Agenesis of Internal Carotid Artery and Ischemic Stroke, One Case Report: A Review of Literature

Abstract

Background: Agenesis of the internal carotid artery (ICA) is a rare anatomic variation of the cerebral circulation. A malfunction during the embryonic peri-od is at stake. It is very often asymptomatic and therefore discovered inci-dentally. Association with ischemic stroke is exceptional. Physiopathology is uncertain; the hypothesis of a blood flow reversal is reported in the literature. The diagnosis is based on the absence of a carotid canal as revealed by CT scans at skull base level with bone settings. Other non-invasive techniques, in-cluding echo-Doppler of the neck vessels, can now make the diagnosis. Objec-tive: Discuss the association between occurrence of an ischemic stroke in the left posterior sylvian territory and discovery of ipsilateral carotid agenesis. Case report: A 24-year-old female patient was prospectively recruited at DAX hospital center (France). Vascular risk factors involved active smoking of 8 pack-years and a combined estrogen/progestin contraceptive. Her family history included an uncle with heterozygote Factor V Leiden mutation. She presented a left upper limb sensorimotor deficit. Nuclear Magnetic Resonance Angiography (MRA) revealed a right superficial sylvian ischemic stroke asso-ciated with agenesis of the right internal carotid artery. CT scan at skull base level with bone settings showed absence of a right carotid canal, thus confirm-ing agenesis. An opinion was then requested for an arteriography which showed an operative polygon of Willis, a sylvian artery or middle cerebral ar-tery (MCA) irrigated by a very large right posterior communicating artery (PCOM) and the left anterior cerebral artery (ACA) supplied by the anterior communicating artery (ACOM), through the left carotid system. The right syl-vian territory where stroke occurred was therefore supplied by the functional vertebrobasilar system. ECG and four-day meticulous monitoring detected no cardiac rhythm disorders. Transesophageal echocardiography was normal. Blood tests results showed normal blood coagulation with glycohemoglobin level at 4.6%. Total cholesterol was 1.42 g/l including LDL-C at 0.82 g/l and HDL-C at 0.36 g/l; triglycerides levels were 1.23 g/l. VDRL-TPHA serodiagnosis for syphilis, and HIV serology were all negative. Thrombophilia testing was performed and showed absence of Factor V Leiden mutation. Homocyste-inemia level was normal. The patient was discharged under KARDEGIC 160 mg, one daily with home rehabilitation. Currently she’s doing well and no re-currence is observed.