Conclusion: Training with an oral screen can improve lip force (LF) and swallowing capacity (SC) in stroke patients with oropharyngeal dysphagia, irrespective of the duration of pretreatment of dysphagia, and irrespective of the presence or absence of central facial paresis. It is more plausible that treatment results are attributable to sensory motor stimulation and the plasticity of the central nervous system than to the training of the lip muscles per se.
Objectives: A close relationship has been demonstrated between LF and SC in stroke patients whether or not they are affected by facial paresis. It is not known how training of lip function can improve swallowing capacity. The present study was therefore designed to ascertain: (i) if training with an oral screen can improve the LF and SC of stroke patients with oropharyngeal dysphagia; to establish (ii) if improvement in LF and SC is connected with the presence or absence of central facial palsy, (iii) on the interval between stroke onset and initiation of treatment, (iv) on age, or (v) on sex.
Subjects and methods: This was a retrospective study of 30 stroke patients, 49-88 years old, who were investigated with a Lip Force Meter, LF100 (LF100) and a swallowing capacity test (SCT) before and after a period of self-training lasting at least 5-8 weeks, using an oral screen. Initial central facial paresis was present in 24 patients.
Results: The median LF was 7 Newtons (N) (range 0-27) before treatment and 18.5 N (range 7-44) after treatment (p < 0.001). The median SC was 0 ml/s (range 0-9.1) before treatment and 12.1 ml/s (range 0-36.7) at follow-up (p < 0.001). There was no significant difference in swallowing improvement between patients with versus those without facial paresis. The interval between stroke attack and start of treatment, ranging from a few days up to 10 years, had no significant influence on the treatment results, nor did age or sex. The facial paresis was improved or at least ameliorated in all patients after the lip training period.