Diaphragm paralysis caused by transverse cervical artery compression of the phrenic nerve: the Red Cross syndrome.

BACKGROUND The etiology of diaphragm paralysis is often elusive unless an iatrogenic or traumatic injury to the phrenic nerve can be clearly implicated. Until recently, there has been little interest in the pathophysiology of diaphragm paralysis since few treatment options existed. METHODS We present three cases of symptomatic diaphragm paralysis in which a clear clinico-pathologic diagnosis could be identified, specifically a vascular compression of the phrenic nerve in the neck caused by a tortuous or adherent transverse cervical artery. RESULTS In two patients the vascular compression followed a preceding traction injury, whereas in one patient an inter-scalene nerve block had been performed. Following vascular decompression, all three patients regained diaphragmatic motion on fluoroscopic chest radiographs, and experienced a resolution of respiratory symptoms. CONCLUSION We suggest that vascular compression of the phrenic nerve in the neck may occur following traumatic or iatrogenic injuries, and result in symptomatic diaphragm paralysis.