Research

During the last ten years we are doing research to the presence of neurovegetative lability in patients with nonorganic habitual dysphonia. Professor Ph. H. Dejonckere from the Institute of Phoniatrics, University Medical Center Utrecht, The Netherlands is assisting us.
The first study was designed to test the hypothesis that there is indeed a relationship between nonorganic habitual dysphonia and subjective experience of dysfunction of the autonomic nervous system (neurovegetative lability). Eighty-three patients (65 women and 18 men) with a nonorganic voice disorder and a matched control group answered a questionnaire of 46 questions. One question replicated in different terms and six nonrelevant questions pointed out that the inquiry forms were answered in a consistent way. It appeared that female patients in all age categories with a nonorganic habitual dysphonia reported significantly more autonomic symptoms and complaints than healthy controls. This hypothesis could not be confirmed for the male subgroup.
.With the second study we wanted to corroborate and nuance this observation by investigating larger groups, and to determine if, after voice therapy, the number of autonomic symptoms and complaints-particularly those ones that have no obvious relation to voice function-decreases. This was a prospective study with a control group; 184 patients with nonorganic dysphonia and 126 normal controls answered a questionnaire of 46 questions with 3 subsets and a consistency control. One hundred and one patients received functional voice therapy and completed the questionnaire before and after treatment. A control group of 42 normal subjects also filled in the questionnaire two times, with an interval of about 6 months. Neurovegetative symptoms and complaints-voice related and not related-were reported in highly significant excess by patients (especially but not exclusively females) with habitual nonorganic voice disorder. After therapy, there was a highly significant reduction in the number of autonomic symptoms and complaints (related or not related to voice), to such an extent that patients reported on average no more general neurovegetative symptoms and complaints than healthy controls (even less). The number of neurovegetative symptoms and complaints connected with voice function was also strongly reduced in patients after therapy, but remained in significant excess when compared with controls.
The third study with a matched control group was designed to test the hypothesis that a specific kind of therapy is more efficient than usual approaches in reducing these neurovegetative symptoms and complaints. The two groups consisted of 34 patients diagnosed with nonorganic dysphonia and referred for voice therapy answered our questionnaire of 46 questions with 3 subsets and a consistency control. The received either coordination therapy – a holistic approach addressing functional, personal and emotional aspects - or a conventional voice therapy (approximately 15 sessions). All patients filled in a similar questionnaire after approximately 6 months.
After the therapy, there was in general a highly significant reduction in the amount of autonomic symptoms and complaints (related or not related to voice) to such extent that patients report in average no more general neurovegetative symptoms and complaints than healthy controls. Symptoms and complaints of other nature (validity control) were not influenced. When compared with patients receiving conventional therapy, those who received coordination therapy demonstrated a significantly higher reduction for the subset symptoms and complaints related to voice and speech.
At this moment we are testing the light reflex in a group of patients with nonorganic habitual dysphonia and a control group. We are using the Forsite pupillometer. Since the pupils are innervated by sympathetic and parasympathetic functions, this seems a proper way to objectivate the findings of the previous studies.