[Recurrent nerve paralysis and Claude Bernard-Horner syndrome following an interscalene block of the brachial plexus].

The association of a recurrent laryngeal block with a Horner's syndrome occurred in one patient after right interscalene brachial plexus block. Hoarseness was the main clinical symptom of recurrent paralysis and lasted 4 h. The subsequent course was totally uneventful and required no specific treatment. But the interscalene route of brachial plexus block may be potentially hazardous in the patient with a full stomach.