Recurring cervical internal carotid artery vasospasm elicited by head rotation: illustrative case

BACKGROUND: Idiopathic extracranial internal carotid artery vasospasm (IEICAV) is a rare cerebrovascular disorder causing transient or permanent cerebral ischemia. The pathophysiology underlying this disorder is not well understood. Although various medical treatments have been tried, complete remission of vasospasm is difficult to achieve. The first case of bilateral IEICAV induced by head rotation, which was successfully treated by carotid artery stenting (CAS), was presented. OBSERVATIONS: A 40-year-old woman with bilateral IEICAV had been conservatively treated for 13 years. However, transient ischemic attacks (TIAs) were not suppressed. She eventually presented with a large brain infarction in the left hemisphere and was referred to our department. Digital subtraction angiography clearly demonstrated the triggering of internal carotid artery (ICA) vasospasm by head rotation. After CAS treatment, the TIAs disappeared completely. LESSONS: Clinicians should recognize that ordinary mechanical stimulation to the ICA by head rotation can induce vasospasm, and CAS should be performed for refractory IEICAV at the appropriate time to avoid cerebral infarction causing severe neurological deficits.