You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is In a patient with head injury, unexplained hypotension warrants evaluation of: and explain in detail?
High thoracic or cervical cord transection causes hypotension and bradycardia due to functional sympathectomy (sometimes with Horner syndrome). Ref: Harrison's Principles of Internal Medicine, 15th Edition, Page 2441; Surgery: Basic Science and Clinical Evidence By Jeffrey A. Noon, Philip S. Barie, Randall Bollinger, 2008, Page 314