Influence of thyroid surgery on voice function and laryngeal symptoms.

A comprehensive examination of voice function and laryngeal symptoms was applied systematically to 20 patients undergoing thyroid surgery. Patients were excluded from the series if there had been previous neck surgery or if postoperative indirect laryngoscopy showed abnormal cord mobility. Examination before operation showed that patients with sporadic non-toxic goitre or medically pre-treated toxic goitre had impaired voice function based on stroboscopy, electro-glottography, phono-oscillometry and determination of voice range, phonation time, pitch, and peak flow. Three months after thyroid surgery the voice function was significantly improved although not normal in non-toxic goitre patients, whereas the voice function in patients with thyrotoxicosis was unchanged. The number of laryngeal symptoms was significantly reduced in non-toxic goitres following surgery and unaltered in the group with thyrotoxicosis.