Recurrent bilateral anterior cerebral artery dissection five years after the initial dissection: a case report

We here report a case of a recurrent bilateral anterior cerebral artery dissection five years after the initial dissection. A 38-year-old man developed headache associated with right hemiparesis. MRI revealed a brain infarction in the left frontal lobe, and the A2 portion of anterior cerebral artery occlusion was shown using MR angiography (MRA). Because there was obstruction of the left anterior cerebral artery and detection of an intramural hematoma using MRA, a diagnosis of a left anterior cerebral artery dissection was made. He was discharged without any neurological sequelae. Five years after the left anterior cerebral artery dissection onset, he developed a sudden headache and was again admitted to our hospital. Brain CT showed a hemorrhagic infarction in the right frontal lobe. MRA showed narrowing of the left anterior cerebral artery and occlusion of the right anterior cerebral artery at the proximal part of the callosomarginal artery. T1-weighted and black-blood contrast-enhanced T1-weighted MRI showed an intramural hematoma in the lesion, and we diagnosed a right anterior cerebral artery dissection. Although recurrent contralateral anterior cerebral artery dissection of long-term course after the initial dissection is rare, we should consider recurrence when headache with or without neurologic symptoms is present in patients with past cerebral artery dissections. For cases in which intracranial cerebral artery dissection is suspected, MRA, T1-weighted imaging, and black-blood contrast-enhanced T1-weighted imaging may show the characteristic vascular pathology.