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 arrests 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.
Clinical Investigations of Intermittent Breathy Dysphonia
Case history and voice data for 17 patients who presented with intermittent moments of breathy dysphonia (IBD) in contextual speech were analyzed. From recorded samples of vowel prolongation four variants of phonation were identified. Of 13 patients examined neurologically, 10 (77%) had positive neurologic signs. Psychiatric and physical illnesses were often associated with onset of the voice disorder. Sex ratio of the patients in this study was nearly the same as that for adductor spastic dysphonia. Age at onset was similar to that which has been described for "functional" voice disorders. Different therapies were generally ineffective in alleviating the disorder. Although not conclusive, patients presenting with IBD in connected speech may have an underlying neurologic or psychologic disorders.