Background: Ischemic stroke is an unusual but important complication of Graves Thyrotoxicosis that is induced by the hypoercoaguable state of thyrotoxicosis.
We present a 24-year old female patient admitted with a 3-day history of intermittent slurred speech associated with numbness of the right side of her mouth and face preceded by left sided headache.
She had a history of uncontrolled Graves disease secondary to noncompliance. Following on her last outpatient endocrine follow up; there was a plan for definitive treatment in the form of radioactive iodine.
She is a smoker of and a teetotaller. She has been on the combined contraceptive pill up until one week prior to presentation.
On examination, she was tachycardic with a normal blood pressure and a blood glucose of 7 mmol/l. She had mild dysarthria and right facial droop but no other focal neurological deficit. CT on admission showed a possible left frontal lobe infarct which was subsequently confirmed on MRI scan.
ECG showed sinus rhythm and her thyroid function test indicated uncontrolled thyrotoxicosis with a Free T4 of 22.5 pmol/L and a fully suppressed TSH.
The overall impression was that her stroke was likely cardioembolic in origin, probably due to thyrotoxicosis-induced atrial fibrillation. However we were unable to capture the atrial fibrillation during the admission and on a subsequent 24 hour tape. The decision was to anticoagulate with Apixiban even in the absence of documented paroxysmal atrial fibrillation.
Her dysarthria improved and she was discharged on a high dose of Carbimazole together with propranolol and Apixiban.
Investigations including a Carotid Doppler and Echocardiogram were both normal. A young stroke screen was performed including a vasculitic screen were all within the normal range.
Conclusion: Whether patients with thyrotoxic atrial fibrillation should be anticoagulated remains controversial and needs further evidence.