A 58-year-old man describes a temporary weakness in his right hand that occurred 3 days ago while driving his truck. He was unable to move his arm for 30 minutes, but he progressively regained his strength. He also had difficulty speaking around the same time with transient loss of vision. All symptoms are resolved now. His temperature is 98.4⁰ F, heart rate is 71 beats per minute, respiratory rate is 16 breaths per minute, oxygen saturation 97%, and blood pressure is 172/101 mm Hg. His past medical history is significant for diabetes, hypertension and coronary artery disease with stable angina. He has been smoking since he was 15 years-old and he currently smokes one pack of cigarettes a day. His current medications include aspirin, insulin, sublingual nitroglycerin, and metoprolol. On examination, bruits can be auscultated over both carotid arteries. The remainder of his physical examination is unremarkable. Of the following, what is your next step in management of this patient?

A 24 year-old male comes to your urgent care center and reports that he has been feeling intense fear that something terrible is about to happen, worrying about losing control of his life, spending sleepless nights fearing he might go crazy, feeling as if he is choking and feeling a sense of impending doom. He insists that his symptoms are not ‘just mental’. He reports he has a pounding heart, upset stomach, diarrhea, shaking, sweating, numbness and tingling in his arms and legs.He has had 5 or 6 episodes of fear attacks in the last two months. He denies any alcohol or substance use. His medical history is unremarkable for medical and mental health histories. Suspecting drug abuse, you ordered a random urine drug screen, which came negative on a 12 panel test. When you ask him to stand during a physical examination, he reports feeling dizzy and lighthearted. When you are planning to order some laboratory tests, he reports that his family doctor checked him for a lot of things to rule out heart disease, gastrointestinal disease and neurological disease and ‘all those tests showed nothing abnormal’. What is the most likely diagnosis in this patient?