Unilateral Diaphragmatic Paralysis in Association with Erb’s Palsy

Abstract

To the Editor: Erb’s palsy is a well-described complication of trauma to the shoulder and neck.1Leffert RD Brachial-plexus injuries.N Engl J Med. 1974; 291: 1059-1069Crossref PubMed Scopus (43) Google Scholar Except in neonates, it is very unusual for Erb’s palsy to be accompanied by an ipsilateral diaphragmatic paralysis. The purpose of this communication is to report such a case occurring in an adult following drug overdosage. A 57-year-old white man was brought to the emergency room of UCLA Hospital after having lain for four days on his right side on the floor of his apartment following ingestion of a large dose of meprobamate. The patient was well developed and well nourished. His temperature was 39.2°C (102.6°F), the pulse rate was 120 beats per minute, the respiration rate was 40/min, and the blood pressure was 120/70 mm Hg. There was dullness to percussion over the entire right pulmonary field, with decreased and tubular breath sounds. There was marked edema of the right arm. On neurologic examination, significant abnormalities were limited to the right arm. There was no evidence of muscular atrophy or “winging” of the scapula. The rhomboid muscles were intact. The following strengths were noted for various muscles: deltoid muscle, 0/5; adductor muscles of shoulder, 3/5; biceps muscle, 0/5; triceps muscle, 3/5; flexor muscles of wrist, 5/5; and intrinsic musculature of hand, 5/5. Areas of decreased sensation and hyperpathia were present over the right shoulder. Laboratory data included the following: white blood cell count, 9,600/cu mm, with a shift to the left; blood urea nitrogen level, 75 mg/100 ml; creatinine level, 3.9 mg/100 ml; serum osmolarity, 341 mOsm; creatine phosphokinase level, 2,200 International units/ml; oxygen pressure, 54 mm Hg; carbon dioxide pressure, 28 mm Hg; pH, 7.44; and serum level of meprobamate, 14.1 mg/100 ml. A chest x-ray film showed consolidation of the entire right lung. By the eighth day of hospitalization, infiltrates on the chest x-ray film had cleared considerably, revealing an elevated right hemidiaphragm and an area of atelectasis above the diaphragm (Fig 1). Fluoroscopic examination (“sniff test”) showed paradoxic motion of the right hemidiaphragm. A chest x-ray film taken two months earlier was normal. Electromyographic studies confirmed the clinical impression of an Erb’s palsy of the C5-6 brachial plexus, with sparing of the rhomboid muscles. A study of conduction by the phrenic nerves showed an intact left phrenic nerve, while the right phrenic nerve did not react. Diaphragmatic paralysis should be suspected in patients with persistent physical and roentgenographic findings of atelectasis and unilateral elevation of the diaphragm. The present case is unusual because unilateral diaphragmatic paralysis was associated with an ipsilateral Erb’s palsy.2Stevens J Brachial plexus paralysis.in: Cogman EA The Shoulder. Boston, private publisher1934: 332-399Google Scholar Neonates born with an ipsilateral Erb’s palsy commonly have a unilateral diaphragmatic paralysis.3Richard J Chevalier V Capelle R et al.La paralysie diaphragmatique obstericale.Arch Fr Pediatr. 1957; 14: 563-598PubMed Google Scholar This syndrome occurs as a complication of delivery in which excessive manipulation of the shoulder and neck is required. It probably results from traction injury to the phrenic nerve and to the upper portion of the brachial plexus. Decreased mobility of the shoulder and neck in adults may account for the fact that this syndrome is so rarely acquired after birth; however, the occurrence in this patient of both hemidiaphragmatic paralysis and an ipsilateral Erb’s palsy strongly suggests the same mechanism as has been proposed in neonates, namely, traction on both the brachial plexus and the phrenic nerve. The absence of conduction in the right phrenic nerve supports the contention. We believe that these traction injuries were sustained during the prolonged period when the patient lay comatose on the floor of his apartment in a position which was probably such that his head and neck were forced to the left, while his right shoulder was pushed caudally. In conclusion, we believe that in adults, as well as in neonates, trauma to the shoulder and neck can cause traction injury to both the phrenic nerve and the brachial plexus, resulting in unilateral diaphragmatic paralysis in association with an ipsilateral Erb’s palsy. Diaphragmatic motion should therefore be assessed in patients with Erb’s palsy, since such patients may have an unrecognized diaphragmatic paralysis.