Post-stroke dysphagia, a potentially fatal complication, affects an estimated 23-50% of all stroke survivors. It is associated with a seven fold increase in the risk for aspiration pneumonia. Aspiration pneumonia increases the catabolic demands of the body and in the settings of impaired swallowing leads to a vicious cycle of malnutrition, dehydration, and further infections (Shaker & Geenen, 2011). Dysphagia affects a significant number of patients with hemispheric stroke which is the main subtype of ischemic stroke in the general population (Kumar et al., 2011). The functions of swallowing are subserved by a vast brain network. The inferior peri-rolandic sensorimotor cortex, however, seems to be consistent across studies. Dysphagia in hemispheric strokes is caused by disruption of the cortical projections to the swallowing centers in the brainstem (Kumar et al., 2011). Clinical recovery is attributed to compensatory changes in the unaffected hemisphere that are thought to entail enlargement of the unaffected hemisphere so as to increase the excitation delivered to the brain stem (Singh & Hamdy, 2005). In the acute phase following a stroke and prior to the development of the compensatory changes, patients with dysphagia rely on alternative feeding methods (Kumar et al., 2011). This paper will describe a clinical scenario involving a patient who developed dysphagia after suffering a hemispheric stroke. It will further identify and critically review a primary research article on interventions for improving post-stroke dysphagia in patients with hemispheric stroke in the acute phase.
Clinical Scenario
The clinical scenario involved a 65-year old patient who had suffered from right-sided hemispheric stroke 3 days previously. The patient was a widow and lived with her daughter and two grandchildren. On assessment, the patient had been diagnosed with post-stroke dysphagia and put on a liquid diet which she had been taking via a straw. The patient started coughing vigorously one afternoon after sipping on juice. Luckily, the coughing helped remove the fruit juice that had entered her airways. The situation prompted me to search for articles on interventions that help to improve dysphagia in the early convalesce phase post-stroke. The current practice at my workplace is to provide alternative feeds through for instance naso-gastric tubes until the swallowing functions of a patient recover.
Article Description
The article identified is authored by Kumar et al. (2011). It is entitled “Non-invasive brain stimulation may improve stroke related dysphagia: a pilot study”. It describes a pilot study that investigated whether non-invasive stimulation of the brain coupled with swallowing maneuvers facilitates the recovery of swallowing in dysphagic stroke patients during the early convalescence period after stroke. This intervention was informed by evidence that suggests that cortical stimulation can help increase pharyngeal representation in the hemisphere not affected by stroke. This in turn increases input to brainstem swallowing centers facilitating the recovery of swallowing functions in patients affected by hemispheric strokes but whose brainstems and peripheral structures are intact. The study sought to bridge a gap in knowledge as currently there are limited treatment options for stroke-related dysphagia. It enrolled 14 participants with unilateral hemisphere infarction in the subacute phase. The participants were randomized into an intervention and control group. The intervention group received single node transcranial direct current stimulation (tDCS) while the control group received sham stimulation. The sensorimotor cortex of the unaffected brain hemisphere is the part of the brain that was stimulated in both tDCS and sham stimulation. Stimulation was done for 20 minutes for 5 consecutive days. Standardized swallowing maneuvers were also performed during stimulation. Dysphagia severity was assessed using a validated scale for swallowing, the Dysphagia Outcome and Severity Scale (DOSS) prior to and following the last sham or tDCS session. A multivariate linear regression model was used to analyze the effect of tDCS and shams stimulation with changes in DOSS as the main outcome variable after adjusting for potentially confounding variables. The DOSS scores of patients in the tDCS group improved by 2.6 points while those of patients in the sham stimulation group improved by 1.25 points. The DOSS scores of 6 of the 7 patients in the tDCS group improved by 2 points while only 3 of the 7 patients in the sham group showed similar improvements. The researchers concluded that measures that improve cortical input as well as sensorimotor swallowing functions of the brainstem can improve post-stroke dysphagia.
Article Critique
The title of the article “Non-invasive brain stimulation may improve stroke related dysphagia: a pilot study”, is appropriate. It provides in concise manner information about the study population, intervention, aim, design, and outcome measure. The abstract of the article is a concise summary of the contents of the research article. It is divided into the following sections; background and purpose, methods, results, and conclusion. It offers a clear overview of the research problem, aim, sample, study design, findings, and conclusion. The background section of the study is merged with the literature review section. The introduction clearly identifies the research problem that is limited options for the management of post-stroke dysphagia. It also described the significance of the study. The researchers note that the current practice of providing nutrition via substitute feeding methods until swallowing functions recover is associated with complications like aspiration pneumonia. The researchers thus contend that development of an intervention that effectively improves swallowing in this patient cohort will help curtail swallowing related complications and enhance swallowing function. Notably though, the researchers do not provide statistics that show the magnitude of the problem for instance the number affected by hemispheric stroke annually or those who develop dysphagia thereafter. Overall though, the problem statement provided builds a cogent and strongly persuasive argument for the study. The research problem also matches with the quantitative paradigm chosen for the study (LoBiondo-Wood & Haber, 2014).
