Delayed thrombectomy for internal carotid artery occlusion in young stroke: a case report.

Background: Internal carotid artery occlusion (ICAO) is uncommon in young adults and may present with mild or transient symptoms, posing challenges in determining the timing and necessity of endovascular intervention. While conservative management is often preferred in patients with minimal deficits, some may experience delayed infarct progression requiring escalation of care. Case Description: We present a 24-year-old male with no prior medical history who developed mild stroke symptoms during physical activity. Imaging revealed complete occlusion of the left internal carotid artery (ICA). Due to rapid symptom resolution and a low National Institutes of Health Stroke Scale (NIHSS) score, he was managed conservatively with antiplatelet therapy and discharged. Twelve days later, he returned with new-onset right-sided weakness and numbness. Imaging showed a new infarct and persistent ICAO with middle cerebral artery (MCA) involvement. Despite medical therapy, he deteriorated neurologically, and a large MCA infarct with midline shift was identified. Emergent mechanical thrombectomy of the first segment of the middle cerebral artery (M1) segment was performed. The patient showed meaningful improvement post-procedure and was discharged to rehabilitation. At follow-up, he remained ambulatory with assistance and functionally independent self-care but continued to have expressive aphasia and right-sided weakness. Conclusions: This case demonstrates that young patients with ICAO and initially mild symptoms may still be at risk for infarct progression and delayed neurological deterioration. Mechanical thrombectomy can lead to favorable outcomes even when performed beyond traditional time windows. Our findings highlight the importance of close monitoring and re-evaluation in this population and support a flexible, individualized approach to intervention timing based on evolving clinical and radiographic evidence.