Key messages
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Swallowing therapy may improve swallowing in stroke survivors following a recent stroke, but no one therapy is effective overall.
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Severity of swallowing problems is probably improved by electrical stimulation of the outside of the neck and brain, nerve stimulation and combined therapies. Acupuncture probably reduces swallowing problems at the end of the trial and increases swallowing safety; medication probably reduces chest infections; and electrical stimulation of the inside of the neck probably reduces the number of people needing a breathing tube at the end of the study.
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Future studies should be larger and of better quality.
Why do people who have had a stroke need swallowing therapy?
People who have had a stroke often have difficulty chewing and swallowing saliva, and food and drink (called 'dysphagia'). It can affect up to 80% of stroke survivors and can lead to:
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choking and chest infections, due to inhaling not swallowing saliva and food;
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malnutrition and weight loss, which might mean slower recovery;
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poor quality of life;
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long stays in hospital; and
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increased risk of death or being sent to a care home.
Many people's swallowing improves without treatment, but between 15% and 51% of people will still have problems swallowing around two weeks after their stroke.
What is swallowing therapy?
Swallowing therapy aims to speed up recovery of swallowing function and reduce the negative effects of swallowing problems on health and well-being.
There are many types of swallowing therapy; we looked at the following:
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acupuncture;
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swallowing exercises;
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medication;
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stimulating the neck with electrical pulses (NMES: outside; PES: inside), or the brain with electrical (tDCS) or magnetic pulses (TMS, TBS);
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physical stimulation with cold, sour flavours or fizzy drinks;
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nerve stimulation; and
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combinations of these therapies.
What did we want to find out?
We wanted to assess the effectiveness of swallowing therapies to improve swallowing in stroke survivors up to six months after their stroke. We were interested in:
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how bad (severity) their swallowing problems were after treatment;
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the number of people who had swallowing problems at the end of the trial;
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how safe their swallowing was;
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whether chest infections or pneumonia were reduced due to improved swallowing; and
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the number of people dependent on a breathing tube.
What did we do?
We searched for studies that investigated different swallowing therapies for adults with swallowing problems after a stroke. Studies had to compare a therapy with usual care, no treatment, or a placebo treatment (that is, an inactive treatment that seems like a real treatment). Usual care could be any treatments or combinations of treatments, but had to be the same for all the people in the studies.
We read the studies carefully and recorded what they found. We also judged how much we could trust the results by looking at how big the trials were and how well they were done.
What did we find?
We found 181 studies with 11,500 people.
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Severity of swallowing problems after treatment: acupuncture, swallowing exercises and medication may reduce swallowing problems but the evidence is very uncertain. Physical stimulation and magnetic brain stimulation (TBS, TMS) may reduce, and NMES, tDCS, nerve stimulation and combined therapies probably reduce swallowing problems. PES may make little to no difference.
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Number of people with swallowing problems at the end of treatment: acupuncture probably results, and physical stimulation and tDCS may result in fewer people with swallowing problems at the end of treatment. We are not sure about the effects of swallowing exercises and NMES. Medication may, and PES and combined therapies probably make little to no difference.
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Safety of swallowing: acupuncture and TMS probably improve, and swallowing exercises and PES may improve swallowing safety. TBS may improve swallowing safety, and NMES and tDCS may have little to no effect on swallowing safety, but the evidence is very uncertain.
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Chest infections or pneumonia: medications probably reduce, and acupuncture, swallowing exercises, PES and physical stimulation may reduce the number of chest infections or pneumonia. We are unsure about the effects of NMES. Combined therapies probably do not reduce the number of chest infections or pneumonia.
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Need for a breathing tube: PES probably reduces the number of people dependent on a breathing tube. We are very uncertain about the effects of swallowing exercises.
What are the limitations of the evidence?
Many of the studies were small and of poor quality. This makes it harder to trust the results. In the future, studies should use more reliable methods, and they should be larger so we can be more confident in the results. Many of the swallowing therapies involved different methods of delivery, so it is still not clear which approach is most effective for each type of therapy.
How up to date is this evidence?
The evidence is current to July 2025. This is an update of the review originally published in 1999 and updated in 2012 and 2018.
