4. Influence of lip force on swallowing capacity in stroke patients and in healthy subjects.

(Included in thesis, Paper III)

Hägg M, Anniko M. ActaOto-Laryngologica 130(11): pp1204–8, 2010

Abstract as published

Conclusion In spite of no clinical signs of facial paresis, a pathological lip force (LF) will strongly influence swallowing capacity (SC). Stroke patients with impaired SC suffer a subclinical facial paresis. The results support earlier findings that LF training can be used to treat dysphagia. Objectives Lip muscle training with an oral screen can improve both LF and SC in stroke patients, irrespective of the presence or absence of facial palsy. The aim was therefore to study the influence of LF on SC. Methods This prospective study included 22 stroke patients, aged 38–90 years, with dysphagia, 12 with initial unilateral facial paresis and 45 healthy subjects, aged 25–87 years. All were investigated with a Lip Force Meter (LF100), and with an SC test. Results A significant correlation was found between LF/SC (p = 0.012) in stroke patients but not in healthy subjects. LF/SC was not age-related in stroke patients. LF was not age-dependent in healthy subjects, but SC decreased with increasing age (p < 0.0001). However, SC did not reach a pathological value and a regression analysis showed that 73 % of the variation in SC is attributable to LF and age.

Relevance to conditions

Dysphagia: Proof of importance of pharyngeal sling competence on swallowing.

Study type

Peer reviewed, Prospective, Cross-sectional.

Aim

The aim was to study the influence of pharyngeal sling force on swallowing ability.

Patients

  • 22 patients with stroke, F=13, M=9. Adult, Median age 78 (range 38–90 years).
  • 45 healthy controls, F=30, M=9=15. Adult, Median age 57 (range 25–87 years).

Methods

Results for pharyngeal sling force and swallowing ability were compared for patients with stroke and for healthy controls

Outcome measurements

  • Pharyngeal sling force was measured with a LF100 lip force meter– lower normal value ≥ 15 N.
  • Swallowing ability was measured using the Timed Water Swallowing Test (TWST) – lower normal value for swallowing rate ≥ 10 ml / sec.

Results

A significant correlation was found between pharyngeal sling competence and swallowing ability (p = 0.012) in stroke patients, but not in healthy subjects. Pharyngeal sling competence and swallowing ability was not age-related in stroke patients. Pharyngeal sling competence was not age-dependent in healthy subjects, but swallowing ability decreased with increasing age (p < 0.0001). Swallowing ability did not reach a pathological value and a regression analysis showed that 73 % of the variation in swallowing ability is attributable to pharyngeal sling competence and age.

Statistical significance of result

(p = 0.012) correlation between pharyngeal sling force and swallowing ability in stroke patients.
(p < 0.0001)swallowing ability decreased with increasing age.

Conclusion

Pathological pharyngeal sling force will strongly influence swallowing ability in patients with oropharyngeal dysphagia despite the absence of clinical signs of facial paresis. Patients with impaired swallowing ability suffered a subclinical facial paresis. In healthy subjects, the swallowing ability is diminished by age – probably due to a certain loss of the sensory function involved in normal swallowing. The results support earlier findings that physical lip muscle training can be used to treat dysphagia.