This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': "Which is not true about thoracic outlet syndrome - \nSelect and explain. \nA. Radial Nerve is commonly affected, B. Neurological features are most common., C. Resection of 1st  rib relieves symptom, D. Positive Adson's test", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Not the Radial nerve, but Ulnar nerve is most commonly affected in thoracic outlet syndrome.\nThoracic Outlet Syndrome\n\nis the collective name which includes -\n\n\nCervical rib syndrome\nScalenus anterior syndrome\nCostoclavicular syndrome\nHyperabduction syndrome\nPectoralis minor syndrome\nFirst thoracic rib syndrome\n\n\n\nThe syndrome is caused by compression of the brachial plexus or subclavian vessels in the region of thoracic inlet. The symptoms may arise from neural, vascular or combined compression.\n\nNeurological symptoms (are more common)\n\nCompression of the brachial plexus usually affects its lower trunk (C8 & T1).\nSymptoms are - Pain, paraesthesia and numbness usually in the finger and hands in the ulnar nerve distribution.\n\nSymptoms of Arterial Compression are seen less frequently in about 1/4 of the cases.\n\nSymptoms are - Pain, numbness, paresthesia, coldness and weakness of the arm or hand. Raynauds phenomenon may also occur.\nVenous symptoms are less common and include edema, venous distention, pain and cyanosis.\n\nDiagnostic tests or manoeuvres :\n\nAdsons test*\nCostoclavicular compressive test*\nHyperabduction test. *', 'role': 'assistant'}]