ODP655 Apathetic Hyperthyroidism

Abstract

Abstract Introduction Apathetic hyperthyroidism is a rare presentation of hyperthyroidism described in the elderly population. It is insidious in onset and symptoms are depression, lethargy, and weight loss. The adrenergic symptoms of hyperthyroidism are often absent. Furthermore, orbital disease associated apathetic hyperthyroidism has not been reported widely in literature. We present a clinical scenario of apathetic hyperthyroidism associated with orbitopathy. A 64-year-old lady presented with acute onset bilateral periorbital swelling that developed over 2 days. About 3 weeks prior, she began experiencing symptoms of brain fog, lethargy, intermittent nausea, anorexia, and headache. She experienced palpitations with exertion. Review of other systems was negative. Clinical exam: HR 70. Thyroid gland was enlarged, symmetric with no nodules and nontender, bilateral periorbital puffiness and mild conjunctival redness was noted. Lab data was significant for TSH at 0. 03 uIU/mL, elevated FT4 2.5ng/dL, total T3 of 222ng/dL, TSI 4.2 and sed rate of 10. Her thyroid ultrasound indicated hypervascular and heterogenous gland. Our patient was diagnosed with apathetic hyperthyroidism and thyroid eye disease. She was started on propranolol 60mg ER one tablet a day and methimazole 10mg a day. CT scan of the orbit indicated symmetric enlargement of extraocular muscles. Evaluation by the ophthalmologist confirmed the presence of thyroid eye disease with a clinical activity score of 6 out of 7 indicating severe thyroid eye disease and she was a candidate for treatment with teprotumumab. Discussion Apathetic hyperthyroidism was first described by Lahey in 1931, as a state of non-activated hyperthyroidism. It is manifested with gradual onset of apathy, depressed mood, lethargy, nausea, lack of appetite, weight loss, proximal muscle weakness, goiter, atrial fibrillation, and congestive heart failure. It lacks the typical presentation of a hyperadrenergic state of hyperthyroidism which include palpitations, anxiety, tremor, heat intolerance, and diaphoresis. Due to the lack of typical presentation of hyperthyroidism, timely diagnosis and treatment may be challenging. Concomitant occurrence of occult malignancy and hyperglycemia have been reported in case reports. Patients can also transition from apathetic state to hyperadrenergic state of hyperthyroidism and vice versa. Lahey emphasized the risk of unexpected death following surgery in apathetic hyperthyroidism. The absence of adrenergic symptoms could be supported by the theory that these patients are in a relative state of catecholamine deficiency or have a state of end organ catecholamine resistance. Significant orbital involvement in apathetic hyperthyroidism is not widely reported in the literature. Blepharoptosis has been mentioned in association with this form of hyperthyroidism. Our patient presented with acute onset eye symptoms which prompted testing of thyroid function. Further review of symptoms led to a diagnosis of apathetic hyperthyroidism with thyroid eye disease.