The literature review is organized in a logical manner. The researchers provide a balanced critique of the available literature specifically on the pathophysiology of dysphagia in stroke and the rationales for the proposed interventions. The literature review mostly includes information from primary empirical sources such as a study by Hummel et al. (2005) although it also incorporates information from secondary sources such as a review by Schlaug, Hummel, & Cohen (2006). Notably, most of the articles included in the literature review are not recent being older than 5 years for instance a 1937 article by Penfield and Boldery and a 1997 article by Hamdy et al. Recent articles included in the literature review include an article by Jefferson et al. (2009). In spite of the use of relatively old sources, the literature review provides a solid base for the study.
On the issue of methods, appropriate procedures were used to safeguard participants’ rights for instance, a written informed consent was obtained from participants or their legal representatives before enrollment for the study. The study was also reviewed and approved by the hospital’s institutional review board. The authors also state that the study intervention tDCS and sham stimulation of the brain have no known adverse effects on patients. On the study design, the study design is clearly identified and is appropriate for the purpose of the study. The study used a prospective, single-center, randomized, blinded design. This study design allowed the blinding of participants and assessors to the intervention received by each participant. The study intervention that was being tested is also adequately described allowing its replications in future studies. The sample for the study is also amply described. The severity of dysphagia was measured using DOSS, a validated dysphagia scale, used to rate the functional severity of dysphagia and level of disability. Patients are scored from 1-7 depending on the severity of their dysphagia. It appears that the participants for the study were identified through convenience sampling. Participants were included in the study if they met the set inclusion criteria. Consequently, it is possible that the findings of the study were influenced by extraneous variables. The data collection procedures used and the variables measured are adequately described. Variables measured included age, gender, lesion time, and lesion volume.
On the statistical analysis, the effects of tDCS and sham stimulation on dysphagia scores were analyzed using a multivariate linear regression model. Linear regression was appropriately used to estimate the effects of tDCS and sham stimulation of the brain on dysphagia while controlling for the impact of potentially confounding variables like patient’s age and lesion volume (Alexopoulos, 2010). Regarding the results, discussion, and limitations of the study, the findings of the study are clearly presented in narrative form and are further summarized in tabular form. The discussion section of the study contextualizes the findings of the study in light of what is currently known about the phenomena of interest. The limitations of the study are also described and include the use of a relatively small sample, the fact that the optimal dose for stimulation of the pharyngeal motor cortex is yet to be established, and inter-rater variations in DOSS scoring. The researchers recommend further studies to refine the intervention by exploring the impact of timing of intervention, frequency of intervention amongst other variables.
Reflection
Engaging in this exercise helped to refine my evidence-based practice (EBP) skills especially in searching for relevant articles from medical databases. The article critiqued was identified from the reference list of another article. It also helped me improve my knowledge and skills for critiquing research articles as I consulted a number of articles and textbooks when preparing the article critic. The exercise has also enlightened me about tDCS, a potential intervention for improving post-stroke dysphagia in the early period following a stroke. Lastly, engaging in this exercise has helped me realize that one of the major shortcomings of EBP is the lack of strong evidence on some issues encountered in clinical practice. In this case, there are limited options for management of post-stroke dysphagia and tDCS is still yet to be fully explored (Yates, 2013).
Conclusion
In summary, this paper has described a clinical scenario that involved a patient who developed dysphagia after suffering from a stroke. In addition, it has critiqued an article by Kumar et al. (2011) that investigated the effects of tDCS and sham stimulation on DOSS scores in stroke survivors in the subacute phase of the condition. The title and abstract sections of the article give a clear overview of the contents of the article. The introduction section of the article justifies the need for the study. The literature review section provides a solid base for the study. The research design used was appropriate for the study. The study used a small sample of 14 patients though. The intervention employed is adequately described. Linear logistic regression was appropriately used to analyze data. The findings of the study are clearly presented in narrative format and summarized in a table. The discussion section contextualizes the findings of the study in light of what is known about post-stroke dysphagia. The study had several limitations which are clearly described. Engaging in this exercise has enhanced my EBP knowledge and skills.
References
Alexopoulos, E. C. (2010). Introduction to multivariate regression analysis. Hippokratia, 14(1), 23-28.
Kumar, S., Wagner, C. W., Frayne, C., Zhu, L., Selim, M., Wuwei, F., & Schlaug, G. (2011). Non-invasive brain simulation may improve stroke related dysphagia: A pilot study. Stroke, 42(4), 1035-1040.
LoBiondo-Wood, G. & Haber, J. (2014). Nursing research: Methods and critical appraisal for evidence-based practice. St. Louis, MS: Elsevier Mosby.
Shaker, R. & Geenan, J. E. (2011). Management of dysphagia in stroke patients. Gastroenterology and Hepatology, 7(5), 308-332.
Singh, S. & Hmady, S. (2005). Dysphagia in stroke patients. Postgraduate Medical Journal, 82(968), 383-391.
Yates, C. (2013). Evidence-based practice: The components, history, and process. Counseling Outcome Research and evaluation, 4(1), 41-54.
