Adductor spastic dysphonia as a sign of essential (voice) tremor.

Adductor spastic dysphonia may not be one disorder but a voice sign of several different neurologic and psychiatric syndromes. This study evaluates whether rhythmic voice arrests, often components of "spastic dysphonia," are signs of essential tremor, a neurologic disorder. Data on 22 patients originally diagnosed as having spastic dysphonia, who had tremor-like or rhythmic voice arrests, were compared with data on two groups of patients who had essential (voice) tremor. The frequency of voice arrest on vowel prolongation in the group labeled spastic dysphonia was compared with the frequency of voice tremor in the groups with essential tremor. The median frequencies of 5.7, 5.0, and 5.5 Hz were not significantly different among the three groups. Patients in all three groups had tremor in other parts of the body, other scattered neurologic signs, and histories of life stress associated with the onset of their voice disorders. Although the results do not prove conclusively that the patients diagnosed as having spastic dysphonia in this study actually had essential tremor, the similarities to that disorder strongly suggest a linkage.