Differential Diagnostics in Spasmodic Dysphonia versus Muscle-Tension Dysphonia
Referrals for diagnostic evaluation and treatment for a patient with possible spasmodic dysphonia (SD) can be challenging given that symptoms are not always categorical. In addition, symptoms related to muscle-tension dysphonia (MTD), a much more common dysregulation of muscle coordination, can mimic those of SD, making accurate diagnosis even more difficult. This case represents an example of a clinical pathway for the differential diagnosis of SD and MTD.
C is a 29-year-old female marketing professional referred for evaluation and diagnostic therapy to define whether her symptoms were related to MTD or SD. C summarized her problem with the following statements: “I sound nervous even when I’m not. It feels like my voice just sort of seizes up, but it feels shaky.” She reported a functional voice until late 2012 when she noticed asubtle and intermittent tremor in her voice, especially while on the telephone; her tremor often occurred in the absence of anxiety or stress. In October 2012, C developed an upper respiratory infection with several days of hoarseness. Upon recovery, her vocal symptoms became much more frequent and exacerbated in severity to the point where her friends began commenting on the quality of her voice. Her voice was characterized by worsening voice quality while on the telephone, primarily during conference calls, and when initially arriving somewhere and initiating voice. Her voice progressively improved with increased use. She denied significant improvement in voice with alcohol. She stated, “It’s hard for me to know since it seems to be better, but then once I start to notice it, the voice breaks start to happen.” She also reported some voice symptoms during singing.