A 48-year-old Haitian man with a history of hypertension presented to our hospital following an episode of loss of consciousness. The episode occurred while the patient was standing at a sink, and was preceded by several hours of non-exertional chest discomfort and a brief period of dizziness. He regained consciousness on the floor and felt diffusely weak. There were no lateralized symptoms, post-ictal confusion, incontinence, or tongue contusions. When he returned to a standing position, he saw prominent ‘‘beating, pulsating’’movements of his periorbital and perioral muscles in the mirror, and also noted some blurred vision. There was additional muscle twitching involving the hands, legs, chin and neck, which the patient described as ‘‘a heart beating under the skin’’. There was no associated pain, weakness, or numbness. The patient revealed that he had experienced intermittent but frequent abnormal beating of the periorbital muscles for approximately two months prior to presentation. He initially thought it was secondary to anxiety. One month after the onset of these symptoms, he developed similar sensations in his fingers and legs bilaterally, and then in the perioral muscles. In addition to these symptoms he had diarrhea as well as an unintentional 25 pound weight loss over three months, due to anorexia. He had not had fevers. He reported hyperlacrimation which he felt was the result of frequently rubbing his eyes. He denied dysphagia, paresthesias, muscle cramps, headaches, or difficulty with balance. He had had a few episodes of near syncope in the two months prior to presentation, which were not associated with falls.

Past medical history included essential hypertension which had been diagnosed five years prior to presentation, as well as vitiligo of the bilateral hands and lips which had been noticeable for six months prior to presentation. He denied neonatal or childhood infections and achieved normal developmental milestones. There was no personal or family history of seizures or other neurological disease. Medications included nifedipine, hydrochlorothiazide, and lisinopril, and there had been no recent medication changes. On initial evaluation, the patient was afebrile, with supine blood pressure 90/50 and heart rate 65, and standing blood pressure 74/50 and heart rate 82. General examination