Background <p>Transient perivascular inflammation of the carotid artery (TIPIC syndrome), previously known as carotidynia, is a rare, self-limiting inflammatory condition of the carotid artery wall and surrounding tissues. It typically causes unilateral neck pain at the carotid bifurcation without underlying atherosclerosis or significant luminal stenosis. Hemodynamic flow is usually preserved, and symptoms often resolve with conservative treatment, such as nonsteroidal anti-inflammatory drugs. Severe complications such as thrombus formation and stroke are exceedingly uncommon.</p> Case presentation <p>A 42-year-old Asian woman presented with acute right-sided neck pain, headache, blurred vision, and left-sided weakness. Examination showed right carotid tenderness, severe right-eye visual loss (light perception only), and left hemiparesis. There were no traditional vascular risk factors or evidence of connective tissue or autoimmune disease. The levels of inflammatory markers were mildly elevated. Initial brain imaging revealed multiple infarcts in the right watershed territories (between the middle and posterior cerebral arteries), implying occlusion of the right internal carotid artery (ICA).</p> <p>Carotid Doppler ultrasound revealed eccentric, hypoechoic wall thickening of the distal right common carotid artery (CCA) extending into the carotid bulb, with no flow detected in the distal CCA/ICA, indicating near-occlusion. Subsequent CT angiography confirmed a long segment thrombus occluding the distal right CCA, carotid bulb, and entire ICA, with a faint rim of contrast around a central filling defect. Ill-defined perivascular soft tissue enhancement surrounding the affected arterial segments was also observed. The patient was managed with anti-inflammatory therapy and further stroke prevention measures. Over the following weeks, her neck pain resolved, and there was a partial improvement in her neurological deficits.</p> Conclusion <p>This case illustrates an unusual complication of TIPIC syndrome, in which severe carotid artery inflammation leads to long-segment thrombosis and ischemic stroke. TIPIC syndrome is generally a benign, self-limited condition, but our findings underscore that it rarely results in significant vascular complications, including stroke. Prompt recognition of this entity and appropriate imaging are crucial for diagnosis, differentiation from other causes (such as dissection or vasculitis), and timely management to prevent complications.</p>