[The immobile vocal cord]

Usually dysphonia is the result of a functional disorder of the larynx. It can also result from paresis or paralysis of a hemilarynx. Four patients, men aged 57, 41, 42 and 18 years, had a neurological cause of paralysis of a hemilarynx. Processes responsible for this kind of pathology can appear at three different levels: central, nuclear and peripheral. Each of the four patients had a disorder at the peripheral level: two had a tumour, in one the vagus nerve was severed during lobectomy for squamous cell carcinoma (iatrogenic), and in the last one an upper respiratory viral infection was the probable cause. Other causes of these peripheral lesions are toxicological, traumatic or idiopathic. When dysphonia does not improve within three weeks, inspection of the larynx and palpation of the neck, including examination of the aspect and mobility of the vocal folds by an otorhinolaryngologist should be performed. If paresis of a hemilarynx is seen, an orientation examination of the cranial nerves and selective additional examination is necessary, as paresis of a hemilarynx is a symptom, not a diagnosis.