Oropharyngolaryngeal disorders in scleroderma: development and validation of the SLS scale

Systemic sclerosis (SSc) is a multisystemic disorder characterized by functional and structural abnormalities of small blood vessels and fibrosis of the skin and internal organs. Eighty percent of subjects with SSc have orofacial manifestations. No tests for oral manifestations have been validated for this pathology, and in the literature there are few studies of speech therapy for subjects with SSc. These facts suggested the need for an exhaustive assessment of mouth mobility and muscle strength, and also of swallowing and voice, in order to plan a targeted and effective speech therapy. The Scleroderma Logopedic Scale (SLS) has been developed to assess disorders in five domains: Impairment, Swallow, Voice, Multifield, and Quality of Life. Perception of these disorders was assessed in 84 subjects with SSc and in 40 healthy subjects. After the first draft, a shorter form (39 items) was obtained after statistical analysis. This scale showed good discriminant and concurrent validity. Internal consistency was good: three of five subscales had a Cronbach alpha coefficient higher than 0.8. The test/retest coefficient for the total score was 0.94. Thirty-six percent of examined subjects showed moderate to severe oropharyngolaryngeal disorders. Swallowing disorders and impairment of mouth (e.g., decrease in mobility and strength) were the most commonly reported problems. Conversely, the change of voice due to the pathology was not perceived as a problem. Fifty-five percent of subjects reported a decreased level of quality of life.