Clinical Reasoning: An unusual diagnostic triad

A 44-year-old woman with a history of hypothyroidism taking daily levothyroxine was admitted to an outside hospital with subacute cognitive decline. Her symptoms had started 3 weeks previously with headache, sore neck, and upper respiratory symptoms for which she sought care at a local emergency room. She did not complain of confusion or demonstrate signs of cognitive decline at that time and was discharged home with a prescription for antibiotics. A few days later, she was hospitalized after appearing disoriented, exhibiting signs of confusion, responding slowly, and running into things at work.