Myxedema Psychosis after Levothyroxine Withdrawal in Radioactive Iodine Treatment of Differentiated Thyroid Cancer: A Case Report.

Neuropsychiatric symptoms, especially acute psychosis (often referred to as myxedema madness or psychosis), are rare but possible clinical presentations of patients with hypothyroidism. A 42-year-old woman with papillary thyroid carcinoma and recent total thyroidectomy had developed flat affect, paranoid delusion, and visual and auditory hallucination during inpatient admission for elective radioactive iodine treatment. On admission, her history and physical exam did not reveal symptoms and signs of significant hypothyroidism. Other medical causes of acute psychosis were excluded, and the patient was immediately treated with thyroid hormone replacement therapy. Subsequently, her thyroid function normalized, and her psychotic symptoms gradually improved. Although there is a lack of classic signs and symptoms of hypothyroidism, myxedema madness should be recognized as one of the potentially treatable causes of acute psychosis.