Swallowing function after stroke: prognosis and prognostic factors at 6 months

Swallowing dysfunction (dysphagia) is common and disabling after acute stroke, but its impact on long-term prognosis for potential complications and the recovery from swallowing dysfunction remain uncertain. We aimed to prospectively study the prognosis of swallowing function over the first 6 months after acute stroke and to identify the important independent clinical and videofluoroscopic prognostic factors at baseline that are associated with an increased risk of swallowing dysfunction and complications.

We prospectively assembled an inception cohort of 128 hospital-referred patients with acute first stroke. We assessed swallowing function clinically and videofluoroscopically, within a median of 3 and 10 days, respectively, of stroke onset, using standardized methods and diagnostic criteria. All patients were followed up prospectively for 6 months for the occurrence of death, recurrent stroke, chest infection, recovery of swallowing function, and return to normal diet.

At presentation, a swallowing abnormality was detected clinically in 65 patients (51%; 95% CI, 42% to 60%) and videofluoroscopically in 82 patients (64%; 95% CI, 55% to 72%). During the subsequent 6 months, 26 patients (20%; 95% CI, 14% to 28%) suffered a chest infection. At 6 months after stroke, 97 of the 112 survivors (87%; 95% CI, 79% to 92%) had returned to their prestroke diet. Clinical evidence of a swallowing abnormality was present in 56 patients (50%; 95% CI, 40% to 60%). Videofluoroscopy was performed at 6 months in 67 patients who had a swallowing abnormality at baseline; it showed penetration of the false cords in 34 patients and aspiration in another 17. The single independent baseline predictor of chest infection during the 6-month follow-up period was a delayed or absent swallowing reflex (detected by videofluoroscopy). The single independent predictor of failure to return to normal diet was delayed oral transit (detected by videofluoroscopy). Independent predictors of the combined outcome event of swallowing impairment, chest infection, or aspiration at 6 months were videofluoroscopic evidence of delayed oral transit and penetration of contrast into the laryngeal vestibule, age >70 years, and male sex.

Swallowing function should be assessed in all acute stroke patients because swallowing dysfunction is common, it persists in many patients, and complications frequently arise. The assessment of swallowing function should be both clinical and videofluoroscopic. The clinical and videofluoroscopic features at presentation that are important predictors of subsequent swallowing abnormalities and complications are videofluoroscopic evidence of delayed oral transit, a delayed or absent swallow reflex, and penetration. These findings require validation in other studies.