[Sudden-onset monoplegia of the upper limb due to traumatic subclavian artery pseudoaneurysm after an interval of three days from tumbling].

A 66-year-old woman was admitted to our institution with sudden-onset weakness of her left upper limb. Neurological examination revealed monoplegia and sensory loss of the limb. A brain MRI did not find evidence of an acute ischemic stroke. Her medical history revealed that she had fallen and bruised her shoulder 3 days earlier. Detailed physiological examination revealed that there was a mild subcutaneous ecchymosis with tenderness in the left shoulder. An additional contrast-enhanced chest CT scan showed a fracture of the clavicle diaphysis and a pooling contrast agent demonstrating a 60*40 mm mass near the left subclavian artery (SUB-A) which suggested a pseudoaneurysm. We determined that her symptoms were due to compression of the brachial plexus by immediate growth of a traumatic SUB-A pseudoaneurysm (TSAP) due to her earlier fall. For reduction of pressure to the brachial plexus by the TSAP and prevention of rupture, an endovascular treatment team performed endovascular internal trapping of the left SUB-A just distal to the orifice of the left vertebral artery and a cardiovascular surgeon performed percutaneous drainage of the pseudoaneurysm. After the procedure, the palsy and sensory loss of the left hand gradually improved. A TSAP could be one of the causes of sudden-onset palsy of the upper limb within a few days after a fall.