Difficulty in Voicing in A Patient with Parkinson's Disease— Freezing Phenomenon of Vocal Cords

Abstract

A 62-year-old man with juvenile Parkinson's disease was reported. When L-Dopa was working the patient felt difficulty in voicing although he could walk smoothly. Meanwhile, when L-Dopa was not working his difficulty in voicing disappeared but he was unable to walk. This discrepancy between voicing and walking is disussed. Laryngofiberscopic examination showed the following intriguing findings. When L-Dopa was working the patient's vocal cords assumed the hyperabduction position. Also, during an attempts at phonation, the vocal cords developed a tendency to adduct but were unable to. This movement seemed to correspond to a “freezing” phenomenon in walking. The adduction tendency of the vocal cords ameliorated temporazily by voluntarily making a cough instead of voicing. Such a phenomenon appeared as a freezing of vocal cord movement with kinesie paradoxale. Two hypotheses were raised to explain this “see-saw” phenomenon between voicing and walking. First, the mechanism of the freezing phenomenon might differ for voicing and walking. Second, the threshold for the effectiveness of L-Dopa might differ for the intrinsic laryngeal muscles controlling voicing and for the limb and truncal muscles controlling walking. The task of hawking which we attempted was very useful in speech therapy on PD patients who exhibited the freezing phenomenon of the vocal cords with kinesie paradoxale. © 1997, The Japan Society of Logopedics and Phoniatrics. All rights reserved.