematic Review

Background and Purpose— Screening for dysphagia is essential to the implementation of preventive therapies for patients with stroke. A systematic review was undertaken to determine the evidence-based validity of dysphagia screening items using instrumental evaluation as the reference standard. Methods— Four databases from 1985 through March 2011 were searched using the terms cerebrovascular disease, stroke deglutition disorders, and dysphagia. Eligibility criteria were: homogeneous stroke population, comparison to instrumental examination, clinical examination without equipment, outcome measures of dysphagia or aspiration, and validity of screening items reported or able to be calculated. Articles meeting inclusion criteria were evaluated for methodological rigor. Sensitivity, specificity, and predictive capabilities were calculated for each item. Results— Total source documents numbered 832; 86 were reviewed in full and 16 met inclusion criteria. Study quality was variable. Testing swallowing, generally with water, was the most commonly administered item across studies. Both swallowing and nonswallowing items were identified as predictive of aspiration. Neither swallowing protocols nor validity were consistent across studies. Conclusions— Numerous behaviors were found to be associated with aspiration. The best combination of nonswallowing and swallowing items as well as the best swallowing protocol remains unclear. Findings of this review will assist in development of valid clinical screening instruments.

Lingual Discoordination and Dysphagia following Acute Stroke: Analyses of Lesion Localization

Abstract. The mechanism and neural substrates that mediate lingual coordination during swallowing have not been well characterized. Although lingual discoordination during swallowing has been difficult to quantify, it has been defined as the random disorganization of anterior–posterior tongue movements evident in bolus propulsion. In a sample of consecutive acute stroke patients (n= 59), videofluoroscopic evaluation showed a 19% incidence of lingual discoordination during swallowing. Lingual discoordination during swallowing was not commonly associated with buccofacial apraxia, apraxia of speech, nor limb apraxia. Hemisphere and anterior–posterior localization did not predict occurrence of lingual discoordination. Lingual discoordination during swallowing occurred commonly in patients with subcortical lesions with the periventricular white matter (PVWM), the most common site of involvement. PVWM lesions may disconnect anterior and posterior cortical regions that are critical to oral control and coordination in swallowing, thereby producing lingual discoordination during swallowing. These data also suggest that the neural mechanisms that mediate lingual coordination may at least in part be independent of the neural systems that mediate buccofacial, limb, and speech praxis functions.

Lesion Localization in Acute Stroke

The objective of this prospective study was to determine whether specific neuroanatomical sites were associated with increased risk of aspiration in acute stroke patients. Videofluoroscopic swallow studies (VSS) and computed tomography or magnetic resonance imaging scans were completed on consecutive male stroke patients (n = 54). Videofluoroscopic swallow studies were scored on a scale from 0 (normal swallowing) to 4 (severe dysphagia). Patients with scores of 0–1 were grouped together as having no risk of aspiration, and patients with scores of 2–4 were grouped together as having a risk of aspiration. Lesion analyses revealed that location appeared to be more critical than hemisphere or lesion size in predicting patients at risk of aspiration. Anterior locations and subcortical periventricular white matter sites were commonly lesioned in patients with risk of aspiration, whereas patients without risk of aspiration were more likely to have posterior lesions and lesions to subcortical gray matter structures. These data demonstrate that swallowing appears to be mediated by a distributed neural network that involves both cerebral hemispheres with descending input to the medulla; however, specific lesion locations may put patients at a greater risk of aspiration.

Swallowing physiology of sequential straw drinking.

The goal of this study was to examine deglutitive physiology during sequential straw drinking in healthy young adults (n = 15) to learn how sequential swallowing differs from single swallows. The physiology of single swallows has been studied extensively in healthy adults and in adults with a variety of debilitating conditions, but the physiology of sequential swallows has not been studied adequately. Videofluoroscopic analysis revealed three distinct patterns of hyolaryngeal complex (HLC) movement during sequential straw swallows: opening of the laryngeal vestibule after each swallow (Type I, 53%), continued vestibule closure after each swallow (Type II, 27%), and interchangeable vestibule opening and closing during the swallow sequence (Mixed, 20%). Unlike discrete swallowing, the onset of the pharyngeal swallow occurred when the bolus was inferior to the valleculae in the majority of subjects and was significantly associated with HLC movement pattern. The leading bolus edge was inferior to the valleculae at swallow onset for Type II movement patterns. For Type I movement patterns, bolus position at swallow onset was randomly distributed between three anatomical positions: superior to the valleculae, at the level of the valleculae, and inferior to the valleculae. Preswallow pharyngeal bolus accumulation, which is common during mastication, was evident and significantly associated with the HLC pattern of opened laryngeal vestibule after each swallow. These data suggest that in healthy young adults, sequential swallows differ physiologically from discrete swallows and indicate substantial variability in deglutitive biomechanics.

