Posterior Sternoclavicular Subluxation - A Rare Mechanism of Stroke (1121)

Objective: Posterior sternoclavicular subluxation is a rare orthopedic condition occurring secondary to trauma. Anatomical proximity of the sternoclavicular joint to the superior mediastinum puts critical vascular structures, such as the brachiocephalic artery, at risk of injury. We present the case of a young patient who suffered malignant cerebral infarction secondary to brachiocephalic artery injury following traumatic posterior sternoclavicular subluxation. Background: A 27-year-old man with history of methamphetamine abuse presented to an outside hospital after being found unresponsive by his roommate. Per report, he had difficulty walking and speaking earlier that day. A head CT revealed early hypodensity consistent with complete right middle cerebral artery territory infarct. His subsequent CT angiogram revealed posterior sternoclavicular subluxation with adjacent hematoma compressing the brachiocephalic artery. There was a large area of focal thrombus within the brachiocephalic artery with distal embolization observed in the external carotid artery branches and the right middle cerebral artery M1 division. Design/Methods: He arrived at our hospital intubated and sedated with an initial NIHSS of 30. Due to the infarct burden, he developed malignant cerebral edema requiring 23.4% hypertonic saline and decompressive craniectomy. His condition stabilized and he was extubated on hospital day 7. His neurologic examination when off sedation showed dense left-sided hemiplegia, neglect, homonymous hemianopia, rightward gaze preference, eyelid apraxia, and dysarthria (NIHSS 15). Results: On hospital day 12, he underwent open reduction of the sternoclavicular subluxation. Given the high risk of complications associated with this procedure, it was performed in a joint manner with the assistance of a cardiothoracic surgeon. On day 15, he was started on therapeutic anticoagulation for persistent brachiocephalic thrombus. Conclusions: This case of malignant cerebral infarction represents a life-threatening complication of posterior sternoclavicular subluxation, an uncommon orthopedic injury. Disclosure: Dr. Mohl has nothing to disclose. Dr. Streib has nothing to disclose. Dr. Cusic has nothing to disclose.