Diplophony

Specialty: Otolaryngology.

• Double voice
• perception of two simultaneous tones in the voice
• bitonal dysphonia

Why it occurs

• Severe mass or tension asymmetry between both vocal cords due to giant unilateral sessile polyp
• Paralysis of a vocal cord in a paramedian or lateral position that vibrates asynchronously with the contralateral one
• Severe vocal scar or unilateral sulcus vocalis that alters the rigidity of a single vocal fold
• Extrinsic laryngeal compression due to massive thyroid or esophageal tumors

Initial workup

Nasofibrolaryngoscopy with laryngeal stroboscopy to determine the fundamental frequency of vibration of each vocal cord separately, CT of the neck and chest with contrast to rule out lesions along the course of the recurrent laryngeal nerve bilaterally, and laryngeal electromyography (EMGl) if paralysis or paresis of neurological origin is suspected.

Standard management

• Management is predominantly surgical (laryngeal microsurgery or injection laryngoplasty/thyroplasty) or phoniatric rehabilitation.
• Systemic corticosteroids if there is an acute inflammatory component associated with recent vocal trauma
• Mucolytic support treatment to optimize the physical vibration conditions of the residual vocal mucosa.