SAT503 Acute Psychosis and Paranoia as an Initial Manifestation of Myxedema Madness

Disclosure: S. Atam: None. M. Ahmad: None. G.A. McGrath: None. Introduction: Hypothyroidism is a common disease affecting approximately 1 in 300 Americans, with autoimmunity being the most common cause in the United States. Hypothyroidism is known to present with numerous psychiatric manifestations, including depression, cognitive deficits, and rarely psychosis. We present a case of profound hypothyroidism found in a patient who presented with visual hallucinations and paranoia. Case description: The patient was a 64-year-old man with past medical history of follicular Non-Hodgkin's Lymphoma, Type 2 diabetes, hypertension, and sinus bradycardia who presented to the emergency department with three-week history of increasing agitation, insomnia and cold intolerance. He had auditory and visual hallucinations with paranoid ideations, which started a few days prior. His initial vitals were temperature: 98.2°, heart rate: 81 beats per minute, respiratory rate: 20 breaths per minute, and blood pressure: 135/88 mmHg. The patient’s initial lab work was significant for: sodium: 143 mmol/L, potassium: 3.6 mmol/L, creatinine: 1.55 mg/dL (baseline of 1.2 mg/dL), AST: 240 IU/L, ALT: 252 IU/L, INR: 1.1, ammonia: 20 mcmol/L, TSH: 51.7 uIu/ml, free t4: <0.1 ng/dL, free t3: <0.4 ng/dL, and urine drug screen positive for cannabinoids. MRI imaging of the patient’s brain was negative for any acute intracranial process. Although the absence of hypothermia made myxedema coma unlikely, both the acuity and the severity of his psychiatric symptoms in the context of profound hypothyroidism, with no other identifiable cause, collectively suggested “myxedema madness”. The patient was started on intravenous levothyroxine therapy along with quetiapine and haloperidol for agitation. Further lab work demonstrated an anti-tpo antibody of 9.0 IU/mL (< 9) along with a benign lumbar puncture (glucose: 89 mg/dL, protein: 54 mg/dL, WBC: 9/uL, RBC: 1/uL). A review of his recent medical history revealed that last summer, as part of a chemotherapy regimen for relapsed lymphoma, he had been started on Lenalidomide, which is reported to cause primary hypothyroidism in 7% of patients. His overall neurologic function improved over a two-week course, and he was subsequently discharged. Discussion: Hypothyroidism can present with a spectrum of different psychiatric manifestations. However, cases of hypothyroidism-induced psychosis are infrequent. It is reported that only 5-15% of myxedematous patients develop some form of psychosis. Treatment of this altered mental state is centered on thyroid hormone supplementation along with the administration of antipsychotic medications. Improvement in psychotic symptoms is typically seen within weeks to months after initiation of treatment. Through this case, we hope to highlight this rare presentation of hypothyroidism and current proposed treatment strategies. Presentation Date: Saturday, June 17, 2023