Hoarseness after laryngeal blunt trauma: a differential diagnosis between an injury to the external branch of the superior laryngeal nerve and an arytenoid subluxation. A case report and literature review.

Arytenoid subluxation is a well-known cause of hoarseness due to incomplete glottic closure with intact inferior laryngeal nerves after severe laryngeal trauma. We report the case of a young man presenting after laryngeal blunt trauma with hoarseness, easy fatigue during phonation, marked difficulty with his high-pitch and singing voice and decreased phonation time, but intact function of both inferior laryngeal nerves, intact endolaryngeal mucosa sensibility and normal CT scans of the larynx and the neck. Due to the asymmetric anteromedial position of the right arytenoid with incomplete glottic closure, the primary diagnosis was arytenoid subluxation, and the patient was referred for instantaneous relocation therapy. The stroboscopic and electromyographic diagnosis of a unilateral paresis of the external branch of the right superior laryngeal nerve caused the therapy to be changed. Without repositioning, the patient had a total recovery of voice quality when the paresis receded 2 months later. In conclusion, the unilateral paresis of the external branch of the superior laryngeal nerve after laryngeal blunt trauma is reported here for the first time. Although the clinical findings are familiar sequelae of thyroid surgery, they may be misdiagnosed as arytenoid subluxation after laryngeal blunt trauma. Stroboscopy and electromyography permitted the correct diagnosis.