Post-stroke dysphagia is among the most common and serious complications of stroke, with reported incidence in acute patients ranging from 30 to 78 percent. It slows rehabilitation, erodes quality of life, and places a substantial burden on health systems. During swallowing, the tongue does far more than push food backward: it forms and propels the bolus, helps trigger the swallowing reflex, seals the back of the oral cavity, and prevents regurgitation. The pressure generated when the tongue presses against the hard palate accelerates pharyngeal pressure generation during forceful swallows and helps drive the pressure wave into the pharynx, smoothing the bolus’s passage into the esophagus. When tongue muscle function declines, tongue-palate contact pressure falls, and both the efficiency and the safety of swallowing suffer.

Traditional tongue pressure tools capture only a single global value, which limits their ability to reflect the functional state of individual tongue regions. The Chinese team addressed this with a T-shaped, five-point sensor built from force-sensitive resistors, a sensing pad, and a recording device, mounted on the hard palate so that sensing elements contacted the midline at anterior, middle, and posterior sites plus the left and right anterior regions. Participants sat upright with the Frankfort horizontal plane parallel to the floor and elevated the tongue maximally against the palate; each measurement was repeated three times and averaged to yield a maximal pressure value, or Pmax, for each of the five channels. The device was calibrated before each session according to the manufacturer’s instructions.

The study retrospectively enrolled 70 patients with dysphagia confirmed by videofluoroscopic swallowing study, 70 post-stroke patients without dysphagia, and 70 healthy controls. The dysphagia group comprised 55 men and 15 women with a mean age of 59.6 years, and stroke subtypes spanned atherothrombotic infarction, cardioembolic infarction, lacunar infarction, intracerebral hemorrhage, and other causes. Non-dysphagic status in the second group was verified with the EAT-10 questionnaire and a 30-milliliter water swallow test administered by a trained speech-language pathologist, with anyone showing abnormal results or reporting difficulty referred to videofluoroscopy and excluded. Demographic and clinical characteristics were well matched across the three groups.

The pressure map was strikingly consistent. Within every group, posterior Pmax was significantly the highest and right anterior Pmax significantly the lowest, and the between-site differences were highly significant in each cohort. Between groups, pressure at all five sites ranked highest in healthy controls, intermediate in stroke patients without dysphagia, and lowest in those with dysphagia, with all comparisons reaching statistical significance. In absolute terms, healthy controls reached roughly 75 kilopascals at the posterior site, non-dysphagic stroke patients about 53, and dysphagic patients about 33 — a stepwise decline that suggests lingual weakness after stroke is measurable even in patients who pass bedside swallowing screens.

To connect pressure with actual swallowing physiology, the researchers paired the tongue measurements with two instrumental assessments. Videofluoroscopic swallowing study captured six graded physiological parameters — oral motor function, swallowing reflex, soft palate lift, cricopharyngeal opening, glottic closure, and pharyngeal residue — along with kinematic and temporal measures such as hyoid displacement and oral transit time, using a 5-milliliter nectar-thick contrast bolus. Fiberoptic endoscopic evaluation of swallowing, performed with a yogurt bolus dyed green for visibility, scored eight components including laryngeal function, residue in the valleculae and pyriform sinuses, and cough reflex. Two blinded clinicians scored all recordings independently, and airway invasion was graded on the eight-level Penetration-Aspiration Scale, with scores of six or above defined as aspiration.

Within the dysphagia group, posterior tongue pressure emerged as the one regional value tied to pharyngeal-stage physiology on videofluoroscopy. It differed significantly across grades of cricopharyngeal muscle opening and across grades of vallecular and pyriform sinus residue, with higher posterior pressure associated with better upper esophageal sphincter opening and less post-swallow residue. No other site showed a significant association with any videofluoroscopic physiological component, and no site distinguished grades of any fiberoptic endoscopic component. The authors attribute the endoscopic null result partly to methodological differences: fiberoptic endoscopy is more sensitive than videofluoroscopy for detecting residue, its semi-quantitative scales may not map linearly onto a continuous pressure variable, and it cannot provide the deep dynamic measurements needed to quantify tongue-pharyngeal coupling.

The temporal correlations told a complementary story about which part of the tongue does which job. All five regional pressure values correlated negatively with oral transit time — stronger pressures meant faster oral transport — with the strongest coefficients in the left and right anterior regions, implicating the front of the tongue in bolus movement through the mouth. Soft palate elevation time showed weak negative correlations with left anterior, middle, and right anterior pressures. Hyoid movement time correlated positively, weakly to moderately, with left anterior, anterior, and right anterior pressures, which the authors interpret as a possible compensatory mechanism in which greater tongue force is accompanied by enhanced hyoid motion to assist the pharyngeal swallow. Pharyngeal phase initiation time correlated negatively with middle and posterior pressures, underscoring the rear tongue’s role in triggering the pharyngeal swallow. No pressure value correlated with hyoid pause time or with anterior or superior hyoid displacement.

Aspiration proved a different matter entirely. Binary logistic regression found that none of the five pressure variables entered the prediction model for aspiration on either videofluoroscopy or endoscopy. The authors argue this reflects the biology rather than a measurement failure: aspiration emerges from the interaction of multiple subsystems — respiration, tongue, hyoid, and larynx — and depends on laryngeal elevation, glottic closure, cough reflex sensitivity, and pharyngeal sensation, as well as on the viscosity of the aspirated material, oral hygiene, and the patient’s overall condition. Static maximal tongue pressure, they conclude, has limited discriminatory power on its own and should be used to evaluate oral-phase efficiency, not as a standalone aspiration screen; it must be combined with instrumental swallowing assessment.

The study has acknowledged limitations. The validity and test-retest reliability of the five-point sensor still require formal validation, the optimal number and placement of measurement sites remains unresolved, and the researchers did not collect neuroimaging findings, lesion side, handedness, or bolus placement data, so the neural and behavioral mechanisms behind the site-specific pressure distribution cannot be determined from this cohort. Even so, the authors recommend routine multi-point tongue pressure measurement in post-stroke dysphagia, use of anterior pressures to monitor oral-phase efficiency, posterior tongue strengthening to target pharyngeal function, continued tongue monitoring in non-dysphagic stroke patients, and development of individualized reference values accounting for age, sex, and stroke type. Multicenter longitudinal studies combining neuroimaging and kinematics are the stated next step toward validating the five-site approach and establishing normative values.

Subject of Research: Regional tongue pressure measurement and its relation to swallowing physiology and aspiration in post-stroke dysphagia

Article Title: Tongue pressure in patients with post-stroke dysphagia

Article References: Cui, Q., Zhang, Q., Jia, W., Wang, H., Zhang, L., & Dai, X. (2026). Tongue pressure in patients with post-stroke dysphagia. Frontiers in Physiology, 17, 1889535. https://doi.org/10.3389/fphys.2026.1889535

Image Credits: AI Generated

DOI: 10.3389/fphys.2026.1889535

Keywords: post-stroke dysphagia, tongue pressure, aspiration, videofluoroscopy, FEES, swallowing rehabilitation, case-control study, oropharyngeal swallowing, lingual weakness, Penetration-Aspiration Scale, stroke complications, five-point sensor