Endocrine, Physiology, USMLE Step 1 - Full Vignette with Extended Explanations скачать в хорошем качестве

Endocrine, Physiology, USMLE Step 1 - Full Vignette with Extended Explanations

A 34-year-old woman on multiple medications for primary myelofibrosis presents with two weeks of palpitations, heat intolerance, tremor, unintentional weight loss, and insomnia, shortly after an iodinated contrast CT. With a complex medical background and recent acute worsening of symptoms, how should clinicians proceed when usual thyroid imaging studies may be unreliable? What clinical strategies help identify the underlying cause of thyrotoxicosis in multifactorial cases? VIDEO INFO Category: Endocrine, Physiology, USMLE Step 1 Difficulty: Hard - Advanced level - Challenges experienced practitioners Question Type: Diagnostic Step Case Type: Complicated Condition Explore more ways to learn on this and other topics by going to https://endlessmedical.academy/auth?h... QUESTION A 34-year-old woman with primary myelofibrosis on ruxolitinib, cervical spondylotic myelopathy, prior squamous cell carcinoma of the forearm resected two years ago, chronic fatigue syndrome, contact dermatitis, tardive dyskinesia managed with a low dose antipsychotic, and Meniere disease presents to the emergency department with two weeks of worsening palpitations, heat intolerance, tremulousness, five-kilogram unintentional weight loss, loose stools twice daily, and insomnia.... OPTIONS A. Measure serum TSH receptor autoantibodies using a TRAb or TSI immunoassay to confirm Graves disease when radioiodine uptake is impractical immediately after recent iodinated contrast exposure. B. Obtain an iodine-123 radioactive iodine uptake and scan today to differentiate Graves disease from thyroiditis despite same-day iodinated contrast administration. C. Order a technetium 99m pertechnetate thyroid scan now because technetium uptake is not affected by recent iodine exposure and will reliably distinguish causes of thyrotoxicosis. D. Measure serum thyroglobulin concentration to diagnose Graves disease directly and replace the need for radioiodine uptake or antibody testing in this setting. CORRECT ANSWER A. Measure serum TSH receptor autoantibodies using a TRAb or TSI immunoassay to confirm Graves disease when radioiodine uptake is impractical immediately after recent iodinated contrast exposure. EXPLANATION The most efficient confirmatory test for Graves disease in the immediate aftermath of an iodinated contrast load is a thyroid-stimulating hormone receptor antibody assay (TRAb or a bioassay for thyroid-stimulating immunoglobulins). The fundamental teaching point is that recent exposure to large iodine loads from intravenous contrast and from amiodarone can suppress or confound radioiodine uptake for weeks, whereas TRAb/TSI assays directly detect the autoimmune driver of Graves and return results quickly. This patient s severe thyrotoxicosis with diffuse goiter, lid lag, and a faint thyroid bruit is highly suggestive of Graves; measuring TRAb/TSI while starting symptomatic therapy will establish etiology without delay. Per the 2016 American Thyroid Association guideline and NICE NG145 (2019), TRAb testing is recommended when radioactive iodine uptake cannot be performed or interpreted due to recent iodine exposure. Competing imaging strategies are unreliable now. Obtaining an iodine-123 uptake and scan on the same day as iodinated contrast ignores the known delay in clearance; prospective data show median 43 days to return to baseline urinary iodine after contrast, with many patients requiring 6 to 10 weeks.... Further reading: Links to sources are provided for optional further reading only. The questions and explanations are independently authored and do not reproduce or adapt any specific third-party text or content. --------------------------------------------------- Our cases and questions come from the https://EndlessMedical.Academy quiz engine - multi-model platform. Each question and explanation is forged by consensus between multiple top AI models (i.e. Open AI GPT, Claude, Grok, etc.), with automated web searches for the latest research and verified references. Calculations (e.g. eGFR, dosages) are checked via code execution to eliminate errors, and all references are reviewed by several AIs to minimize hallucinations. Important note: This material is entirely AI-generated and has not been verified by human experts; despite stringent consensus checks, perfect accuracy cannot be guaranteed. Exercise caution - always corroborate the content with trusted references or qualified professionals, and never apply information from this content to patient care or clinical decisions without independent verification. Clinicians already rely on AI and online tools - myself included - so treat this content as an additional focused aid, not a replacement for proper medical education. Visit https://endlessmedical.academy for more AI-supported resources and cases. This material can not be treated as medical advice. May contain errors. ---------------------------------------------------