Pathophysiological effects of Möbius syndrome on speech and hearing.

The effects of Möbius syndrome (MoS) on the functioning of the peripheral speech and hearing mechanisms has not hithertofore been described, to my knowledge. Speech and hearing function of an 8-year-old MoS speaker was studied. Data were obtained from several sources. These included: electromyography of the facial muscles, physical examination of the peripheral speech mechanism, speech and language test batteries, audiological evaluation, and acoustic analyses of the speech signal. A pathologic condition was found to exist in a number of cranial nerves and in structures in the oral cavity. This resulted in consonant and vowel misarticulations, which notably affected speech intelligibility. Middle ear dysfunction was also present. Neurological mechanisms are discussed to account for these pathologies in human communication. Strategies for speech therapy and future research in MoS are presented.