[Reflex sympathetic dystrophy following electric shock: description of a clinical case].

The acute effects of electrical injuries are well known. However, the occurrence and the mechanisms of the delayed sequelae are still unclear. The effects on peripheral nerves and the sympathetic system in particular are poorly documented. A 47-year old man was injured on the left arm by contact with a 380 V tension switch in January 1990. A few hours after the accident he complained of burning pain, dysesthesia, weakness and motor impairment of the arm. Allodynia and anhidrosis without cutaneous trophic lesions were observed. During the subsequent months the symptoms did not change except for the appearance of signs of autonomous nervous system hyperactivity (hyperhidrosis, edema, atrophy of the skin and nails, excessive sweating). One year later thermographic evidence and the effect of anesthetic blockade of the sympathetic chain on the burning pain, stiffness of joints and weakness of the arm confirmed the clinical diagnosis of reflex sympathetic dystrophy. Analgesia and motility improvement were achieved by means of sympathetic blockades although the patient's hand grip force and thumb-little finger grip were still weakened. Any known etiology besides electric shock could be associated with these clinical signs. The cause of the reflex sympathetic dystrophy may be multifactorial. In this patient the electric shock might have damaged peripheral sympathetic fibres or cervical ganglia. Lesions of the peripheral nerves and sympathetic hyperactivity can contribute to the development of such syndrome.