A 32-year-old man presents 30 minutes after a generalized tonic-clonic seizure, which lasted for around three minutes and was followed by a brief period of confusion. Further questioning reveals that he has been experiencing multiple episodes of abnormal twitching of his facial muscles over the last six weeks. Each episode lasted for a couple of minutes, during which time he remained conscious and rational. His medical history is significant for trauma to the head and neck following a motor vehicle accident around a year ago, from which he obtained a complete recovery. At that time, computed tomography (CT) was negative for intracranial hemorrhages. There is no family history of seizures. He does not smoke and drinks socially. A complete blood count is within normal parameters, as are a random capillary glucose assay, and serum sodium and potassium levels.
Ionized calcium: 3 mg/dL (4.4-5.3)
Serial ECGs appear completely normal.
The non-contrast CT of the brain shows no abnormalities.
Serum magnesium is within normal parameters.