Thirty-nine studies were reported including 2 RCTs, 3 non-randomised controlled study, 33 retrospective and prospective case series and 1 case-control.
Numbers of participants were unclear as some studies were included in more than one category and different numbers of participants were reported in some cases.
Cricopharyngeal myotomy ((10 retrospective and prospective case series for structural cricopharyngeal disorders)(15 retrospective and prospective case series for neuropathic and myopathic dysphagia)): Based on level C evidence the authors' report that there are sufficient grounds to presume that cricopharyngeal myotomy is beneficial in cases of dysphagia caused by structural lesions. They also report that there are no absolute indications for cricophayngeal myotomy, and that currently available clinical data do not strongly support treatment with cricopharyngeal myotomy for neuropathic or myopathic causes of oropharyngeal dysphasia. Outcome measures considered in individual studies included: global assessment, standardized questionnaire, dietary modification, aspiration, dietary consistency, scintigraphy and videofluroscopic.
Diet modification (1 RCT):
There is little evidence that nonoral feeding reduces or eliminates the risk of aspiration. Outcome measures considered in the study were not reported.
Swallowing therapy (2 RCTs, 3 nonrandomised controlled studies and 7 retrospective and prospective case series):
The literature provides reasonable evidence of the plausibility of swallowing therapy but minimal evidence of efficacy. Outcome measures considered in individual studies included: pneumonia, dehydration, nutritional deficit, death, weight change, caloric intake, radiographic aspiration, oral feeding, ease of feeding, dysphagia and other subjective measures.
Other interventions:
There has been little systematic evaluation of the responsiveness of dysphagia to anti-parkinsonian medication. The short-term effect of central dopaminergic stimulation on pharyngeal mechanics is controversial. Improvement of oropharyngeal dysphagia in response to medical therapy for myasthenia gravis (acetylcholinesterase inhibitor and/or immunosuppressive drugs) is variable and often less satisfactory than the response of other disease manifestations. There was insufficient data from the remaining studies to allow reliable inferences to be drawn about the efficacy of palatal prosthesis, thermal stimulation of the fauces and the other unspecified combination therapies. Outcome measures considered by individual studies were not presented.