Read the full abstract
Dysphagia (swallowing problems), which is common after stroke, is associated with increased risk of death or dependency, occurrence of pneumonia, poor quality of life, and longer hospital stay. Treatments provided to improve dysphagia are aimed at accelerating recovery of swallowing function and reducing these risks. This is an update of the review first published in 1999 and updated in 2012.
Objectives
To assess the effects of swallowing therapies on swallowing impairment (SI) among stroke survivors with dysphagia, within six months of stroke onset.
Search strategy
We searched MEDLINE, Embase, OVID, three other databases and trials registries on 31 July 2025.
Selection criteria
We sought to include randomised controlled trials (RCTs) of interventions for people with dysphagia and recent stroke (within six months).
Data collection and analysis
Two review authors independently applied the inclusion criteria, extracted data, assessed risk of bias, used the GRADE approach to assess the quality of evidence, and resolved disagreements through discussion with the third review author (PB). We used random-effects models to calculate odds ratios (ORs), mean differences (MDs), and standardised mean differences (SMDs), and provided 95% confidence intervals (CIs) for each.
The primary outcome was functional outcome, defined as death or dependency (or death or disability), at the end of the trial. Secondary outcomes were case fatality at the end of the trial, length of inpatient stay, proportion of participants with dysphagia at the end of the trial, swallowing ability, penetration aspiration score, or pneumonia, pharyngeal transit time, institutionalisation, and nutrition.
Main results
We added 27 new studies (1777 participants) to this update to include a total of 41 trials (2660 participants).
We assessed the efficacy of swallowing therapy overall and in subgroups by type of intervention: acupuncture (11 studies), behavioural interventions (nine studies), drug therapy (three studies), neuromuscular electrical stimulation (NMES; six studies), pharyngeal electrical stimulation (PES; four studies), physical stimulation (three studies), transcranial direct current stimulation (tDCS; two studies), and transcranial magnetic stimulation (TMS; nine studies).
Swallowing therapy had no effect on the primary outcome (death or dependency/disability at the end of the trial) based on data from one trial (two data sets) (OR 1.05, 95% CI 0.63 to 1.75; 306 participants; 2 studies; I² = 0%; P = 0.86; moderate-quality evidence). Swallowing therapy had no effect on case fatality at the end of the trial (OR 1.00, 95% CI 0.66 to 1.52; 766 participants; 14 studies; I² = 6%; P = 0.99; moderate-quality evidence). Swallowing therapy probably reduced length of inpatient stay (MD -2.9, 95% CI -5.65 to -0.15; 577 participants; 8 studies; I² = 11%; P = 0.04; moderate-quality evidence). Researchers found no evidence of a subgroup effect based on testing for subgroup differences (P = 0.54). Swallowing therapy may have reduced the proportion of participants with dysphagia at the end of the trial (OR 0.42, 95% CI 0.32 to 0.55; 1487 participants; 23 studies; I² = 0%; P = 0.00001; low-quality evidence). Trial results show no evidence of a subgroup effect based on testing for subgroup differences (P = 0.91). Swallowing therapy may improve swallowing ability (SMD -0.66, 95% CI -1.01 to -0.32; 1173 participants; 26 studies; I² = 86%; P = 0.0002; very low-quality evidence). We found no evidence of a subgroup effect based on testing for subgroup differences (P = 0.09). We noted moderate to substantial heterogeneity between trials for these interventions. Swallowing therapy did not reduce the penetration aspiration score (i.e. it did not reduce radiological aspiration) (SMD -0.37, 95% CI -0.74 to -0.00; 303 participants; 11 studies; I² = 46%; P = 0.05; low-quality evidence). Swallowing therapy may reduce the incidence of chest infection or pneumonia (OR 0.36, 95% CI 0.16 to 0.78; 618 participants; 9 studies; I² = 59%; P = 0.009; very low-quality evidence).
Authors' conclusions
Conclusions from our analyses are limited by small trials at high or unclear risk of bias, publication bias and inconsistent results.
Large high-quality trials on specific interventions are needed.
Funding
No dedicated funding.
Registration
Protocol (1997), DOI not available
Original review (1999) DOI 10.1002/14651858.CD000323
First update (2012) DOI 10.1002/14651858.CD000323.pub2
Second update (2018) DOI 10.1002/14651858.CD000323.pub3
