An unusual cause of transient neurologic deficits: compression of the carotid artery by a thyroid cystic nodule.

We report a case of a 93-year-old man, who presented with limb-shaking transient ischemic attacks (TIAs) after orthostatic position change or turning his head to the left. The limb-shaking TIAs resulted from external compression of the carotid artery. Contrast-enhanced magnetic resonance angiography of the head and neck and Doppler ultrasound examination of the thyroid gland revealed a large cystic nodule in the right thyroid lobe, resulting in compression and posterior displacement of the right common carotid artery. Clinicians should be aware that limb-shaking TIAs can not only result from obstructive extracerebral or intracerebral artery disease, but also from external compression of the carotid artery.