Lesion site in unilateral stroke patients with dysphagia

The purpose of this retrospective study was to elucidate specific lesion sites associated with deglutition disorders by studying unilateral left- and right-hemispheric stroke patients with dysphagia. We reviewed computed tomography and magnetic resonance imaging scans and videofluoroscopic swallow studies of 16 consecutive patients with unilateral ischemic infarcts and dysphagia. Results suggest that unilateral hemispheric lesions may produce dysphagia and that patients with left- and right-hemispheric strokes may have different dysphagia characteristics. Although right-hemispheric lesions were significantly smaller than left-hemispheric lesions, dysphagia seemed to be clinically more significant in patients with right-hemispheric strokes, because a higher incidence of delayed pharyngeal swallow (consistency specific) and pharyngeal stasis was recorded in this population. Cytoarchitectonic lesion mapping showed that the insular cortex was the commonest lesion site, suggesting that the insula may be important in swallowing. A prospective double-blind study in a larger sample of unilateral stroke patients with and without dysphagia is warranted to confirm these preliminary findings.

Anomia: Case studies with lesion localization

Abstract In a recent case study of anomic aphasia following a unilateral left hemispheric stroke limited to Brodmanns area 37, it was proposed that this area may be important for object naming by allowing the semantic system access to stored lexical information. Based on this finding and theories postulating a modular system for word retrieval, we proposed that a patient with a lesion to area 37 and another patient with a lesion to a speech production region located serially downstream from area 37 would both be anomic, and in neither case could the anomia be attributed to a significant semantic impairment. Using a case study design to investigate the level of naming disturbance in these two patients with unilateral left hemispheric strokes, we have demonstrated that Patient 1, who had a lesion to area 37, and Patient 2, with a lesion to inferior-lateral portions of Brodmanns area 6, were anomic with semantic knowledge of words relatively preserved.

Dysphagia Screening: State of the Art Invitational Conference Proceeding From the State-of-the-Art Nursing Symposium, International Stroke Conference 2012

Dysphagia screening is a recurring topic of discussion in stroke care and other acute and chronic conditions that can affect swallowing. Many would agree with Wolf and Rudd that “[s]wallowing screening is so obviously important that a trial is not needed, but the hard evidence that screening saves lives is absent.”1 Paradoxically, the 2010 Joint Commission retired the dysphagia screening performance standard for acute stroke because the National Quality Forum could not endorse it, stating that there are no standards for what constitutes a valid dysphagia screening tool, and no clinical trials have been completed that identify the optimal swallow screening.2 Consequently, dysphagia screening was removed from the “Get With The Guidelines” stroke guidelines. This has led to concern among multidisciplinary stroke professionals that dysphagia screening will be entirely omitted from stroke care, leading to worsening outcomes among stroke patients at risk for swallowing problems. An invitational symposium was held January 31, 2012, at the State-of-the-Art Nursing Symposium in New Orleans, LA, to explore the issues and state of the science in dysphagia screening. The present report serves as a conference proceeding that aims to (1) educate multidisciplinary stroke professionals about the important issues related to identifying valid and reliable dysphagia screening tools, (2) identify the strengths and limitations of currently available dysphagia screenings, (3) describe how facilities may make cogent decisions about dysphagia screening selection, based on their specific needs, and (4) provide an example for establishing a dysphagia screening in a stroke care unit. As part of the discussion during the symposium, several expert recommendations were made regarding dysphagia screening in stroke care, which are also presented here. We will begin the report, as we will end, with this caveat: Because dysphagia screening is not a “one size fits all” process, neither the symposium nor the …