Speech production, intelligibility and oromotor function in seven individuals with Möbius sequence

Möbius sequence is a rare disease characterized by congenital facial and abducent nerve palsy. Other cranial nerves may be affected. Cleft palate, intellectual disability and neuropsychiatric disorders are associated with the diagnosis. The aim was to explore speech production, intelligibility and oromotor function in a group of individuals with Möbius sequence.

Three children (5-11 years) and four adults (26-54 years) were recruited to the study via the Swedish Möbius syndrome association. In addition to cranial nerve dysfunction, two had a hearing impairment, one Asperger syndrome and one a cleft palate. Perceptual assessments included an evaluation of intelligibility in single words and spontaneous speech, the percentage of phonemes correct (PPC) and screening of orofacial functions (NOT-S). Objective measurements were used for the evaluation of nasality, lip force and tongue force.

Three individuals had severely impaired intelligibility, two slightly impaired and two had fully intelligible speech. The PPC varied between 59.3-100%. Five individuals had bilateral facial palsy, two unilateral facial palsy and six tongue impairment. One had a slightly increased nasalance score. Compensatory strategies were being effectively used.

This case series contributes more in-depth knowledge of speech production, intelligibility and oromotor function in this rare condition.