Thyroid storm is a clinical diagnosis. Severe thyrotoxicosis + systemic decompensation
The degree of TSH suppression/T4 elevation in patient’s with thyroid storm is comparable to patients with uncomplicated overt hyperthyroidism
Thyroid storm can be differentiated from thyrotoxicosis by the presence of temperature elevation, significant tachycardia, heart failure, gastrointestinal disorders, diarrhea, nausea, vomiting, and sometimes jaundice. Neurologically, agitation and disorientationcan occur.
Etiology of Thyroid Storm
Thyroid storm most commonly occurs in Graves disease and has a higher frequency in younger women, but it also can be due to a toxic adenoma or multinodular goiter.
Can occur in long-standing, untreated hyperthyroidism but usually is precipitated by an underlying condition, such as surgery, infection, trauma, parturition, acute iodine exposure, radioactive iodine (131I) therapy, or ingestion of medications, including amiodarone, salicylates and pseudoephedrine.
Even with aggressive therapy and supportive measures, mortality after thyroid storm is as high as 15% to 20%.
Geriatric (Apathetic) Hyperthyroidism
Hyperthyroidism in elderly patients may be apathetic, rather than having hyperactivity, tremor, and other symptoms of sympathetic hyperactivity.
Older patients more commonly present with atrial fibrillation as well.
Take Home Point: In the elderly patient with new onset atrial fibrillation or depression/somnolence, make sure to consider hyperthyroidism.