Demographics and coexisting tremor, cervical dystonia and vocal fold disorders in a group of patients with spasmodic dysphonia

The primary aim of this study is to describe the demographic and clinical characteristics of a group of patients with spasmodic dysphonia (SD). As a secondary aim, we examined associations of age at SD diagnosis and sex with co-existing cervical dystonia and nonvocal tremor; as well as association of vocal tremor with sex and nonvocal tremor. Seventy-four consecutive patients who were treated for SD at the Mayo Clinic in Jacksonville, Florida between October 1, 2015 and March 31, 2018 were included in this retrospective study. Information was collected regarding sex, age at SD diagnosis, BMI, SD diagnosis type, recent history of major stress/depression, recent history of upper respiratory tract infection (URTI), co-existing neurological diseases, and co-existing vocal disorders. The majority of patients were female (75.7%) and median age at SD diagnosis was 61 years (range: 17 – 80 years). The median BMI was 25.7 (range: 16.9 – 63.7). The most common diagnostic combinations were adductor dysphonia only (52.7%), adductor dysphonia and MTD (18.9%), and adductor dysphonia and tremor (17.6%). Co-existing tremor was present in 36.6% of patients and cervical dystonia was present in 15.5%. Co-existing vocal disorders were observed as follows: paresis/paralysis (3.1%), cyst (3.1%), mass (4.7%), polyp (1.6%), and anterior glottis web (1.6%). Sex was not notably associated with either cervical dystonia or nonvocal tremor (all P ≥ 0.30). Older age at SD diagnosis was significantly associated with cervical dystonia (P = 0.049), but not nonvocal tremor (P = .22). Other than co-existing tremor, most patients had no co-existing neurological diseases or vocal disorders. Additionally, patients who were older at SD diagnosis were significantly more likely to have co-existing cervical dystonia.