A 65-year-old alcoholic man is admitted with generalized weakness.　He reports a several-day history of diarrhea and has muscle cramps. He has no history of trauma or seizures. He is taking no medications but has smoked 1 pack of cigarettes daily for the past 30 years.

　On physical examination, blood pressure is 110/70 mmHg, pulse rate is 95/min, and respiratory rate is 18/min. The neck is supple, and the carotids are normal. The lungs are clear. The abdomen is soft, with bowel sounds. Cranial nerves are normal, and the patient has 3+ reflexes. Carpal pedal spasm is noted intermittently during examination, and Chvosteks sign is present.